Cobra exhaust HELP!!!!

[Mike Drew]

Hi guys,

I just had a killer 427 built for my Contemporary Cobra. It made 565 hp and 597 ft/lbs on the dyno using their optimized exhaust system. I had them run it again with my standard Contemporary exhaust (427 S/C side pipes) and lost an even *100* horsepower!!!!!!

They then looked closely at the system, and found that the headers are fine, the collector is great, but then the glass pack muffler necks down to a measly two inches inside the great hulking pipe. They had two other sets of Cobra sidepipes in the shop, both of which utilized MUCH more efficient mufflers (spiral wound with a larger inner diameter) but for some reason they couldn't attach the pipes to my headers.

PLEASE let me know if you have any ideas as to what to do? I suppose if I could find a suitable insert, I could have my sidepipes cut open and new inserts installed. Failing that, does anybody have any recommendations for better sidepipes that I could buy? I would prefer to be able to use my existing header pipes, especially since the system is Jet-Hot coated...

Thanks!

[427Aggie]

There's not much you are going to be able to do unless you want to cut it. The easiest thing is to cut out the old muffler and get a new high flow one. There are people on here that have different ones and can recommend.

Matt

[maxrpm]

If you look in my gallery you can see how I removed the super-restrictive mufflers. I cut the collector & used a stainless band clamp to re-attach the new pipe which by the way is a 4"dia. diesel truck stack. You could attach any muffler you want or put baffles in the pipes. But what I like best is there's no 3-bolt collector. Works for me. I tried posting the pic. here but I can't figure how. With no other modifications my car picked up 4.5mph at the dragstrip, and I can re-attach those quiet muffs in no time...if for some odd reason I wanted.

[Mr.Fixit]

Find a decent muffler shop.
Have them cut out the middle section (where it gets fatter) of the sidepipe and replace it with a better muffler.