ready for the dyno

[mikiec]

Check out this thread over on ffcobra.

Gordon is building a cobra with a 180 degree exhaust system.

http://www.ffcobra.com/ubb/ultimateb...c;f=1;t=025698

Mike

[rdorman]

But I am not sure why. Sceptical about the expected 60 HP gain as well. I have never looked much into 180 headers except that I know what they are. It will be interesting to see if it is followed up by some hard numbers. Even so, I don't think I would do them in a Cobra but to each there own! Now in a GT40....................
Rick

[Bart Carter]

I would say that the extimated 60 HP is not due exclusively to the 180 degree design. It is also due to the overall design of the headers, stepped, primary diameters and lengths, etc.

Brodix Neal outlawed-from-NASCAR heads, 355 CID aluminum block. Was told peak HP is at 7500 RPM with 8000 RPM readline.

Dyno numbers next week.

[Bart Carter]

Dyno numbers are in. But they aren't the final numbers. Turns out that the dyno was used to ballpark the timing and jets and break-in the engine. After looking at the data it looks like the jets could go a couple sizes larger and less timing could be used. Seems the heads are so efficient that they want less timing. Find out something new every day. Final dyno tuning will be done on a chassis dyno.

Break-in numbers:

668 HP @ 6900 RPM, 532 Ft. Lbs. of torque - open headers.

10 HP and 10 Ft. Lbs. of torque loss through the mufflers. Talk about an efficient exhaust system.