Gt3076r + Manifold

[45ULT]

i have the set up u are putting on my car. 3076r with .82 housing and 38mm gate off standard exhaust manifold. it is an awesome turbo setup. on 16psi with step 1 cams and built engine i made 285kw with a very conservative tune (very little timing, rich afr's). My next step is to push the standard exhaust manifold as far as it can go to see if how far over 300kw it will go. I have noticed that most of the setups that stop making power around the 300 mark are using the .63 housing.

[bozodos]

ok ill jump in before the other guys do, and say that at 300rwkw your stock exhaust manifold and possibly your cams or lack of porting will start to restrict you.

[GTScotT]

the stock cams are 350 capable, wait for ash to chime in. but im a believer anyhow.

stock manifold begins to hold you back above 300, the .63 doesnt seem to be an issue tho, its doing the numbers provided used with a good manifold and gate.

[TiTAN]

you wont get much more than 320kw out of the 0.82 version on pump fuel (98) you need E85 or some other exotic fuel/effective octane enhancer to get much more

[KiwiRS4T]

Wastegate off the turbine housing is best to prevent boost creep. I have just had a manifold made up by Sinco Customs (similar to 6boost) but the wastegate comes off the turbo housing.

[R31Nismoid]

you wont get much more than 320kw out of the 0.82 version on pump fuel (98) you need E85 or some other exotic fuel/effective octane enhancer to get much more

Ye that's pretty much where the upper limits are going to be.

E85 would see you around the 350rwkw marker. Maybe a tad more, maybe a tad less, always subjective.

I was making 270rwkw @ 17psi with a bad 3" exhaust, factory cams, GTS-R manifold.

Held to 8000rpm no problems (GT3040/600hp).

I wish I'd had a chance to test it with a proper 3.5" exhaust that flowed nicely, would have seen over 300rwkw without much of a fuss was the general consensus and this was what… 4 years ago now.

Ended up making 370rwkw on 104 octane/24psi. Guilty-Toy made ~350rwkw factory head with a GT35 in a 3ltr not that long after.

45ULT - most setups (RB25/30s) have all run out around the 300rwkw marker factory exhaust manifold… a few have tried to go further and not really seen much gain. I believe some of those were using GT35's are well.

Change the manifold as well and then I think there was around a 20-30rwkw gain, and nicer midrange once everything was flowing inline with requirements so perhaps have a dig in the RB30 section of the forum.

I'm all for taking stock parts to untested waters, many said for ages you couldn’t make 300rwkw on factory cams (RB25 & 26)… and now there is a good number of cars over that. Some RB26’s making 380rwkw – factory cams!

It would just seem however the RB25 exhaust manifold just don’t have much to offer. That’s not to say there is anything wrong with it. Just don’t hope for much more than 300rwkw, and if you make more then count yourself lucky (but remember a manifold change, could well offer some decent $$ vs gain improvements)

[45ULT]

Ye that's pretty much where the upper limits are going to be.

E85 would see you around the 350rwkw marker. Maybe a tad more, maybe a tad less, always subjective.

I was making 270rwkw @ 17psi with a bad 3" exhaust, factory cams, GTS-R manifold.

Held to 8000rpm no problems (GT3040/600hp).

I wish I'd had a chance to test it with a proper 3.5" exhaust that flowed nicely, would have seen over 300rwkw without much of a fuss was the general consensus and this was what… 4 years ago now.

Ended up making 370rwkw on 104 octane/24psi. Guilty-Toy made ~350rwkw factory head with a GT35 in a 3ltr not that long after.

45ULT - most setups (RB25/30s) have all run out around the 300rwkw marker factory exhaust manifold… a few have tried to go further and not really seen much gain. I believe some of those were using GT35's are well.

Change the manifold as well and then I think there was around a 20-30rwkw gain, and nicer midrange once everything was flowing inline with requirements so perhaps have a dig in the RB30 section of the forum.

I'm all for taking stock parts to untested waters, many said for ages you couldn’t make 300rwkw on factory cams (RB25 & 26)… and now there is a good number of cars over that. Some RB26’s making 380rwkw – factory cams!

It would just seem however the RB25 exhaust manifold just don’t have much to offer. That’s not to say there is anything wrong with it. Just don’t hope for much more than 300rwkw, and if you make more then count yourself lucky (but remember a manifold change, could well offer some decent $$ vs gain improvements)

what about extrude honing the exhaust manifold? has anyone had much sucess with this? I am still keen to see how much past 300kw i can get on the stock manifold before i switch to high mount. If i can get close to 320kw i might not even change the setup

[l0WRB]

yeah i realise this, i will look into a ETM item towards middle/end of this year.

aslong as i get close to 280-300rwkw fullboost 4000rpm nice strong mid range, set limiter to 7500rpm and plan on running 21psi if needed .

just hope its more fun then what i had before being the slowest 300kw ive ever felt.

Edited February 24, 2010 by l0WRB

[l0WRB]

Does anybody know the thread size coming out of the banjo water fitting in side of the rb25 block? i wanna replace it with 90 degree swivel barbed fitting for new turbo makes life easier.

[TiTAN]

the water lines do not screw into the block. they only screw into the turbo.

[l0WRB]

excuse me? lol the banjo bolt screws into the block ....

[TiTAN]

brain fart, one of them screws into the block on the exhaust side (-6 fitting), the other goes behind the engine and plugs onto some coolant hose under the intake.

[l0WRB]

yes that is correct one screws into the block and the other joins up to the metal piping that runs back behind the head. i want to know the thread size thats on the banjo bolt that screws into the block

[GTScotT]

brain fart, one of them screws into the block on the exhaust side (-6 fitting), the other goes behind the engine and plugs onto some coolant hose under the intake.

yes that is correct one screws into the block and the other joins up to the metal piping that runs back behind the head. i want to know the thread size thats on the banjo bolt that screws into the block

Dash 6 fitting like he said lol

Updates Justin?

[l0WRB]

placing order today for speedflow fittings / hose / firesleeve

me and tuner decided to weld the 50mm gate off the stock exhaust manifold now, saves hacking up a .82 turbine

we are going to try and fit a 4" intake aswell

then on the 5th we strap it 2 rollers and throw 21psi in it haha see what it produces

[l0WRB]

so no one has any idea on the thread size for water feed block fitting? does m18 x 1.5 sound right?

[TiTAN]

it will be a -6 speedflow fitting if you are replacing the banjo.

Edited February 25, 2010 by TiTAN

[Adriano]

Sounds about rignt

[l0WRB]

yes im replacing it with a -6 speedflow fitting barbed but wont the speedflow fitting need to screw onto a adaptor with -6 on the speeflow end and whatever thread on other end that goes into the block? i think im just a bit dumb lol

[TiTAN]

you might need a male to male gender bender depending on which speedflow fitting you get otherwise it just screws into the block