OK, lots of great guesses with our contest the other day, but we had four people with guesses within 0.3 HP of the actual measured at the wheels, so that means four T-shirts will be going out. I'll be putting the names and official announcement in next thursdays video, but thanks to all that entered!
I really think that if you do some home porting on the heads and upgrade to a trailblazer SS intake you'll gain quite a bit with the upgraded cam. Also, as far as power adders, a twin screw supercharger is going to be better than a roots supercharger if you go that route.
Tbss Intake would see good gains porting the heads would see a tiny gain for the time and money spent. Those heads stock can support more power then most 4.8s can make
They both have their place. My choice was easy. I bought a Volvo 240 to shove a 6.0 in to it. My truck already had a 6.0, so instead of buying another 6.0, I bought an 8.1 for the truck. Two projects with one engine 😁
You are supposed to open the fender holes up. They are 75% shrouded compared to the airbox inlets. Die grinder and a few minutes work opens it up to match the airbox tubes. Just like a gasket match.
This has been an awesome quest. You are a very talented do-it-all, a jack of all trades. Wish you (and your trucks) the best in the coming future and will be watching the additional improments that you will have for them.
Magnusson is my vote. You already made the exhaust and have a turbo setup. Will really wake up the bottom end and make it feel more like that big block you love ( I do too super stoked for the stroker build!)
Have you not done the basic performance changes to the Power Enrichment? You don’t need any Delay and PE needs to be set at 40-50% throttle. Also do a TPS reset to make sure it’s scaling properly. JD
PE should be set throughout the range and should ramp in around the same time as the power band for the cam that you're using . You definitely don't want it running 50 mmHg and ramping in at 2000 rpm so every time you look at the gas pedal you're in PE . That's a fantastic way to waste fuel and ruin power . You really should have a delay unless you want your computer pulling fuel everywhere you go unless you plan on driving with your foot to the floor all the time . Just taking off from a stoplight you pull 75 mmHg . And in my case that's with a 232/241 cam that robs a s*** ton of vacuum . Stop raping your PE and properly set your VE .
For me, I love the LS2 in my TBSS and it makes for low effort power - I'm in my 50's, I'm done with blowing stuff up. Mild tunes and bolt ons, long tube headers, extensive aftermarket support, easy to tune and diag with HP Tuners, and no DOD makes this particular LS2 my sweet spot - I'd drop it in anything. But hey, NA vs NA, big displacement will win the numbers game. But I'm so dialed into the LS platform, and I'm just done spending time working on stuff rather than simply driving it - so the easy way out for me is anything LS. Great video - I love your methods and hard work and conclusions, they're nuanced and comprehensive. Thanks!
Well, you just stomped the LS with the boat anchor in every category including dollar per hp, then concluded that the LS is better. Lets just agree that given the same modifications, the larger displacement engine usually out performs the smaller.
the problem is, you have to locate & buy the 8.1 engine to swap in which usually aren't cheap. Standard cab 4.8 and 5.3 trucks are dime-a-dozen as long as you'll settle for a high mileage used one.
I really enjoy the BBC vs LS comparison, Turbo's are my favorite form of forced induction but will be gladly following along regardless of which way you go. I would be curious to see you make a 0-60 run without the air filter and that would tell you if the restriction is the air box, filter, or both.
My 8.1 Suburban gets 10 to 11mpg at 80mph with 33x12.50, 4l80e trans, and 4.10s. 7.5mpg in town. Cool thing is my mileage doesn't change unless I'm towing 8k+, or have a large cross section trailer for wind to grab. I can be solo, or at max passengers and payload with a trailer and it doesn't change. I'm also in Utah. I'm cammed, roller rockers, e fans, long tubes, dual 3" exhaust with x pipe, Volant ram air, 4l80 mods, and tuned. When stock i got 12mpg freeway, 9 in town.
Man the difference between a LR4 4.8 and a LQ9 6.0 is really eye opening. My LQ4 made 409whp with a set of speed engineering long tubes and dual 3”, a 218/224 cam and a TBSS intake finished with 90mm throttle body. I am at sea level with great air so that does help.
Considering the LR4 and LM7 share the same bore, different stroke, and the LM7 and LQ4/9, share the same stroke but the LQ4/9 is larger bore. 293, 325, 364CID 7.4 is 454, 8.1 is 496CID
Thank you for using your 4.8. everyone picks the low hanging fruit and gets the 5.3 or 6.0. not everyone has the space and time to swap out the 4.8 to 5.3/6.0. Imma do this with my two Silverados but they'll both stay 4.8. then boost. Thank you again! I fell in love with the 4.8 and I can't seem to get away from it...
I agree might not be the big horsepower monster but that Little motor Winding up Sounds so good yes you could make more power With bigger one But I love the underdog It's the C biscuit
Context matters. Emphasis on race over street? LS, hands down. Everyday driver, (towing, hauling, longevity, low strung), big block all the way. The 496 w/a mild cam, exhaust work, intake help would have probably yielded ~400 HP and well north of 500 ft/lb. Perfect to pull the trailer, load it up at Home Depot, then blow the tires off at the track.
Kids kids kids, i own many big block chevys. I also own a truck with a ls 6.0. First i own a stock 396 L89 big block. Only added headers. This engine is NA with a carb. It put out on the wheels 416hp and 496 tq. Now i own a 1971 Baldwin Motion camaro, i have owned this camaro since 1982. It gas a 454 LS7 from 1971 installed by motion. Only added a 3.5 dual exhaust and hooker headers and it is carburetor. At the wheels it has 577hp and 608tq NA. I will keep my big blocks!!!!!
Following you closely, and trying to keep up financially! Caltracs are on my list for the 81 stepside, but not the 99 AWD. The 6.0 / 6l90 combo is in the 81, and yes I know you said dump that trans, but I think with some higher line pressures and a few other things, it may survive. I did keep the extra 80e, just in case. Stay tuned my friend, and I definitely will too!
