Opinion On Set Up

[R TUNE]

Just after peoples opinion on my planed set up and if im missing anything. The car will be used 70/30 street track.

current.

Rb25DET turbo (45v2)

3" dump pipe

3" RS*R exhaust

14PSI

boost comes on at 4500rpm and power is 138rwkw

planed

ex and in adj cam gears

walbro 500hp in take pump

Nistune ECU

Blitz SE FMIC

[DVS JEZ]

Yep get a nistune. I also recommend a highflow turbo. Running thr stock turbo at 14 psi is on the edge. Might kill the turbo

[R31Nismoid]

+1 to above.

14psi on a RB20 is not too bad, but on the circuit it might be a tiny bit too much.

[GTScotT]

+1

Get the turbo redone before you get the nistune done.

Send the thing down to hypergear and tell him what you actually want and what motor its going on.

GL

[Lonewolf1983]

nistune will pick you up a fair bit of power and some fuel economy.

FMIC is a must at that boost level

fuel pump is a good idea as old ones tend to shit themselves

should be good for 200-220rwhp once that lot is done

[simpletool]

Yeah definitely:

1. Nistune (or some ECU)

2. Intercooler (preferably medium sized with good piping)

3. Fuel pump + replace old fuel hoses/clamps.

Cam gears ? not sure they are a good spend.

Currently the AFRs need to be richer from 4000rpm up. It's running 13-13.2 AFR while coming onto boost. Personally I'd get that down below 12.5 towards 12.0 and then trending down to 11.5 higher up (6000rpm +).

I have no practical experience with RB20 with RB25 turbos but I'd expect the full 14psi by 4000rpm (an RB25 can do 12psi at 3000rpm).

So it's an auto yeah? A manual would expect approx 160-165rwkw.

[bubba]

That boost seems pretty lazy... this was my old RB20 with an RB25 turbo, untuned. The red line was when I tried 14psi but too much ping ping without a tune.

Edited April 13, 2011 by bubba

[Lonewolf1983]

yep, full boost should be approx 3500rpm.

get a turbotech ball+spring boost controller or an EBC if you dont already

[bubba]

I must admit I have an EBC that I spent a fair bit of time dialing in (could never get rid of that tiny spike though ), but I'm pretty sure it wasn't making 1000rpm of difference in spool time. I feel there is some other issue with his setup..

[R TUNE]

Thanks for the reply guys,

The nistune was defently a no brainer and same with the FMIC.

Ash from what your saying im probly better off running say 12psi on the track to exstend the life of the turbo if i dont get it highflowed correct.

Yea the car is manual and thats being adressed, you could defently feel the lag with it.

Ive also included the first dyno run i did when still using the stock RB20 turbo but had up the boost to 14psi, didn't run it like this tho.

[eightsixboy]

With your planned mods i dont see why you cant expect 170-180rwkw on 14psi, 160+ on 12psi. If you want more power I would go a rb20 highflow, I have one on my rb20 and its way more responsive then my old setup with a vg30 and makes 219rwkw. What ever you do dont highflow the rb25 turbo, will be lag city on a 20.

Just remember that more then 180rwkw and you will need to upgrade your injectors and afm.

[R31Nismoid]

Ash from what your saying im probly better off running say 12psi on the track to exstend the life of the turbo if i dont get it highflowed correct.

Ye mate.

A few Vic guys have killed stock turbos on 10psi on the circuit (RB25s). Some are OK.

So it's certainly something to be wary of. 12psi should give pretty good life unless you get one that simply is due to die.

[Josh_TypeX]

I ran an r33 turbo on my old rb20 for a good 2 years at 15psi, that is on top of how ever long the previous owner did so. Car was driven every day, plus a couple if track days and I never had a problem with the turbo. I have heard that the smaller capacity of the 20 allows you to run more boost safely than on a 25. Please note that this is my experience only and not a recommendation at all.

On the topic of lag, I can't remember exactly, but I had 15psi by 3500rpm. That was with standard bolt ons, cam gears and a remapped ecu.

[simpletool]

Yeah the turbos normally crap themselves from getting too hot (which is only loosely related to compressor pressure), heat is much more related to exhaust flow (and the turbine restriction at too high shaft rpm). Therefore the flow of 10psi on an RB25 is similar to 15psi on an RB20.

Simply: you can run a few more psi into an RB20 with an RB25 turbo.

Edited April 15, 2011 by simpletool

[R TUNE]

Cheers guys. I think ill tune it for 12 PSI.

Am still thinking on high flowing, will see if the budget allows. As im pulling the turbo off any way to get the dump pipe and exhaust maifold ceramic coated.