watchout

iTrader: (2)

I was at E-town and had a great time. On the way home I put pump gas in om top of about 4 gallons of race fuel and switched over to my pump gas map. I kept driving and when I downshifted into fourth it was bucking at anything over 20 psi, almost like the car was pulling timing. I got home and figured maybe its bad gas, so I dumped some octane booster in there to see if it helped, it didn't. I lowered the boost down another turn on the controller and the problem is gone but now I am only boosting to like 18-19 PSI. My buddy thinks it is the plugs, switching from race fuel to pump messed them up. Before the race it was fine with the boost setting I always used, now it bucks like it is hitting a wall repeatedly at anything over 20. Any thoughts? Everything else is fine, car is running well and boosting well as long as it is under 20 PSI. Any thoughts?

Shane

02MaximizedVQ

That is exactly what fuel cut feels like in a DSM. It feels like you've run into a wall or hit some type of sudden resistance. Which would be very strange on the stock turbo at only 20 psi. Another thing it could be is an intercooler clamp or coupling losing its seal at that high boost pressure, causing a sudden loss of positive pressure which would of course screw up your a/f ratio in the cylinders.
I've experienced both and they feel just as you've described. Good luck...

MalibuJack

iTrader: (5)

It could be fuel cut.. But if it wasn't happening before, I'd check and change your plugs.. On the other hand if the weather has gotten cooler, it very well could be fuel cut.

You could have "used up" your plugs.. Not so sure how hard race gas can be on plugs, but its possible they were nearing the end of their useful life. I had the symptoms you were describing for a few months, thinking it was fuel cut, until I swapped to colder plugs (just the fact that they were new plus, not just that they were colder than stock)

1QWKEVO

iTrader: (3)

IF its as harsh as i'm thinking it is DO NOT continue to boost hard on it.. A friend was getting massive knock in his SR20 and it was actually cutting out and bucking at higher RPM's and boost, after abotu 20-30 mins of driving hard on it he finally burnt a hole in the piston and scored the cylinder wall

watchout

iTrader: (2)

Talked to Mark @ Turbo Trix, he is pretty sure it is bad gas and the car is hitting the knock threshhold which is still set at a very safe level, meaning it could be increased. Need to fill up with new gas and see if the problem persists.

Shane