I fucking love how you seem to be one of the only people who actually get out and dyno these sort of things after years of people speculating and comparing different dynos and setups to try and get to the bottom of it. You rock!
Andrew, when you are comparing cross sectional areas at the throttles what you are missing is something called hydraulic diameter. Even though the 6 throttles have a greater combined cross section the wetted surfaces with the throttle plates all create more drag on the air because of the increased boundary layer. Also when you refer to the time taken to pressurise a given plenum, don't forget the sort of quantities of air going through the system. A standard 2.6L RB at 8k rpm and 1 bar of boost is consuming 10,400 litre of air a minute or 173L a second. Your 3.2 at 8k and 2 bar its more like 25,600L per min of 426L a second!!!! Picture that much air!! So that pressurisation time is negligible. Where 6 throttles do help is on lift off as there is considerable less volume to drain from just one runner per throttle over the single where you've got to drain 6 runners and the manifold volume itself, so response is better there.
@@clubsport9334 Nah, I love going down the nerd technical rabbit hole. I just wanted to bust your balls a bit! Much love from Georgia, USA my savage brother!
Seeing the content evolve, the channel growing and the cars getting better by the day! Really enjoyed seeing you guys build this up on RUclips from the beginning. I can still remember seeing you for the first time on MCM with the 180.😄👌 Good work!
I have been learning from you for over a decade and it makes me so happy. I applied your knowledge on my own R32 GTR over the years; Thank you! This helped me make up my mind about going DBW on my K20/Sequential NSX build. I cannot ignore all the benefits that will let me focus on keeping the thing on the circuit and save my equipment.
From the research i did and years of forums and racing, ive noticed that ITB setups have better benefits on N/A applications especially with dual length runners, running single length runners usually leaves a part of the rev range lacking on torque. im still a sucker for Gantry fuel injection aha im loving how your GTR is going, change alot over the years
Shoutout to the motive DVD series that I use to collect when I was in high school. Was like a magazine, came out monthly but was on aDVD. Was super cool as a young kid. Anyway, cheers mate.
Hey guys! Love the content! I just bought a Stagea 260RS from Japan which will arrive in the US in December and I can’t thank you all enough for creating all of this content
Very educational as always, we have learnt a lot from you mate during last few years and applied on our cars in UK. Looking forward for more contents. Much appreciated
No real surprise in the results. Other than I'm surprised it was so close. The 45mm throttles are too small for such an engine. 48 or 50mm throttles wild likely see the gap disappear entirely. In real terms the difference can be attributed to the resistance the throttle shaft is having in the modest 45mm runner. Where in the single setup, there is no such imposition.
Did you even watch the vid? He calculated the net area where the throttle plates were subtracted. The 6 throttles had more net area, though the actual opening on the plenum is almost the same as the single throttle.
About half way through this now and the amount other stuff you ended up doing to the car is hilarious! Can't really call it scope-creep when it sounds necessary for one reason or another but it was pretty amusing to see how much extra you ended up spending🤣
Makes sense the single throttle does better at the top. Those ITBs take up some of the runner volume even full flat. Always wondered about a slide throttle. Probably deep into diminishing returns on effort to gains. Tip in works different that i'da expected then. I figured 6 cracking open would introduce more volume per port. Man she's a monster!
Can you just imagine driving around Sydenham and seeing that f***ing weapon of war rolling around freaking out the very rock and tar it chooses to grace with its presence. Roll on sweet machine roll on ❤️
You're bang on about the drivability being different going to DBW. I grew up driving carby and cable throttle cars and they are infinitely more polite to you when you're trying to drive them smoothly when you're on and off the throttle in traffic, the initial burst of airflow from opening isn't linear at all and ends up quite jerky to drive, even on a smaller diameter DBW. I love the response and tunability of DBW, but I can't shift the notion that every DBW car I've owned would've been better with a cable.
The inlet size was different on both manifolds test voided 82mm opening on single throttle inlet and you made the intercooler piping bigger on the inlet side for the single throttle plenum also.
Go do some transient throttle through corners on a race track! can't just putt around the street then do wide open pulls on a drag strip. Why would you run individual throttles on a drag strip its wide open throttle application.
The test should have been done with a mechanical single throttle since comparison with an electric throttle puts it at an advantage over the mechanical type.
The cars so well put together that first run seemed like a walk in the park 🤣 But watching out the windscreen fly by like you’re in warp speed is madness, the car seems so calm inside
My only question is what was the ambient temp during both tests? I think the difference is negligible and either way you are going to do ok. Killer gtr bro. Definitely makes me want to pull my finger out on mine.
