BrokeSolid

Is there fitment issues with any of the 3 axle options and a 4" system like the sinister.

I'm planning to buy the exhaust before the axle, so I won't be able to send it back if it doesn't fit. It also doesn't sound like this is that popular of an exhaust system, so I might be shooting in the dark.

American Psycho

Isn't that from Hawks Third Gen? I would call them.

Once I installed the 9inch rear; my GMMG catback wouldn't sit properly and it rubbed over the Axel. I had to wrap that area in header wrap, cut, and reweld the right tail pipe so it looked normal coming out the back.

stealth355tpi

Not sure how close their system is to the mufflex 4in, but I'm running theirs with a 12bolt and lowered with bmr springs without any issues.

11z71

iTrader: (10)

I run a mufflex 4 inch cat back with a Strange S60 and it's close, but it doesn't hit.

Paul Bell

iTrader: (9)

4 inch cat back is a waste. And not worth the clearance issues.

99Bluz28

iTrader: (35)

Yes, you'll have less clearance than with a smaller 3" diameter pipes, but if the pipes are properly adjusted, and the hanger bushings don't have excessive wear there should be no issues. IMO a poorly adjusted 3" exhaust can have clearance issues to. The only difference is that a 3" exhaust is easier setup for the novice installer to avoid any possible issues.
As far as a 4" cat-back beings a waste, yes it would be if the engine is still using the stock exhaust manifolds instead of LT headers. Now if was using LT headers then it wouldn't be any more of a waste than a dual 3" exhaust, or a 3.5" single pipe exhaust compared to a 2.5" dual exhaust.

Paul Bell

iTrader: (9)

I had a 4" exhaust, installed by Mufflex in their shop in NJ. It was a mess. It hit everything. The rubber block they jammed between the pipe and the body fell out. The rear U-joint bashed the pipe. The muffler dropped off it's hangers. Shameful install and workmanship. Worst exhaust job ever.

A 3-1/2 inch cat back from say Magnaflow is plenty for just about any level of engine.

BrokeSolid

My car has some old hooker LT's on it now with custom true dual dumps that scrape all the time. I can't stand it the way it is. My car also has heads and cam so not going to install a 3" y pipe exhaust. I also would like the exhaust to exit out the back. I know cut outs are an option but I've put them down as my last resort because I like to fire and forget. I'm thinking about doing the tsp 1 7\8 LT's and y when I do the rest of the exhaust. I like the sinister better than mufflex and I can run my own muffler. Kooks is just way too much money. I do like stainless works 3.5 but if the sinister would work then I want to go that route.

Thanks for all the input guys!

99Bluz28

iTrader: (35)

Sorry to hear that, I didn't have any issues with the install or fitment of my 3.5" Mufflex . IMO, I would have been very upset to have it installed there at Mufflex if it had anything other than a perfect fit, especially since
they do all their own mandrel bend there to. So if you don't mind me asking what reason/s did they have for all the issues you had..?

Paul Bell

iTrader: (9)

I don't know. I didn't even notice the tails were crooked until I got home.

It's a small little shop, nothing special. Their website makes them look pretty good & big.

I mentioned my experience to show the reality of how difficult it is to properly fit a 4" exhaust.

stealth355tpi

I bought my mufflex used and literally threw the exhaust right on without any issues.

11z71

iTrader: (10)

Same here, believe me I had my doubts but figured it was worth a shot. It fit like a glove. I couldn't be happier with it.

KFC_Or_Bust

iTrader: (5)

Paul, you got your stuff installed by a shitbag shop, that doesn't mean a 4" exhaust won't fit.

My Trans Am has big exhaust from the front to the back and I have zero issues rubbing. 1 7/8" headers, 3" y, 4" merge and Hawk's 4" catback. Stock ride height. No scraping either, just a proper install by someone who knows what they're doing.

Paul Bell

iTrader: (9)

I would think that the 4" exhaust I had installed by the very company that came out with it and made the parts would've got it right.

Shitbag shop yes, it was Mufflex themselves.

Here's exactly how Mufflex installed it:

https://ls1tech.com/forums/generatio...l#post12081612