We all go to these extremes to keep our stock-fuel-setup car under 9 or 10 PSI when we do breathing mods. I was wondering, in lieu of a $2000+ "correct" solution to the problem (standalone, injectors, fuel pump, whatever else), why don't we utilize an electronically controlled solenoid that opens up a bypass valve on the intake side (kinda like a BOV but not really), when it reaches 9 psi (or 10psi or whatever..) it opens up and doesn't allow boost to creep any higher.

Reason I ask is because I'm not about to take my turbo off to port the wastegate on my S5 turbo, and I've heard that even doing this doesn't always solve the problem. This would remove the need for a fuel cut defender if limited at factory boost maximum, AND keep it from blowing up from overboost with a FCD around 9 or 10 lbs.

Anyone's thoughts?

 

you could use a pop off valve which just opens at a set pressure. these are available from most turbo shops. problem will still be the detonation and tuning problems associated with elevated boost levels. hopefully the pop off valve opens quickly and vents quickly enough so the engine does not detonated a blow up. kind of a band aid that may work.

 

pop off vavle does not work. it's a fuse. it lets off all boost at once when it goes off.

top way wouldn't work either. tunning nightmare. the AFM is still seeing all the air comming in. so you'd be running so rich... plus the turbo is still spinning at full boost. so it'll wear out fast, and the air will be hoter.

 

how would it be a tuning nightmare? You use it AFTER the AFM just like the BOV.

 

It's a tuning nightmare because all that air that's been metered by the AFM is now being vented to the atmosphere, instead of being ingested by the engine.

I'm going to be seriously thinking about the implications of an on-boost compressor bypass valve, however. If opened up early enough, I think it may be able to control boost. It'd be hell to tune, though.

Brandon

 

pulling off the turbo isn't that big of an ordeal. I've done it many, many times now. Biggest pain in the *** is the heat shield. I think mazda putt the bolts in the most awkward angles just to **** us off. If you ever have a weekend where you aren't doing anything, bite the bullet, pull the turbo, and port the wg.

 

When I do any mods I always restrict the intake for testing and then slowly make it less restrictive until I'm satisfied.

This can be done with Duck tape wrapped around the filter.

 

no.. no.. the bypass valve goes from the pressurized side of the turbo (just like the BOV) and moves BACK to just before the turbo (the non-pressurized side), it's essentially "wasting" pressure, but it's better than the alternative of a blown motor.

 

Your turbo will spin to 500,000+ rpms

 

Just buy an external wastegate from turbonetics.