Stock To 1bar Boost

[R32Ninja]

Hi, just a quick question..

I was thinking of upping my boost to a bar with the pfc, the only other engine related mods I have is exhaust. Is 1 bar noticably different from the stock boost level? thanks

[123456]

nah, 1 bar is bordering on the turbo's max efficiency, some people report a performance drop even, from 12 psi. Anyway, 14 psi (1 bar) is too high for the standard turbo and it wont last long, try out 12 psi (.83 bar i think) it'll still feel quite a bit faster than stock

[R32Ninja]

forgot to add, the car is a r32 gtr

[R31Nismoid]

it is noticeable different.

But your playing with fire IMO.

Stick to 12psi. With a good tune, and a set of cam gears... you wont know the car it'll be much nicer to drive

[R32Ninja]

yea, I was thinking of just keeping it around stock for everyday driving, then just changing it before I really wanna push it. pushing a bar for a few hours everyweek shouldn't be that bad?

p.s.

is there a noticeable gas mileage difference also? forgot to ask that one before

[cameron]

Here's your options...

1bar / 14.5psi - possibly blow turbos to bits.

.83? / or 12psi - Car will go well, turbo's will last longer!

More power = more fuel, so yes if you have a heavy right foot on high boost the economy is worse!

Cruise shouldnt be any different.

[AndrewD]

it is noticeable different.

But your playing with fire IMO.

Stick to 12psi. With a good tune, and a set of cam gears... you wont know the car it'll be much nicer to drive

What is with you and cam gears. They do squat! Changing to slotted cam gears isnt of much benefit unless you can verify either retarding or advancing the cam is adventageous.

And your avatar. It merits ridicule.

[The Dan]

Has anyone got a compressor map for the stock turbo?

Does anyone actually have any idea or are we all just talking shit about what the guy next to us has said?

The GTR runs half total boost on each turbo. So by my calculations, that would mean the stock turbos WILL blow up if they run more than 7.5psi each. Holy shit, and here I was thinking that 10-12psi each was more of a realistic maximum for each one.

[The Dan]

What is with you and cam gears. They do squat! Changing to slotted cam gears isnt of much benefit unless you can verify either retarding or advancing the cam is adventageous.

And your avatar. It merits ridicule.

I second that notion. He advised a customer of mine to not worry about cams and just put the gears on. Makes the same power it did before. Drives exactly the same after the tune. Definately looks prettier though.

[MBS206]

Has anyone got a compressor map for the stock turbo?

Does anyone actually have any idea or are we all just talking shit about what the guy next to us has said?

The GTR runs half total boost on each turbo. So by my calculations, that would mean the stock turbos WILL blow up if they run more than 7.5psi each. Holy shit, and here I was thinking that 10-12psi each was more of a realistic maximum for each one.

I'm glad I cleared that one up then.

Um, if you run a single turbo system at 14PSi, the turbo sees 14PSi.

If you run a twin turbo system at 14PSi, each turbo STILL sees 14PSi... You don't halve it.

What gets halved, is the CFM through each turbo. Two TOTALLY different things.

[R31Nismoid]

The are a great RB26 mod, thats whats with it

One of the best value for money mods, cheap as chips and can return upto 25rwkw in the midrange.

So i'd say thats pretty adventageous, wouldnt you?

If you dont get a gain, so be it, lots of people have. For $150... well... hard not to try it.

[The Dan]

Um, if you run a single turbo system at 14PSi, the turbo sees 14PSi.

If you run a twin turbo system at 14PSi, each turbo STILL sees 14PSi... You don't halve it.

What gets halved, is the CFM through each turbo. Two TOTALLY different things.

The stock actuators open at 4psi. Yes....halve it.

And at any rate, 14psi is not going to kill a pair of GTR turbos. Sure it may have screwed a few in history but that doesn't mean it was caused by running that much boost.

[AndrewD]

The are a great RB26 mod, thats whats with it

One of the best value for money mods, cheap as chips and can return upto 25rwkw in the midrange.

So i'd say thats pretty adventageous, wouldnt you?

If you dont get a gain, so be it, lots of people have. For $150... well... hard not to try it.

I cant see how just 'replacing' the cam gears is going to net you gains. 25 kw gains at that.

Please elaborate more. Are you talking about a direct swap, or adjustable 'slotted' cam gears you can adjust valve events start / end timing with?

[AndrewD]

The stock actuators open at 4psi. Yes....halve it.

And at any rate, 14psi is not going to kill a pair of GTR turbos. Sure it may have screwed a few in history but that doesn't mean it was caused by running that much boost.

Nah mate, the other dude is right, however its actually about mass flowrate not volumetric flowrate (CFM) as that implies that temperature effects are negligble. i.e. you could one volumetric flowrate but different mass flowrates for varying temperatures.

So two turbos running at 9 psi nets 9 psi MAP but twice the massflowrate than one would at the same boost pressure.

But i agree with you nismoid should really stop giving out crap advice, but hes victorian, the home of material boys. Im guessing he gets a commission for selling as many cam gears as possible. That or dreams of them

[R32Ninja]

so then a bar is okay then?

[MBS206]

The only evidence, I've been told of, for not wanting to run over 12PSi on a 'Line turbo, is the ceramic wheel.

Do the GTR still run ceramic wheels on there turbos?

The best way to decide on your boost level, is on the dyno, you can see what increase you get, and usually people dial in the most boost they can, before power doesn't seem to increase... Unless of course the turbo is likely to fail (From delamination etc)

[sinistaGTR]

No dont run 14psi things will go bang

Edited October 14, 2006 by sinistagtst

[Beer Baron]

i have to say I dont buy the 14psi=blown turbo myth. Providing you keep exhaust temp under control, the car is tuned well and things are generally in good condition 14psi should be fine for a squirt every now and then.

as for the cam gears. andrewd, he's talking about adjustable cam gears. i can't say i've ever seen replacement cam gears tha weren't adjustable so I guess he assumed you could figure that out. obviously just fitting them doesn't do shit, they need to be tuned. on my GTR power went from 220kw atw to 247kw atw purely though cam gear adjustment. midrange was up around 30kw from about 3500rpm upwards.

andrewd, a little bit of personal advicee. you may not like 31nismoid, but have your wits about you and recognise that he is a long standing, respected member and moderator of this forum. you on the other hand have been a member here for just under 1 month and so far have not contributed much at all so lay off the personal attacks (to nismoid or anyone else for that matter) as things will progress very simply from there. warning, warning, ban.

[R31Nismoid]

Yes - adjustable cam gears... I thought anyone would realise the stock ones arent adjustable so you need to either

1) mod the stockers (cheap)

2) purchase adj ones (little more costly)

Ah yeah, what Beer Baron said for the rest of it.

[Faid]

The 26 benefits a lot from some cam gears, as i have experienced last week. i dont know why people talk shit when they dont know a thing about what they are talkin about. And nismoid ur advice can hit hard and sarcastic at some times, but till now i have read good advice from your posts, especially when i was about to build my engine.

Edited October 14, 2006 by Faid