Originally Posted by
JEFASOLD
I had my stock SC pulley machined from 74 mm to 70 mm. This was done at Carrs Machine Shop between Danville and Bloomsburg Pa. Tim is a friend and charged me $60. The limit is about 67 but with a 181 main pulley, 70 was as low as I wanted to go to keep the SC from exceeding the safe limits. Tim Carr is an excellent machinist, he is an instructor at the local Vo-Tech school. This is the same guy who produced my two piece front wheel bolts.
Jim, from all of the posting and research I have done it seems that the SC should not spin more than 15,000rpm. So since I have a 178 to put on a 70mm crank pulley would be perfect. That would be about a 5 percent increase over the 155/65. I have seen 18/19 psi with my current set-up with E/C data logging.
maybe I would not need larger injectors with the 70 also. I don't understand how running 550cc inj's would run at a 14.x:1 under normal driving. Would the ECU adjust trims to get to the right AFR's and how long would it take. The fellow I got the pulleys from said he never got his running running with correct AFR's, always rich normal driving.
I'll look into a 70mm pulley now. Thanks guys for bearing with all of the questions, just want to get it right the first time. Mark