My little brother in law has just had his 09 VXR remapped with a 3" turbo back cobra system. I think he is running to much boost it peaks at 25psi. I followed him the other day and on gear change it kicks out smoke.

What should the PSI be roughly and what could the smoke be.

Cheers

Thought i would ask here before joing the VXR forums

 

if its been remapped, then it depends what it been set too.....

Standard PSI = 13-15 PSI

 

Yeah i get that mate, was just wondering what the general setting was for stage 1 that was all

 

Wouldn't have thought stage 1 remap would raise boost up to 1.7 bar myself but could be wrong and good luck trawling the vx forums

 

I have looked and cant find anything. They use KO4's dont they? Can they handle that much boost?

 

I don't really know mate, I would expect it be be low 20psi at the most but guessing......If I'm honest

 

Is the gauge accurate ?

 

who mapped it? ask around on migweb matey

 

It was mapped by big fish turning in the north east.

 

Yes the gauge is spot in buddy

 

Wot colour is the smoke

 

It's only a slight puff after hard right foot and gear change. I would say white

 

With those mods it will be a stage 2 remap, psi depends who has mapped it but upto 20 at peak, some car when remap at stage 2 had good results with nearly 300bhp.

Vxr owners site are really helpful, I use to have a stage 2 nurburgring edition. Tell him to keep an eye on the manifold as they are prone to cracking and it's a new turbo or secondhand manifold.

 

Probably rich at the top end. Alot of stuff is mapped that way for safety

 

Thanks for your help guys

 

21psi overboost absolute maximum (car can only see 20.75) and should hold around 17psi, anymore and you are waiting for turbo to pop and a piston to crack! Is he running stage 3?

 

Sorry just read, Just a turbo back exhaust no cooler so stage 2, Not sure I would even want 21psi overboost on stage 2...

 

I'm an ex-vauxhall fanatic, i know these engines inside and out....

The VXR engine is a Z20LEH and can handle a fair few horses before it goes pop because they added under piston oil jets when remaking from the previous Z20LET, i'd say around 350,

BUT

The turbo they use made by KKK are made out of chocolate, they are a K04-049 and the metal used for the thrust bearing is too soft and wears down due to too much boost, it definitely seems like your VXR is running too much boost as if i remember correctly there only good for upto about 20/22 over boost and holding around 17, if i'm honest i reckon the turbo won't last 12 months!

When being mapped above stage two, you have to make sure you are running good fuel as there prone to melt piston number 3.

The smoke i wouldn't worry about too much if its only as you come onto boost it will more than likely be fuel but should be a blackish colour. They are common for valve stem seals too, but that usually only occurs on over run / idle.

Hope this makes some sort of sense lol

 

Totally agree..... Intake temps must be sky high!

 

So what would you recommend he do now then?

Thanks for the input lads