How refreshing to see a young bloke who has such knowledge on a component level. I am 70 and spent 45 years specialising in high performance engines, from top fuel to Bathurst, boats bikes and acrobatic planes. You are a legend young fella.
Thank you for ALL your honest and easy to understand results with this test. I am just about to update from a 32/36 Weber (which has been running super rich) on my 1966 1500cc Isuzu Bellett to a 38/38 Retroject EFI Throttle body and Autronic ECU.....this is a great insight to the fact it is NOT going to make it into a horsepower monster. All I am trying to achieve is better acceleration and driveability, as currently it is a slug off the line. I am also aiming to turbocharge it next year to get just a little bit more get up and go. Thanks.
EFI is great. The only thing that stopped me going EFI over my twin (a million hours to tune) webers is that I wanted to keep my car true(ish) to its 1970’s heritage. I already have modern EFI cars and I find the webers quite fun from an enthusiast aspect.
Wow, that was some of the most objective testing, you really bent over backwards to keep it 'like for like'. I agree, having modern ignition mapping is the shiznit, I think I could live happily with a simple old Holley 4 bbl if I was able to map the spark so precisely. Springs vs. weights and a vacuum diaphragm are so friggin caveman, they're brutal tools and in my experience rarely give repeatable performance. At least I haven't managed to make them work very well. I'm in Canada so I rarely see a well modified domestic inline 6 cylinder engine. The saddest thing about the inline sixes is that horrid iron log intake that most of them were strangled with, along with often a single throat carburetor. 160 wheel horsepower in an old school (relatively lightweight) car and manual box would be so much fun to drive, especially being as well sorted out as this one appears to be. Great stuff.
Good video and I like the car (I had an LC with a 202 at 11:1 on 36/72 with triple SU), it serves as a good reminder of what we used to know when aftermarket EFI was hitting the streets with Holley throttle bodies, that the main difference is you don't have to retune EFI every time you change elevation. A perfectly tuned multiple carb setup on dialled runners for the throttle response is basically the same performance as multiport EFI on the same ignition, except you have to pull over and retune if you drive up or down a mountain or lose power with altitude change. Seasonal weather too. Basically I had to retune the SUs and reset the valve lash every second weekend plus whenever I changed elevation, which was the difference between beating or losing to a Brockie. Different story but the same my now ride is an 80s Merc six with a big cam and that was on K-jet, tried a franken standalone but couldn't reconcile the Bosch system so that's getting EFI now. On the milder cam though you wouldn't have got any benefit, the K-jet is a remarkably adaptive closed loop for a narrow band, being a vacuum system, it'll self adjust and auto-retune for any mods you throw at it until you do significant valve overlap, then it goes haywire. For a mild power build K-jet is better than EFI with barely any sensors, no wonder Porsche and Ferrari used it.
Really good test. I think to make it better you could get someone to 3d print some new velocity stacks with an identical bell mouth profile and length to the webers big with a flange for the jenvey bodies.
Good test. Have you ever heard of Keith Frank? He makes a replacement emulation tube that works on a totally different operating principle. He calls them Venturi Pump Tubes, or VP tubes. He is not great at marketing but i really want someone like you, with a dyno and weber ecperience to check them out. He also makes a bunch of other trick parts like idle jets with adjustable air bleeds.
If the carbs and throttle bodies are the same diameter, the tbs will act as a much larger carb. A big advantage of efi is if you use the vehicle in different ambient temps.
I think a 12 port head would be better for this testing, the weber DCOE's thrive on a single runner setup. If I had to choose between injection and carbs for a "fun" car, I would use carbs, they have character.
If I make another comment. Can you give intake runner length as the distance from the back of the inlet valve to the end of the trumpet. This measurement takes into consideration the differences in intake manifold length and design, the length of the throttle body or carburetor and the length of the trumpet with or without spacers. Cheers
I think the real boost of EFI comes from a redesign of the inlet tract and the assurance of efficient atomization. It would be interesting to (me) to put the spacers between throttle bodies and the head !?
The true advantage of EFI is when you go drive in the mountains. In closed loop the EFI can compensate for air pressure drop and lesser oxygen content as you go from sea level to 4000m
I got a bombed 12 port alloy headed blue MTR. Was running turbo twin SU drawthru. Could barely crack 300 atw. Went injection with VK injection manifold straight away shot up to high 400s. I can understand with your setup not making much of a difference as fuel is being placed similarly but in my draw thru setup vs VK injection manifold it was night and day.
One advantage that some EFI ECUs have is ability to adjust fuel trim per cylinder. If you take the time to put an AFR sensor on each cylinder you'll see why this is helpful. There are carbs that can adjust (well direct) fuel in ways to compensate for varying airflow to cylinders... But it's arguably easier with EFI. Once you have your individual trims set you can go back to a regular single sensor per bank.