My old truck. 2004 Silverado 2500 hd, I had a 2-1 magnaflow with the 4” tailpipe, afe cold air intake, on my buddy dyno, it made 278hp/340 torque roughly, glad you bought the 4” tailpipe from magnaflow, that little 4.8 that could can’t wait to see you do more with it
Great comparison surprised even with fuel injection at the 4.8 still isn't making one horsepower per cubic inch especially the 8.1 stock boat anchor had one in a 2500 heavy duty with a factory 410 and an Allison 6 speed it seemed way down on power plenty of torque but yes a supercharger or turbo would have definitely been fun and pept that motor up seems as though it's been replaced by the 6.0 that over the years has become more efficient and definitely better gas mileage
In my experience the small spikes you see on the wideband under full throttle are misfires. Not complete misfire, but small misfire. That could be part of your missing power.
Similar times on the 4.8 as my 72 el Camino here at 1200 ft elevation. I’ve got a gen 3 5.3 with a tbss intake and 90mm throttle body, 4l80 and 2.73 gears. Best times on my draggy 0-60 8.03, 1/8th mile 10.45 @71. In the process of change to a 9 inch and 3.70 gears. Turbo soon. Love the content.
I enjoyed the video. I especially appreciate the methodical approach to tuning and the practical suggestions on measuring performance improvements without a dyno session. I found it really helpful. The air box hack is a great example of quick low cost way to test a hypothesis and then using the data logger to infer the improvement. Very clever, thanks.
I'd love to see a procharger on the step side. A roots or screw blower would really help the low end torque but I feel a procharger would really play into the 4.8s short stroke and need to rev out. Either way, excited to see where this goes
I’m leaning towards your restrictions being TB, even with a 4” intake tube, that’s still the deadhead point of stacking air and just bottle necking it right there, but my guess is also if you stepped up to a bigger TB you’re going to lose some on the bottom end. But I agree with most everybody, it’ll respond best with some boost or nitrous and the bigger TB
Wow that LS made the same power a stock Ford 4.6 3valve makes. the 4.8 is gettin there. I’m super excited for the big block stroker. Can’t wait to see that torque monster eat!!
Thanks for the fun comparison LT! I’ve owned a 8.1/Allison 2500HD; all said I would rather have an LS in a truck in most 1/2 ton scenarios for the same reasons you mentioned. Especially an aluminum block, just so much lighter, much much bigger aftermarket support, higher rpm = more smiles for me. Conversely, the 8.1 makes more sense where weight is a good thing or you’re running 38”+ tires offroad.
absolutely awesome comparison and well done videos, loved every minute of them!!! would love to see how much you spent on the 8.1 to turbo it and use the same budget to turbo/s.c the 4.8 and then compare the numbers again! I love the David vs Goliath theme so I say build out the 4.8 before you swap it out.
@@LawrenceTolman I'll definitely check it out! yea I think it'd be awesome to see what the $$/hp is once they both have forced induction and same money spent as well as which one is quicker on the strip/draggy 👍👍
They both need heads and an intake manifold, but as the 4.8 sits, if you dumped 29.4 psi of boost in it you are looking at ~556 rwhp/~667 crank, if it can move the air and fuel.
I did not follow or understand your logic for using the MAF to determine engine power based on ignition timing... How is airflow through the motor affected by ignition timing? Both valves are closed when the spark goes off. Can someone explain to me what I'm missing? The only only possible thing I can think of is that by making more power with more advance you'd somehow gaid additional scavenging effects on the exhaust event which would possibly draw more air through the motor? That seems really hokey to me though because at perfect efficiency, the motor is an air pump, and knowing the cylinder volume, spinning the motor at any specific RPM will move X amount of volume of air through it... Valve timing could change things, but ignition timing, I'm not biting on that.
Very hard to beat an LS for inexpensive and solid power gains. I've had three, including an LSA and they all have been home runs. 8.1 is intriguing as it incorporates a lot of LS technology, and it's a great motor.
Hey LT! You are always putting out great content! Thank you! I’m in the process of swapping my 94’ K1500 and was wondering about the dual 3” to single 4” exhaust and how it would sound. Then how convenient for me you are doing the same exact set up I’ve been building in my head! Haha. Looking forward to the completed system with tail pipe! Thanks again, Keep up the good work!
You should hands down do the whipple 2.9l if you are thinking about a roots style, because it has the front inlet, and cost the same as the smaller 2.3l….. then if you go up in engine size aka 6.0 or 6.2 you won’t have to get a different blower!🙌🏼🔥
I did similar upgrades on my 07 Tahoe a couple of years ago. Custom Cam new springs full rebuild full headers intake etc. spent $3500 at the engine shop. Dino in SC shows 320 hp 321tq at the wheels. I did have a full day with a reputable tuner. 5.3 and a generation newer. Still get 18mpg. Wife drives it everyday now. Most likely an elevation issue for you. The 4.8 supposed to have thicker cylinder walls which makes it better for boosted applications. Love the challenge. Smart move
You can just make a pull without the air filter to really narrow it down. Then you'll know if it's mostly filter or intake piping. You can keep going with timing until you don't make any gains and adjust knock sensors accordingly on the same day with the same fuel. You won't hurt an NA engine that way, the knock sensors will pull timing.
so for towing would you prefer modifying a 5.3 or running the 454? I'm pulling a 10,000 lb travel trailer with a 2500 suburban. Or would you go with a larger stock LS? Need opinions from folks. I haven't the time or money to try it all out myself. I know somebody out there has the answer.
Did you say you didn't include all the gaskets etc... for the 4.8? Wouldn't that add a lot to the price list of the 4.8 and give a better comparison of cost?
