ok my car makes good boost in all gears if i dont rev past 6k. if i rev past 6k it will make no boost untill the revs drop wayyyy down. but if i keep them below 6k boost is strong 10-8-10. but some times boost wont hold to red line it falls down at like 7k but not all the time? please help

 

fuel cut off? just a guess

 

check your map sensor and your intercooler hoses.

 

It could be fuel cutoff. What are your mods?

 

If you have aftermarket ecu or piggy back, check your maps...Mine was leaning out on the midrange and would not rev on boost unless i backed off. it was ok from idle to about 4500rpms die out and then come back at like 7k again. I had to play with the gas or just stay at or over 7k...

 

my mods are HI-FLOW Cat, Cat Back, Apexi twin air intake twin filter, GReady IC piping and a ECU chip i havent installed yet. how would i know if it was fuel cut? or something else

 

You may be collapsing an air intake hose.

 

so i found out that i have no boost when i shift at WOT in the high rev rang unless i drop my RPMs below 3500rpms. eny ideas.

 

? what are you guys on about ? Fuel Cut ? Fuel Cut is to limit your speed. It does not kill you boost pressure.

Check Your Rats nest, Actuators and Boost lines.

 

Check out Damian's postings on this . Might help you

 

^^LOL? fuel cut is not to limit your speed. Fuel cut goes into effect when you have mods, that allow the car to produce more boost. if you dont have a BC. It will fuel cut and just give the car enough fuel to idle so you dont pop your motor. That way on stock ecu it cant handle over 10 psi. So it fuel cuts at 10 psi so you dont put stress on your motor.

 

Well think of it this way: If gas stops being delivered (fuel cut) boost will drop instatenously. Fuel cut = the same as getting your foot of the gas = no boost

 

I think I know what it is.

Are you running a 10-8-10 boost pattern, and then it's slowly driopping off in the high revs? And, when you get on it, and shift up, is your car not boosting in the next gear until you drop the rpm's almost all the way down?

If this is the case, then your waste gates may be fluttering. What's happening is your waste gates are opening to let off boost, but when you shift quickly into the next gear your instantly putting the car back in boost before the waste gates have time to close. So your boost is keeping the waste gates open and basically all your boost is flowing right out the gates. The gates are closing to slow. You can adjust them. They sort of stick, and aren't closing fast enough.

That might be the case b/c it happened to me a few weeks ago. BE CAREFUL if you decide to adjust the gates yourself. If you adjust them wrong you can cause that car to just to really high boost levels.

Good luck

 

Thats Exactly What it was doing. i didt think of the wastgate. how do you ajust it?