My car had vaccum leak, gas leak, and bad wiring harness before. It was finally fixed today. I now has a dp with a cheap weld-on knock off muffler. I only got 8 lbs of boost in both primary and secondary. I am running 91 octane.
So does that mean I still have some leak around or my turbo is bad??

Thx

 

How are you reading your boost? Do you have a gauge or running a PFC? If you have a autometer guage they are notorious for being off by a pound or pound and a half. I had the same problem until I bought the Blitz sbc-id boost controller. I compared the boost readings on the autometer and the blitz and the diff was about 1.5psi on low boost and on higher boost it was about 0.5psi diff. I guess it all depends on the scale on your boost guage. Try to get one that is 0-15psi vs 0-30 psi.
And if you find that it isn't the gauge then I would check for boost leaks. There are many places to look. Try the eaasy ones like the intercooler couplings/hoses. The cross over pipe. If there is a split in one of the hoses it will be hard to see because there is no pressure on the hose. Do a search on other possible places for boost leaks. Good luck.

R.K.

 

Also your main cat could be plugged.

R.K.

 

you might want to check the boost restrictor/pill that is in the line between the primary turbo compressor elbow and the wastegate actuator. there are two of them. check out Rob's Site. Boost Restrictor

if you look at the site you'll see some pics describing exactly where the pills are.

 

good post...i had an issue similar to yours but only got 7 psi...it ended up being a pill. it was in the line but was moving around in there...talk about a hard problem to solve! First time we checked it was there so we didnt think it was an issue..it was months later that we found it was moving around.

 

yeah
i am using the autometer guage~
i usually have 16~17 Hg mm vacuum
and have like 8-6-8 (not very sure) pattern in 3rd gear

thx

 

is there any better way to troubleshoot the leaks?

 

I would check your main cat first.

If there is anyone local to you that has switched to a midpipe or something, they may have one you could use to test. Also, I don't recommend this, but you could slap on a midpipe just for a test. Just make sure not to overboost since I don't think you have an upgrade ECU.

 

As crazyrx7 said, a good place to start is with the instake hoses, the most notorious of which is the y-pipe coupler. It's a fairly easy job to get it off completely and check it for splits. Also, make sure all clamps are tight on the intake hoses.

 

thx for input~

but does a bad turbo contribution lesser boost??