anyone tried one? how well do they fit? rattles?
looking to put one on a 94 z28.

 

I ran the 4" Mufflex with Flowmaster race series when I had the blower. The sound was excellent. Sounded like a musclecar with turn downs underneath the car at idle and absolutely ripped at high rpm.

I also had the Mufflex 3" y-pipe. The whole thing hung about as low as the header collectors. My car is lowered and would hit the collectors, y-pipe and the 4" section under the car fairly regularly on our poor Michigan roads here.

One proposal to gain some clearance was to cut the collectors and angle them up at the floor boards slightly to get the entire system up higher. I never tried this but it I'm sure it would get you another 1.5" or so (I ran Hooker Longtubes).

So alot of the positioning will depend on the collector location and the y-pipe itself.

All in all, I liked the setup and could have gotten it tucked up tighter with some work - and that was on a lowered car.

hth,

-Scott.

 

A friend has one on his 440rwhp 396. He gains 1 HP with the cut-out open, so I guess it works pretty well. He is a shop manager and has all the dyno time he wants.

 

I ran with and without the Mufflex 4" catback (without, means with Borla XR1's on the collectors). No measureable difference in HP, at 800HP. A buddy of mine was pushing 1,125HP through the Mufflex 4". Removed it (Borla XR1's, as above) and saw no difference in HP. Did reduce wieght by 50#.

The Flow' has an annoying resonance at about 2,500rpm that will vibrate the interior of the car. But from the outside, it sounds pretty beefy.

 

i have the 4" catback with spintech muffler and hooker LT's, and to be honest, the ground clearance really sucks. I love the sound though. Nice and quiet at idle (not too quiet) but it sounds amazing at high RPMs and will scare the **** out of most people haha.

Also, i think the spintech sounds great 2500, as well as the rest of the RPMs

 

I've got their exhaust as well w/ the race series flow master. Love the sound of it too. Healthy is the best way can describe it. I don't have the 2500 resonance Fred speaks of either, mines a little lower in the rpm but last all of a 100 rpm's. Ground clearance...got more ground clearance than I ever expected and my car is lower than Sportline Eibach spring height. The I-pipe doesn't touch the frame anywhere either and I did nothing fancy to get that kind of clearance either, just put it on w/ the help of some friends and had to modify the DS exhaust hanger and that was it. It's a heavy SOB that's for sure. I can use the extra weight in the rear howerver.

 

I've installed many on many different cars, from an L98 '92 Z to an LS car. All of them sound great with the spintech. Everyone believe it or not didn't want the flowmaster, partly due to the sound, and in my experience flowed a little less. But they sound great, and fit really well (as well as can be expected from a sewer pipe exhaust). And as long as the car isn't too low you won't have an issue. If you're down about 2" expect to hit it over every little rock....