I do and I dont miss my LC, it was a 192 with tripples, when the SB barina GSI came out, it absolutely distoryed the LC lol Plus all the 12'a and 13b's went turbo, so I had no hope racing them anymore. Then i started playing with the 1986 60 series Landcruiser.12Ĥ-T diesel 250hprwhp and 650 NM of torque lol
Not true… catalytic converter is easier to control with efi, but carbs can be very clean, but not ever changing based on converter needs…. That’s the hiccup
@@michaelbyrnes7944 obviously your understanding of combustion is set in the 70's. The world has learnt much in the last 50 years about getting a more efficient burn. FYI - cleaner emissions means more of the fuel energy is turned into power. Maybe you can rethink your Neanderthal ways
Does the Jenvey throttle body flow as well as the Weber throttle body? When similar length trumpets were used, the power for EFI was down, so one can conclude that flow wasn't as good as when the carbs were used, assuming everything else was the same. (AFR's, coolant temp, air temp, ignition timing, fuel used etc) Using the longer trumpets with the efi brought the power back because of harmonics, despite the poorer flowing throttle body? It would have been interesting to have tested the carbs with longer trumpets as well before the change over to see their effect on the engines output. I like what you have done here and your methodology. I'm currently optomising my EFI setup using a Haltech E750 and a Nissan L28 engine. I'm getting some excellent results from testing and tuning, on the dyno and at the drag strip. The biggest shock was using an airbox which is normally considered a performance stumbling block and a flow restriction. I managed to increase power everywhere by using one, especially from 4000 to 7200rpm. At around 5800 rpm, I increased power by 18 rwkw (24 rwhp) just by adding the air box. Although the looks and sound is there with just trumpets, an airbox helps with the resonance and if setup correctly, boosts power significantly.
It’s likely the opposite effect. The throttle bodies don’t have venturis as a restriction. A 45mm Weber will usually have 36mm or 38mm venturis which increases air velocity. The throttle bodies don’t have that restriction so airflow speed is slower and doesn’t atomise the fuel so well. The velocity stacks being longer may have helped this effect somewhat.
@@reubenhopkins1996 I'm really no expert on carbs but the purpose of the chokes is to create a pressure drop, not increase air speed, although that does happen. The theory is, when the air is sped up, it creates an area of lower pressure and that low pressure draws fuel into the airstream via the jets. Any 'work' the air has to do requires energy and that will come from the fast moving air, slowing down to do the 'work'. Fuel atomisation is typically superior with injectors but the same injectors can atomise the fuel quite differently based on the pump pressure applied to them. Also the way they are delivering the fuel plays a part as well, batch or sequential...as well as the timing of the injectors relative to the phase of engine rotation ie intake valve open, closed or during the overlap period. These are just a few of the variations. Just as not all carburetors are the same, I suspect not all throttle bodies are the same, so having said that, perhaps EFI Hardware throttles could have been tested to see if there was a difference there. Interesting test. It certainly has invoked some critical thinking!
@@DAT28C You’re right regarding the low pressure effect of the venturis. Good point. I just know that going too big on carb or ITBs will hurt low end performance, and on an engine like an old Holden 6, it doesn’t rev high enough to see the potential gain at high RPM. It may also just be that the throttle bodies react to e fine pulses differently due to location of the injector or throttle plates etc in the air stream. It would be cool to play around with different combinations to see what happens (40mm, 42mm, and 45mm ITBs, and different velocity stack lengths, diameters etc).
@@reubenhopkins1996 Absolutely! Webers have a fantastic reputation as being one of the best carbs out there. Finding an equivalent performance throttle body may be what's needed to make the test valid from that aspect. Different bore sizes as you suggest, with or without taper, injector position and angle, injector spray pattern type...yeah, a lot has been left on the table here. It would be an interesting test but it would take time and cost a fair bit to set up. Manufacturers of the hardware probably wouldn't be too keen to chime in unless they know their product is the best already through their own testing. Nobody likes to admit their product is off the podium, so to speak. Maybe that's the issue, the throttle body here is just middle of the road and compared to a premium carb such as the Weber, just comes off second best in the baseline testing.
4:50 I never realised changing the gearing or tyres changed RWHp.... (unless of course you're trying to turn tractor wheels). Learnt something today! ahem.
Thats still puzzling my mind as to why that happens. Must be due to some losses in the system since in theory the power at the wheels should not really change
@@288gto7 I think it relates to different mechanical gearing being the parallel to mechanical leverage.... a force of 10 kg on one end of a lever turns into a force of 100Kg at the other end.... but work done is the same, because the force is applied over different distances. A bit like those truck wheel nut crackers.... where a tiny girly in a bikini can crack a truck wheel nut, when mighty man bouncing on the end of a helper bar can't. The one thing I'm sure of.... is that no energy disappears by changing gearing! All that extra torque at the back wheel delivers oomph!
Excellent vid. I'm a hard-core efi guy and tuner, but I'm surprised to see the carbs proved hard to beat in terms of outright performance. I feel we can take away from this that there was quite possibly a bit more throttle bore size than necessary, and I feel the other let down that may have helped efi win was in part being restricted to batch injection instead of sequential and being able to adjust injector timing, and possibly the 9 port head. Atleast with efi the customer will have a win in terms of fuel economy, cold starts, oil dilution etc, but I would be curious to know which one feels or goes better under transient throttle conditions!
I'm forever amazed that a self-contained metal contraption, with only 3 inputs (throttle position, engine vacuum and airflow), can do such an amazing job of keeping the engine running in all situations, and be not too far from what EFI can do. The problem is that people expect to bolt on the "house brick" and somehow have everything optimised by the factory that built it. They dont realise that the carby doesn't know what it's bolted to. Just as with EFI, it needs to be tuned to the engine. If the owner doesn't know how to do that, that's on them, not the poor old carby they got off marketplace for $180. I'm running a "dog" of a carby on my 302C, a Holley spreadbore double pumper. I built it to my specs and can safely say that after messing with 3 others before it, it's the best by far in all areas except maybe off-idle torque (the Street Demon was the best for that). Joe you might remember my car from a dyno day a few years back. A brown XE wagon 5-speed that you were pretty impressed with despite its mediocre power output (but your dyno is savage)
It depends on the quality of the port design in the head. You can get the fuel/air and timing more accurate with the EFI, but on a head with poor flowing intake ports, the difference is small. We have done extensive testing comparing EFI and a single Holly on big block hemis and Chevvies, and the gain with EFI is less than 15hp at the 500hp level. But a good flowing head that maintains intake velocity will not show much of a difference.
