Rb26 Not Makeing What It Should Be..

[d1_GTR]

hi all, i currently have a 96' r33 gtr running 17psi on HKS 2540's, its currently makeing 320hp at all 4. i've been reading through the forums and it seems like its not makeing what it should be. any thoughts on why?

mods-

weisco pistons, scat rods, 650cc sards, 2x 044 and 040 lift, e11v2, 4" exhaust, FMIC, HKS cam gears.

[R31Nismoid]

incorrect cam timing, poor tune, blocked exhaust

I mean surely your tuner has some input?

[Granthem]

you can get that power on stock turbos. Definitely some issues there. even if the dyno is low... it shouldnt be that low.

Surely if you build the car you would have some idea of what may be wrong, or if you paid a workshop to build it you would wanna hope they had some ideas aswell

[d1_GTR]

yeah im not sure what it may be. i got it tuned at godzilla motorsport so im sure i can get them to narrow it down. they had to replace the CAS on the last tune. just out of curiousity anyone have a good estimate of what it should be making?

[BezerkR32]

dude, you are so asking the wrong people. the builder and the tuner are the people to ask as mentioned, FYI, pistons and rods dont make power, and the fact you have cam gears asks the questions on whether you have stock cams. a standard internalled rb25 with bolt on mods is capable of making 300kw atw. this is usually achieved at 20 psi through a gt35/40

  d1_GTR said:

yeah im not sure what it may be. i got it tuned at godzilla motorsport so im sure i can get them to narrow it down. they had to replace the CAS on the last tune. just out of curiousity anyone have a good estimate of what it should be making?

[EFI Performance]

Check pressure drop from one side of the intercooler to the other, simple test. easy answer.

[d1_GTR]

whats involved in trying to measure pressure drop? and its running standard cams

  EFI Performance said:

Check pressure drop from one side of the intercooler to the other, simple test. easy answer.

[R31Nismoid]

  d1_GTR said:

yeah im not sure what it may be. i got it tuned at godzilla motorsport so im sure i can get them to narrow it down. they had to replace the CAS on the last tune. just out of curiousity anyone have a good estimate of what it should be making?

at least 350rwkw

[d1_GTR]

well considering its only make 240awkw atm theres a pretty big problem

  R31Nismoid said:

at least 350rwkw

[Swiper the Fox]

no one left a rag in the piping when the build was done?...its been done before. Id check the pipework, check the camshaft timing and then drop the exhaust and give it a run.

Mark should be able to sort it out for you. He's a great tuner...he may just need the car for a day to test a few things.

[EFI Performance]

  d1_GTR said:

whats involved in trying to measure pressure drop? and its running standard cams

Messure pressure coming out of the turbo before the cooler core, then another power run with Vac/boost gauge after the cooler core on inlet side. (properly where the dyno was reading)

You say your only getting that HP on 17psi, (inlet side) your turbo's might be trying to push 20-24 psi on there side.

That making your cooler core not allowing the CFM the engine requires to make horse power.

[d1_GTR]

yeah i'll give it a good check over tommorrow, surely he would of picked up on incorrect camshaft timing when he was retuning it, he had the car for two weeks and also compression tested and regapped my plugs, i'll give him a call tommorrow aswell and get his thoughts on it. thanks for all the inputs anyways.

  DiRTgarage said:

no one left a rag in the piping when the build was done?...its been done before. Id check the pipework, check the camshaft timing and then drop the exhaust and give it a run.

Mark should be able to sort it out for you. He's a great tuner...he may just need the car for a day to test a few things.

[Swiper the Fox]

are the injectors new or second hand? if not new id get Mark to give them a clean and test on his new machine to make sure they are all good. We had a car down on power due to a faulty injector that was brand new.

[d1_GTR]

injectors are pretty new. it was rebuilt less than 2000km ago, although i only drive it once a month for a hour or so

  DiRTgarage said:

are the injectors new or second hand? if not new id get Mark to give them a clean and test on his new machine to make sure they are all good. We had a car down on power due to a faulty injector that was brand new.

[James_03]

I had my last run done by Mark he's a very good tuner.

Just ask him for input as others have suggested. My first point of call would be to drop the exhaust and take it for another run. Will the 040 be OK acting as a lift for the twin 044's? I would check that out too.

Edited February 9, 2010 by James_03

[paulr33]

whatever is wrong, its pretty fundamental, your 100rwkw under the mark

check the basics

check timing

check fuel

check spark

check boost

check AFR's

check timing

any one of those will likely yield the low power

im not sure an in-efficient intercooler would account for 100rwkw missing, but certainly a rag in the intake pipework woud

[our12]

Hi.

My guess would be ignition map.

[Swiper the Fox]

  James_03 said:

I had my last run done by Mark he's a very good tuner.

Just ask him for input as others have suggested. My first point of call would be to drop the exhaust and take it for another run. Will the 040 be OK acting as a lift for the twin 044's? I would check that out too.

I used an 040 as a lift pump for 2 x 044's and it supported over 620AWKW...so that part should be just fine.

[R.3.2.G.T.R]

so u got the car tuned n no mention was made that it's making shit power for a reason??

stock GTR make that much around 1 bar mark

[bubba]

twin 2540's on my 30 in its' old car (25DE head, stock cams, stock t/b & plenum) made 490rwhp @ 22psi.

Same turbos on a new 30 in a different car (25DET head, GReddy plenum, Q45 t/b, big cams) made 530awhp @ 21psi.

So yeah, you're down a fair bit on power

Edited February 10, 2010 by bubba