Hey everyone. Hoping someone with experience might be able to explain what’s going on. I recently installed the Stillen supercharger kit and also the TransGo HD2 kit (auto tranny).

It drives great. Had the tranny fully rebuilt and it’s a super fun ride. This is my daily driver and also road trip car so I’m not looking for a crazy setup, just something to make driving a bit more fun and cool.

Anyway, it drives great but the only quirk is that the rev bounces at WOT in first and second gear until it shifts up, then it goes back to normal acceleration.

My AFR gauge will also bounce between 12-15 when this happens. The boost gauge at WOT maintains 0 psi, and at idle+cruising it has negative pressure so I don’t think there’s a vacuum leak but I’m not too experienced with FI so I’m not 100% sure.

I’m doing some research and trying to find out how to diagnose and if anyone else has experienced this, but I haven’t seen anything related to this quirk.

I would appreciate any help! Thanks

 

AFR should be between 11.5 and 12.5. If you're on the stock pulley, boost should be around 7psi.

Are you able to post a video clip of what's happening as you go WOT?

What are you tuning the fuel with? Vortech FMU? or?

 

Thanks for looking into this Wizard. Yeah I’m running the FMU that came with the Stillen s/c kit, and I have the stock pulley. I’ll take a video soon, I have a road near me where I can safely floor it without worrying about traffic or cops!

Also about the boost and AFR… I haven’t seen the boost go above 0 psi, but it stays in the negatives at idle and cruising. I think I saw it hit 1 psi a single time. The AFR is always near 14-15 at cruising, I haven’t really seen it go below 13…

 

I got a video, uploaded to YT because filesize was too big for the forum:
In the video, it actually seems to be driving as expected! Boost went into the positives (didn’t hit 7 though, it upshifted), and the AFR was in that 11-12 range until I let off the accelerator.

Unfortunately, just an hour after this video, my Max randomly lost 1st gear. I remembered that 1st is tied to reverse so I tried going into reverse, gave it gas, and it didn’t move at all… Luckily I was able to get home but I can tell it’s driving in limp mode and I really don’t want to mess it up by driving it any more.

Tragic.