Max Boost With Std. Intercooler

[-Joel-]

What would be the max boost that I can run with the std. Intercooler.

Some of these places like Viper motor sport say "slap on an exhaust and turn the boost up to 14psi" and you will be getting around the 160rwkw mark....

HOW TRUE IS THIS?

When I had the Stock Dyno Done I think Tim said that It peaked at 8.5psi then dropped to 7psi or something after 5500..

[GTS-4 Ben]

with stock everything except exaust/filter/and fuel pump I run 14psi without any trouble.

With a larger turbo this would be less..

[-Joel-]

What about the Hot 40 Degree Summer days?

Do you flick to a lower boost setting?

[[TWUBLE]]

With Std cooler, but aftermarket exhaust, filter and remapped computer i run 13.5psi... its fine... one good thing to do would be to make a duct to your std cooler... thermo wrap the intake pip (the part that goes over the engine...) and put silver around that... should be fine to about 15psi wouldnt wanna go much over 1 - 1.1bar with std turbo tho

[SlowGts-t]

I actually think that skylines only go pop at 14psi if the fuel pump is suspect or if something else is wrong . Er.. A/F on my car was about 11.8 or so at 14.0 psi, so there's plenty of fuel there.

Er.. only have filter and exhaust.

[[TWUBLE]]

oooh how did you wind up the boost?

[-Joel-]

Well my fuel pump is excellent apparently as tim when he dyno'd it put a fuel pressure reg. bleed kit as it was running way rich on full boost..
It ended up getting an extra 10rwkw from the fuel pressure reg. bleed kit.

<checks receipt>
The fuel pressure was $68.. Fitted and setup..
I got him to do a dyno diagnostics to see if there were any problems around the corner, I also wanted a dyno print out to go off of when I do the exhaust, filter, turbo and on the list goes.

Going from the dyno read out and that 2 psi gives around 10rwkw.
Starting from 125rwkw.
Exhaust around the 140rwkw mark
Boost from about 8-9 to around 14.
Should get me up around the 165rwkw mark.. I hope..

R8 250kw Commodore

[UK GTR OWNER]

On stock intercooler and stock injectors and stock fuel pump and stock cams ie totally stock engine, except exhaust and air filter I ran 1.2bar (about 18psi) and got 420bhp at crank. It also ran at 1.3 bar (about 19.5psi) and got 440bhp, but turned it back down for safety.

The turbos are stock size but with steel wheels, to allow higher boost.

This was on my R33 Le Mans that I have now sold..........running fine with new owner.

However, it is obviously less hot over here in England, so I can't say whether it would be safe to run this boost in 30 or 40degrees centigrade.

Guy

[SlowGts-t]

UK GTR OWNER, GTS-t's my friend. Your GTR puts out more power than any of our cars even on stock boost

Hmm i think the KW figure varies with different boost control methods. I'm sure EBC's give a higher kw figure as they hold boost even at high revs as opposed to a bleeder where the boost is highest in the mid range. er.. anyone?

[-Joel-]

Hit the nail on the head SlowGts-t.

[whatsisname]

-Joel-,
Take note of the location of the other guys posting in this thread mate, UK & NZ, not the hottest places on earth, having been to the UK a fair few times, & living in Tassie for 1/2 my life (similiar climate to NZ) I know it can get very warm, but on average not like OZ (current temps in Adelaide & outer South Australian areas, mid 30's to over 45'c).

Now, I'm not sure with the 32 GTS-t IC, but I can assure you the 33 GTS25t IC (which is probably bigger?) will NOT cope "safely" with more than 10-11psi (YES!!! I mean 10-11psi) without some detonation. It may not be audible, & you might run it higher for a yr or 2, but it's not doing much good in the long term.

If you don't believe me on this, fill up with a tank of 98 fuel, wait till a cool night, go to a spot where you can go WOT a few times, set boost to 12+psi, & turn off the stereo & listen hard as you nail it in 2nd.

Or.... find someone willing to lend you their 32 GTS-t Power FC & watch the dash eng light (PFC uses it as a knock indicator) flash it's tits off!!! Don't think this option will be easy though

[whatsisname]

Originally posted by SlowGts-t
Hmm i think the KW figure varies with different boost control methods. I'm sure EBC's give a higher kw figure as they hold boost even at high revs as opposed to a bleeder where the boost is highest in the mid range. er.. anyone?

A good quality EBC (in fact most EBC's) will not only provide peak rwkw gains but also noticeable gains throught the rev range, as they hold the wastegate actuator line closed until the preset boost level is reached (ie:no wastegate creep & faster boost response) + they monitor the manifold boost level & then attempt to maintain that preset boost (opening & closing the bleed via stepper motors/solenoid as required).

But they cost big $$$, on a bang for your buck the humble bleed valve wins hands down.

[whatsisname]

Originally posted by UK GTR OWNER
1.2bar (about 18psi) and got 420bhp at crank. It also ran at 1.3 bar (about 19.5psi) and got 440bhp

How did you go about measuring BHP @ the crank??? eng dyno?

[-Joel-]

It is very difficult to compare the R33 RB25DET to the R32 RB20DET as I know the RB25DET will not handle much more than 10-12 psi without a fmic due to its high compression ratio compared to the rb20det.

I'm going to get the boost wound up on a hot day on a dyno as to make sure there is no detonation.

So when I wind the boost up I also have to change to a colder range spark plug and also change the gap to .8mm is that correct?..

Would any one have to plug part no. that they use for their r32gts-t running around 14psi?

[whatsisname]

True, very true, 9.0:1 comp' ratio RB25DET vs. 8.5:1 RB20DET.

Still, it's a good idea to set your max boost on a hot day (as you plan to do).

Plugs, you don't "need" colder range plugs, but it will help reduce the chance of pinging, although a colder plug can tend to foul easier too.
If you do go to a colder plug I'd only go 1 heat range colder (7's).
Reducing the gap to ~0.9-0.8 is a good idea to help prevent misfires.

I run copper NGK's, BCPR6ES's gapped to 0.85 & have found them to be very very good (RB25DET though).

I've tried standard Platinums, VX Platinums, & the new Iridiums (+ others) & have found the cheap coppers to work best of all (strange I know?) But they work, & @ less than $30 a set you can't go wrong (I change my plugs every 5k anyway). In fact a # of workshops around OZ have mentioned the coppers have given better results.