Would love to see a roots supercharger on that 4.8. I don't know if they're popular as turbocharging is so common, but I just love the sound of that little LS revving out. The 4.30s would be right at home, no doubt.
i had 04 chevy 1500 with a 6.0 cam,milled 243,nnbs intake,90mm tb,lt's,80e,4.30 gears, made 417hp/414tq @ the wheels. my mud truck has 8.1/allison combo and there is no comparison when it comes to torque.. now the 8.1 is cam,d intake mod,lt's, 90mm tb,roller rocker its a beast now.
On that filter box modification just wanted to mention it’s very common for bmw guys to do a “charcoal filter” delete. Idk if Chevy did this where they put an activated charcoal filter after the regular air filter, but if they did and you remove that you might be able to rid some of that restriction and maybe gain some throttle response. Did it on my e92 and I makes enough difference to notice
I have a 98 single cab stepside with a 8.1 and allison 1000 transmission , its flawless and love it. in my opinion the 8.1 is under rated . i would like to see more aftermarket performance parts out there.
If you're swapping, you may as well go with the biggest LS you can afford. No LS is RPM limited, so big rpm just means bigger power with a bigger LS. Unless you intentionally want to keep it mild.
It would be neat to see the 4.8 with a nasty turbo set up. I’m building a 408 stroker for my rcsb right now, and the numbers I see on these boosted 4.8s make my build look like a waste of time!
The 4.8 is definitely choking for induction. And I think the cam is a little tame for NA power, but it should be very good for FI. All in all, the mods you made are really just pulled punches for NA, but they’ll pay dividends when you have forced induction. In the meantime, having more torque and horsepower everywhere is no small achievement, well done!
The 4.8 sounds great and I thought that the HP numbers would be higher but I forgot that you are at a higher altitude, how about doing some porting on the heads and maybe having the heads milled a little bit for higher compression and/or swapping out the pistons for a higher dome piston instead of milling the heads? Just a thought. On that airbox where you drilled the holes, take it out and cut it so that the bottom half is more shaped like a "cage" so the airbox is almost totally unrestricted. Just my 2 cents. Thanks for the great videos and looking forward to seeing more!! Hope you and your family have a Merry Christmas!! :)
The stock 8.1 setup would be great for towing and you said it Best there is no replacement for displacement but the little 4.8 did great considering the displacement and you're turning the 4wd components I think it was a very good comparison because each trucks setup they'll have their place like ugly truck trailering the step side to the track
Nice that the 8.1 makes those numbers on 87 octane gas. Doesn't need premium. Also with the numbers the 4.8 is making I don't think the 3 inch tube is a restriction at all. A 3 inch exhaust would be ok at those numbers so the intake would be too. Maybe pull the filter out of the box and run it a few times and read the kpa
What’s the weight difference in these trucks? I’d be curious how much faster the SCSB truck would be with the “naturally aspirated” 8.1 like in the ugly truck.
What gear were the pulls done in? And does the 8.1L have a 4L80 while the 4.8L have a 4L60? If the pulls were done in 2nd, it would be expected that the 4L80 would read higher than a 4L60 since it has a 1.482 2nd gear while the 4L60 has a 1.625 ratio. It won’t be enough to make up the 25-30 hp difference, but it should lessen it.
Looks like Saratoga Springs, I'll keep my eye out next time I'm over visiting the Brother and Sister inlaw. Any plans to come to Boise and run your trucks at Firebird? Hoping to have my Turbo 99' Silverado at the track next summer. And I agree 100% there is no replacement for displacement...
The 2 degrees less made less power... did you put 1 or 2 degrees over baseline of the original tune? Just cuz every other ls doesn't like more timing, doesn't mean that little engine wont..
If you are planning to beef up the 4.8L, at least all aftermarket forged crankshafts are roughly the same price, either 3.622" or even 4.00". That little iron block with a 4" stroke will become a monster @ either 363CID at stock bore or even up to 383CID if you want to stretch the cylinders out a bit to LS1 bore size.
port and polish your heads, gasket matching the intake. spend some love on the heads. fan modulation for a slightly higher temperature. change final drive for more torque.
LT IF You can fid a 08 model LY6 6 liter add an Elgin sloppy stage 2 cam and find a good used 6 speed trans you will be AMAZED with the end result Regards Sid Nice projects and thanks for sharing with us
Very good video LT. I was a little optimistic on my 320 HP guess. I hope you plan on putting a roots style blower on it. I really want to put one on mine but, they are $$$$$$$
The Amazon 4" intake is what I'm using. But I have completely shrouded the filter from the engine and rad. Much better performance just sealing off from those 2 areas
This was fun to watch.. my opinion... supercharge the 4.8 , push it as far as u can. Then maybe a cool project where you put the 4.8 into something else, like a dude buggy or something, and than let's do a 5.3 or 6.0 with a turbo for the long term motor.... its been fun to watch... keep it up
I think it was good testing with good results however had you started with a 5.3 I think the numbers would have been much better. Personally I just like the 5.3, the 4.8 always seemed slightly lacking to me. Boost would obviously change that. Haha
Here's what I know the 5.3 starts out more hp and responds better to modifications. If you don't think so, jump over to Richard holdner's channel and watch his 4.8 videos and 5.3 videos, he has many 5.3 builds that go over 500 chp but the 4.8 do not.
Will timing changes really show up in the MAF readings though? Because timing is a cylinder pressure thing vs an airflow thing. I wouldn't think that a power gain from timing change would necessarily correlate to a change in airflow. As for the MAP restriction, you could try porting the manifold and maybe a larger throttlebody. The plastic intakes are pretty simple to do minor porting on and unless you're a caveman they're pretty hard to mess up. There's also always the TBSS manifold as well
I've gotten several questions like this about the timing changes affecting MAF freq, and It's made me think a lot about it. I don't have a good solid explanation or answer, but I think with more testing we could definitively answer the question. All I'd have to do is pull a ton of timing, do a 0-60 WOT run and log the MAF, put back the timing and do the same run back to back, and make a chart in excel that overlays both MAF frequency curves on top of each other, and that should answer the question. If the two curves are statistically indifferent, then that answers the question, but if they differ significantly, then that may be evidence that supports the theory. But to be honest, at the moment, I am torn as to which it would be.