Honestly love that you guys test and debunk this stuff. Im surprised how close the results were. However i dont know how controlled you can consider this experiment. You made alot of subtle changes between the two manifolds, including new injectors and dbw. Could all the small changes have contributed to the difference in power? Old injectors may have not flowed as well, dbw may have contributed to better driveability, etc. Was the test with the itb manifold done with itbs that were in good condition, not leaking like most do? Just feel like there could be some more factors there. Would love to see the same test done on the every mans 500hp rb26 setup, I wonder if the difference would be more obvious or less. Keep up the great work!
They used the same base port matched to the head and port matched to the manifold the intercooler pipe is inconsequential as it just matches the size of the intake opening we literally couldn’t have made it any fairer.
You can tune the throttle curve to get rid of that initial throttle opening too. When I first fitted my link ecu to an old 350z I had. It came with a linear throttle curve and it was horrible. Adjusted it so up till half pedal it only gave about 25% throttle and then ramped up after that. And it transformed the car.
When i went single throttle body on my car (90mm) on a 2.6 making about 750 wheel the biggest thing i noticed was the car didnt feel like a slouch driving around ourside of boost anymore. I wasnt as much worried about how fast the boost came on but when you crack that big throttle body the car gets moving stop light to stop light and didnt feel like a turd. Im sure the big cams helped as well.
Another cool vid👌 my 1st thought is the single TB would make more power as they both have relatively the same surface area at the inlets smallest part of the plenum but the 6 throttle has 6 restrictions in the runners. Look forward to the next vid!
He calculated the net area where he subtracted the throttle plates, the 6 throttle still had more. But the opening on the plenum does not match the total area of the 6 throttles.
also with the DBW you can tune the amount the throttle opens for a given amount of pedal input for a given RPM for example 10% TPS could be 5% throttle and can ramp up and into being 1:1 for higher TPS so you can make the car MUCH more managable at low speed
Interesting comments around the initial throttle openning, in Haltechs video on ITBs that was the main disadvantage of ITBs compared to single throttle. What the difference maybe is the OEM throttle had some progression on the opening so at small throttle % it actually openned less than you moved the pedal. This is really common on bikes to soften the initial throttle openning and something we tune in ride by wire bikes to suit the preference of a rider so that is something you can add to your single throttle setup as well
Yeah I was going to say - that's the main advantage of DBW, you can make the throttle work however you want, if you need the pedal to be a bit less responsive or have 1% pedal to 0.5% throttle opening
@@MotiveVideo I understand that concept for comparing 2 single throttles but its doesn't apply when comparing 6 ITbs to a single, and Haltechs comments are comparing a ITb and single throttle setup capable of the same power (not stated but its implied). I did some maths comparing the open cross section of 6 x 45mm throttles vs 1 x 82mm and at different throttle openings and at 5% open the ITB have 80% more open area and this doesnt start to even out until past 40% throttle. This isnt 100% but its a good indication. Either way tuning a progressive DBW map for the initial throttle opening will make the car easier to drive at those low TPS%
12:34 this is the first time I’ve heard the phrase “GTR snowball effect”, I have fallen victim to this for the past 4 years and didn’t know there was a medical term for it🤣 finally almost done with my build though!
@@MotiveVideo Yep that makes sense. Yea no doubt in my mind, the GTR looked like it leveled out fairly quickly and was still catching him once it hooked up.
This works out very easily, when you have itb’s that throttle plate has to flow enough air for that 1 port, when you have a single TB for all 6 it is only actually feeding 2 cylinders at any one time. So you have an ITB with 11.4cm feeding 1 port and a single TB setup with 43cm feeding 2 ports, there is no comparison, the total area of 6 itb’s combined means nothing, the other itb’s don’t contribute to any port but there own. Going on your 11.4cm2 area for the itb that is a max flow rate of 258cfm at 28” test pressure, as a ballpark I will say with the itb’s power peaked just under 8500rpm? Now remove the the itb’s and those intake runners now have the full 15.9cm2 area to use, that’s a 350cfm potential flow at 28” test pressure, so no restriction at all, as I doubt the head itself flows anywhere near that. This is purely why your results are the way they are, put 50mm itb’s in it either runners blended to suit and it makes the same power again because it will be the head itself that is the next restriction.
I would love to see the tests done again with the upgraded/larger I.t.b setup. Or even with shaftless butterflies. The 6 throttle body setup is iconic and it's a shame to see it beat without seeing much on people working the I.t.b setup
Motive quality as per, love it man. 🔥 Be good if Motive had a 25 something with all the contradicting info about those intakes & the style difference between stock, stock runners with FFP & the GReddy is potentially a bigger difference, there's plenty of comparisons but usually there's some other variables.
I would have liked to see those milliseconds in response difference just overlayed dynographs matched by tps or something if there even is a tps on itb maybe when you get to testing the drive by wire itbs
The benefits of modern fly by wire and the control with an aftermarket ecu will always out preform 90s 6 throttle technology. Be interesting to see electronic 6 throttle...
