Lack Of Power

[R31Nismoid]

A T04Z really is not the turbo for 500hp mate...

500hp = 300rwkw (roughly)

Do you want 500hp or 500RWhp?

[Muff]

Im looking at between 500awhp and 600awhp...

so im thinking better manifold, (i have a sub zero) manifold getting coated atm, Bigger dump pipe, Decat pipe. cam gears, and with the stuff ive done, it should pull it up a bit. some more boost and we should see something a bit better.... the only thing i would like to see, which is y im looking at a diffrent turbo is some more response... would like to see it come in hard at bout 4000rpm.. at the moment its comming in hard at bout 5200... any sugestions????

[STATUS]

Im looking at between 500awhp and 600awhp...

so im thinking better manifold, (i have a sub zero) manifold getting coated atm, Bigger dump pipe, Decat pipe. cam gears, and with the stuff ive done, it should pull it up a bit. some more boost and we should see something a bit better.... the only thing i would like to see, which is y im looking at a diffrent turbo is some more response... would like to see it come in hard at bout 4000rpm.. at the moment its comming in hard at bout 5200... any sugestions????

GT3582 or K3-660R

To4Z on a realistic ramp 5000 is about the minimal on a std rb26

[STATUS]

interesting... r32-gts t04z was making 520rwhp on 16psi and mine made over 500 on 17psi

both were also making loads more torque between 4000-5000rpm compared with the graph you posted... something wrong with the setup?

like i said earlier though a decent manifold does drop it abit over the Chinese one that was used on that setup but no more than 400rpm. All the to4z setups we have had come through have been done elsewhere and we were trying to "fix" them.... as customers were generally told to expect full boost @ 4000rpm.... which just isnt a reality with the TO4Z regardless of what their graphs told them..

i could if i was so inclined change the response with ramp rate like alot of guys do to make it pretty for customers but its not realistic, ive had quite a few come through from various workshops with graphs that show unrealistic response but when run on my dyno at a realistic ramp they are all about the same.

post up the graph and i will soon be able to tell.

[archie01]

I have had both a single TO4z and -5's on my standard stroke GTR and this was set up by Racepace.

Couldn't agree more with what Trent is saying in terms of lack of decent boost response (ie full boost at 4000 rpm) from a TO4z.

[Muff]

So with either of these im assuming that i would be expecting a decent 4000rpm full boost???? what sorta power range are these turbos. should i expect the same sorta power to boost setting??????

I have been in contact with billet turbos and have gotten quite a good response , say that they can get me about 800 rpm eariler response with a billet cartridge, bout 800 dollars. so with that and the new manifold and dump we should see a little over 1200rpm response.

still what would be better.....???? new turbo or keeping the t04z and modifing it.....

sugestions, ps thanks alot guys

[SimonR32]

like i said earlier though a decent manifold does drop it abit over the Chinese one that was used on that setup but no more than 400rpm. All the to4z setups we have had come through have been done elsewhere and we were trying to "fix" them.... as customers were generally told to expect full boost @ 4000rpm.... which just isnt a reality with the TO4Z regardless of what their graphs told them..

i could if i was so inclined change the response with ramp rate like alot of guys do to make it pretty for customers but its not realistic, ive had quite a few come through from various workshops with graphs that show unrealistic response but when run on my dyno at a realistic ramp they are all about the same.

post up the graph and i will soon be able to tell.

fair enough... to give you a rough idea of what i was getting on the road (6-boost, z with split 0.84 rear standard stroke 2.6l) boost would hit 24psi (shown on both sbc idiii and defi recall and both tacho and recall of max revs on power fc were usually around 3800-4000rpm when ramping up from just under 3000rpm on a flat road

[archie01]

fair enough... to give you a rough idea of what i was getting on the road (6-boost, z with split 0.84 rear standard stroke 2.6l) boost would hit 24psi (shown on both sbc idiii and defi recall and both tacho and recall of max revs on power fc were usually around 3800-4000rpm when ramping up from just under 3000rpm on a flat road

Which gear?