@@LawrenceTolman I’m genuinely curious but I’d be surprised if it’s a popular idea for a video/test. I feel like one of the EngineMasters videos had something where they were measuring cfm and saw power gains while seeing no cfm increase but I can’t remember if they determined timing was the cause or distribution or whatever. I wouldn’t be surprised either way though lol
the magnuson!! love the Zip of a twin screw, and theres no apool time! dwf get that down low toraque. and thats what kills me, the LS is popular cuz everyone uses it. if the 8.1 had the same support, it would be no contest.
This comparison of data and thoughts/conclusions is really cool. But I’m honestly only here for one reason…what will he name the little 4.8?!? Lol. Only kidding about being here for one reason. These videos are great, LT! Your knowledge and research is top notch. Keep up the good work!!
LT, you could do a 363 stroker low compression and run boost with the 4.8l. I have a 2000 Sierra with the 4.8l and not sure what route to go. I think the 4.30 gears maybe a little too much gear to daily drive. I daily drive my truck so I can't have that much gear. Thanks for the content LT
First time to this channel, and I'm super impressed with your organized presentation. Thoughts though: I've always though it was odd that people try to make their old trucks go faster. Keep the old truck stock for when you need to haul stuff...and get an old Camaro or whatever to put the money into for performance. Would this not be a smarter path?
My 00 Sierra BONESTOCK 4.8 single cab stepside 3.42 gears 2wd ran a best of 16.4 on the 1/4 at sealevel. I had done a tuneup prior to racetrack time. It had around 70k miles. Pretty slow in my opinion.
I really enjoy watching your build vids even back to your days on Trucks. I personally would keep the LMG 5.3 in my Silverado with a few upgrades. I have the speeding ticket to prove that it will get you in trouble in a hurry.
Sure the LS has a gate following but the mighty Big Bock has been here for a long long time kid, you wanna go fast ? there is still no replacement for displacement Big Block for the win !
Nice data analyzing! Next need to figure the weight of the vehicle into the matrix... Great stuff!! More Power Tim (err LT) the toolman taylor, grunt grunt!
Far as testing a good one is acceleration rate graph in HP tuners . Gives the ability to see where it's accelerating good and where it may be lacking and you can adjust just areas of the tune in the weaker places . Find if your shift point should be raised or lowered etc.. I've forgotten the pids and math it took to set it up but to give credit where it's due I got it from Goat rope garage here on RUclips
Unless you duct air from in front of the radiator cutting hole in the filter box may reduce horsepower. Cold air intakes rarely add power they simply keep power by not having to pull timing etc because the intake is sucking in hot air A must is an air intake temperature sensor and manifold temperature sensor that you can data log to see if the ECU is pulling timing to prevent knocking.
OK, lots of great guesses with our contest the other day, but we had four people with guesses within 0.3 HP of the actual measured at the wheels, so that means four T-shirts will be going out. I'll be putting the names and official announcement in next thursdays video, but thanks to all that entered!
well now that this series is done, there is no point to your channel. it holds no more entertainment value. peace!
My 88 reg cab short bed.....I'm dropping the 502 4l80e package deal in it. Big Block all the Way!
LSA WITH a turbo, if you're going for the supercharger only approach though go for a twin screw (e.g. KB/whipple)
Hi Lawrence, where did you source the 8.1??
(I'm in Riverton)
@@2S1L3NT they can be had from suburban 3500s, many 2500+silverados, the avalanche 2500/3500, and most gmc equvalents
I really think that if you do some home porting on the heads and upgrade to a trailblazer SS intake you'll gain quite a bit with the upgraded cam. Also, as far as power adders, a twin screw supercharger is going to be better than a roots supercharger if you go that route.
Port the heads, twin screw it!
Tbss Intake would see good gains porting the heads would see a tiny gain for the time and money spent. Those heads stock can support more power then most 4.8s can make
They both have their place. My choice was easy. I bought a Volvo 240 to shove a 6.0 in to it. My truck already had a 6.0, so instead of buying another 6.0, I bought an 8.1 for the truck. Two projects with one engine 😁
Destroy that Volvo asap
You are supposed to open the fender holes up. They are 75% shrouded compared to the airbox inlets. Die grinder and a few minutes work opens it up to match the airbox tubes. Just like a gasket match.
This has been an awesome quest. You are a very talented do-it-all, a jack of all trades. Wish you (and your trucks) the best in the coming future and will be watching the additional improments that you will have for them.
Thanks!
Magnusson is my vote. You already made the exhaust and have a turbo setup. Will really wake up the bottom end and make it feel more like that big block you love ( I do too super stoked for the stroker build!)
Have you not done the basic performance changes to the Power Enrichment? You don’t need any Delay and PE needs to be set at 40-50% throttle.
Also do a TPS reset to make sure it’s scaling properly. JD
PE should be set throughout the range and should ramp in around the same time as the power band for the cam that you're using . You definitely don't want it running 50 mmHg and ramping in at 2000 rpm so every time you look at the gas pedal you're in PE . That's a fantastic way to waste fuel and ruin power . You really should have a delay unless you want your computer pulling fuel everywhere you go unless you plan on driving with your foot to the floor all the time . Just taking off from a stoplight you pull 75 mmHg . And in my case that's with a 232/241 cam that robs a s*** ton of vacuum . Stop raping your PE and properly set your VE .
For me, I love the LS2 in my TBSS and it makes for low effort power - I'm in my 50's, I'm done with blowing stuff up. Mild tunes and bolt ons, long tube headers, extensive aftermarket support, easy to tune and diag with HP Tuners, and no DOD makes this particular LS2 my sweet spot - I'd drop it in anything. But hey, NA vs NA, big displacement will win the numbers game. But I'm so dialed into the LS platform, and I'm just done spending time working on stuff rather than simply driving it - so the easy way out for me is anything LS. Great video - I love your methods and hard work and conclusions, they're nuanced and comprehensive. Thanks!