Your only criticism is the single throttle is too touchy coming off idle, this is an issue with a big cable throttle but you can tune it out with DBW on Haltech.
@@MotiveVideo it's driver preference that takes time to perfect, I'm still fine tuning this on my own 2jz with hypertune/82mm combo, though was instantly much better to drive than the 90mm throttle it used to have, and these issues are amplified by having an aggressive clutch in the mix..
God, I just finished my Calculus 2 final. I don't want to think about math hahaha. Awesome video. Hopefully I finish school and can afford to mess with RBs one day.
Very nice comparison. A new comparison between Twin Turbo vs. Single Turbo with Twin G25-550 and a Single G Series Turbo with Same Power Output Would be nice :).
Have you looked at trying a Bosch Gen 2 iBooster, electric brake booster from a Honda Accord or Telsa Model 3/Y, would be a lot simpler and lighter than vacuum pump, It only requires 3 wires to work, Ground, 40A fused Positive and switched Positive. SuperfastMatt did a good video on it call "Inside Tesla's Brake Booster (And How To Use It On Any Car)" about a year ago.
@@luker3456 You want to back that statement up with a source, because I can't find a single review of the Honda model year they were introduced where anyone complains about brake pedal feel, but more than one that says brakes were easy to modulate. The brake pedal is still mechanically connected to the master cylinder and the assist is relative to force on pedal. The assist ratio is programmable.
@@taznz1 its from experience mate, almost every car has an electronic brake booster now and they are all horrible as they all use the bosch off the shelf part.
Andrew, quick question. Why did you go with Area and not Volume? As in how much Volume a single throttle body flows compared to 6. Seeing as both the intake plenums are the same volume? Keep up the great content.
Andrew you probably know, but you should see if you can use a pipe with a less aggressive bend or a straight section at the turbo because your just throwing in bunch of turbulant air into your turbo. It needs space to become laminar or close to.
@ 20:19 you mention the big throttle body can cause hesitation from low revs. That could also be because of the very large injectors? I know some folk use twin injectors (one big, one smaller) to tune for low revs.
Flow is about air velocity, so rpm. If you increase the boost the velocity doesn't change. I calculate your car only needs a 50mm throttle body. A throttle body size comparison would be nice with dyno results.
For Comparison, rally cars have a 36mm restriction before the turbo making 280kw, which is about a 65mm restriction before your turbo for the power you are making. That equates to a 36-40mm throttle body on the inlet manifold. Big difference from what is needed, to what people actually have.
Going to ditch the ITB's on my GTIR, being a 4cyl the lack of vaccum at part throttle and tuning around that with TPS and boost compensation sucks, plus all the leaky spaghetti under the intake also goes away.....
Great research guy, good to see that common sense prevailed. Less than 800 stay with standard, not worth the money for so little. Me having run with 643bhp I never went that route but glad now I didn't
Every single person that Ive followed has tried drive by wirer and ever single one of them has gotten rid of them because all they did was caused more problem then it was worth. It's to dangerous to run in a drift car and it's useless in a drag car because as soon as you put power to the they shut themselves close. If you could somehow make that work I'd be truly impressed. Also you'd be the only GTR that I've seen on this channel that I've seen have one because all the other ones you features don't have one.
Was the error around the 16:30 mark the reason the video was pulled earlier today? (was mid watching it when it was pulled). Anyways, great and infromative content as always!
The fill times for the plenum and all is literally milliseconds. The idea that big plenums, intercoolers and pipes (within reason) that it increases boost threshold is just bunk.
So single throttle = more power, we expected that But they aren't undrivable. The six is smoother, but if you get used to it, it's streetable Damn, it's hard to love the sixes more and more as it goes on...
I would love to see a modern take on an F40 engine. Twin turbo V8 with ITBs and a cross ram dual plenum intake. Would it be worth it, or any better then a single plenum, single TB intake everyone runs?
Love content like this. Question for you though, on rb25det factory inlet manifold the throttle body is in the centre a common thing to do was have it re welded onto the front to create a front entry to tidy up the engine bay, and as a much cheaper option to buying a greddy intake, but a lot of people said that this causes cylinder 5 and 6 to go lean, is this true or a load of bollocks?
You can adjust the injector in each cylinder to compensate. Stock RB26 does it as well. EGTs and data show everything. How many people have said “it does this” but shown no data?