Personally, I care much less about peak HP than I do drive-ability. That's the test I'm interested in. And when the car is a daily driver, you can add fuel economy on top of that.
Charge cooling from carbs. You're getting the effect of phase change in the Venturi since at WOT Venturi vacuum is inversely proportional to manifold pressure. In this low depression the fuel tends to boil due to pressure drop around the boosters. There isn't really enough time for it to properly boil per se because manifold pressure = atmospheric pressure at WOT (minus air cleaner restriction but close enough) the constant phase change in the Venturi area is having an effect on power by increasing air density slightly. In injection systems the fuel is injected but the system doesn't require a Venturi, but it seems you've compensated by playing with ram tubes positively varying volumetric efficiency.
Hi mate, I'm running triple 45mm webers. I'm interested in what you have done with the computer ignition set up, and also the throttle linkage. Can I get some help or info please
Man miss my LJ it was a import from Oz to here in New Zealand put a JP 202 in it had a 350 2 br Holley then a 465 4br holley bit soft down low and a 2 br weber off a V6 Capri for long trips or daily ,holley for Fridays and weekend ,semi hi stall converter frankinstein Trimatic guy built me at work from HQ,HX,VB bits he had lying around had to buy new seals and few other little bits and a cut down EL Xr6 LSD 3.3 maybe fast sorted car ,commo front brakes big sway bars ,gtr wheels on 225 low and fast with a cheesy XU1 rear spolier,early 90s they wernt worth alot lol got rid of it for a Yamaha FZR1000 that i got into heaps of trouble getting chased by cops losing licence uuug should of keep the Torana it was a happy car
The problem with your initial run, being less hp than base (carb'd), was the target AFR of 14.5:1. While that is good for emissions & economy it is not for power. Use 14.5:1 when the throttle is open less than ~70%, from there up work towards an AFR of more like 13:1.
I don't see a problem with running different trumpets with the efi compared with the carbs. That's all part of it. Each system needs its own special parts and equipment. It would be a bit like saying we will run fuel injection but we won't use injectors because the carbs don't have them. That's silly, each system has its own parts it needs that will be different to the other system. If the combination of parts in the injection system gives you more power or it drives more to your liking, then that is the superior system for you and whatever combination of parts it consists of works for you.
Totally agree, this was exactly my thoughts. Presumably the ram tubes on the carb's had been optimised (if not why not?) for them so why should the EFi system not have the same treatment rather than be stymied by something specific to the carb's? This is not the same as changing fuel and ignition systems at the same time. I don't see why the results are surprising though, why one fuelling system optimised for WoT create more power than the other, it's the engine which is making the power, as long as air and fuel restrictions were similar the overall power should be the same. In fact it seems 8BHP extra was developed, maybe not life changing but that's still >5%. Point is that carb's are always a compromise, optimising one area of the fuelling always seems to give suboptimal performance or behaviour elsewhere with EFi it's much easier to optimise fuelling (within the physical limits of the hardware) across the RPM and load ranges as well as giving benefits such as over-run fuel shut-off and closed loop control (and diagnostics).
It’s a Haltech Elete 750. It could be a 550? It was a while ago so I can’t quite remember. In any case, it’s one of the lower spec Eleite’s. 99 percent sure it’s a 750.
@@jdfilms1426 Thanks for your reply. Im building an engine for my EH with an Irving stage 2 cylinder head with triple Webbers. I was going to run a wideband o2 sensor until I saw what you did.
I have A Deceleration fuel Cut out system in my 750 demon carburator !!! These Webber style carburetors Have so many adjustments that you can get the correat fuel ratio at all Engine demands More so than a Holley Style carburetor !!! IT CAN BE DONE !!! If you have $8000( My friend wants to buy one for his Subaru) to buy an Aftermarket ECU for your fuel management by all means go for it to each their own ! 🤷♂️
Very hi psi injection via fuel pumps and injection can make a increase in Hp. Very costly for a top notch system. A cold air box on that application would also pick up around 10 or so Hp
Well adjusted carbs exactly to your local weather can't be beat. But that's not easy to do, and ideally you need standalone ignition, expensive, and just all the jets alone are also starting to get pretty expensive now. Carbs are also expensive, DGV's aside, a full double or triple set DCOE's with intake, linkage, funnels = Not cheaper than ITB's, and Weber's are now Spanish made and can have quality issues, as opposed to the older Italian made ones. Fuel consumption isn't the best with carbs either, can be temperamental, and may require a certain throttle technique. That's where EFI shines, you trade a few horses for overall health of engine, fuel economy, QoL & driveability. For me, it's EFI all day until solar flare.
