Welcome to the Ford Mustang forum built for owners of the Mustang GT350, BOSS 302, GT500, and all other S550, S197, SN95, Fox Body and older Mustangs set up for open track days, road racing, and/or autocross. Join our forum, interact with others, share your build, and help us strengthen this community!
I just installed the 90mm BBK. Easy install. Car runs great. No CEL. I will get it down the 1/4 next week to see if it gained any MPH. I would post a pic, but I can't figure out how to do it. If I had the nads, I would bore out the intake manifold to 90mm.
No I will not not dyno the car. What I will do is a before and after MPH at the track. IMO dyno's are great for tuning but they are not the best test for actual power increases. MPH over a fixed distance is a true test.
After installing the 90mm BBK my MPH improved from a best of 113.07 mph to 115.24 mph. The air was about 10 degrees cooler at 73 degrees. The car runs great with the BBK. Here's the catch. There was another bone stock Boss 302 with the exception of 17" drag radials. That car was also going 115 mph. His best time was 11.97@115mph. My best time was 12.29@115mph.
If the other Boss wasn't there tonight I would have said the Throttle body was worth 2 mph. It could be that the mph came from the cooler air though. Or, it could be that his motor just makes more power than mine and my car really picked up power from the BBK.