Cant Get More Than 315Kw Atw

[s13_Skyline_inside]

hi guys, just got my rb3026 run in and the proper tune done on it but we cant get it past 315kw atw, doesnt make any more power, can wind in more boost pressure but it doesnt make a difference. here is the mod list

rb3026

t04z .84 rear housing

50mm gate

hdi rs spec cooler (95mm thick one)

pon cams b spec 9.15mm lift 260 duration

cam gears

ported head standard size valves

3.5" turbo back and cat, 3" from cat back

splitfire coil packs

1000cc injectors

built engine etc

its like there is a restriction somewhere, pulled exaust off before cat, made no difference, took of turbo inlet pipe, made no difference, checked the cooler incase i left a rag in the but nope. as I said the boost pressure is there but its like the flow is not and the pressure holds steady till redline it doesnt taper off at all. this setup should be able to make 400kw so yeh if anyone has any ideas id love to hear them

car goes fkn hard but yeh id like the extra kilowasps that should be there lol

cheers

[R31Nismoid]

cams/gears etc all set-up correctly?

Could be the cooler restricting? (have you measured it?)

[s13_Skyline_inside]

messured? boost pressure or flow across the cooler? I looked the cooler up on hdi's website and they say its good for 900+ hp, Its new and there arent any leaks.

spent the better part of a day fiddling with the cam gears on the dyno, got good midrange but just cant get past 315.

I just remembered when putting the exaust manifold on it didnt line up perfectly with the exaust ports (used indian ink to check), its not a cheapy though, is a stainless one off the shelf from gcg. I dont know if that would cause this to happen though

I just remembered, I have a split pulse exaust housing and a non split pulse manifold. (I know got a bit excited when I started this build 2+years ago and went out and bought a manifold and stuff before id come to the point of needing it)

Edited December 19, 2010 by s13_Skyline_inside

[tm_r33]

i was about to suggest taking a look at exhaust manifold. by how much did the ports not perfectly line up?

are u checking boost close to manifold as u wind it up? as in is the engine actually seeing more boost? wastegate spring isnt at it thresh hold and bleeding off or anything is it?

[STATUS]

messured? boost pressure or flow across the cooler? I looked the cooler up on hdi's website and they say its good for 900+ hp, Its new and there arent any leaks.

cause there are plenty of 900hp cars in china to do r&d for them....

[Adriano]

Stock valve springs?

[s13_Skyline_inside]

sorry forgot that one too, tomei valve springs, the exaust manifold didnt line up on a few of the ports by 2-3mm.

checking boost from inlet manifold so yeh its getting the boost.

[R31Nismoid]

cause there are plenty of 900hp cars in china to do r&d for them....

+1

measure pressure before cooler, and after.

I think you might find the problem there.

[tm_r33]

yer accross cooler core would be somewhere to start.

2-3 mm doesnt seem right on the exhaust manifold not lining up to me.

are u using map sensor or afm? at what psi does it stop making power?

[bradsm87]

The divided .82 turbine housing is WAY too small. it's equivalent to about 0.5-0.6 a/r in a regular housing. Definately not great having a regular manifold and divided turbine housing either.

Port match the exhaust manifold to the head and get a .82 regular turbine housing and it should be all sweet!

Edited December 19, 2010 by bradsm87

[wasnt me]

Frst thing i would be trying is dropping the exhaust at the cat the doing a power run. 3" cat back seems a little small for big power.

edit, should have read the whole post.... you already tried that

[SimonR32]

The divided .82 turbine housing is WAY too small. it's equivalent to about 0.5-0.6 a/r in a regular housing. Definately not great having a regular manifold and divided turbine housing either.

Port match the exhaust manifold to the head and get a .82 regular turbine housing and it should be all sweet!

0.8 divided rear housings on a T04Z have been shown to make between 430-470rwkw

[bradsm87]

hmm. That A/R doesn't seem right to me. I obviously believe U but shit that's pushing a lot through a tiny housing. a 0.82 divided has literally less inside area than a .63.

[GTScotT]

I just remembered, I have a split pulse exaust housing and a non split pulse manifold. (I know got a bit excited when I started this build 2+years ago and went out and bought a manifold and stuff before id come to the point of needing it)

I dont know why anyone has not realised yet, but I believe this is definitely the problem.

You have an open frame T4 manifold with a split pulse T4 turbine housing, the entry to the turbo has a serious restriction in it. As does the manifold if it doesnt like up perfect.

I think you should ditch whatever manifold that is and switch to a 6boob immediately, you have 400kw to crack.

[s13_Skyline_inside]

yeh im leaning towards the mani being the issue, I do love the 6 boost ones, but I have a few things to check first before I fork out the dough, will keep the post updated if (should say when) i make any progress

[Jap_Muscle]

its not the rear housing thats for sure.

A friend is making close to 450kw with the same t04z .82 turbo. To be on the safe side drop the exhaust while your at it and check the cooler. If power shoots up, rebolt the exhaust back on. If the problem reappears you know its the exhaust. If it dosnt, Most likely the cooler.

[R31Nismoid]

.82 split or single?

a.d the exhaust was ruled out in the first post.

[Jap_Muscle]

my bad.

What ECU are you using? Are you still running AFMs?

Sorry if these are stupid questions. Just trying to help =]

[DVS JEZ]

Possibly exhaust back pressure due to the split pulse issue.

Can u post a pic of the dyno graph. Would be good to see if the power holds or dies away.

[GTScotT]

.82 split or single?

a.d the exhaust was ruled out in the first post.

Split pulse housing on single entry manifold as per post 3.

Considering the ports off the head arent perfect and we have well and truely established that the turbo flange is wrong, I am willing to put money on it that this is the issue.

I would go throw that chinese made POS back at GCG and get the real deal. If it was them who sold you the turbo with the manifold you should seriously flame them (though I would just cut my loses and move on).

Im not sure how many times I have harped on about this, yet on an basic SR, I saw a 76mm test pipe mated to a 80mm system stop the motor from making any more than some pathetic number.. Popped an 80mm cat on and hey presto pushing over 200rwkw instantly.