Well, you just stomped the LS with the boat anchor in every category including dollar per hp, then concluded that the LS is better.
Lets just agree that given the same modifications, the larger displacement engine usually out performs the smaller.
the problem is, you have to locate & buy the 8.1 engine to swap in which usually aren't cheap. Standard cab 4.8 and 5.3 trucks are dime-a-dozen as long as you'll settle for a high mileage used one.
@@91CTD and? That doesn't disprove what the original post states.
I really enjoy the BBC vs LS comparison, Turbo's are my favorite form of forced induction but will be gladly following along regardless of which way you go. I would be curious to see you make a 0-60 run without the air filter and that would tell you if the restriction is the air box, filter, or both.
How does the fuel economy of the 4.8 and 8.1 compare at 75mph? For those of us that rack up highways miles.
My 8.1 Suburban gets 10 to 11mpg at 80mph with 33x12.50, 4l80e trans, and 4.10s. 7.5mpg in town. Cool thing is my mileage doesn't change unless I'm towing 8k+, or have a large cross section trailer for wind to grab. I can be solo, or at max passengers and payload with a trailer and it doesn't change. I'm also in Utah.
I'm cammed, roller rockers, e fans, long tubes, dual 3" exhaust with x pipe, Volant ram air, 4l80 mods, and tuned. When stock i got 12mpg freeway, 9 in town.
@@davemcdaniel4856 bigger engines are affected less by towing ford even said they used the new 7.3 gas engine to save fuel.
My little 4.8 gets 19 per the gallon on highway my older 99 suburban 8.1 got like 9mpgs
Man the difference between a LR4 4.8 and a LQ9 6.0 is really eye opening. My LQ4 made 409whp with a set of speed engineering long tubes and dual 3”, a 218/224 cam and a TBSS intake finished with 90mm throttle body. I am at sea level with great air so that does help.
Considering the LR4 and LM7 share the same bore, different stroke, and the LM7 and LQ4/9, share the same stroke but the LQ4/9 is larger bore.
293, 325, 364CID
7.4 is 454, 8.1 is 496CID
Yeah I’m surprised too! My 5.7 LS1 with a TSP 233/239 cam, headers and a homemade CAI made 382whp.
@@TheMotorman80 why wouldn't you just get an slp intake?
@@DontStopReeling Because it’s an LS1 in a 1995 S10. SLP doesn’t exactly make an intake for that, plus it’s way cooler to fab up your own stuff!
@@shadowopsairman1583 not sure what any of this has to do with his comment...
Thank you for using your 4.8. everyone picks the low hanging fruit and gets the 5.3 or 6.0. not everyone has the space and time to swap out the 4.8 to 5.3/6.0. Imma do this with my two Silverados but they'll both stay 4.8. then boost. Thank you again! I fell in love with the 4.8 and I can't seem to get away from it...
I agree might not be the big horsepower monster but that Little motor Winding up Sounds so good yes you could make more power With bigger one But I love the underdog It's the C biscuit
Context matters. Emphasis on race over street? LS, hands down. Everyday driver, (towing, hauling, longevity, low strung), big block all the way. The 496 w/a mild cam, exhaust work, intake help would have probably yielded ~400 HP and well north of 500 ft/lb. Perfect to pull the trailer, load it up at Home Depot, then blow the tires off at the track.
Kids kids kids, i own many big block chevys. I also own a truck with a ls 6.0.
First i own a stock 396 L89 big block. Only added headers. This engine is NA with a carb. It put out on the wheels 416hp and 496 tq.
Now i own a 1971 Baldwin Motion camaro, i have owned this camaro since 1982. It gas a 454 LS7 from 1971 installed by motion. Only added a 3.5 dual exhaust and hooker headers and it is carburetor. At the wheels it has 577hp and 608tq NA.
I will keep my big blocks!!!!!
The exhaust setup on the step side is perfect! Thing sounds really really good.
LT mic drop. What a grand conclusion a really fun series. Great work LT.
Following you closely, and trying to keep up financially! Caltracs are on my list for the 81 stepside, but not the 99 AWD. The 6.0 / 6l90 combo is in the 81, and yes I know you said dump that trans, but I think with some higher line pressures and a few other things, it may survive. I did keep the extra 80e, just in case. Stay tuned my friend, and I definitely will too!
My old truck. 2004 Silverado 2500 hd, I had a 2-1 magnaflow with the 4” tailpipe, afe cold air intake, on my buddy dyno, it made 278hp/340 torque roughly, glad you bought the 4” tailpipe from magnaflow, that little 4.8 that could can’t wait to see you do more with it
I've enjoyed following your builds. The stepside reminds me of my buddies truck. He put a Magnusson TVS1900 on a 4.8 and it made good low end torque.
I did this but on a L9H 6.2 i love the trucks it’s amazing also full bolt ons.
Great comparison surprised even with fuel injection at the 4.8 still isn't making one horsepower per cubic inch especially the 8.1 stock boat anchor had one in a 2500 heavy duty with a factory 410 and an Allison 6 speed it seemed way down on power plenty of torque but yes a supercharger or turbo would have definitely been fun and pept that motor up seems as though it's been replaced by the 6.0 that over the years has become more efficient and definitely better gas mileage
In my experience the small spikes you see on the wideband under full throttle are misfires. Not complete misfire, but small misfire. That could be part of your missing power.
Similar times on the 4.8 as my 72 el Camino here at 1200 ft elevation. I’ve got a gen 3 5.3 with a tbss intake and 90mm throttle body, 4l80 and 2.73 gears. Best times on my draggy 0-60 8.03, 1/8th mile 10.45 @71. In the process of change to a 9 inch and 3.70 gears. Turbo soon. Love the content.
I enjoyed the video. I especially appreciate the methodical approach to tuning and the practical suggestions on measuring performance improvements without a dyno session. I found it really helpful. The air box hack is a great example of quick low cost way to test a hypothesis and then using the data logger to infer the improvement. Very clever, thanks.
