Need Some Advice

[l0WRB]

My GT3082R on my RB25 was a brilliant turbo... relatively responsive and went hard.

Jesus some of you guys inflate power outputs and what people should expect from their car. Jump on the RB25 results thread, you dont see too many people with bolt on mods cracking 400rwhp (genuine). Its not that easy.

cactus you are not wrong mate

people with a built motor and cams and head work only just crack 400+rwhp with small boost like what im running

why would i go back to a 3076 turbo when ive just spent and setup my 3582, seems like a downgrade to me.. and a 3076 pushing 380rwkw? u run 30psi on e85 on a built motor with cams? lol

im asking what i can do to get response down even a few hundred rpm

mid range is important yes i mean at 4000rpm or there abouts im making 200kw @ wheels ( but lets be honest 200kw felt fast in 2001) then it ramps up in the next 1000rpm to like 300kw @ wheels, but whos going to be doin 120mph past the 110mph mid range car in the top end lol

looks like rain is gone mite try the wastegate line thing and go from there

Edited February 8, 2010 by l0WRB

[GTScotT]

Jesus some of you guys inflate power outputs and what people should expect from their car. Jump on the RB25 results thread, you dont see too many people with bolt on mods cracking 400rwhp (genuine). Its not that easy.

+1 the results are all there, enough nonsense

lowrb, im tempted to say the exhaust housing and gate combo are holding you back. While the cheap gate is probably robing you of spool the small housing is probably not promoting flow when you need it either.

to keep costs down, id consider getting stao to mate up a bigger housing with an internal gate and supply you with a hi pressure actuator. alternatively if you want to stay ex gated i would seriously consider getting a good one, perhaps even a slightly smaller one.

edit: the exh cam gear retarded 3-4 degrees is a proven method also. find it in the forced induction quick ref guide

[l0WRB]

+1 the results are all there, enough nonsense

lowrb, im tempted to say the exhaust housing and gate combo are holding you back. While the cheap gate is probably robing you of spool the small housing is probably not promoting flow when you need it either.

to keep costs down, id consider getting stao to mate up a bigger housing with an internal gate and supply you with a hi pressure actuator. alternatively if you want to stay ex gated i would seriously consider getting a good one, perhaps even a slightly smaller one.

edit: the exh cam gear retarded 3-4 degrees is a proven method also. find it in the forced induction quick ref guide

well stao suggested he build me a .82 4 bolt flange exhaust housing like what comes with gcg's gt3582r turbo, this has come into my mind alot. ive also thought about hi mount manifold setup but its such a expensive excercise lol

id be even more cranky if i bolted .82 on and gained 1000rpm lagg hahaha

oh so u retard the exh side to build boost quicker? hmmm

[kwickr33]

The only way to bring up response is either by reducing the sizes of the current wheels, or Reduce the size of current housings. Both of them will reduce your current power flow.

Or you can run adjustable came gears which can bring up about 2~300RPMs in response.

Also I noticed KKR 480 is actually running off a split pulse turbine housing. If you run a single pulse turbine housing it should smooth the power curve a little towards midrange.

[l0WRB]

yes that is correct they run a split pulse turbine

mite go 4 a drive now test out wastegate wish me luck haha

[GTScotT]

lol id be spewing too if that happened.. but its a risk you may have to take. Have you considered going for a tighter spring in the gate? I would have chosen a branded 44mm with a spring set close to target boost.

the exh cam gear will help, in theory it will bring on boost more suddenly rather than a progressive spool. so it will probably start spooling in around the same place but hit full boost quicker.

either way, the results thread will show you that building boost and power are not the same... hiflows and stocks are the quickest to build boost yet have the weakest midrange, which is what wins the races. if your making power ontime and the car is not sluggish then its not too big a deal.. yet experiment with the gate before you spend any big money.

[GTScotT]

yes that is correct they run a split pulse turbine

mite go 4 a drive now test out wastegate wish me luck haha

dont forget to block the vac line u disconnect LOL

[l0WRB]

Ok just got back, had to get some bread from IGA for lunch hahaha so thought why not disconnect the vac line on the way there

bad news or the bad news haha.. yeh i put a bolt in the vac line once disconnected.

this was all done in 2nd gear.

first run i done come out of roundabout completey flat in 2nd gear reved it to only 5000rpm and then checked my blitz electric timer/gauge thing and it read .7 bar boost.. ok thats really f**kEN laggy.

next run was the same flat out of roundabout in 2nd gear revved to 5800rpm and hit 1.4 bar with lots and lots of wheel sping around 5200-5300rpm still 2 fkn laggy .

so theory disconnecting the wastegate didnt bring anything on sooner, if anything it felt worst.

[Dale FZ1]

For the relative expenses involved, and considering the untouched internal engine spec, you'd need to play it cool with power targets IMO.

Cheapest spend is on an adjustable cam gear. Try it, and if no major gain you haven't spent too much.

Otherwise the marriage between KKR housing and GT35 turbine rotor may not be a happy one. Yes it is obviously dealing with the max flow rates, but no, it may not be driving the compressor early enough.

Strongly consider a Garrett GT35IW housing if you wish to stick with the 3582 spec.

Is the tune a good one? Getting fuelling and ignition right when spooling makes a big difference.

[R31Nismoid]

DON'T use a GT3082R .63 as an example of ALL GT30 turbos.

I think your best bet is to chuck on a GT3076R .82 and U won't be disappointed. They're good for about 330rwkw (440hp) with stock cams and about 360rwkw (480hp) with some drop-in 260 tomei cams or similar. Should hit boost hard at 3500 and just HAUL to redline.