@@MotiveVideo been a wifes tale for years over here in the UK but as usual no hard facts. The rb scene has slowly been disappearing here so its good to watch your content for ideas and tips, the rb25 in mine has been running over 500bhp since 2008 un touched but i was thinking about a front entry purely for aesthetic purposes for under the bonnet, but at the same time im in the mentally of, if it aint broke dont fix it
How do you know your out of turbine as opposed to compressor …..what’s the back pressure and what drop do you have across the intercooler are logging any of this data or do you just drive it and know? I want to see data and time slips, put some sensors in it. Even those 180 and 90 bends on the cold side could effect it or just say one intake looks better than than the other and that’s why you change them.
Off North Rocks road onto Loyalty road....you're about 200 metres from where I grew up and learnt how to drop the clutch and do burnouts! Memory lane.....BTW...what were you doing up there??
For the ITB setup, wouldn't the boost have been higher at the lower RPM band because of what you discussed about volumetric efficiency and how you do not need the entire manifold to be full of air?...so my meaning is that when you roll into the throttle and open up the ITB's, it builds boost quicker and hence, you get more response? That interior flapper valve sounds like a rotary! Either way, will never be able to afford a GTR again but I appreciate the videos.
13:30 off-topic question: which injectors should I go with for my RB26 build? Bosch Motorsport 1650cc or Injector Dynamics 1700X? Going for 600 to the rear hubs with flex fuel.
Although this was a great video I'm still disappointed you didn't go to the trouble of doing some data logs to try capture a throttle response comparison witch is the only real advantage of ITBSs Id love to see FBW ITB compared single FBW TB there is no doubt about the terrific functions of FBW
Honestly the only reason I'm going to single v2 hypertune is I'm rebuilding the engine and don't wanna work with the itb setup once it's back in the car.
The shifting at 21:26 almost sounds like a fake sound effect haha, sounds bonkers Would that be the BOV only? or is it the combination with the sequential?
I genuinely enjoy how little you F around getting to the point of the modifcations and don't milk content for the sake of content.... Thanks Andrew
What he said
ken oath
Yeah it's refreshing isn't it
Best thing about your channel, please never change
Fr can’t stand a video of some dude laughing and showing his buddy
I fucking love how you seem to be one of the only people who actually get out and dyno these sort of things after years of people speculating and comparing different dynos and setups to try and get to the bottom of it. You rock!
Andrew, when you are comparing cross sectional areas at the throttles what you are missing is something called hydraulic diameter. Even though the 6 throttles have a greater combined cross section the wetted surfaces with the throttle plates all create more drag on the air because of the increased boundary layer.
Also when you refer to the time taken to pressurise a given plenum, don't forget the sort of quantities of air going through the system. A standard 2.6L RB at 8k rpm and 1 bar of boost is consuming 10,400 litre of air a minute or 173L a second. Your 3.2 at 8k and 2 bar its more like 25,600L per min of 426L a second!!!! Picture that much air!! So that pressurisation time is negligible. Where 6 throttles do help is on lift off as there is considerable less volume to drain from just one runner per throttle over the single where you've got to drain 6 runners and the manifold volume itself, so response is better there.
Nerd! Haha
@@johngray5360 bit too complicated for you to follow along there mate? Some of those numbers were pretty big yeah!
@@clubsport9334 Nah, I love going down the nerd technical rabbit hole. I just wanted to bust your balls a bit! Much love from Georgia, USA my savage brother!
Oh yeah, apparently maths and actual sciencing is not equitable!
Wouldn’t the draining on lift off also be very negligible? The engine is pumping a lot of air as you say
Seeing the content evolve, the channel growing and the cars getting better by the day! Really enjoyed seeing you guys build this up on RUclips from the beginning.
I can still remember seeing you for the first time on MCM with the 180.😄👌
Good work!
Dude, Andrew's been around the scene for about 20 years longer than MCM!!!
Technically MCM started before Motive but Andrew worked for Autosalon and Ignition DVD since 2005
@@danielbrealey2924 Never said that he wasn’t around. The first time I saw him on RUclips was in said video.
@@alexb4089 yep same here 😂
"Do you want to hear how ridiculously loud it is with the flapper valve open?"
Yes. Yes, we do.
I have been learning from you for over a decade and it makes me so happy. I applied your knowledge on my own R32 GTR over the years; Thank you!
This helped me make up my mind about going DBW on my K20/Sequential NSX build. I cannot ignore all the benefits that will let me focus on keeping the thing on the circuit and save my equipment.
From the research i did and years of forums and racing, ive noticed that ITB setups have better benefits on N/A applications especially with dual length runners, running single length runners usually leaves a part of the rev range lacking on torque.
im still a sucker for Gantry fuel injection aha
im loving how your GTR is going, change alot over the years
Shoutout to the motive DVD series that I use to collect when I was in high school. Was like a magazine, came out monthly but was on aDVD. Was super cool as a young kid. Anyway, cheers mate.
Whether it is for a GR Yaris or a GTR, your R&D videos are amazing Andrew ! Can't wait to watch the video with larger drive by wire ITBs.
