speed density with bigger cams
Thread Starter
Instructor
Joined: Sep 2006
Posts: 142
Likes: 1
speed density with bigger cams
I'm almost done build my new motor. So my thought are migrating more towards how I want to go when replacing the carb with FI
I really like the First Fuel injection intake and the fact that the GM electronics would make it easy to find replacement parts and plugging a tuner into it. So I emailed them for a quote on a system that would work with my setup. The price was one of the cheapest I've seen for an all inclusive kit (Just under $2k). However, they suggestion that I not go with their electronics, which are OBD1 GM electronics and use a Speed density monitoring system. They said that any cam over about 225 in duration would not run well with a speed density system. My cam has a 230intake, 236exhaust, duration which I expect a bit of lope but didn't think that was radical... So should I really look for electronics with a different monitoring system (which seem to be more expensive) or are they just trying to be on the safe side when they tell me my cam is too big for speed density?
I really like the First Fuel injection intake and the fact that the GM electronics would make it easy to find replacement parts and plugging a tuner into it. So I emailed them for a quote on a system that would work with my setup. The price was one of the cheapest I've seen for an all inclusive kit (Just under $2k). However, they suggestion that I not go with their electronics, which are OBD1 GM electronics and use a Speed density monitoring system. They said that any cam over about 225 in duration would not run well with a speed density system. My cam has a 230intake, 236exhaust, duration which I expect a bit of lope but didn't think that was radical... So should I really look for electronics with a different monitoring system (which seem to be more expensive) or are they just trying to be on the safe side when they tell me my cam is too big for speed density?
Melting Slicks
Joined: Mar 2002
Posts: 2,164
Likes: 7
From: Beringen
Their statement is B.S. IMO. You can run an EFI system with any cam, but you will need to adjust fuel tables to make it work. If the question is : will a stock ecm work with any cam, the answer is clearly no, unless the cams specs are very close to stock.
Melting Slicks
Joined: Mar 2007
Posts: 2,100
Likes: 12
From: Frederick Maryland
I think what they're telling you is that a bigger cam won't work with THEIR speed-density system. Their electronics can't compensate for cams over a certain spec. As Belgian said, the fuel tables have to be calibrated to the cam specs, either by a laptop or specific chip added to the ECU.
