Superformance Exhaust

[FUNFER2]

I can make you a pair of highly polished 3.5" stainless steel exhaust from the header flange to the turn out. If you're interested, send me a PM or email. Guaranteed to make more HP/TQ than the stock exhaust. The muffler is louvered and can be turned away or inward for loud or more quiet. Both the collector and turn out slide neatly into the muffler for a clean and tight fit, there for the weld is very small. It's a "Kit" with extra long primaries to fit your application. They sound incredible.

http://www.youtube.com/user/427HISS

[wanab5150]

Kevin, mine are already in progress, but these are beautiful. For the others here near Sacramento can you give me a price for a pair with 3" mufflers like this for a Superformance?

[wanab5150]

I went to Stevens shop in Reno today and checked out both the 402 headers and a set of the older style that came off another car. I took some close-up photos to analyze.

I took the old used headers and separated the mass which is blocking the port and in Photoshop superimposed that mass inside the existing port of the header. I placed a 1/32' grid over the entire exhaust port. Not being a math whiz, I simply counted the square grids in the blocked mass and inside the open portion of the port, subtracted the blockage from the open port and came up with a 38% blockage over the 402 headers for the Roush/AFR heads.

If you look closely at the port in the old headers and VISUALLY move the burnt portion on the flange into the open port you will realize this is pretty accurate. And they told me I needed to redo Algebra in Summer school!!! Screw'em!

Taking into consideration that there is a huge blockage (over a third)and the fact that the spent gasses are rebounding off the blunt wall of the flange and having to compress over and over again trying to fight their way out, these older headers are suppressing loads of HP in your big inch motors.

Think of shooting a .45 round inside a 6'x6'x6' steel cube. It will ricochet over and over until it loses velocity…….or escapes. Thank God gasses compress, or the heads would have been blown into orbit as soon as it was fired up the first time.

I will say it again.....If you are running the old headers you might as well leave the 2 inch mufflers on your Superformance. The 3" mufflers may sound better but performance CAN'T really change much. If you have the 402 headers and the 2 inch mufflers it's like putting a golf ball in a garden hose! Bye Bye 100 ponies!

[greg schroeder]

Originally Posted by wanab5150

I went to Stevens shop in Reno today and checked out both the 402 headers and a set of the older style that came off another car. I took some close-up photos to analyze.

I took the old used headers and separated the mass which is blocking the port and in Photoshop superimposed that mass inside the existing port of the header. I placed a 1/32' grid over the entire exhaust port. Not being a math whiz, I simply counted the square grids in the blocked mass and inside the open portion of the port, subtracted the blockage from the open port and came up with a 38% blockage over the 402 headers for the Roush/AFR heads.

If you look closely at the port in the old headers and VISUALLY move the burnt portion on the flange into the open port you will realize this is pretty accurate. And they told me I needed to redo Algebra in Summer school!!! Screw'em!

Taking into consideration that there is a huge blockage (over a third)and the fact that the spent gasses are rebounding off the blunt wall of the flange and having to compress over and over again trying to fight their way out, these older headers are suppressing loads of HP in your big inch motors.

Think of shooting a .45 round inside a 6'x6'x6' steel cube. It will ricochet over and over until it loses velocity…….or escapes. Thank God gasses compress, or the heads would have been blown into orbit as soon as it was fired up the first time.

I will say it again.....If you are running the old headers you might as well leave the 2 inch mufflers on your Superformance. The 3" mufflers may sound better but performance CAN'T really change much. If you have the 402 headers and the 2 inch mufflers it's like putting a golf ball in a garden hose! Bye Bye 100 ponies!

Do you know the width and height of the inlet on the 402 header?

[Jim Vander Wal]

I have the FireFlyPermormance sidepipes mufflers with the 3" hole - real loud and the first set of SS headers, 2" tube built for AFR 225s. These are now being built with 1 7/8" primaries which is probably better for most small blocks unless you have big cubes and run high RPM.

Contact Ron Roberts
http://www.fireflyperformance.com/
Headers for SBF and other and sidepipes for all SPF MKIIIs

Not cheap but excellent products.

Jim
RDI AL-427w, AFR 225, Vic Jr., ProSystems

[wanab5150]

Originally Posted by greg schroeder

Do you know the width and height of the inlet on the 402 header?

No Greg I did not measure it. The shape of the 402 header is the same dome shape, and eyeballing it, it appears right on. You could dremmel a little around the inlet to clean them up, but comparing the two headers and the head, it's realllllly close if not perfect.

Email me at wanab5150@comcast.net and i will send you the new photos I took.
No one emailed me how to put them here when I asked so.......