Cheers 👍
Hey guys! Love the content!
I just bought a Stagea 260RS from Japan which will arrive in the US in December and I can’t thank you all enough for creating all of this content
Watching that roll racing was like watching a space ship go into warp drive. Fast!
Thank you for being part of the older generation that still uses HP instead of that KW crap the youngsters use.
Very educational as always, we have learnt a lot from you mate during last few years and applied on our cars in UK.
Looking forward for more contents.
Much appreciated
No real surprise in the results. Other than I'm surprised it was so close. The 45mm throttles are too small for such an engine. 48 or 50mm throttles wild likely see the gap disappear entirely.
In real terms the difference can be attributed to the resistance the throttle shaft is having in the modest 45mm runner. Where in the single setup, there is no such imposition.
Did you even watch the vid? He calculated the net area where the throttle plates were subtracted. The 6 throttles had more net area, though the actual opening on the plenum is almost the same as the single throttle.
About half way through this now and the amount other stuff you ended up doing to the car is hilarious! Can't really call it scope-creep when it sounds necessary for one reason or another but it was pretty amusing to see how much extra you ended up spending🤣
Snowball effect. Plan was literally just wiring for drive by wire and new injectors. It got out of hand.
KILLER VIDEOTAPE!!
Andrew has done allot for this industry!
Makes sense the single throttle does better at the top. Those ITBs take up some of the runner volume even full flat. Always wondered about a slide throttle. Probably deep into diminishing returns on effort to gains. Tip in works different that i'da expected then. I figured 6 cracking open would introduce more volume per port. Man she's a monster!
He says at 550kw, "And now to make some real power"😂 Geez, great work as always guys!
Can you just imagine driving around Sydenham and seeing that f***ing weapon of war rolling around freaking out the very rock and tar it chooses to grace with its presence. Roll on sweet machine roll on ❤️
You're bang on about the drivability being different going to DBW. I grew up driving carby and cable throttle cars and they are infinitely more polite to you when you're trying to drive them smoothly when you're on and off the throttle in traffic, the initial burst of airflow from opening isn't linear at all and ends up quite jerky to drive, even on a smaller diameter DBW.
I love the response and tunability of DBW, but I can't shift the notion that every DBW car I've owned would've been better with a cable.
The inlet size was different on both manifolds test voided 82mm opening on single throttle inlet and you made the intercooler piping bigger on the inlet side for the single throttle plenum also.
Go do some transient throttle through corners on a race track! can't just putt around the street then do wide open pulls on a drag strip. Why would you run individual throttles on a drag strip its wide open throttle application.
@@driftpig2462 I was hoping to see a bit of circuit work with the two different manifolds as well
The test should have been done with a mechanical single throttle since comparison with an electric throttle puts it at an advantage over the mechanical type.
Killer Content !! That R32 GTR is a weapon and sounds absolutely insane at full boost. Never Stop Watching !
Great video again!!! Thank you we are about to build two RBs and a 2J with haltech Drivebywire setup. Great test!!!
Some of the best content on youtube…how you dont have alot more followers baffles me!
The cars so well put together that first run seemed like a walk in the park 🤣
But watching out the windscreen fly by like you’re in warp speed is madness, the car seems so calm inside
My only question is what was the ambient temp during both tests? I think the difference is negligible and either way you are going to do ok. Killer gtr bro. Definitely makes me want to pull my finger out on mine.
Honestly love that you guys test and debunk this stuff. Im surprised how close the results were. However i dont know how controlled you can consider this experiment. You made alot of subtle changes between the two manifolds, including new injectors and dbw. Could all the small changes have contributed to the difference in power? Old injectors may have not flowed as well, dbw may have contributed to better driveability, etc. Was the test with the itb manifold done with itbs that were in good condition, not leaking like most do? Just feel like there could be some more factors there. Would love to see the same test done on the every mans 500hp rb26 setup, I wonder if the difference would be more obvious or less. Keep up the great work!
They used the same base port matched to the head and port matched to the manifold
the intercooler pipe is inconsequential as it just matches the size of the intake opening
we literally couldn’t have made it any fairer.
You can tune the throttle curve to get rid of that initial throttle opening too. When I first fitted my link ecu to an old 350z I had. It came with a linear throttle curve and it was horrible. Adjusted it so up till half pedal it only gave about 25% throttle and then ramped up after that. And it transformed the car.
Was that with DBW or mechanical? Itb or single throttle? Can you explain further? Very interesting
This is very detailed. You definitely didn't mess around on this test
When i went single throttle body on my car (90mm) on a 2.6 making about 750 wheel the biggest thing i noticed was the car didnt feel like a slouch driving around ourside of boost anymore. I wasnt as much worried about how fast the boost came on but when you crack that big throttle body the car gets moving stop light to stop light and didnt feel like a turd. Im sure the big cams helped as well.
this is an awesome channel. it should have like 10 times more subs.
