1toofastlt1

iTrader: (4)

Hey every one I was at the track racing and at 6200 rpm the opti rotor broke. The car basically just died but my log show it just started idling around 300 rpm. It wasnt making any strange noises untill I was just pulling off the track it started jumping in rmp from 1000 to 2500 and knocking kinda bad and back firing into the intake. I was still sloing down from the race and trying to pull over so itknocked like that for about 5 sec. I now replaced theopti with a new one and the car runs really really rich. My car is a forged 383 with a vortech ysi blower. Any suggestions on what might have happened? Could it be the map sensor got messed up? My log shows when it back fired into the intake it maxes out my 2 bar map sensor.

1toofastlt1

iTrader: (4)

I should mention since the car is running really rich what my fuel set up is. I have twin in tank 255 pumps with aeromotive 1:1 boost referenced fuel regulator and 60lbs injectors. When I say rich I mean black smoke popping and it dies. I cant even drive it

leadfoot4

iTrader: (1)

I think you're on the right track there....

96capricemgr

iTrader: (1)

Not that I have ever heard of it happening but along the same lines as worrying about the MAP I might worry about the regulator.

I would also consider that the opti rotor might have in part been a symptom, 6200rpm is pretty low.

1toofastlt1

iTrader: (4)

I have a 1 bar map sensor sitting on the shelf and I have a1 bar tune that runs pretty good so I will try that. Thanks for the input

1toofastlt1

iTrader: (4)

So I installed the new map sensor and there was no change. I checked my fuel pressure and its good. I even tryed lowering it some and no change. I took out 10 deg of timing and it helped some but its still rich. Any other ideas?

1toofastlt1

iTrader: (4)

Has any one experienced a timing chain slipping?

leadfoot4

iTrader: (1)

The LT1 chains seem to have more "slack" than a lot of chains I've seen, but I really don't see how they could "slip" or jump a tooth.

1toofastlt1

iTrader: (4)

So I found the problem. The opti rotor was drilled wrong so it was about 30 deg off from where it should point