Need Some Advice

[l0WRB]

hey guys i need some advice on my setup currently

here are the mods

completey stock rb25 motor

hypergear GT3582 turbo anti surged slotted

50mm external wastegate

740cc injectors

Link G1 ecu

walbro intank pump

stock fuel regulator

splitfire coilpacks

now with the turbo exhaust side i re used my kkr .69 housing which has been modified to suit 50mm gate off it.

I got the car tuned 2 weeks ago and made 400atw on 1.3 bar boost

The dumpipe currently on the car is a 2.75" vband cast iron thing u get from otomoto which then connects to 3" front pipe thru to gutted cat and 3" xforce canon

What i wanna know is basically the car is very laggy, im not seeing 1.3 bar boost until 5000-5500rpm, even between gear changes it will lagg if i dont slam gears to build boost back up.

Could i do something to bring this on harder/sooner? bigger dumpipe? adjustable exh cam gear?

any advice would be great thanks guys.

[R31Nismoid]

Take off the feed to the gate, see how fast it builds then.

[Granthem]

flatshift

its a big turbo for a 25ltr... the rear housing is a good size tho imo..

when does it start building boost?

[l0WRB]

haha cant flatshift man syncros are on there way out to 8 test n tunes will do that

nismoid, that i mite try, u mean just take off the vacum line and see how fast it builds boost hmmm i think link is set 21psi boost cut so should be fine

[R31Nismoid]

boost will climb without stopping

so you need to be careful, just see it comes on earlier.

what gate/spring setup is in there?

[TiTAN]

i think he is referring to the map based ecu cutting ignition @ anything over 21psi. so as long as it is tuned with enough tolerance for that much boost it should be o.

Does your wastegate have any preload adjustment? mine with no extra preload would quickly ramp to 15psi and then slowly edge its way to ~19psi @ 5500-6000. wind some preload into the gate and boost ramps up to 19 around 3500

Edited February 7, 2010 by TiTAN

[Adriano]

NO offense, but your turbo is a bitsa, front is capable of over 360rwkw, with a tiny exhaust housing that is probably worse than the .63 garrett. Im surprised hypergear suggested such a setup

[Adriano]

Which kkr turbo was the housing off? FWIW i made 327rwkw on a 3582 .63 @ 18psi on a stock 26, but for the power i felt it was slow to make boost/had a high boost threashold, but was not laggy between gearchanges.

Edited February 7, 2010 by Adriano

[kwickr33]

From KKR's website it says its a .69 Turbine. But who knows. Still, 400rwhp on a fully stock Rb25 at 18psi is not bad.

The size of the turbo is just too big for fast response. Sale that and get them to make you a GT3071 equivalent or high flow your stock turbo.

[JonnoHR31]

as nismoid said, remove the vac line for the gate and see when you reach your target boost. takes 5 mins and will tell you if its a boost control problem or not

[l0WRB]

  Adriano said:

NO offense, but your turbo is a bitsa, front is capable of over 360rwkw, with a tiny exhaust housing that is probably worse than the .63 garrett. Im surprised hypergear suggested such a setup

He never suggested i re use my exhaust housing, i asked for it because its already modified to fit external wastegate setup so it was less fabrication 2 be done.

The wastegate is a 50mm purple looking one from otomoto.com.au runs 1bar spring, ive actually got the top pre load screw wound all the way in to hold 1.3 bar boost

there is also 1 more vacum fitting on top of the wastegate near the pre load screw not 2 sure wot it does?

do u think i would gain anything by buying a .63 garrett exhaust housing? is 400rwhp at 18psi still achievable?

or would .82 be more the go?

not interested in gt30 series ive been in a r33 with gt3082 and it didnt wow me at all.. had near 380rwhp and felt boring as...

as for highflow , i wouldnt want to waste my money, i been thru 2 highflows from slide yrs ago and they were just plain boring.

[JonnoHR31]

you use both vacuum fittings if your using an ebc.

have you gone for a drive with the vac line disconnected yet? no point looking at different housings until you sort your boost issues out

[l0WRB]

  JonnoHR31 said:

you use both vacuum fittings if your using an ebc.

have you gone for a drive with the vac line disconnected yet? no point looking at different housings until you sort your boost issues out

not yet its been raining and storming all day

i will tommorrow though

[bradsm87]

  l0WRB said:

He never suggested i re use my exhaust housing, i asked for it because its already modified to fit external wastegate setup so it was less fabrication 2 be done.

The wastegate is a 50mm purple looking one from otomoto.com.au runs 1bar spring, ive actually got the top pre load screw wound all the way in to hold 1.3 bar boost

there is also 1 more vacum fitting on top of the wastegate near the pre load screw not 2 sure wot it does?

do u think i would gain anything by buying a .63 garrett exhaust housing? is 400rwhp at 18psi still achievable?

or would .82 be more the go?

not interested in gt30 series ive been in a r33 with gt3082 and it didnt wow me at all.. had near 380rwhp and felt boring as...

as for highflow , i wouldnt want to waste my money, i been thru 2 highflows from slide yrs ago and they were just plain boring.

probaby because a GT3082 is a totally rubbish mis-matched turbo and to make things worse, if that's all the power it made, it's probably .63 which makes the mis-match of compressor and turbine way worse again. If u get in a car with a RB25 and a GT3076R .82 and a really good tune and it WILL wow you!

[Adriano]

You need to remember that the R in an A/R is effectively the radius of the exhaust turbine, so when your exhaust housing was opened up for the 3582 wheel, it decreased the A/R, possibly to .5

[Dale FZ1]

  Adriano said:

You need to remember that the R in an A/R is effectively the radius of the exhaust turbine, so when your exhaust housing was opened up for the 3582 wheel, it decreased the A/R, possibly to .5

No amount of overboring a housing to accept larger turbine rotor will impact on the A/R.

A = cross sectional area of the scroll

R = radius from the shaft axis to centroid of the scroll at the point of measuring the cross sectional area.

Basically A/R is fixed.

I'd suggest a call to Hypergear and consult with Stao.

[l0WRB]

Dale i have had a few talks with him and he suggests exh cam gear but my tuner says it prob wont gain much if anything at all.

bradsm87

yes ur are correct its .63 and its so boring and linear power sorta just revs from 3500 onwards speedo moves but u get no kick what so ever

[Granthem]

You do realise midrange is best for 99% of applications. It may not "feel" as fast as a laggy turbo kicking in hard at 5, but the boring car is already 3 car lengths ahead

[bradsm87]

  l0WRB said:

bradsm87

yes ur are correct its .63 and its so boring and linear power sorta just revs from 3500 onwards speedo moves but u get no kick what so ever

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.

Edited February 7, 2010 by bradsm87

[cactus]

  bradsm87 said:

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.

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.