Safely running boost creep?
 

Hey guys, im in the middle of pulling my motor, as im replacing the clutch and installing a 3in full exhaust. Ive read about the boost creep people experience when theyve put in a larger exhaust and i was wondering if my power fc is able to adjust for the increase in boost to run it safely, or is porting my wastegate an absolute must?

with a full 3inch exhaust a ported wastegate is pretty much standard.

the amount of air is just too much for the tiny wastegate. even with a boost controller. its best to port the wastegate no matter what.
since your motor is out. its pretty wise to do so.
and i also suggest you pull the injectors and have them sent out for service. RC dose a great job and like 24$ per injector ?
changed the orings while your at it. heck, do the fuel lines too. test your coils since your already there. the list goes on but lets not get too ahead of our selfs lol

You cannot adjust for boost creep. The only thing you can do is tune for the boost level it creeps to providing your fuel and ignition systems can keep up. That being said, I strongly advise against running a full 3" exhaust on a twin turbo car unless you port the wastegate and even then it sometimes isn't enough to stop the creep completely. Temporarily you can add a 2.5 or 2.25" restrictor plate in the exhaust to try and prevent the creep.

There is actual creep, where the waste gate can't keep up with flow, and there's the stock boost control system running away with boost.

If you have the engine out, take the time and port the waste gates. Isn't that hard and won't take you very long. I would also research boost control, either using a Datalogit and MAC solenoids or an aftermarket boost controller.

Dale

Thanks for the replys, my next question is which wastegate am i acutally porting? https://cimg1.ibsrv.net/gimg/www.rx7...de2ee9bf17.jpg
https://cimg2.ibsrv.net/gimg/www.rx7...50f13bce84.jpg

Open the flapper on the second pic and then enlarge the hole

Is there a write-up on this anywhere? Drawing/specs?

There may be. The principle is you want to open the hole up underneath the flapper but still have enough material for the flapper to seal to. Really you only need 1-2mm of lip around the hole to seal up to the wastegate flapper.

Also, just a small amount of porting makes a pretty substantial difference.

Dale

yeah i was thinking that would be the case, what is the function of the other gate? looks like it redirects gas through that spacer chamber to the other turbo or something?

In general, is porting the wastegate worthwhile if you already have the engine out?

If the motor is out and you plan to run a full exhaust on twins you might as well port the wastegate.

might want to replace/fix whatever is showing all of those cracks in it

Those cracks are common/inevitable and on every used set of twins I've seen. And I've seen alot worse. You can't practically do anything about them. As long as they don't extend beyond the gasket they're usually not an issue.