Another cool vid👌 my 1st thought is the single TB would make more power as they both have relatively the same surface area at the inlets smallest part of the plenum but the 6 throttle has 6 restrictions in the runners.
Look forward to the next vid!
He calculated the net area where he subtracted the throttle plates, the 6 throttle still had more. But the opening on the plenum does not match the total area of the 6 throttles.
also with the DBW you can tune the amount the throttle opens for a given amount of pedal input for a given RPM
for example 10% TPS could be 5% throttle and can ramp up and into being 1:1 for higher TPS so you can make the car MUCH more managable at low speed
This is some damn good content! Amazing it gained that much. I know it's less than 4%, but gains are gains!
Interesting comments around the initial throttle openning, in Haltechs video on ITBs that was the main disadvantage of ITBs compared to single throttle.
What the difference maybe is the OEM throttle had some progression on the opening so at small throttle % it actually openned less than you moved the pedal. This is really common on bikes to soften the initial throttle openning and something we tune in ride by wire bikes to suit the preference of a rider so that is something you can add to your single throttle setup as well
Big throttles let a lot of air in the moment they open. For example an 82mm vs a 65mm at 5% opening is way more air from the 82mm
Yeah I was going to say - that's the main advantage of DBW, you can make the throttle work however you want, if you need the pedal to be a bit less responsive or have 1% pedal to 0.5% throttle opening
@@MotiveVideo I understand that concept for comparing 2 single throttles but its doesn't apply when comparing 6 ITbs to a single, and Haltechs comments are comparing a ITb and single throttle setup capable of the same power (not stated but its implied).
I did some maths comparing the open cross section of 6 x 45mm throttles vs 1 x 82mm and at different throttle openings and at 5% open the ITB have 80% more open area and this doesnt start to even out until past 40% throttle. This isnt 100% but its a good indication.
Either way tuning a progressive DBW map for the initial throttle opening will make the car easier to drive at those low TPS%
Thanks for the video Andrew. Would have been nice to see the results between gears on a H pattern car.
The roll racing clips were Awesome! 👍
12:34 this is the first time I’ve heard the phrase “GTR snowball effect”, I have fallen victim to this for the past 4 years and didn’t know there was a medical term for it🤣 finally almost done with my build though!
That Evo 9 was epic, what sort of power was that making? Really good response and just hooked up all the way.
It has nitrous and paddle shift and makes around 900. We’ll set up and awesome car. We were on lower power for testing that pass anyway.
@@MotiveVideo Yep that makes sense. Yea no doubt in my mind, the GTR looked like it leveled out fairly quickly and was still catching him once it hooked up.
Very interested in your road rules regarding full cages and harness. I'm pretty sure it's a hard no in qld.
Fine if the cafe was installed before 2011 or something
This works out very easily, when you have itb’s that throttle plate has to flow enough air for that 1 port, when you have a single TB for all 6 it is only actually feeding 2 cylinders at any one time.
So you have an ITB with 11.4cm feeding 1 port and a single TB setup with 43cm feeding 2 ports, there is no comparison, the total area of 6 itb’s combined means nothing, the other itb’s don’t contribute to any port but there own.
Going on your 11.4cm2 area for the itb that is a max flow rate of 258cfm at 28” test pressure, as a ballpark I will say with the itb’s power peaked just under 8500rpm?
Now remove the the itb’s and those intake runners now have the full 15.9cm2 area to use, that’s a 350cfm potential flow at 28” test pressure, so no restriction at all, as I doubt the head itself flows anywhere near that.
This is purely why your results are the way they are, put 50mm itb’s in it either runners blended to suit and it makes the same power again because it will be the head itself that is the next restriction.
I'm sure your aware. But you can tune the throttle open % vs pedal press. So you can make the first 30% of pedal only move the blade 15-20%
I would love to see the tests done again with the upgraded/larger I.t.b setup. Or even with shaftless butterflies. The 6 throttle body setup is iconic and it's a shame to see it beat without seeing much on people working the I.t.b setup
Motive quality as per, love it man. 🔥
Be good if Motive had a 25 something with all the contradicting info about those intakes & the style difference between stock, stock runners with FFP & the GReddy is potentially a bigger difference, there's plenty of comparisons but usually there's some other variables.
your content is awesome! So much knowledge coming from you guys
I would have liked to see those milliseconds in response difference
just overlayed dynographs matched by tps or something if there even is a tps on itb
maybe when you get to testing the drive by wire itbs
The benefits of modern fly by wire and the control with an aftermarket ecu will always out preform 90s 6 throttle technology. Be interesting to see electronic 6 throttle...
