The majority of you will know I have just put on my new Nizpro exhaust manifold and turbo - externally gated. I am running the EXACT same tune as Simon B that went 489kw ATW at around 21psi with an initial spike to 22 or 23 I believe.

Problem is, mine will NOT make more than 16-17. I have checked EVERYTHING - please don't tell me I have a boost leak..................... I have even pulled the turbo off and apart this morning, put it all back together - same result!

So, what's a man to do to see if it is hardware? Run in very carefully with the wastegate feed disconnected.................. Well, let me tell you, 4th gear, half throttle and watching the boost gauge like a hawk it had NO problem on getting to 20-22 psi real quick!!

BTW, I even put in a new boost solenoid just in case so it aint that either.

So, it is not hardware. Assuming the tune is commanding the full whack of boost ( I am sending the box back to Simon to check), anyone got any other ideas before I burn it??????

Maybe factory blow-off valve leaking boost ?.... Perhaps try disconnecting it as some have already done.. I guess its worth a go and may well be safer than some of the other tests you have already tried. Mal

Sorry Mal, the factory BOV is long gone.

As I said though, it boosts up with the wastegate disconnected so it cannot be the BOV as it is still running fine.

does the waste gate have the right spring in it?? sounds silly I know but maybe it wont hold the power and is dumping it

Beat me to it, I was going to suggest checking the sping in case it is faulty. It must be bleeding boost off somewhere and if you have replaced the solenoid that is all I can think of. I am running a 15 pound spring in mine for example.

Can you bypass the solenoid with your setup. Connect the vac line without the solenoid inline and watch what boost your wastegate makes?

Edited February 3, 200719 yr by xrdreaming

Yes I can, but I basically did that already by disconnecting the wastegate feed completely so it was reliant upon the spring only to hold it - no problem.

I had the same thought about the spring too. I can (but haven't) just feed the wastegate direct from the manifold and see what pressure spring is in it but I don't think that is it.

Simon B has the same spring in his...........no problem..........

Keep the ideas coming boys!

Edited February 3, 200719 yr by F6 RAPID

External gate people.. external gate

If it makes boost without the line connected, then the issue is what's controlling the line, or the line it's-self!!

Just make sure your boost signal point is a good one ( try the manifold for starters ) and work from there.

Edited February 3, 200719 yr by F6 UTE

Maybe there is a software problem? I know you said you run the same tune as simon but maybe there is an issue with that somehow.

Have you tried to re flash the tune in?

Yep, Tial 38mm