Wont Boost Over 7psi after going Non Sequential
 

Car drives fine but i wont make over 7psi boost.



Current mods on car
DP
Cat back
full intake
stock catalytic converter (wondering if this is clogged) ?

Would a clogged cat cause this sort of boost problem?


Any one else suffer these symptoms after going non sequential?

What should I look for in particular when trying to troubleshoot the system to make proper boost (10psi)

If it was boosting to 10 right before you went non-seq. then I doubt it is a cat problem. A cat doesn't clog overnight. My guess would be a vacuum line issue when you switched over to non-seq.

Did you do the Poor man's NS? What are you using to control boost? Factory boost control system, EBC, MBC?

If you are using the factory boost control system, check to make sure the solenoids are hooked up correctly, the 2 connected to the UIM. You may need to experiment with pills to get the boost where you want it.

I was making decent boost with stock ecu. But still wasnt full potential...

I did have intermittent boost problems a few months back before all the modding. (5psi with a weird noise) Would have to roll into it to get the boost to come on full



after i replaced my stock ecu with a PFC, it was tuned and it ran very strong and boosted perfect..

Was doing 10psi for about 2 days after the tune.

Woke up one morning and took the car out for a drive and it wouldnt make over 5psi...

Went non sequential still have similar problem...

Its a full non sequential with porting and the whole shabang...

Boost is controled by a manual boost controller.


I did have a small crack/hole in the rubber intercooler pipe, this was replaced and the car did boost a few times to 10psi on a test run...

after the test run car sat for a bit and took it out again, and it was doing the same thing 7psi....

There is the possibility that you waste gate actuator is not working/stuck which is why you will see the 10 then it won't go past 7 after it sits. I haven't ever had one fail but have heard of it happening. If you were getting 10 and now you are getting 7 and nothing else has changed I would suspect there is a leak in one of your vac lines or intercooler couplers. Do you hear air being forced out when the turbos start to spool up at all? Its either that or your boost controler isn't closed shut enough or it sucks as the homemade one I have now does and is causing you a lot of problems.

well why would the boost controller have to be shut that tight ?

What is the symptoms? Hits 7psi like it should or gradually gets there? If the boost controller is opened all the way then it should only hit 7psi because that is when the stock wastegate opens. Sounds like you either have some boost controller/wastegate issue or IC piping issue as you said it did work a few times at 10psi before having the problem.

The more detail you use to describe exactly how the car is acting will help us determine what the problem is. :)

^ what he said, mabye your boost controller isnt working because 7psi is the stock wastegate spring.

How to run straight pipe and not get boost spiking
 

Turns out my intercooler end tanks were shot.

Now my only problem is I dont see full boost until around 4-4.5k rpms is this normal for full non sequential with Ported WG and Turbos ?


Through all the troubleshooting that was done, a straight pipe exhaust was put on the car..

What precautions can be taken to minimize the potential for a really big boost spike?

The mods on the car as we speak are..

Full Intake
Full Exhaust
DP
PFC

sounds like its using the stock wastegate solenoid to control boost.. its preset at 7psi

In any NS setup I have owned with full exhaust I always see 10-12lbs easily before 4k rpms. You might have a small leak somewhere.

David