[discopotato03]

Say I was to go to a Gt3582r, Yes my manifold has a t3 flange, would that drop my response and produce the same sorta power??? im looking at about 500hp..

Your final call but yes I think a T04Z is overkill for 500 Hp , particularly on a T3 sized footprint . Arguably HKS do the more responsive T04Z because they use more appropriate housings for performance petrol engines .

I would have leaned more towards a GT3582R for 500 crank Hp and even then I don't think it'd rip your head off much under 4000 , particularly with the 1.06 A/R turbine housing .

I think the hard association to make is how much real world usable performance suits you vs this hard Hp number you have .

Your call , I think the Z turbo is too big for what you're trying to do .

A .

[Muff]

so buy leaving the to4z the way it is i could boost it and ipull a big number . or have less Hp with more streetable response. the manifold i have has t4 flange but i also have a t3 manifold. say i was 2 go 4 a Gt 35 would it be worth it? really? how much more response am i gonna get? am i going 2 drop power?

[Harey]

Turn the boost up as is and see how you like it. Yes it wont improve response but maybe the shear amount of power will make you happy.

A GT3582R will make the power you are making now with a lot better response.

Do you plan on building an engine one day?

[R31Nismoid]

Comment about the motor being "rather fresh" on the first page i assumed it was built...

If it's a stocker motor though, hohoho... this will be interesting

[SimonR32]

Which gear?

sorry my bad 4th...

3rd was a few hundred rpm higher and 1st and 2nd too fast to get accurate readings

Edited April 22, 2010 by Cerbera

[Harey]

Your final call but yes I think a T04Z is overkill for 500 Hp , particularly on a T3 sized footprint . Arguably HKS do the more responsive T04Z because they use more appropriate housings for performance petrol engines .

+1 for HKS T04Z mmmmmmmmm

[Muff]

yeha Built engine..... thinking bout going for custom twins.. not to sure....

prob just look at better dump and manifold with some more boost....

[Muff]

Have been thinking bout the rear housing. waht bout a smaller housing... liek a .70. this would give me better response wouldnt it? because at the moment the revs die off before the turbo... maybe change the zorst housing down a bit and we might get better response.......or would this just f*k up???? sugestions?????? im pretty happy with the power even 450atwhp is sweet buta bit more response would be nice.,..

[600hp]

Put some cams in it!!!!

[Harey]

Have been thinking bout the rear housing. waht bout a smaller housing... liek a .70. this would give me better response wouldnt it? because at the moment the revs die off before the turbo... maybe change the zorst housing down a bit and we might get better response.......or would this just f*k up???? sugestions?????? im pretty happy with the power even 450atwhp is sweet buta bit more response would be nice.,..

Quote from another site:

"I'm thinking of going a T04Z with a 0.7 rear. That is a bigger turbo than a GT3582. The T04Z 0.7 rear is a similar size to a GT35R .82, but its bigger everywhere else (bigger turbine and compressor wheels etc). The bloke recommending this says it will both outpower and outspool a GT3540 1.06. He says he made a custom T04Z with a smaller housing than 0.7 for a 1J and it made 326rwkw at only 15psi."

You need to make sure the exhaust housing can flow the amount of air for the horsepower you want to make. There are lots of negative comments on this forum about a GT35 with a 0.63 on an RB25 for this reason. The consensus is to go down a size in turbo and get a well matched housing (GT3076 with 0.82 rear).

I am not saying this is the answer but just something to think about.

Edited April 22, 2010 by Harey

[Harey]

prob just look at better dump and manifold with some more boost....

My vote is better dump and more boost!! The better dump will reduce some lag. I dont mind a bit of lag, just makes it more fun when it does hit

[Muff]

how much do we think a set of cams will drop boost response????

thinking a .70 rear.. talking to gcg they say its bout 800rpm drop, but with only 8000rpm limit will be fine... still peek the same power figures aparently....

trying the bigger dump, and better manifold first... if no luck then we play with the exhaust housing......