Mazdadrifter has a ball valve boost controler. Its for sale if you want it. A ball valve is fine but is a PITA to adjust. I helped him w/ adjusting and could see how a blown engine could very easily happen if you are not quick with your right foot. They are very touchy. The benefit of a electronic one is basically ease of adjustiblity. I can change my boost as easily as I can change the volume on my radio.



I did not want to get into the whole debate on the workings of them because it was not the point of this thread. I have done a ton of research on every part I have put into my car and know what I am talking about.



I prefer real world "butt dyno" over what companies claim.



Fedrex from Teamfc3s had the identical setup as me except bo boost controler my car would clobber him in a race. He was wasting time spooling up I was pulling away.



Higher gears we were even but 1st and 2nd I had the advantage.

i love my blitz sbc-id the limiter function is great.... stops overboosting!

because the stock turbo is only set at 5psi.

a boost controller will not help it spool from 0-5psi any faster then stock.



however with no boost controller. at 5psi the wastegate is fully open. any boost after 5psi is boost creep. and creeping is "slow rising".



your turbo at 5psi. creeping to 10psi. is ALOT slower then a boost controller set at 10psi.

because the stock turbo is only set at 5psi.

a boost controller will not help it spool from 0-5psi any faster then stock.



however with no boost controller. at 5psi the wastegate is fully open. any boost after 5psi is boost creep. and creeping is "slow rising".



your turbo at 5psi. creeping to 10psi. is ALOT slower then a boost controller set at 10psi. [/quote]

Thank you, Scott! That makes a whole lot of sense. I don't know where I got it in my head that the wastegate spring was set for 10 psi. I swear I read it somewhere. I may be mistaken.



Hmm. It seems I need a boost controller...

The ProfecB is the best bang for the buck with EBC's. If you can find a used one on E-Bay then go for it. You'll love it.

Like I said best mod you'll ever do. https://www.nopistons.com/forums/pub...DIR#>/wink.png

Okay. Update time. Car is back together and running with the new turbo. It makes boost just fine, but I didn't dog it too hard tonight. Majestic says to idle the car for 5 minutes without revving it. I did that. Also drove it around a bit. Any other "break in" required for rebuilt turbos?



I'm not crazy. The 1988 Mazda factory service manual describes testing the wastegate by applying 10 psi to the actuator and verifying that it moves. Hence my prior belief that the wastegate didn't come into play until 10 psi.



To settle the issue once and for all, I hooked up an air pump and a pressure gauge to my wastegate actuator today. Sure enough, it starts to move at around 5 psi. Pretty much wide open by 8 or 9 psi.



As much as I find the fancy-schmancy electronic BC's attractive, I suspect I'll go with a cheapie manual boost controller 'cause my budget is spent.