Advice Requested Re Max Boost With This Setup

[Jpowys]

Hey guys

This is a question to do with boost. I tried searching, but without much luck

my r32 GTR has the following mods:

garrett 2560r turbos

recently rebuilt engine (15000 clicks ago)

full 3.5 inch exhaust system with high flow cat and hks dump pipes

apexi pods

600hp fuel pump (not sure of the brand - the mechanic fitted and told me the name but i forgot).

What would be a safe level of boost to run based on these mods. It currently runs about 18psi. There is no boost controller fitted, so i assume that the wasegates have been changed prior to me buying this. The mechanic thinks that 18 psi is too high, and he thinks that he should fit wastegates which will allow it to boost to about 12psi. My understanding is that stock is about .8 bar (11-12 psi).

Can anyone advise:

1) what stock boost is on a r32 GTR; but more importantly,

2) what is a safe level of boost for my set up

Any help would be really great.

Thanks

Edited June 9, 2007 by Jpowys

[JonesyGTR]

Standard boost on a BNR32 is 7psi. Just by changing exhaust/intake it can go up to around 9-10psi.

Given what mods you have listed I wouldn't recommend going over the 18psi you are running.

What did you rebuild your engine with? Do you have splitfires?

Cheers!

Dan

[Jpowys]

Standard boost on a BNR32 is 7psi. Just by changing exhaust/intake it can go up to around 9-10psi.

Given what mods you have listed I wouldn't recommend going over the 18psi you are running.

What did you rebuild your engine with? Do you have splitfires?

Cheers!

Dan

Thanks Dan, that's good to know.

I don't know the specifics of the rebuild, since it was done before i bought it. The guy i bought it from told me it had forged pistons, but there's nothing to prove this, so who knows.

Do you think that 18psi is a safe "everyday" level? I hope to have the car for a few years, and definately don't want to have to be forking out for a new engine... oh, and the turbos are brand new...

thanks again

[JonesyGTR]

If you can go back to the guy that you got the car from, try and find out whats in it - or better yet, get receipts. If you are not sure they are forged internals, dont treat them like forged internals.

If they ARE forged, 18psi is fine, you control the boost with your right foot anyways!

Cheers!

Dan

[Jpowys]

If you can go back to the guy that you got the car from, try and find out whats in it - or better yet, get receipts. If you are not sure they are forged internals, dont treat them like forged internals.

If they ARE forged, 18psi is fine, you control the boost with your right foot anyways!

Cheers!

Dan

Thanks again

I tried to get these details from the previous owner, and he produced a receipt, but no details of what's inside. Given this, i'm treating it as though the internals are not forged - as you suggested. Given this, assuming that the engine is a reco and just stock, what level boost is safe to run? I'm wondering whether i need to go and source some wastegates with a tighted spring, therefore running lower boost - maybe 15-16 psi.. what do you think?

I'd also be interested in others' opinions too (not discounting what you're saying of course Dan, it's just good to have different perspectives)

[saliya]

2) what is a safe level of boost for my set up

My personal experience:

I ran 18psi on the twin stockers for about 2 years (with a PowerFC, exhaust, k&n)

before I suffered the dreaded exhaust-wheel-in-cat syndrome. Plenty of track days etc.

Without management changes, I don't know that boost that high is a good idea - because

I don't know that the stock computer is mapped for those airflow rates.

Put a wideband 02 sensor on it and see what it's doing. If you're running good AFRs and

no detonation I can't see any reason for you not to run 18psi - the stock internals of my motor

still seem to be running strong after several months of 18psi T04Z goodness (165 across all

cylinders about a month ago).

As always, YMMV and you might want to err on the side of caution - perhaps my motor is

a freak of nature. If you were doing that, maybe back it off to 16psi...

Regards,

Saliya

[SLIPPERY]

Thanks again

I tried to get these details from the previous owner, and he produced a receipt, but no details of what's inside. Given this, i'm treating it as though the internals are not forged - as you suggested. Given this, assuming that the engine is a reco and just stock, what level boost is safe to run? I'm wondering whether i need to go and source some wastegates with a tighted spring, therefore running lower boost - maybe 15-16 psi.. what do you think?

I'd also be interested in others' opinions too (not discounting what you're saying of course Dan, it's just good to have different perspectives)

Your turbos already have wastegates

To be running 18psi you most probably have upgraded wastegate ACTUATORS

The spring inside the wastegate actuator is what determines the boost level at which the wastegate flap will be pushed open

Therefore you need a SOFTER spring so that the wastegate opens with less boost. Not a 'tightened' spring as you say

Just trying to clear that up for you

[Jpowys]

Your turbos already have wastegates

To be running 18psi you most probably have upgraded wastegate ACTUATORS

The spring inside the wastegate actuator is what determines the boost level at which the wastegate flap will be pushed open

Therefore you need a SOFTER spring so that the wastegate opens with less boost. Not a 'tightened' spring as you say

Just trying to clear that up for you

Thanks for clarifying, that's what i meant, the actuators

I'm able to get this spring changed to adjust the boost, but what i'm trying to work out is how much boost is safe to run as a daily driver with the mods listed above?

Anyone else have any advice?

[SLIPPERY]

if youve got programmable management then no. 18psi would be a good number and with a good tune you should make some decent numbers

if standard ecu then i wouldnt go past 14psi.

[Jpowys]

if youve got programmable management then no. 18psi would be a good number and with a good tune you should make some decent numbers

if standard ecu then i wouldnt go past 14psi.

sorry for ignornace, but "programable management", you mean an aftermarket ECU?

I was actually thinking about doing a Dr Drift tune, and doing it that way to save some $.

[femno]

I think you need to find out exactly whats been done with your car.

[SLIPPERY]

yeah an aftermarket ecu is what i mean

Power FC second hand on the forums can be had for $650 if you look...thats not too expensive

Im with femno here, take it somewhere that knows GTRs, that can tell you exactly whats on the thing and give you proper advice

[STATUS]

sorry for ignornace, but "programable management", you mean an aftermarket ECU?

I was actually thinking about doing a Dr Drift tune, and doing it that way to save some $.

if your going remap speak to CREATD in campbelfield, nice new hands free dyno dynamics and a world of GTR experience. If you look in my signature you can see how clean their workshop is... the floor nearly blinds you....

[Jpowys]

if your going remap speak to CREATD in campbelfield, nice new hands free dyno dynamics and a world of GTR experience. If you look in my signature you can see how clean their workshop is... the floor nearly blinds you....

thanks, i will bare that in mind if i end up getting an aftermarket ECU...

Cheers