View Full Version : Boost issues 5857 1.8

10-22-2011, 12:32 PM
Hey I am trying to figure out why I lose boost in high RPM when shifting at redline(look at the video 1:05 sec)

If any can help me pin point this issue that would be much appreciated. No boost leaks, the boost holds as you can see in the video during 3rd gear, then when shifting into 4th the boost goes from 25psi to 21psi. I have a Turbosmart MBC on the car, wondering if this could be the cause of the issue..

Fast forward a bit**


10-22-2011, 04:35 PM
lol holy shit... i was watching the video, and was like ZOMG did he just spin the tires, or is his clutch fried?!?!

then i saw fwd - whew lol

what was your time?

10-22-2011, 04:35 PM
are you getting spark blow out at high rpm?

10-22-2011, 04:49 PM
embarrassed to post lol...13.9 @ 110....it was the small tires on my stock 15's and the clutch which is only rated for 350 crank hp and im making 400+crank hp....my 60 ft was terrible bc i couldnt let the clutch slip. I can do a pull in 4th gear and go all the way to 7k rpm at 25psi so i dont think the spark is getting blown out. Maybe it could be the clutch all together causing boost to drop off bc the clutch slipping where i am making my peak power, and possibly i get a bit of a spike when i shift quickly

10-22-2011, 09:11 PM
most likely your slipping clutch is screwing with your timing. the load is much higher in 4th gear and the clutch can't hang on.

10-22-2011, 11:03 PM
^^Thats what im thinking.. Im going to throw a clutch in and see what happens