Exhaust question

[DSMboostin15]

I just installed my new 3" turbo back and now I think I'm experiencing boost creep. When my car is at idle, the boost gauge reads 21 in Hg, which is what it did before. But when I rev up the car in neutral with no load to about 5,000 rpms, the boost gauge only reads like 3 psi but my BOV sounds like it has 13 psi. I have the boost gauge teed into one of the solenoids on the driverside firewall, I can't remember which one. But to top it all off, when I just tap on the gas, the boost gauge hesitates then jumps from 21 in Hg to 0 without a smooth sweep like it use to. I had the MBC set to 14 psi on the stock 14b, but now I turned it back down to stock boost just to be safe. Anyone with advice would be great. Thanks.

 

[kenamond]

I just installed my new 3" turbo back and now I think I'm experiencing boost creep. When my car is at idle, the boost gauge reads 21 in Hg, which is what it did before. But when I rev up the car in neutral with no load to about 5,000 rpms, the boost gauge only reads like 3 psi but my BOV sounds like it has 13 psi. I have the boost gauge teed into one of the solenoids on the driverside firewall, I can't remember which one. But to top it all off, when I just tap on the gas, the boost gauge hesitates then jumps from 21 in Hg to 0 without a smooth sweep like it use to. I had the MBC set to 14 psi on the stock 14b, but now I turned it back down to stock boost just to be safe. Anyone with advice would be great. Thanks.

That's not boost creep. Boost creep is when your wastegate can't divert enough exhaust around the turbine wheel to limit boost. You'll only see creep if you're in gear and on the gas.

The larger exhaust will help your turbo spool up faster, but because your engine isn't under any appreciable load in neutral, it's not generating enough exhaust to drive your boost up anywhere near stock or higher boost.

Not sure why your boost gauge is responding immediately now but not before. There is a tech article about where to T your boost gauge line, and it's off of the FPS line near where you said you installed yours. Check the article out and make sure you got the correct line.

 

[DSMboostin15]

Thanks for the reply. I knew that a larger exhaust would help the spool, but I just didn't realize that it would help THAT much. I guess with the turbo spooling that quick, I freaked out. And I remember seeing that tech article once about where to tap in the boost gauge, and that's where I tapped in at. I just guess that I'll live the with boost gauge now.

 

[Ultimatedsm]

Well, if you haven't ported your Exhaust manifold and o2 housing, you will experience boost creep.