Superformance side pipes

[Perf. Eng. Eric]

We just tried a set of our new 3 inch I.D. stainless steel mufflers welded into a stock Superformance exhaust system. Early results on a stroked 351 W looked good on the torque( +27). The horsepower only went up around 10 on the first test, but the air fuel with the old mufflers was around 12.9 to 1, and with the new ones ,it jumped up to 14.6 to 1. The stock Superformance muffler is only around 2.250 on the I.D. We have allways felt on our higher H.P. motors, the pipes were a big factor on the H.P. loss from our engine dyno, to our chassis dyno. I think Tuesdays dyno results will be interesting. I will be changing jets and timming in the morning. I think the big blocks will really wake up with these new mufflers. When the testing is done ,we will re-ceramic coat the side pipes back to the original color, and the system will look stock. The mufflers are the same length and O.D. as the stock ones, so no one will know you have made the change. Oh, and the sound is much deeper, and I love it.

[Rodney]

We hope to see some power increase with our 3.5" ID straight through stainless tube with a cone insert as a muffler, might be a tad loud though. Good to see some good HP numbers!
Thanks

[RedBarchetta]

Would be VERY INTERESTED to learn what jet changes you ended up performing (carb type and size, and from jet size X to Y). Also any timing adjustments. I'm doing the same exact mod on a stroked 351W (RDI 392). Bought the mufflers from Stainless Specialties. There is a third SPF owner that has bought the same ones, too, and recently put them on (unless your customer is "Karl", then we are talking about the same car).

Thanks,

-Dean #747

[Zoom This]

Eric....do you plan on selling this new muffler system for SPF cars after you are done with testing??

[blykins]

Yeah, how much?

[RedBarchetta]

blykins, if the cores he used are the same ones that I had fabbed, they run about $160 each, plus shipping. You would then be on your own to have a local welder do the cuts and welds to "section" them in place of the factory glass (steel wool) packs.

I have a call in to my fab guy now. Once he confirms when he'll be back in his shop, then my pipes come off and I get him to work.

Here's a link to my original thread (hope it works). It has pics of the cores.
http://www.clubcobra.com/forums/show...123#post566123

[Dustin Mustangs]

Any more progress on these Eric? Final dyno numbers, price, availability, pics??



Very intrested....

[got snake?]

Originally posted by Rodney


with a cone insert as a muffler, might be a tad loud though. Good to see some good HP numbers!
Thanks

Can someone explain these cone inserts. How are they different/better then the standard steel wool stuff. And how do I get them?

Sid

[Perf. Eng. Eric]

I am done with the pipes . I will post the dyno numbers over the weekend. I have been very busy getting our Cobras done, and have not had time to get on the net for the last couple of days. The price will be around 1000.00 to 1200.00 depending on the color. Sorry it is taking so long. So many Cobras,so little time!

[SPF1061]

Hey Eric -
Re: pricing = $1000 to $1200

1. Is this just for the muffler insert or the complete sidpipe?
2.Is this each or per pair?

Thanks,
Steve

[RedBarchetta]

Eric, are these the same cores I bought from Stainless Specialties? BTW, dropped my pipes off at the local Jet-Hot coat facility yesterday. Will have a full pictoral of the fab work later tonight on CC.

-Dean #747

[Dustin Mustangs]

Originally posted by Perf. Eng. Eric


I am done with the pipes . I will post the dyno numbers over the weekend.

I for one would appreciate it if you posted the before and after graphs rather then just the peak numbers so we can see where power is lost or gained throughout the entire powerband. Some more info on the test engine/vehicle would be great also.

I'm certainly looking forward to the results!

[Perf. Eng. Eric]

I will try to post the graphs on Saturday or Sunday. Here are the peak numbers. Fist run with original stock mufflers. HP 431 and torqe 417. After the new mufflers were installed, and we re-jetted to get the air fuel back to the original settings. HP 451 and torque 435. This is on a 408 windsor with AFR 205 heads and a victor jr intake manifold. 825 carb. and a hydralic roller with around .600 lift. RedBarchetta, I think our muffler is almost the same as the muffler you are talking about. Hope this helps.

[Perf. Eng. Eric]

SPF 1061, The posted price will be for an exchange of a complete set of side pipes, with new mounting brackets and hardware.

[RedBarchetta]

Eric,

Thanks for posting the dyno numbers. Some may argue that the 20HP increase is not a lot considering the cost outlay, but it's a combination of the factory mufflers and the headers that really rob the power on a Superformance. I will probably tackle the headers next year (there are offerings out there that smooth the bends exiting the exhaust ports). Or I might just take my old ones to Alex and tell him "Here, improve these, will ya?!?"

I posted my fabrication shots in my previous thread...take a look when you get a moment.

-Dean

P.S. The I.D. on my stock Superformance mufflers was 2.0" exactly. Are you working on a new model...perhaps they increased the I.D. slightly since more and more owners are installing big blocks now?

[JAM1775]

Eric.......Great results.
Could you advise what jets the 825 carb was running before & after to get your motors AF down from 14.6 to the 12's ??

[bremillard]

Originally posted by Rodney


We hope to see some power increase with our 3.5" ID straight through stainless tube with a cone insert as a muffler, might be a tad loud though. Good to see some good HP numbers!
Thanks

This is what I did but I also used a baffle besides the cone. You are correct in thinking they will be loud. Mine, with the cones and baffles, are LOUD. -Bob

[Dustin Mustangs]

No graphs yet?