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OK so I have just installed a HKS EVC in my GTT coupe. The car has a full exhaust with split dump, but no other mods (other than a better boost gauge!). My question is, what is the highest boost I should be setting the EVC to with just the exhaust? The car is in good over all nick with good compression on all cylinders. I also run good oil and it has a K&N panel filter too.

You will get few answers...

Safest - standard

Ideal - 10psi

timebomb - 12psi

Some idiots will say 14psi

Been covered plenty of times. Most people say 12psi though 10psi on tracks etc but I say 10psi max.

I have seen turbos blow at 10psi and others hold for years at 16psi.

It's a game of "Russian roulette", but your odds are better when running 10psi.

In either case, a dyno check is always in order when playing with boost.

My R33 turbo lasted for over 2yrs on 13.5psi, but i was ready/willing to replace it, in the end i got feed up of waiting for it to go so i upgraded anyway, and sold it for $350 as it was still in top nick.

I have seen turbos blow at 10psi and others hold for years at 16psi.

It's a game of "Russian roulette", but your odds are better when running 10psi.

In either case, a dyno check is always in order when playing with boost.

My R33 turbo lasted for over 2yrs on 13.5psi, but i was ready/willing to replace it, in the end i got feed up of waiting for it to go so i upgraded anyway, and sold it for $350 as it was still in top nick.

x 2

i too have been running about one bar for almost two years. had turbo checked out no play still going strong 10 year old car. but i am also upgrading shortly so regardless if it goes i wont be fussed. upgrading.

I've got a profec B spec II on lo setting 9 psi hi setting 12psi

I'm assuming you have some form of piggyback a/f controller or ecu tune to stop your car hitting r&r all the time?

I see lots of differing opinions on this subject and it has been covered many times.

When I got my car tuned the tuner said 12 psi is highest safe level for a stock turbo and an ecu or a/f controller as the stock turbo will struggle to hold 12 psi higher in the rev range anyway (said it tails off back to 9-10 psi)

Have since taken my car to 2 other workshops for power runs on the dyno for a checkup and the tuners there also agreed about this

another vote here...

ran mine @ 14-16 for over a year driving every day...

Yeah but your turbo doesn't look stock, we even talked about it looking highflowed or something... maybe not the best example of a 'stock' turbo running at 14-16psi

I have been running my stock turbo for the last 6 months on my 34 on 12psi. The tuner even asked if i wanted it tuned to 14 but i said no, as i didn't have the funds to replace a turbo if it went and felt that 12 would be a bit safer.... have a few supporting mods though like FMIC, fuel pump, injectors, etc. :action-smiley-069:

Edited by SLEEPR85

I think 12psi street and 10psi track. I ran 12psi the whole time and blew it at the track. The stock ECU is a bitch at 12psi btw. You might be happier at 10psi without the massive hole in the power curve.

post-7957-1219735614_thumb.jpg

If you have the stock management in place I would leave it on stock boost, or no more than 10psi. It is simply a waste to go past 10psi with stock management. I would then boost it up to around 12-12.5 with a remap/new ecu.

mate of mine blew his at 12psi, after less than 10,000km. car was bought stock with what seemed to be genuine 60k on the clock, he did exhaust, front mount, PFC and boost, and he very rarely drove it on boost, he drives worse than any old woman i've ever seen. so it really is russian roulette

  • 2 weeks later...

the R&R is weird.

Here is my car with a boost up, running only cat back and .8 bar. and it didnt seem to hit any sort of "hole" in the revs (small flatten off though present, but nothing like i have seen on some)

After a while at this boost it now does have a massive hole, you can feel it when driving. The flatten off it major and the second kick feels like its hit boost again. But i cant remember it being there when it was first boosted.

Judging on this thread, maybe the way to make your turbo last at this boost is to treat em mean and keep em keen :banana:

post-41581-1220579287_thumb.jpg

R34 25det ignition map is too high between 3600-4000rpm for Australia 98 octan fuel.

So when R34 boosted up, it may ping around 10 psi.

If R34 25DET owner worry about this , please try this.

Accelrate the car to 4500rpm then let it go to decelerate down to 3500rpm then full acceletion once again to 4500rpm.(repeat 2-3 times)

R34 ignition map like a R33, this means if you boost up,ignition timing will retard.

So you can not get power over 11-12psi.

i believe std ecu is like a chain holding back power.

I have remapped previously and it reached nearly 200kw.

Also R34 have boost limitter around 14 psi (R33 do not have), so piggy back can not remove boost remitter.

I recomend R34 remap or full ecu is best.

toshi if you install exhaust cam gear can you alter timing to dial in one or two more psi of boost above 12 psi?

UAS installed a bigger plenum, exhaust cam gear and with stock ECU (with fuel cut defender) made 220kw on a R33 Gts-t standard turbo

http://www.uniqueautosports.com/pricelists...ylineturbos.htm

P.S. im still waiting for UAS to ring me for my short shift kit. when it does im popping over for remap. get ready for me lol.

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