How do I do this??? I need to dial out the overlap or as much as I can because I am using the NOS kit. Do I need to retard the exhaust and advance the intake? Advance the exhaust and retard the intake? Or is it the total opposite like retard both intake and exhaust or advancing both??? I need help soon guys, the races start this Saturday and I have the last appointment at the dyno on Friday. I am running a 125 shot on the NOS kit # 02040 and on the dyno I am only gaining 73 hp. I think that I am losing the other 50hp thru blow-by, because of both intake and exhaust valves being open at the same time.

 

Overlap is when the exhaust valve is closing at the end of the exhaust stroke and the intake is opening at the beginning of the intake stroke. Four strokes in order are intake-compression-power-exhaust. If you advance the exhaust cam you will reduce overlap because the exhaust valves will close sooner.You can also reduce overlap by retarding the intake cam so that the intake valves will open later. Be careful not to go too far. I would'nt go more than a couple of degrees on either cam.

 

true b19 but there are different set-ups. i have seen the total opposite when tuning on a dyno. so basiclly get camgears and take it to the dyno.

 

I agree 100 percent. I was just answering the question. He may find more power with more overlap. Dynoing is the only way to know for sure.

 

I agrre with you guys but the problem is that I pulled a 245 hp to the ground. Up only 70hp from baseline without NOS and I had it jetted for a 125 hp shot. So I am thinking that I am losing the other 50 thru blow-by.Need to slove it or at least get an idea on what to do before this Friday . Got another dyno appointment before the races on Saturday.

 

Do you have a fuel pump to deliver the needed fuel for that large of a shot?