Which header size 1 3/4 or 1 7/8"?
12-20-2014, 01:56 AM
#21
My 71' has a cnc motorsports 415ci engine that came with a dyno sheet showing 551 hp.
551hp - 6000 rpm
550hp - 6100
551hp - 6200
545hp - 6300
533hp - 6400
526hp - 6500
532hp - 6600
10.25 compression
Edelbrock RPM gap
Tremec 600
I haven't weighed the car, but it's an LT-1 with Van Steel coil overs up front, and the rear is a composite spring. Weight is likely below 3000 lbs.
So, which header size? BTW, it was dynoed with a 1 3/4" stepped to 1 7/8" dyno headers. Right now, it has wimpy 1 5/8" Tri Y's. Not sure how much power is being killed with those.
Thanks!
551hp - 6000 rpm
550hp - 6100
551hp - 6200
545hp - 6300
533hp - 6400
526hp - 6500
532hp - 6600
10.25 compression
Edelbrock RPM gap
Tremec 600
I haven't weighed the car, but it's an LT-1 with Van Steel coil overs up front, and the rear is a composite spring. Weight is likely below 3000 lbs.
So, which header size? BTW, it was dynoed with a 1 3/4" stepped to 1 7/8" dyno headers. Right now, it has wimpy 1 5/8" Tri Y's. Not sure how much power is being killed with those.
Thanks!
12-20-2014, 05:40 AM
#22
Drifting
Whilst mine is a relatively 'mild' 489 big block - it was dyno'd on 2 1/8" ID headers (528hp/585ftlb @ 5850/3850rpm). I installed the engine in the car with the existing 1 7/8" headers. When I later installed 2 1/8" Super Comps and 3" diameter system the improvement in performance at higher rpm was really significant and surprising!