Great video. You now need to test how much difference a velocity stack on the end of the intake, or inside the airfilter (like a Ramair) makes.
Your only criticism is the single throttle is too touchy coming off idle, this is an issue with a big cable throttle but you can tune it out with DBW on Haltech.
Correct. It was literally second drive off the dyno.
We can finesse it further
@@MotiveVideo it's driver preference that takes time to perfect, I'm still fine tuning this on my own 2jz with hypertune/82mm combo, though was instantly much better to drive than the 90mm throttle it used to have, and these issues are amplified by having an aggressive clutch in the mix..
God, I just finished my Calculus 2 final. I don't want to think about math hahaha. Awesome video. Hopefully I finish school and can afford to mess with RBs one day.
Very nice comparison. A new comparison between Twin Turbo vs. Single Turbo with Twin G25-550 and a Single G Series Turbo with Same Power Output Would be nice :).
That’s a fast red evo. That thing sounds amazing with the dump open
Have you looked at trying a Bosch Gen 2 iBooster, electric brake booster from a Honda Accord or Telsa Model 3/Y, would be a lot simpler and lighter than vacuum pump, It only requires 3 wires to work, Ground, 40A fused Positive and switched Positive.
SuperfastMatt did a good video on it call "Inside Tesla's Brake Booster (And How To Use It On Any Car)" about a year ago.
Those electric brake boosters are horrible, zero feel on the brake pedal just all or nothing
@@luker3456 You want to back that statement up with a source, because I can't find a single review of the Honda model year they were introduced where anyone complains about brake pedal feel, but more than one that says brakes were easy to modulate. The brake pedal is still mechanically connected to the master cylinder and the assist is relative to force on pedal. The assist ratio is programmable.
@@taznz1 its from experience mate, almost every car has an electronic brake booster now and they are all horrible as they all use the bosch off the shelf part.
Andrew, quick question. Why did you go with Area and not Volume? As in how much Volume a single throttle body flows compared to 6. Seeing as both the intake plenums are the same volume? Keep up the great content.
Rocker the concept simple for people who don’t study engineering and not spend thousands of dollars on flow benches etc
Andrew you probably know, but you should see if you can use a pipe with a less aggressive bend or a straight section at the turbo because your just throwing in bunch of turbulant air into your turbo. It needs space to become laminar or close to.
Cant without cutting the body up. Plenum sits quote far forward
I could swear for a second when you opened that flapper valve at the end, that your GTR sounded like a rotary all of a sudden! Sacrilegious!
Big set-up GT-Rs have every lumpy idle. Our full exhaust masks it a little.
@ 20:19 you mention the big throttle body can cause hesitation from low revs. That could also be because of the very large injectors? I know some folk use twin injectors (one big, one smaller) to tune for low revs.
Flow is about air velocity, so rpm. If you increase the boost the velocity doesn't change. I calculate your car only needs a 50mm throttle body. A throttle body size comparison would be nice with dyno results.
For Comparison, rally cars have a 36mm restriction before the turbo making 280kw, which is about a 65mm restriction before your turbo for the power you are making. That equates to a 36-40mm throttle body on the inlet manifold. Big difference from what is needed, to what people actually have.
Going to ditch the ITB's on my GTIR, being a 4cyl the lack of vaccum at part throttle and tuning around that with TPS and boost compensation sucks, plus all the leaky spaghetti under the intake also goes away.....
Love it! Great clip
Andrew this content is awesome mate, cheers
Great research guy, good to see that common sense prevailed. Less than 800 stay with standard, not worth the money for so little. Me having run with 643bhp I never went that route but glad now I didn't
Every single person that Ive followed has tried drive by wirer and ever single one of them has gotten rid of them because all they did was caused more problem then it was worth. It's to dangerous to run in a drift car and it's useless in a drag car because as soon as you put power to the they shut themselves close. If you could somehow make that work I'd be truly impressed. Also you'd be the only GTR that I've seen on this channel that I've seen have one because all the other ones you features don't have one.
Would the stroker mask the off boost performance and that you would maybe see more of a difference if it was still 2.6L?
Air is air and doesn’t know what engine if it is. I think bottom end may change a bit but top end power is still top end power
Was the error around the 16:30 mark the reason the video was pulled earlier today? (was mid watching it when it was pulled).
Anyways, great and infromative content as always!
The fill times for the plenum and all is literally milliseconds. The idea that big plenums, intercoolers and pipes (within reason) that it increases boost threshold is just bunk.
Great episode
Would love to see you guys take the to drag challenge in the US it would stand out
You boys are the God's with the rbs
So single throttle = more power, we expected that
But they aren't undrivable. The six is smoother, but if you get used to it, it's streetable
Damn, it's hard to love the sixes more and more as it goes on...