Glad you enjoyed it!
Glad you enjoyed it!
I'd love to see a procharger on the step side. A roots or screw blower would really help the low end torque but I feel a procharger would really play into the 4.8s short stroke and need to rev out. Either way, excited to see where this goes
Twin screw it.
I’m leaning towards your restrictions being TB, even with a 4” intake tube, that’s still the deadhead point of stacking air and just bottle necking it right there, but my guess is also if you stepped up to a bigger TB you’re going to lose some on the bottom end. But I agree with most everybody, it’ll respond best with some boost or nitrous and the bigger TB
Wow that LS made the same power a stock Ford 4.6 3valve makes. the 4.8 is gettin there. I’m super excited for the big block stroker. Can’t wait to see that torque monster eat!!
Thanks for the fun comparison LT! I’ve owned a 8.1/Allison 2500HD; all said I would rather have an LS in a truck in most 1/2 ton scenarios for the same reasons you mentioned. Especially an aluminum block, just so much lighter, much much bigger aftermarket support, higher rpm = more smiles for me. Conversely, the 8.1 makes more sense where weight is a good thing or you’re running 38”+ tires offroad.
absolutely awesome comparison and well done videos, loved every minute of them!!! would love to see how much you spent on the 8.1 to turbo it and use the same budget to turbo/s.c the 4.8 and then compare the numbers again! I love the David vs Goliath theme so I say build out the 4.8 before you swap it out.
Hey made a video about a year ago showing the cost to turbo the 8.1, but that was my plan to try to continue the budget comparison in stages
@@LawrenceTolman I'll definitely check it out! yea I think it'd be awesome to see what the $$/hp is once they both have forced induction and same money spent as well as which one is quicker on the strip/draggy 👍👍
yes that would be awsom
To get the most performance? Big Block!!!! To enjoy it and drive it too.... LS.
Stoked to see this awd conversion
Put the 8.1 in the stepside then you would have something when awd happens , love my 8.1 over my 5.3,6.0 , nice video thanks
They both need heads and an intake manifold, but as the 4.8 sits, if you dumped 29.4 psi of boost in it you are looking at ~556 rwhp/~667 crank, if it can move the air and fuel.
I did not follow or understand your logic for using the MAF to determine engine power based on ignition timing... How is airflow through the motor affected by ignition timing? Both valves are closed when the spark goes off. Can someone explain to me what I'm missing? The only only possible thing I can think of is that by making more power with more advance you'd somehow gaid additional scavenging effects on the exhaust event which would possibly draw more air through the motor? That seems really hokey to me though because at perfect efficiency, the motor is an air pump, and knowing the cylinder volume, spinning the motor at any specific RPM will move X amount of volume of air through it... Valve timing could change things, but ignition timing, I'm not biting on that.
truck sure sounds awesome. I had a 4.8L sierra and it was a great reliable truck, and never had issues.
Very hard to beat an LS for inexpensive and solid power gains. I've had three, including an LSA and they all have been home runs.
8.1 is intriguing as it incorporates a lot of LS technology, and it's a great motor.
Hey LT!
You are always putting out great content! Thank you!
I’m in the process of swapping my 94’ K1500 and was wondering about the dual 3” to single 4” exhaust and how it would sound. Then how convenient for me you are doing the same exact set up I’ve been building in my head! Haha.
Looking forward to the completed system with tail pipe!
Thanks again, Keep up the good work!
You should hands down do the whipple 2.9l if you are thinking about a roots style, because it has the front inlet, and cost the same as the smaller 2.3l….. then if you go up in engine size aka 6.0 or 6.2 you won’t have to get a different blower!🙌🏼🔥
I did similar upgrades on my 07 Tahoe a couple of years ago. Custom Cam new springs full rebuild full headers intake etc. spent $3500 at the engine shop. Dino in SC shows 320 hp 321tq at the wheels. I did have a full day with a reputable tuner. 5.3 and a generation newer. Still get 18mpg. Wife drives it everyday now. Most likely an elevation issue for you. The 4.8 supposed to have thicker cylinder walls which makes it better for boosted applications. Love the challenge. Smart move
I'd start at 25 degrees advance and lean out afrs to 12.5:1 maybe even 13:1 after 5krpm. You gotta git rid of that KR.
You can just make a pull without the air filter to really narrow it down. Then you'll know if it's mostly filter or intake piping. You can keep going with timing until you don't make any gains and adjust knock sensors accordingly on the same day with the same fuel. You won't hurt an NA engine that way, the knock sensors will pull timing.
Problem is if that's a oiled KNM air filter it dirtied up the maf
@@crautoguy8384 If it wasn't dryed for 12 hours maybe. Or if it isn't K and N filter oil. It dries completely overnight.
High altitude is definitely a challenge. I live in Colorado so I feel your pain.
so for towing would you prefer modifying a 5.3 or running the 454? I'm pulling a 10,000 lb travel trailer with a 2500 suburban. Or would you go with a larger stock LS? Need opinions from folks. I haven't the time or money to try it all out myself. I know somebody out there has the answer.
I think people get caught up racing dyno numbers.
Did you say you didn't include all the gaskets etc... for the 4.8? Wouldn't that add a lot to the price list of the 4.8 and give a better comparison of cost?
Would love to see a roots supercharger on that 4.8. I don't know if they're popular as turbocharging is so common, but I just love the sound of that little LS revving out. The 4.30s would be right at home, no doubt.
i had 04 chevy 1500 with a 6.0 cam,milled 243,nnbs intake,90mm tb,lt's,80e,4.30 gears, made 417hp/414tq @ the wheels. my mud truck has 8.1/allison combo and there is no comparison when it comes to torque.. now the 8.1 is cam,d intake mod,lt's, 90mm tb,roller rocker its a beast now.
