Hello everyone.

I’m new to the forum and an evo owner since last July. I had notice since I bought my car used, that when it past around 5000 rpm it makes a loud pssst like it’s leaking. The only mod the car had when I bought it was a cone air filter and also the plastic bov was mounted backwards so I removed it and installed the right way. So yesterday I installed a prosport premium boost gauge and tested the car after the installation and its reading only 15psi max.

I’ll be buying this weekend the materials for the boost leak tester that are listed on the How-To forum. But in the meantime I made a short video tonight running the car in 3rd till 7000 rpm so you guys give me an opinion.

Video -> http://www.youtube.com/watch?v=r1NQi8KrET8

Thanks in advance for the advice.

 

it is possible that the previous owner had a MBC on it and took it off and didn't put all the vacuum lines back on correctly. that might be why your car is running low boost.

 

have it check for boost leak asap. if you're not boosting over 15 psi then you definitely have a leak somewhere

 

AF-Evo8 is spot on. The previous owner of my car was running a MBC but had removed it before I bought it. I put on a gauge and was hitting about 14 and the car didn't feel right. I checked into it and noticed the previous owner had just reconnected the hoses so I was running wastegate pressure. That sounds more likely versus a leak UNLESS you've noticed the car recently seems slower than it did before. It is very easy to slap on a MBC and turn up the boost and slap it back together when they're getting rid of the car. This way it looks stock (minus the filter).

 

Is it possible to have a boost leak or van line leak and still be boosting in the 20's???

I still boost fine, but when not boosting it bogs around 3000-3500 and the in hg vacuum reads like 3-11 idleing andd like RANDOM number riding...


Vac line possibly??

 

Probably not a leak. You are just boosting wastegate pressure I bet.

 

%99 sure that your just boosting waste gate pressure. I actually tried connecting my factory solenoid back up with the lines my MBC was using and it did this. The factory solenoid uses certain length lines and some restricter pills in-line. If you plan on modding your car don't even bother getting it to work with the factory unit. Just get a MBC and dial it in.

-Ethan

 

Thanks for the replies.

I searched the forum for the diagram of the vacuum lines for the factory boost controller solenoid and took a look at the lines on my car. Well I found that in fact the vacuum line was shorter and the restrictor pill that goes close to the solenoid was missing. So probably that you guys said, the previous owner indeed had a MBC and took it off before selling it.

So the car will be stuck at 14-15psi until I buy a mbc then