I just read your first post. I hope that's 400 kilowatts at the wheels and not horsepower. If it's horsepower, you can make MORE than that with 3076. I'm guessing it's horsepower because there's no way a walbro in-tank could supply enough fuel for 400rwkw.

I'd argue highly that a GT3076 will make 360rwkw... that is seriously getting to the upper end of possibility. Unless people are talking E85 again and confusing the topic.

Cams are not required to make the power, several people have proven that now.

Remember also it's not 480hp, its about 600hp, being the "480" is rwhp. No pump is ever spce'd @ the rear wheels.

Jesus some of you guys inflate power outputs and what people should expect from their car. Jump on the RB25 results thread, you dont see too many people with bolt on mods cracking 400rwhp (genuine). Its not that easy.

In what way? If you cant hit 300rwkw (400rwhp) with a 550-600hp turbo there is something wrong.

[R31Nismoid]

well stao suggested he build me a .82 4 bolt flange exhaust housing like what comes with gcg's gt3582r turbo, this has come into my mind alot. ive also thought about hi mount manifold setup but its such a expensive excercise lol

id be even more cranky if i bolted .82 on and gained 1000rpm lagg hahaha

oh so u retard the exh side to build boost quicker? hmmm

Why don't you just buy a proper genuine Garrett housing?

[l0WRB]

Why don't you just buy a proper genuine Garrett housing?

well thats kind of the next step i think? any idea on pricing for these housings

would i be dumb for going a .63 over the .82? could i still achieve the 400rwhp with .63?

[cactus]

I'd argue highly that a GT3076 will make 360rwkw... that is seriously getting to the upper end of possibility. Unless people are talking E85 again and confusing the topic.

Cams are not required to make the power, several people have proven that now.

Remember also it's not 480hp, its about 600hp, being the "480" is rwhp. No pump is ever spce'd @ the rear wheels.

In what way? If you cant hit 300rwkw (400rwhp) with a 550-600hp turbo there is something wrong.

Its only a 2.5Ltr in the end... Surely someone with your knowledge would know that you're not guaranteed 400rwhp with a GT3582R etc. Like I said, jump on the FI thread and you will see for yourself. A lot of people on there running 3076/GT35Rs hitting 380 - 400rwhp with big boost (20psi). It just seems that everyone carries on about cars making 450rwhp 'easily' when really thats not the case.

[Harey]

well thats kind of the next step i think? any idea on pricing for these housings

would i be dumb for going a .63 over the .82? could i still achieve the 400rwhp with .63?

Just a reference point, this guys making 300rwkw with a GT35 with 0.63 rear on 20psi but has a lot of mods (intake plenum, aftermarket manifold etc etc).

http://www.skylinesaustralia.com/forums/Fs...tt-t294613.html

[Adriano]

BUt the point is that there is a big difference between a 3076 and a 3582. Leaning moderately on a 3076 will see around 300rwkw, with good response. Making 300rwkw out of a 3582 is a waste of a bigger turbo, as it will be laggy.

At the end of the day there is only 2 ways you are going to make this setup responsive, fit a 3076, or fit a 3litre with a .82 exhaust housing.

[l0WRB]

thanks for that harey, he has got a few goodies, mines running a custom inlet manifold aswell, but still uses stock exhaust manifold.

[R31Nismoid]

Its only a 2.5Ltr in the end... Surely someone with your knowledge would know that you're not guaranteed 400rwhp with a GT3582R etc. Like I said, jump on the FI thread and you will see for yourself. A lot of people on there running 3076/GT35Rs hitting 380 - 400rwhp with big boost (20psi). It just seems that everyone carries on about cars making 450rwhp 'easily' when really thats not the case.

A GT35 has a compressor wheel that will see you at 700hp worth of flow.

If you are only making 300rwkw through a GT35, then there is something very much wrong.

My own GT3082 with a .82 rear (GT30R 600hp) was making 280rwkw on around 17psi and that was with a very bad/restrictive exhaust. So going another step up again in turbo, larger exhaust - 350rwkw would have been a bare minimum realistic result.

A GT35 with a .63 rear end is like trying to blow a ice-cream through a maccer's straw. The compressor wheel is just too big for that type of housing.

The biggest you should be going with a .63 rear is a GT3071 IMO.

GT3076/GT30R/GT35R all should be minimum .82 rear ends to make use of the 550-700hp worth of compressor flow.

BUt the point is that there is a big difference between a 3076 and a 3582. Leaning moderately on a 3076 will see around 300rwkw, with good response. Making 300rwkw out of a 3582 is a waste of a bigger turbo, as it will be laggy.

[3LGODZILA]

u said your running a gutted cat, that would be 2.5inch. why dont you try a bigger cat or a 3inch de-cat pipe?

[kwickr33]

A GT35 has a compressor wheel that will see you at 700hp worth of flow.

If you are only making 400rwkw through a GT35, then there is something very much wrong.

.....

You will never get 400rwkws with a GT3582 on a stock Rb25det on 98 fuel. maybe E85 with 500Hp Shot Nos if engine doesn't fly in pieces.

Edit: Never mind. Its probably Nismoid's typo.

Edited February 8, 2010 by kwickr33

[l0WRB]

yeah gutted stock cat not sure on exact size of them.

fair enough well .63 is out of the question

gcg want $591 for a exhaust housing haha

think i might just put up with the laggy 400hp