Haveing Problems Making Power When Runnin Big Boost

[timsr33]

ive just finished builing my new single turbo setup with a t04z use to have twin t517zs making 511 hp on 22 psi

with the to4z it makes 353kws at 15psi as soon as you wind the boost up fom 15 psi it stops making the power goes back wards its like its hitting a brick wall

afrs are 12

ignitons not breaking down was thinking the cams are to small or the standard plume and throttle bodys could be doing it any help would be appreciated thanks tim

engine specs

built bottom end

pored head

tomei type b springs and cams

new guides

800cc injectors

m and w cdi ignition

haltech e11v2 with 3 bar map

[tridentt150v]

cat/exhaust or wastegate?

[bozodos]

Had the same problem, turned out to be a blocked cat (not before the backpressure blew out the non standard exh gasket though)

[timsr33]

  tridentt150v said:

cat/exhaust or wastegate?

the car has

no cat striaght pipe

three and a half inch from turbo back straight through exhaust

and a turbo smart 50mill pro gate

i think they should be up to the task

[peter_fc]

need some more info. What amount of ign timing? does the timing drop off very rapid once it hits the higher load point? Sounds like its running out of cam though. What specs are the cams. What comp ratio is the engine. etc.

Just throwing around some ideas.

[bozodos]

possibly a boost/exhaust leak then? have you checked all your piping, vacuum hoses, exhaust flanges and the rest?

[timsr33]

  peter_fc said:

need some more info. What amount of ign timing? does the timing drop off very rapid once it hits the higher load point? Sounds like its running out of cam though. What specs are the cams. What comp ratio is the engine. etc.

Just throwing around some ideas.

the timing is about between 32 at 5000 and 20 at 9000 the cams are 260 by 9.15 and the comp is 8.3

[timsr33]

  bozodos said:

possibly a boost/exhaust leak then? have you checked all your piping, vacuum hoses, exhaust flanges and the rest?

theres no leaks checked every thing in the leak department ive also done a compresion test today and they are all between 120 and 122

[peter_fc]

Hmm. Sounds very odd. That turbo should be able to generate much more hp.

Any other mods done at the time of the turbo change or just the turbo change.

[R31Nismoid]

  timsr33 said:

the car has

no cat striaght pipe

three and a half inch from turbo back straight through exhaust

and a turbo smart 50mill pro gate

i think they should be up to the task

Have you dropped the exhaust from before the cat to be 100% certain?

[timsr33]

  peter_fc said:

Hmm. Sounds very odd. That turbo should be able to generate much more hp.

Any other mods done at the time of the turbo change or just the turbo change.

only the turbo gate and manifold and exhuast to cat all new and its also laggy compared to others on the forum should a t04z with a .82 split housing make 22 psi before 6000

[timsr33]

  R31Nismoid said:

Have you dropped the exhaust from before the cat to be 100% certain?

the car has no cat i dont run one as the car is a track car

[peter_fc]

Exhaust manifold design?

Where are the cams set also

[timsr33]

  peter_fc said:

Exhaust manifold design?

Where are the cams set also

the exhaust manifold is a 1.5 inch steam pipe equally length runner at 500 mill each and the cams are set to 0 on inlet and exhaust should such little cams be really lumpy

[peter_fc]

the manifold collector has to have all the runners peaked for good flow. How lumpy? will be a little lumpy.

Who is the tuner.

So many factors will cause lag.

Can give you the name of a really good tuner in the area, may be able to help you out

[timsr33]

  peter_fc said:

the manifold collector has to have all the runners peaked for good flow. How lumpy? will be a little lumpy.

Who is the tuner.

So many factors will cause lag.

Can give you the name of a really good tuner in the area, may be able to help you out

mark at mrc has been tuning it and he cant figure out why its not making power and why its so laggy he does a good job its lumpyer then the rb26/30 he tuned with 290 by 12 cams what do you mean by peaked

[peter_fc]

All 6 runners merge into a peak and then into the turbo unlike some of them that have runners facing eachother.

Have you guys played with cam timing yet?

[R31Nismoid]

  timsr33 said:

the car has no cat i dont run one as the car is a track car

I know that...

Well from where the "de-cat" pipe is, same spot, matters not... So i take it as a NO you have not tried the 10mins quick test to totally discount exhaust

[timsr33]

  peter_fc said:

All 6 runners merge into a peak and then into the turbo unlike some of them that have runners facing eachother.

Have you guys played with cam timing yet?

all the runner come to a point then into the turbo tryed playing with the timing on the old setup but didnt make much of a difference only moved the powerband around no gains from it whats the name of the tuner that you no thanks tim

[peter_fc]

Scott from insight motorsports is very switched on. Check out his website. He is very helpful. May have some suggestions