94greencamaro

iTrader: (8)

I got a 383 LT1 with a F1A blower on it. Went to dyno it today and ran into some problems:



1) the car gets up to about 5000 rpms and then its basically like you just turn the key off. your foot is still on full throttle yet the car just drops back to about 2000 rpms. This is only at about 6 psi...so id assume the inlet isnt being sucked shut. Fuel pressure is up around 50 at WOT. Ignition box rev limiter is set at 6500. Anybody have this type of problem before?

2) the car isnt even making boost until 4500-5000 rpms....could this be caused by the bypass valve opening too soon? We didnt have time to really check but i figure that is what it would have to be.

Its frusterating because the car is so close to being able to run down the track....but these little problems. Im starting to think it may be in the tune because everything we looked at seemed to check out alright mechanically.

any input would be greatly appreciated

lt170chevelle

iTrader: (2)

make sure you have no cut couplers and tiight clamps, also make sure you are not losing boost through the bov..if ya have one, and also yeah maybe its your bypass valve. also make sure your filter isnt colapsing or maybe something is colapsing shut.ive had this happen on a previous car and feels just like the key gets turned off

94greencamaro

iTrader: (8)

Will do
I thought maybe it was collapsing shut but at 6 psi i didnt even check because it shouldnt be haha. I was too busy watching other things. However the mass air flow was being maxed out at 5000 so it was getting plenty of air.

BLK02WS6

iTrader: (2)

Its in the tune - the MAF is reaching its cutoff and that causes the injectors to cut in half and shut the engine down. You need to raise the limit for the MAF in the tune...