On that filter box modification just wanted to mention it’s very common for bmw guys to do a “charcoal filter” delete. Idk if Chevy did this where they put an activated charcoal filter after the regular air filter, but if they did and you remove that you might be able to rid some of that restriction and maybe gain some throttle response. Did it on my e92 and I makes enough difference to notice
I have a 98 single cab stepside with a 8.1 and allison 1000 transmission , its flawless and love it. in my opinion the 8.1 is under rated . i would like to see more aftermarket performance parts out there.
Still cool. I’m building a 5.3 to a 5.7 so basically a iron block LS1, with a BTR Truck Norris cam and a TBSS intake.
I’m really interested in that cam
I think the little 4.8 is the perfect LS if it’s in a lighter truck. I want one to swap in my 99 S10 Extreme.
dream swap man id love an s10 extreme. send it! would be nasty as hell
If you're swapping, you may as well go with the biggest LS you can afford. No LS is RPM limited, so big rpm just means bigger power with a bigger LS. Unless you intentionally want to keep it mild.
@@Levibetz it’s just going to be my daily driver. The 4.8 should give me 300 ish hp and better mpg than the V6.
The quicker 0-60 with wheel spin tells me you need more gear.
Which with a 4.8 is a given anyway. 4.56s for the win
It would be neat to see the 4.8 with a nasty turbo set up. I’m building a 408 stroker for my rcsb right now, and the numbers I see on these boosted 4.8s make my build look like a waste of time!
Super Charge it lol
The 4.8 looks good with boost right up until you boost the 408.. there is still no replacement for displacement. :)
Just remember though....when you increase displacement if you can gain 100hp na in therory thats 200 hp gained at 15psi
The 4.8 is definitely choking for induction. And I think the cam is a little tame for NA power, but it should be very good for FI.
All in all, the mods you made are really just pulled punches for NA, but they’ll pay dividends when you have forced induction. In the meantime, having more torque and horsepower everywhere is no small achievement, well done!
The 4.8 sounds great and I thought that the HP numbers would be higher but I forgot that you are at a higher altitude, how about doing some porting on the heads and maybe having the heads milled a little bit for higher compression and/or swapping out the pistons for a higher dome piston instead of milling the heads? Just a thought. On that airbox where you drilled the holes, take it out and cut it so that the bottom half is more shaped like a "cage" so the airbox is almost totally unrestricted. Just my 2 cents. Thanks for the great videos and looking forward to seeing more!! Hope you and your family have a Merry Christmas!! :)
The stock 8.1 setup would be great for towing and you said it Best there is no replacement for displacement but the little 4.8 did great considering the displacement and you're turning the 4wd components I think it was a very good comparison because each trucks setup they'll have their place like ugly truck trailering the step side to the track
Nice that the 8.1 makes those numbers on 87 octane gas. Doesn't need premium. Also with the numbers the 4.8 is making I don't think the 3 inch tube is a restriction at all. A 3 inch exhaust would be ok at those numbers so the intake would be too. Maybe pull the filter out of the box and run it a few times and read the kpa
those are other good factors that I didn't consider, but they do make it appealing for the big block.
Great content LT. I enjoyed that you stuck to your process and modded the 4.8 even if swapping in a 5.3 or 6.0 seems to make more sense.
What’s the weight difference in these trucks? I’d be curious how much faster the SCSB truck would be with the “naturally aspirated” 8.1 like in the ugly truck.
i am half tempted to swap in my built 547 into the stepside lol... that would be so fun to do a 4 wheel burnout/launch
What gear were the pulls done in? And does the 8.1L have a 4L80 while the 4.8L have a 4L60?
If the pulls were done in 2nd, it would be expected that the 4L80 would read higher than a 4L60 since it has a 1.482 2nd gear while the 4L60 has a 1.625 ratio. It won’t be enough to make up the 25-30 hp difference, but it should lessen it.
Looks like Saratoga Springs, I'll keep my eye out next time I'm over visiting the Brother and Sister inlaw. Any plans to come to Boise and run your trucks at Firebird? Hoping to have my Turbo 99' Silverado at the track next summer.
And I agree 100% there is no replacement for displacement...
The 2 degrees less made less power... did you put 1 or 2 degrees over baseline of the original tune? Just cuz every other ls doesn't like more timing, doesn't mean that little engine wont..
No replacement for displacement. The big motors will almost always have more power lol I s dad that people still don't get it .
LS reluctor wheels are known to be as much as 14 degrees off. Id either verify timing with a light or keep adding until hpt shows knock
I know it's not the point of these builds, but I am curious what the fuel mileage is on the 4.8 NA vs the 8.1 NA?
If you are planning to beef up the 4.8L, at least all aftermarket forged crankshafts are roughly the same price, either 3.622" or even 4.00". That little iron block with a 4" stroke will become a monster @ either 363CID at stock bore or even up to 383CID if you want to stretch the cylinders out a bit to LS1 bore size.
port and polish your heads, gasket matching the intake. spend some love on the heads. fan modulation for a slightly higher temperature. change final drive for more torque.
on the stock air box, the upper air intake can be removed, you can also remove the holding ring from the MAF and remove the screen.
That timing revelation is interesting. Up here in the Boise area most LS' like between 24-26°
Absolutely LOVE the way the 4.8 sounds!
Install a couple of mini fans in the fender well at the openings for the fresh air and pull in the air in the filter box
Neat comparison. Thank you for all the hard work.
LT
IF You can fid a 08 model LY6 6 liter add an Elgin sloppy stage 2 cam and find a good used 6 speed trans you will be AMAZED with the end result
Regards Sid
Nice projects and thanks for sharing with us
Love what your doing, let em breathe, let em eat. Nice video. Thanks
This mind sound silly, but is the MAF de-screened? It SEEMED to make a difference on my 4.3 blazer when I did it
There used to be a saying ( No replacement for displacement) . So if apple's to apple's comparison. Big block should always win.
