How Much Boost?

[r33747]

Got a dyno tune the other day and when i got the car back

i noticed that the tuner set boost at 18psi which i thought was i little high.

Im running a GT30R turbo with all the usual supporting mods. I want to know is 18 psi too much on stock internals considering this is a daily driven car.

Car drives well and acelerates hard and smooth but when i take the foot off the acelerator i get popping sound from the

exhuast, sounds like a race car backing off. Is that normal. Thought it might off been the spark plugs so i replaced them with iriduims during that i expected the coilpacks( spitfires) and they looked fine. Took it floor a drive and it still does it. Personally i dont mind the sound but i dont wont to damaged the engine.

[battery]

the tuner didn't talk to you about boost? where did you get it done?

some people wont run more than 10psi on the stock engines, 18 is high i'd be happy with 1 bar, but alot of people would say less!

[PM-R33]

http://www.skylinesaustralia.com/forums/Gt...ssure&st=40

Read that thread, page 3 is where most of the information is. It's not boost you have to worry about, its how much power the engine is making and the tune.

As for the "afterburn" its just that, exhaust gases containing enough fuel to ignite in the exhaust pipe due to the heat and causing the popping sound you are hearing. Absolutely normal and nothing to worry about, just means the tune is probably on the richer side.

And as for the above post i think you are referring the stock turbo being 10-14psi, not how much boost an engine can take because there is no such thing.

Edited August 6, 2008 by PM-R33

[Travis Bickle]

http://www.skylinesaustralia.com/forums/Gt...ssure&st=40

Read that thread, page 3 is where most of the information is. It's not boost you have to worry about, its how much power the engine is making and the tune.

As for the "afterburn" its just that, exhaust gases containing enough fuel to ignite in the exhaust pipe due to the heat and causing the popping sound you are hearing. Absolutely normal and nothing to worry about, just means the tune is probably on the richer side.

And as for the above post i think you are referring the stock turbo being 10-14psi, not how much boost an engine can take because there is no such thing.

i read page 3 of that thread and just saw to women bickering at each other about who knows more than the other.

[limpus]

Honestly...if the tune is decent and the supporting mods are there...and if the engine is healthy to begin with...18psi is fine...i mean...its not like you are at WOT and full boost everywhere...its all about throttle modulation...you can drive around like a granny and have that 18psi on tap to get past that pesky car thats holding you up...

[l0WRB]

ive been running 19psi daily for 20,000kms on stock motor that just had new rings put in 20,000kms ago. so i guess stock internals can handle it if you have a nice safe clean tune?

[TiTAN]

if you are making the power @ 5psi or 20psi it makes no difference to your engine as long as you keep the power below around 300kw with a good tune, and your engine was/is serviced properly.

[R31Nismoid]

Its not a question of boost really.

Its a question of a good, safe tune.

If the tune is good, AFR's are tidy and boost control is solid then you shouldnt have many drama's.

Thats provided the motor is in very good condition to start with of course

[The Mafia]

I'm running 22psi on a stock engine, still going strong

ran 18psi without the water meth kit though.

All you need to worry about is, if its pinging or running lean.

[PM-R33]

i read page 3 of that thread and just saw to women bickering at each other about who knows more than the other.

Well you obviously missed half the posts in there saying that boost has nothing to do with it, there is no such thing as an RB25 can take x amount of boost. What the engine internals can take before failure in horsepower wise is another story.

As said above by a few guys, its power or pinging you need to worry about, not boost pressure.

Edited August 7, 2008 by PM-R33

[monga]

Turbo 1cm big runs 40psi and makes 20hp

Turbo 5cm big runs 5psi and makes 20hp

Simple really.