What about the fact the efi bodies don’t run chokes and the Webber do run chokes, did you think the over all size of the throttle Bodie bore where too Leigh in diameter , Been here done this! Been a engine builder/ tuner for a very long time, car engines and bike engines, fuel control via efi is always better, you just need to make sure your intake air speed is correct for the engine, the fact you needed to speed up the air flow with the carby ram tubes is telling me , with the chokes in the carby increasing air speed, the throttle bodies bore size was too big. After all this is a street car with a small cam, I have the best results by choking Webbers down to 38mm and seen power losses when going to Webber style throttle bodies cause of the slower air speed due to larger bore size
I agree. He didn't tell us what size the carbs were (or the chokes in them) or the ID of the ITB's, but that little HP won't even need 40mm ITB's, especially as it has a nine port head. It would be interesting to see the power graphs on different throttle percentage openings (which he would have done) to see what that engine needed.
Why would you not use an EFI Hardware DCOE throttle body's being they are manufactured here in Australia? I will say though Webber DCOE style carburetors are the closest thing to injection due to the way the fuel travels into the chokes & into the cylinder head. EFI hardware throttle bodies are a lot more direct & simpler design. By the looks of things the efi throttle bodies your using look very complicated.
Its interesting i have always had the thought EFI injectors were an odd design very clumsy when you consider the better part of 60 70 years of development went into carb design and we arrived at a Venturi to deliver fuel at the ideal position in the intake stream with little fuel Pressure (relative) Why move it and redesign the wheel then try to compensate with higher injection pressures Why not retool the carb body and use the efi injector to metre the fuel to the Venturi then you get the best of both worlds
I have run with Dellorto Carborators 48mm Chevy 356cui 0.40 borr 4 bult block.Corvette 1974 No no transbrake run 10sek taimes 1992 1600kg car.Th400 (Aut) 201M 6.9sek Real Street car..I Build Twin Turbos 95-96 Efi Vems In may Corvette.Hope com tou The Streets 2025...Real Street car offcors..Turbos are smal K27 Have k29 if I want more flow...I tink thes K27 are god.Have Bigger Rear end 12 bult 31 splains.Toms parts..
Is that the customer who is banned from many workshops / machine shops in Sydney because he just hangs around like a bad smell? I think i met him at Dominator Engines one day
Fact you can run more cam on a analogue engine. Webers dont care about manifold vaccuum. Everyone wanks themselves silly about efi but there will be more power made with an engine built for carbs. Near certain it will not be as smooth to drive so efi does make some sense on a road car. But not on a race car. Computerised ign is MAYBE an advantage, on a road car. I have always used factory Commodore HEI which is better than most others. BUT I would love to try a MSD. On V8 racecars an improvement, on V8 road cars chalk and cheese. Starts easier, runs smoother and uses a bit less fuel. I have it on my mild 400 Ford and have fitted it to a Mustang and a 350 Chev for a ski boat. My 400 is using white wire on a points dissy. The electronic dissy died. Though I have had [Crane] ign boxes die on the 400 and the 351 raceengine. So far ok with basic MSD. Streetfire on the 400 as it never runs past about 4500. MSD 6 on the racecar. Those rock strainers over the ram tubes is killing power,, effects the standoff which usually makes it richer and less driveable. Unifilters, K&Ns etc on the ram tubes resolves this. Been there and done that. 45s on a healthy road race 202 with 40mm chokes. Engine ran between 3500 and 6500. Weber ram tubes always seem to be the best, I once tries some with a bigg entrance and lost power, so put the originals back on. This on a chassis dyno. Holley efi is never an answer, just continual dramas. And will make less power
nope, if that was the case, all performance cars would still run carbs. I wouldn't even be looking at cars for this test, motorcycle carbs and injection is leaps and bounds better than anything running on cars, and you won't find a carb that works better than injection on a race bike ever.... Motorcycle tech is miles ahead of anything car related, always has been...
@@MickH60 it's because new cars have efi. Pro stock stayed carbs until forced to go efi to keep up with emissions and what people have in their every day cars. I owned a Dyno so I am telling you that carbies made more peak hp every time on my engine Dyno. That was 10 years ago. That is NA car engines I'm talking about.
How refreshing to see a young bloke who has such knowledge on a component level.
I am 70 and spent 45 years specialising in high performance engines, from top fuel to Bathurst, boats bikes and acrobatic planes.
You are a legend young fella.
Thank you for ALL your honest and easy to understand results with this test. I am just about to update from a 32/36 Weber (which has been running super rich) on my 1966 1500cc Isuzu Bellett to a 38/38 Retroject EFI Throttle body and Autronic ECU.....this is a great insight to the fact it is NOT going to make it into a horsepower monster. All I am trying to achieve is better acceleration and driveability, as currently it is a slug off the line. I am also aiming to turbocharge it next year to get just a little bit more get up and go. Thanks.
EFI is great. The only thing that stopped me going EFI over my twin (a million hours to tune) webers is that I wanted to keep my car true(ish) to its 1970’s heritage. I already have modern EFI cars and I find the webers quite fun from an enthusiast aspect.
Wow, that was some of the most objective testing, you really bent over backwards to keep it 'like for like'. I agree, having modern ignition mapping is the shiznit, I think I could live happily with a simple old Holley 4 bbl if I was able to map the spark so precisely. Springs vs. weights and a vacuum diaphragm are so friggin caveman, they're brutal tools and in my experience rarely give repeatable performance. At least I haven't managed to make them work very well.
I'm in Canada so I rarely see a well modified domestic inline 6 cylinder engine. The saddest thing about the inline sixes is that horrid iron log intake that most of them were strangled with, along with often a single throat carburetor. 160 wheel horsepower in an old school (relatively lightweight) car and manual box would be so much fun to drive, especially being as well sorted out as this one appears to be. Great stuff.
Great video and very informative. Thanks for sharing your knowledge with us minions.