Very good video LT. I was a little optimistic on my 320 HP guess. I hope you plan on putting a roots style blower on it. I really want to put one on mine but, they are $$$$$$$
I had an 01 suburban with an 8.1. It was a strong running vehicle. It didn't have problems hauling the whole family and a heavy load
This has been a fun comparison to watch. You should call it "the little engine that could". Keep up the great content!
Merry Christmas!
The Amazon 4" intake is what I'm using. But I have completely shrouded the filter from the engine and rad. Much better performance just sealing off from those 2 areas
Boker mermaid on the bench! This man knows what quality is
This was fun to watch.. my opinion... supercharge the 4.8 , push it as far as u can. Then maybe a cool project where you put the 4.8 into something else, like a dude buggy or something, and than let's do a 5.3 or 6.0 with a turbo for the long term motor.... its been fun to watch... keep it up
I think it was good testing with good results however had you started with a 5.3 I think the numbers would have been much better.
Personally I just like the 5.3, the 4.8 always seemed slightly lacking to me. Boost would obviously change that. Haha
only difference is dished pistons and wee bit more stroke
Lmao not much difference at all
Here's what I know the 5.3 starts out more hp and responds better to modifications.
If you don't think so, jump over to Richard holdner's channel and watch his 4.8 videos and 5.3 videos, he has many 5.3 builds that go over 500 chp but the 4.8 do not.
I wound up cutting out the whole side of my stock airfilter box just where the two original holes were and it works great..
Will timing changes really show up in the MAF readings though? Because timing is a cylinder pressure thing vs an airflow thing. I wouldn't think that a power gain from timing change would necessarily correlate to a change in airflow.
As for the MAP restriction, you could try porting the manifold and maybe a larger throttlebody. The plastic intakes are pretty simple to do minor porting on and unless you're a caveman they're pretty hard to mess up. There's also always the TBSS manifold as well
I've gotten several questions like this about the timing changes affecting MAF freq, and It's made me think a lot about it. I don't have a good solid explanation or answer, but I think with more testing we could definitively answer the question. All I'd have to do is pull a ton of timing, do a 0-60 WOT run and log the MAF, put back the timing and do the same run back to back, and make a chart in excel that overlays both MAF frequency curves on top of each other, and that should answer the question. If the two curves are statistically indifferent, then that answers the question, but if they differ significantly, then that may be evidence that supports the theory. But to be honest, at the moment, I am torn as to which it would be.
@@LawrenceTolman I’m genuinely curious but I’d be surprised if it’s a popular idea for a video/test. I feel like one of the EngineMasters videos had something where they were measuring cfm and saw power gains while seeing no cfm increase but I can’t remember if they determined timing was the cause or distribution or whatever. I wouldn’t be surprised either way though lol
2:48 is that a Saab 9-2x Aero I see? I'm not sure about the mirror, but that hood scoop is identical to my old one.
Try making a pull with no air box on the 4.8 to see if that is the restriction.
the magnuson!! love the Zip of a twin screw, and theres no apool time! dwf get that down low toraque. and thats what kills me, the LS is popular cuz everyone uses it. if the 8.1 had the same support, it would be no contest.
Wow I was wicked close with my guess! I figured that would be about right, they aren’t the best NA.
This comparison of data and thoughts/conclusions is really cool. But I’m honestly only here for one reason…what will he name the little 4.8?!? Lol. Only kidding about being here for one reason. These videos are great, LT! Your knowledge and research is top notch. Keep up the good work!!
LT, you could do a 363 stroker low compression and run boost with the 4.8l. I have a 2000 Sierra with the 4.8l and not sure what route to go. I think the 4.30 gears maybe a little too much gear to daily drive. I daily drive my truck so I can't have that much gear. Thanks for the content LT
First time to this channel, and I'm super impressed with your organized presentation.
Thoughts though: I've always though it was odd that people try to make their old trucks go faster. Keep the old truck stock for when you need to haul stuff...and get an old Camaro or whatever to put the money into for performance. Would this not be a smarter path?
My 00 Sierra BONESTOCK 4.8 single cab stepside 3.42 gears 2wd ran a best of 16.4 on the 1/4 at sealevel. I had done a tuneup prior to racetrack time. It had around 70k miles. Pretty slow in my opinion.
I really enjoy watching your build vids even back to your days on Trucks. I personally would keep the LMG 5.3 in my Silverado with a few upgrades. I have the speeding ticket to prove that it will get you in trouble in a hurry.
BTW, your friend, Pat from Engine Power, did a junkyard 5.3 build that put down decent power on his dyno.
You added nice big holes more air, yes but your holes added hot underhood air, add power or lose power?
Sure the LS has a gate following but the mighty Big Bock has been here for a long long time kid, you wanna go fast ? there is still no replacement for displacement Big Block for the win !
Nice data analyzing! Next need to figure the weight of the vehicle into the matrix... Great stuff!! More Power Tim (err LT) the toolman taylor, grunt grunt!
The one ratty tie down on the back bumper and vehicle parked 3 feet in front of you on the dyno had the hair on the back of my neck standing up.
I love the 8.1 it's basically a modern fuel injected 454 punched out to a 496👌
The 8.1 is a 454 stroked .375 inches.
Well that didn’t age well
Far as testing a good one is acceleration rate graph in HP tuners .
Gives the ability to see where it's accelerating good and where it may be lacking and you can adjust just areas of the tune in the weaker places .
Find if your shift point should be raised or lowered etc..
I've forgotten the pids and math it took to set it up but to give credit where it's due I got it from
Goat rope garage here on RUclips
Unless you duct air from in front of the radiator cutting hole in the filter box may reduce horsepower.
Cold air intakes rarely add power they simply keep power by not having to pull timing etc because the intake is sucking in hot air
A must is an air intake temperature sensor and manifold temperature sensor that you can data log to see if the ECU is pulling timing to prevent knocking.
Thank you for the great content and look forward to another year of it. Merry christmas LT. Claiming that hill to one mill!