header/collector size question

[aekrot]

359 CID Small Block Ford 4.100 x 3.400
AFR 225 heads (330/265 @.700")
8200 shift point, 8400 rpm redline
ProCharger F2 Reverse Rotation


What size header tubes, collector and bullet/turndowns would best match this combination?

I presently have 2" tubes into 3.5" collectors with merge spikes, into 6" long 3.5" bullets with 3.5" turn-downs.

Some told me that I should have at least 4" collectors, maybe 4.5". This person also suggested that I go with 2 - 2.250 step headers.

My goal is to get as close to the 1600 hp capacity of that blower that I can!

Alex Ekrot

[Trace Meyer]

i ran 2 1/8" to 2 1/4" with a 4" collector on my 358" sbf w/ f1r. it worked great.

[aekrot]

Thanks for your reply. The F-1R is good for about 1300 hp and your car appears to be getting real close to that depending on your weight ;)

In hindsight, I'm probably loosing HP having to 'push' the exhaust out instead of it scavenging - my trap speeds show this, while my early track performance is good. Also, it didn't seem to matter what I did WRT camshafts, the mph was always the same and the motor just stopped pulling hard around 8000.

I've also had trouble with headgaskets. I've mostly ran copper w/Oring/receiver latelly and always seems to get some leaking and I've tried a lot of different sealing procedures. Maybe I am heating up the heads more than I thought...

[Trace Meyer]

if your engine stops pulling you have a restriction some where. with the f1r i would run 170-171 and with the side slinger f2 177-178 at 3400lbs. not sure what the horsepower is.