Good video and I like the car (I had an LC with a 202 at 11:1 on 36/72 with triple SU), it serves as a good reminder of what we used to know when aftermarket EFI was hitting the streets with Holley throttle bodies, that the main difference is you don't have to retune EFI every time you change elevation. A perfectly tuned multiple carb setup on dialled runners for the throttle response is basically the same performance as multiport EFI on the same ignition, except you have to pull over and retune if you drive up or down a mountain or lose power with altitude change. Seasonal weather too. Basically I had to retune the SUs and reset the valve lash every second weekend plus whenever I changed elevation, which was the difference between beating or losing to a Brockie.
Different story but the same my now ride is an 80s Merc six with a big cam and that was on K-jet, tried a franken standalone but couldn't reconcile the Bosch system so that's getting EFI now. On the milder cam though you wouldn't have got any benefit, the K-jet is a remarkably adaptive closed loop for a narrow band, being a vacuum system, it'll self adjust and auto-retune for any mods you throw at it until you do significant valve overlap, then it goes haywire. For a mild power build K-jet is better than EFI with barely any sensors, no wonder Porsche and Ferrari used it.
Really good test. I think to make it better you could get someone to 3d print some new velocity stacks with an identical bell mouth profile and length to the webers big with a flange for the jenvey bodies.
That's a properly racy rana! Love it.
I think you have done a great comparison.
Honest test mate. Very well presented.
Good test. Have you ever heard of Keith Frank? He makes a replacement emulation tube that works on a totally different operating principle. He calls them Venturi Pump Tubes, or VP tubes. He is not great at marketing but i really want someone like you, with a dyno and weber ecperience to check them out. He also makes a bunch of other trick parts like idle jets with adjustable air bleeds.
I thought you meant 'the world's fairest carburettor' as in the prettiest :)
A very good test and informative,the Ice ignition system does make a big difference running a carburettor with a hot cam.
Good test , thanks for doing it , I have a turbo EFI car and a turbo blow through carb car , no problems with either of them.
If the carbs and throttle bodies are the same diameter, the tbs will act as a much larger carb.
A big advantage of efi is if you use the vehicle in different ambient temps.
Great explanation👍
I think a 12 port head would be better for this testing, the weber DCOE's thrive on a single runner setup. If I had to choose between injection and carbs for a "fun" car, I would use carbs, they have character.
If I make another comment. Can you give intake runner length as the distance from the back of the inlet valve to the end of the trumpet. This measurement takes into consideration the differences in intake manifold length and design, the length of the throttle body or carburetor and the length of the trumpet with or without spacers. Cheers
Great video gents.
Where did you get the wig from I need one :)
Top vid by the way
Good work mate
Very good test, i just miss the Torque diagramm, would be intresting how different the torque is.
I think the real boost of EFI comes from a redesign of the inlet tract and the assurance of efficient atomization. It would be interesting to (me) to put the spacers between throttle bodies and the head !?
Would have been interesting to see what happened with the throttle bodies spaced off the head
I really really want to learn to adjust Weber DCOE's, I think you could be the one that could make such a video. You succeeded with this one 🙂
The true advantage of EFI is when you go drive in the mountains. In closed loop the EFI can compensate for air pressure drop and lesser oxygen content as you go from sea level to 4000m
I got a bombed 12 port alloy headed blue MTR. Was running turbo twin SU drawthru. Could barely crack 300 atw. Went injection with VK injection manifold straight away shot up to high 400s. I can understand with your setup not making much of a difference as fuel is being placed similarly but in my draw thru setup vs VK injection manifold it was night and day.
One advantage that some EFI ECUs have is ability to adjust fuel trim per cylinder. If you take the time to put an AFR sensor on each cylinder you'll see why this is helpful. There are carbs that can adjust (well direct) fuel in ways to compensate for varying airflow to cylinders... But it's arguably easier with EFI. Once you have your individual trims set you can go back to a regular single sensor per bank.
I do and I dont miss my LC, it was a 192 with tripples, when the SB barina GSI came out, it absolutely distoryed the LC lol
Plus all the 12'a and 13b's went turbo, so I had no hope racing them anymore.
Then i started playing with the 1986 60 series Landcruiser.12Ĥ-T diesel 250hprwhp and 650 NM of torque lol
Presents a lot of good points. I think you missed mentioning one of the key benefits, much cleaner emissions.
You know what you can do with your emissions bullshit
@@michaelbyrnes7944 I'm guessing U want me to do what you do daily?? Nah. I'm good.
I agree with this comment.@@michaelbyrnes7944
Not true… catalytic converter is easier to control with efi, but carbs can be very clean, but not ever changing based on converter needs…. That’s the hiccup
@@michaelbyrnes7944 obviously your understanding of combustion is set in the 70's. The world has learnt much in the last 50 years about getting a more efficient burn.
FYI - cleaner emissions means more of the fuel energy is turned into power. Maybe you can rethink your Neanderthal ways
Does the Jenvey throttle body flow as well as the Weber throttle body? When similar length trumpets were used, the power for EFI was down, so one can conclude that flow wasn't as good as when the carbs were used, assuming everything else was the same. (AFR's, coolant temp, air temp, ignition timing, fuel used etc) Using the longer trumpets with the efi brought the power back because of harmonics, despite the poorer flowing throttle body? It would have been interesting to have tested the carbs with longer trumpets as well before the change over to see their effect on the engines output. I like what you have done here and your methodology. I'm currently optomising my EFI setup using a Haltech E750 and a Nissan L28 engine. I'm getting some excellent results from testing and tuning, on the dyno and at the drag strip. The biggest shock was using an airbox which is normally considered a performance stumbling block and a flow restriction. I managed to increase power everywhere by using one, especially from 4000 to 7200rpm. At around 5800 rpm, I increased power by 18 rwkw (24 rwhp) just by adding the air box. Although the looks and sound is there with just trumpets, an airbox helps with the resonance and if setup correctly, boosts power significantly.
