Hi every body ,

i posted befor about my h2 hummer with sts turbo , in the begining i fixed the wonderful sts turbo on my car with procharger intercooler and i was already taken off the catalystic converts out. the basic kit i have is 5 psi . the car was screaming damn fast i raced with silverado truck that has a camshaft and K&N air filter . Guys i gave that guy big time like 10 meters infront of him . but i was facing problems with the loud sound of the exhuast not the turbo it self . i spoked to the great support at sts and they asked me to fix a muffler after the turbo . i fixed flowmaster muffler and it seems its my mistake to choose the bad muffler it was flowmaster 70 series with cat back . the car gave me a very bad tone and alot of back pressure the turbo gave me only 1 psi max which is a loose of 4 psi .

today i took off that F***&&& muffler and in other side fixed the catalystic converters . The sound now is amazing its damn amazing very loud turbo sound with almost no exhuast sound and the car is smoother now .

but the car is now only doing 3 psi which is increase of 2 psi vs muffler .

i want my 5 psi back i dont know what to do iam satisfied with the sound with the catalystic converters but i dont wanna remove them cos it decreased the sound of the exhuast alot .

what do you think i shall do .

without the catalystic converter am reaching 5 psi and i feel the turbo will flow out this 5 psi it was pure 5 psi .

i dont wanna add high flow catalystic converters cos i dont wanna take the risk of the welding .

would if i add 7 psi spring it will help me to reach 5 psi which is stupid sulotion ?

does it might be a tuning problem since i have catalystic converters am getting different flow so i should retune it ?

any comment will help and thanks for sts for the great turbo

 

you can get a b/c but just make sure your not running lean!!! i dont know y u dropped so much boost with a muffler? u can up the boost but make sure u got the fuel to back it up!!!!

 

You should not have a drop in boost because of the cats unless they are plugged. I have cats and a muffler before the turbo and no loss of boost. I get 7 psi on the red .4 bar spring. I am not really sure what your problem is. Take the cats off and if you get your boost back put a 3" in/out 14" long magnaflow muffler after the turbo. See if that is quiet enough for you.
Also check to see where you are getting your reference for your waste gate. If it is on the end of the compressor scroll that should be fine. If it is on the scroll close to the start of the scroll it will work poorly and limit your boost. Maybe the best thing would be to run a line from the intake manifold for your boost reference.
What ever you do make sure you have enough fuel and are not going lean under boost.

 

thanks guys all the problem solved my hummer is flying with 5~6 psi .

i love my sts turbo have a nice day all

 

So , What were the final mods?

 

slowec , the problem was cos i have intercooler i should change the wastegate refrence to the compressor scroll and it solved it . i fixed a temperarly hose which is lil bit weak till i order new one .

 

so u got ur ref. off the manifold?

 

All of the Dodge sts guys I know use the manifold to ref the wg and boost controller. Not the compressor scroll.