ok heres the story... this past spring my friend and i performed a swap from a S4 to a S5, but not just the block the whole shibang so currently im running on the S5 ECU, we've fix all the minor problems and what not but there is still one issue that we have yet to deal with... THE BOOST!~ at first the car wasnt boosting because the waste gate was stuck open, we fixed that... it now boost's but not as hard as my previous S4, which leads me to disapointment, with my S4 i could build boost up to 10 psi, and my BOV was extreamly loud like a bus even loader! now im only boosting 5psi and my BOV sounds like a silent but deadly fart and most embarrassing of all i lost to a friends GSR . my friend who did the swap for me is a very busy bee, and doesnt have time to find the problem. this is a plea for help...

 

if theres anyone who can take a look for me and has the know how to fix ill pay them for thier time $40/h , thats if something is acomplished!

 

Were you using a boost controller to get 10 psi before? If not, keep in mind the S5 wastegate is more efficient and will control boost better. Also, is your boost control solenoid hooked up and working correctly?

 

nope didnt have a boost controller, only had a full exhaust and a custom intake, then i over boosted and cracked a corner seal! im not to sure bout the solenoid, would this have anything to do with the factory boost guage... cause when we did the swap that was the only thing that we couldnt get to work... we didnt really bother with it cause i have a after market boost guage...

 

Did you also swap in the stock S5 TII boost solenoid? (not correct term) but there is a solenoid/valve that is near the oil fill cap that controls that acts as a boost controller.

 

I think whats happening is that your boost control solenoid is not hooked up, and the better wastegate is able to control your boost level.

If you hook up the solenoid properly, you should see boost levels increase to whatever the stock s5 boost is (I think its around 7-8 psi?).

The proper way to increase boost further is to get a boost controller(even a cheap manual controller is enough). Make sure you have some fuel mods and an FCD(if stock ECU) if you are raising the boost to 10 psi again, otherwise this engine will probably blow too.

 

ok i finally had time to check and its a S5... any other thought... this is seriously pissing me off

 

dude i hope you get your car fixed, i'm not sure what the prob. could be but i wish you the best of luck....

 

Ok... so you are telling me it's a S5. But you are not telling me if you hooked up the S5 stock boost control solenoid.

 

everything is hooked up... error* and i quickly went through some of the lines and found a cracked line... fixed that... now i have some what proper vacume on the guage (15) but still not boosting close to what it was before, BOV sounds a little better, but still like a loose *** letting out a fluffer