It’s likely the opposite effect. The throttle bodies don’t have venturis as a restriction. A 45mm Weber will usually have 36mm or 38mm venturis which increases air velocity. The throttle bodies don’t have that restriction so airflow speed is slower and doesn’t atomise the fuel so well. The velocity stacks being longer may have helped this effect somewhat.
@@reubenhopkins1996 I'm really no expert on carbs but the purpose of the chokes is to create a pressure drop, not increase air speed, although that does happen. The theory is, when the air is sped up, it creates an area of lower pressure and that low pressure draws fuel into the airstream via the jets. Any 'work' the air has to do requires energy and that will come from the fast moving air, slowing down to do the 'work'. Fuel atomisation is typically superior with injectors but the same injectors can atomise the fuel quite differently based on the pump pressure applied to them. Also the way they are delivering the fuel plays a part as well, batch or sequential...as well as the timing of the injectors relative to the phase of engine rotation ie intake valve open, closed or during the overlap period. These are just a few of the variations. Just as not all carburetors are the same, I suspect not all throttle bodies are the same, so having said that, perhaps EFI Hardware throttles could have been tested to see if there was a difference there. Interesting test. It certainly has invoked some critical thinking!
@@DAT28C
You’re right regarding the low pressure effect of the venturis. Good point.
I just know that going too big on carb or ITBs will hurt low end performance, and on an engine like an old Holden 6, it doesn’t rev high enough to see the potential gain at high RPM. It may also just be that the throttle bodies react to e fine pulses differently due to location of the injector or throttle plates etc in the air stream. It would be cool to play around with different combinations to see what happens (40mm, 42mm, and 45mm ITBs, and different velocity stack lengths, diameters etc).
@@reubenhopkins1996 Absolutely! Webers have a fantastic reputation as being one of the best carbs out there. Finding an equivalent performance throttle body may be what's needed to make the test valid from that aspect. Different bore sizes as you suggest, with or without taper, injector position and angle, injector spray pattern type...yeah, a lot has been left on the table here. It would be an interesting test but it would take time and cost a fair bit to set up. Manufacturers of the hardware probably wouldn't be too keen to chime in unless they know their product is the best already through their own testing. Nobody likes to admit their product is off the podium, so to speak. Maybe that's the issue, the throttle body here is just middle of the road and compared to a premium carb such as the Weber, just comes off second best in the baseline testing.
My friend had a long reach manifold on his triple SU LJ Torana. No long reach manifolds for triple Webers?
great video by the way, keep up the good work
Wouldn't having the injectors as close to the cyl head ports be better for atomisation and spray pattern in the direction of airflow?
Enjoyed this alot! You obviously do customer cars?
4:50 I never realised changing the gearing or tyres changed RWHp.... (unless of course you're trying to turn tractor wheels). Learnt something today! ahem.
Thats still puzzling my mind as to why that happens. Must be due to some losses in the system since in theory the power at the wheels should not really change
@@288gto7 I think it relates to different mechanical gearing being the parallel to mechanical leverage....
a force of 10 kg on one end of a lever turns into a force of 100Kg at the other end.... but work done is the same, because the force is applied over different distances.
A bit like those truck wheel nut crackers.... where a tiny girly in a bikini can crack a truck wheel nut, when mighty man bouncing on the end of a helper bar can't.
The one thing I'm sure of.... is that no energy disappears by changing gearing! All that extra torque at the back wheel delivers oomph!
Excellent vid. I'm a hard-core efi guy and tuner, but I'm surprised to see the carbs proved hard to beat in terms of outright performance. I feel we can take away from this that there was quite possibly a bit more throttle bore size than necessary, and I feel the other let down that may have helped efi win was in part being restricted to batch injection instead of sequential and being able to adjust injector timing, and possibly the 9 port head.
Atleast with efi the customer will have a win in terms of fuel economy, cold starts, oil dilution etc, but I would be curious to know which one feels or goes better under transient throttle conditions!
I'm forever amazed that a self-contained metal contraption, with only 3 inputs (throttle position, engine vacuum and airflow), can do such an amazing job of keeping the engine running in all situations, and be not too far from what EFI can do.
The problem is that people expect to bolt on the "house brick" and somehow have everything optimised by the factory that built it. They dont realise that the carby doesn't know what it's bolted to. Just as with EFI, it needs to be tuned to the engine. If the owner doesn't know how to do that, that's on them, not the poor old carby they got off marketplace for $180.
I'm running a "dog" of a carby on my 302C, a Holley spreadbore double pumper. I built it to my specs and can safely say that after messing with 3 others before it, it's the best by far in all areas except maybe off-idle torque (the Street Demon was the best for that).
Joe you might remember my car from a dyno day a few years back. A brown XE wagon 5-speed that you were pretty impressed with despite its mediocre power output (but your dyno is savage)
but would the carbs have gained from longer tubes ? as well
It depends on the quality of the port design in the head. You can get the fuel/air and timing more accurate with the EFI, but on a head with poor flowing intake ports, the difference is small. We have done extensive testing comparing EFI and a single Holly on big block hemis and Chevvies, and the gain with EFI is less than 15hp at the 500hp level. But a good flowing head that maintains intake velocity will not show much of a difference.