I would love to see a modern take on an F40 engine. Twin turbo V8 with ITBs and a cross ram dual plenum intake. Would it be worth it, or any better then a single plenum, single TB intake everyone runs?
what about the sound? the best part i like about the ITB is the sound! how much different does it sound ?
If you can hear a difference, we will be impressed
Great content you are putting out these days.
Love content like this. Question for you though, on rb25det factory inlet manifold the throttle body is in the centre a common thing to do was have it re welded onto the front to create a front entry to tidy up the engine bay, and as a much cheaper option to buying a greddy intake, but a lot of people said that this causes cylinder 5 and 6 to go lean, is this true or a load of bollocks?
You can adjust the injector in each cylinder to compensate. Stock RB26 does it as well.
EGTs and data show everything. How many people have said “it does this” but shown no data?
@@MotiveVideo been a wifes tale for years over here in the UK but as usual no hard facts. The rb scene has slowly been disappearing here so its good to watch your content for ideas and tips, the rb25 in mine has been running over 500bhp since 2008 un touched but i was thinking about a front entry purely for aesthetic purposes for under the bonnet, but at the same time im in the mentally of, if it aint broke dont fix it
How do you know your out of turbine as opposed to compressor …..what’s the back pressure and what drop do you have across the intercooler are logging any of this data or do you just drive it and know? I want to see data and time slips, put some sensors in it. Even those 180 and 90 bends on the cold side could effect it or just say one intake looks better than than the other and that’s why you change them.
This is the motive video I love
Off North Rocks road onto Loyalty road....you're about 200 metres from where I grew up and learnt how to drop the clutch and do burnouts! Memory lane.....BTW...what were you doing up there??
what vacuum pump did you use?
For the ITB setup, wouldn't the boost have been higher at the lower RPM band because of what you discussed about volumetric efficiency and how you do not need the entire manifold to be full of air?...so my meaning is that when you roll into the throttle and open up the ITB's, it builds boost quicker and hence, you get more response?
That interior flapper valve sounds like a rotary! Either way, will never be able to afford a GTR again but I appreciate the videos.
In theory, but in real life we had no noticeable difference
You can adjust the APP vs TPS curve to fix your throttle opening issue.
We know. Its all just fine tuning on the street
APP?
Accelerator Pedal Position
@@rollinrobo Thanks
13:30 off-topic question: which injectors should I go with for my RB26 build? Bosch Motorsport 1650cc or Injector Dynamics 1700X? Going for 600 to the rear hubs with flex fuel.
My understanding is 120 mm big single is good for top end... individual throttles should be more track response...I'm 2jZ guy
Although this was a great video I'm still disappointed you didn't go to the trouble of doing some data logs to try capture a throttle response comparison witch is the only real advantage of ITBSs Id love to see FBW ITB compared single FBW TB there is no doubt about the terrific functions of FBW
2.6-2.7L don’t need more boost to make the same power then 3-3.2L
Yes they do
That’s exactly how engines an turbos work. Same set up but more capacity means same power on less boost. Literally how it works.
Gotta be single throttle body as there is less restrictions in the airflow, big power single throttle body ,resonable power stock gtr mani
What happened to Robs white rocket bunny s13 from back in the day?
Love it mate 👍great video
great work , what turbo were you running on the dyno ? i know you said rear was 1.01
G45-1500
What was that grease he was using when he installed the plenum spacer? Was it locktight or some anti seize on the bolts?
Could you change the 1-5% throttle pedal to open the throttle blade less, and smooth out the transition to fix the on throttle feel?
Love this video great info
Honestly the only reason I'm going to single v2 hypertune is I'm rebuilding the engine and don't wanna work with the itb setup once it's back in the car.
Main reason many do.z
@@MotiveVideo it's good to know that when I get to making more power the setup will be good to go.
God I love that GTR, If i ever won lotto would be sending a GTR to CRD and say build me one
It’s the perfect combination to copy 😁
what about running a 102mm inlet and 48mm tb for the 6 throttle?
Great video, solid tech, great race!
#withoutdataitsjustanopinion.
With the big single throttle being an e throttle, you could probably tune the initial curve for it to behave similar to the ITB’s right?
No, you can’t fake ITBs
You can get larger 6 throttle that some Japan work shops make that have larger 6 throttles
Greddy plenum with larger 6 throttles
IEE in NZ do them and we have them here waiting to test.
@@MotiveVideo 👍
Love these vids
One throttle to rule them all
The shifting at 21:26 almost sounds like a fake sound effect haha, sounds bonkers
Would that be the BOV only? or is it the combination with the sequential?
With ecus and programming I don't see why you can't run both systems. You can also go 3 throttle bodies.