Personally, I care much less about peak HP than I do drive-ability. That's the test I'm interested in. And when the car is a daily driver, you can add fuel economy on top of that.
Charge cooling from carbs. You're getting the effect of phase change in the Venturi since at WOT Venturi vacuum is inversely proportional to manifold pressure. In this low depression the fuel tends to boil due to pressure drop around the boosters. There isn't really enough time for it to properly boil per se because manifold pressure = atmospheric pressure at WOT (minus air cleaner restriction but close enough) the constant phase change in the Venturi area is having an effect on power by increasing air density slightly.
In injection systems the fuel is injected but the system doesn't require a Venturi, but it seems you've compensated by playing with ram tubes positively varying volumetric efficiency.
Good on you. Thanks
Very interesting video. But have to ask, the car is very similar to the Opel Ascona A here in Europe, is it the same?
Looks somewhat similar around the nose, but not in other angles. The car has it's origins with the English Vauxhall Viva.
Hi mate,
I'm running triple 45mm webers. I'm interested in what you have done with the computer ignition set up, and also the throttle linkage. Can I get some help or info please
Man miss my LJ it was a import from Oz to here in New Zealand put a JP 202 in it had a 350 2 br Holley then a 465 4br holley bit soft down low and a 2 br weber off a V6 Capri for long trips or daily ,holley for Fridays and weekend ,semi hi stall converter frankinstein Trimatic guy built me at work from HQ,HX,VB bits he had lying around had to buy new seals and few other little bits and a cut down EL Xr6 LSD 3.3 maybe fast sorted car ,commo front brakes big sway bars ,gtr wheels on 225 low and fast with a cheesy XU1 rear spolier,early 90s they wernt worth alot lol got rid of it for a Yamaha FZR1000 that i got into heaps of trouble getting chased by cops losing licence uuug should of keep the Torana it was a happy car
If its a classic car, the mechanical beauty of the carbs is where its at. Just my opinion.
Much difference in fuel economy?
First thing I did after watching the intro was come down to the comments looking for discussion on this topic.
The problem with your initial run, being less hp than base (carb'd), was the target AFR of 14.5:1.
While that is good for emissions & economy it is not for power. Use 14.5:1 when the throttle is open less than ~70%, from there up work towards an AFR of more like 13:1.
Have you tried an Aussie Rotec ITB?
Do you have a Rotec TBI fitted to a car or bike
@@carlmitchell4297 Will be fitted to my next project.
@@amraceway I have a pair of 34mm Rotec TBI's which are going on a 1959 6 cylinder engine.
@@carlmitchell4297 Mine will be going on a 202 inch Holden six cylinder..
@@amraceway Mine is for a 132 grey motor in FC Ute
I don't see a problem with running different trumpets with the efi compared with the carbs. That's all part of it. Each system needs its own special parts and equipment.
It would be a bit like saying we will run fuel injection but we won't use injectors because the carbs don't have them.
That's silly, each system has its own parts it needs that will be different to the other system.
If the combination of parts in the injection system gives you more power or it drives more to your liking, then that is the superior system for you and whatever combination of parts it consists of works for you.
Totally agree, this was exactly my thoughts. Presumably the ram tubes on the carb's had been optimised (if not why not?) for them so why should the EFi system not have the same treatment rather than be stymied by something specific to the carb's? This is not the same as changing fuel and ignition systems at the same time.
I don't see why the results are surprising though, why one fuelling system optimised for WoT create more power than the other, it's the engine which is making the power, as long as air and fuel restrictions were similar the overall power should be the same. In fact it seems 8BHP extra was developed, maybe not life changing but that's still >5%.
Point is that carb's are always a compromise, optimising one area of the fuelling always seems to give suboptimal performance or behaviour elsewhere with EFi it's much easier to optimise fuelling (within the physical limits of the hardware) across the RPM and load ranges as well as giving benefits such as over-run fuel shut-off and closed loop control (and diagnostics).
Watched from Old Harbour Jamaica.
Should have spaced the injections not the trumpet. Or used 2 injections per cylinder for better atomisation
What model Haltec is that running ?
It’s a Haltech Elete 750. It could be a 550? It was a while ago so I can’t quite remember. In any case, it’s one of the lower spec Eleite’s. 99 percent sure it’s a 750.
@@jdfilms1426
Thanks for your reply.
Im building an engine for my EH with an Irving stage 2 cylinder head with triple Webbers.
I was going to run a wideband o2 sensor until I saw what you did.
I have A Deceleration fuel Cut out system in my 750 demon carburator !!!
These Webber style carburetors Have so many adjustments that you can get the correat fuel ratio at all Engine demands More so than a Holley Style carburetor !!!
IT CAN BE DONE !!!
If you have $8000( My friend wants to buy one for his Subaru) to buy an Aftermarket ECU for your fuel management by all means go for it to each their own !
🤷♂️
no air cleaners?
Very hi psi injection via fuel pumps and injection can make a increase in Hp. Very costly for a top notch system. A cold air box on that application would also pick up around 10 or so Hp
Well adjusted carbs exactly to your local weather can't be beat.
But that's not easy to do, and ideally you need standalone ignition, expensive, and just all the jets alone are also starting to get pretty expensive now.
Carbs are also expensive, DGV's aside, a full double or triple set DCOE's with intake, linkage, funnels = Not cheaper than ITB's, and Weber's are now Spanish made and can have quality issues, as opposed to the older Italian made ones.
Fuel consumption isn't the best with carbs either, can be temperamental, and may require a certain throttle technique.
That's where EFI shines, you trade a few horses for overall health of engine, fuel economy, QoL & driveability.
For me, it's EFI all day until solar flare.
Just buy motorcycle carbs, way better responsiveness, cheap af, don't loose tuning as easy has webers.
What about the fact the efi bodies don’t run chokes and the Webber do run chokes, did you think the over all size of the throttle Bodie bore where too Leigh in diameter , Been here done this! Been a engine builder/ tuner for a very long time, car engines and bike engines, fuel control via efi is always better, you just need to make sure your intake air speed is correct for the engine, the fact you needed to speed up the air flow with the carby ram tubes is telling me , with the chokes in the carby increasing air speed, the throttle bodies bore size was too big. After all this is a street car with a small cam, I have the best results by choking Webbers down to 38mm and seen power losses when going to Webber style throttle bodies cause of the slower air speed due to larger bore size
I agree. He didn't tell us what size the carbs were (or the chokes in them) or the ID of the ITB's, but that little HP won't even need 40mm ITB's, especially as it has a nine port head. It would be interesting to see the power graphs on different throttle percentage openings (which he would have done) to see what that engine needed.
nice fair comparison
very interesting
Why would you not use an EFI Hardware DCOE throttle body's being they are manufactured here in Australia?
I will say though Webber DCOE style carburetors are the closest thing to injection due to the way the fuel travels into the chokes & into the cylinder head.
EFI hardware throttle bodies are a lot more direct & simpler design. By the looks of things the efi throttle bodies your using look very complicated.
The Jenvey heritage throttle bodies are designed to look like carbs, they keep things looking period.
the most interesting part, how much stronger did the engine get? its torque that matters
That’s not fair 🦣🦓🐆🦒
Well with the price of carbs now, they not cheaper.
Класс. У меня машина на двух olex c40 addhe 1600cm3 Lada
Needs a pop bang tune if anything g. Get her spitting flames
Buy some fireworks. A tuned engine is for performance not snap crackle and pop.
Its interesting i have always had the thought EFI injectors were an odd design very clumsy
when you consider the better part of 60 70 years of development went into carb design and we arrived at a Venturi to deliver fuel at the ideal position in the intake stream with little fuel Pressure (relative)
Why move it and redesign the wheel then try to compensate with higher injection pressures
Why not retool the carb body and use the efi injector to metre the fuel to the Venturi then you get the best of both worlds
I have run with Dellorto Carborators 48mm Chevy 356cui 0.40 borr 4 bult block.Corvette 1974 No no transbrake run 10sek taimes 1992 1600kg car.Th400 (Aut)
201M 6.9sek Real Street car..I Build Twin Turbos 95-96 Efi Vems In may Corvette.Hope com tou The Streets 2025...Real Street car offcors..Turbos are smal K27 Have k29 if I want more flow...I tink thes K27 are god.Have Bigger Rear end 12 bult 31 splains.Toms parts..
Is that the customer who is banned from many workshops / machine shops in Sydney because he just hangs around like a bad smell? I think i met him at Dominator Engines one day
Fact you can run more cam on a analogue engine. Webers dont care about manifold vaccuum. Everyone wanks themselves silly about efi but there will be more power made with an engine built for carbs. Near certain it will not be as smooth to drive so efi does make some sense on a road car. But not on a race car.
Computerised ign is MAYBE an advantage, on a road car. I have always used factory Commodore HEI which is better than most others. BUT I would love to try a MSD. On V8 racecars an improvement, on V8 road cars chalk and cheese. Starts easier, runs smoother and uses a bit less fuel. I have it on my mild 400 Ford and have fitted it to a Mustang and a 350 Chev for a ski boat. My 400 is using white wire on a points dissy. The electronic dissy died. Though I have had [Crane] ign boxes die on the 400 and the 351 raceengine. So far ok with basic MSD. Streetfire on the 400 as it never runs past about 4500. MSD 6 on the racecar.
Those rock strainers over the ram tubes is killing power,, effects the standoff which usually makes it richer and less driveable. Unifilters, K&Ns etc on the ram tubes resolves this. Been there and done that. 45s on a healthy road race 202 with 40mm chokes. Engine ran between 3500 and 6500.
Weber ram tubes always seem to be the best, I once tries some with a bigg entrance and lost power, so put the originals back on. This on a chassis dyno.
Holley efi is never an answer, just continual dramas. And will make less power
I always found carbies made more peak power then efi. I always put it down to better atomisation with a carburettor
nope, if that was the case, all performance cars would still run carbs. I wouldn't even be looking at cars for this test, motorcycle carbs and injection is leaps and bounds better than anything running on cars, and you won't find a carb that works better than injection on a race bike ever.... Motorcycle tech is miles ahead of anything car related, always has been...
@@MickH60 it's because new cars have efi. Pro stock stayed carbs until forced to go efi to keep up with emissions and what people have in their every day cars. I owned a Dyno so I am telling you that carbies made more peak hp every time on my engine Dyno. That was 10 years ago. That is NA car engines I'm talking about.
1000%
@@petergehle4222 Sounds like you don't know how to tune EFI
@hatface547 haha 😂 or you don't know how to tune carbies