Hey guys. I got a 1995 Formula stock with bolt-ons....roller rockers, cold air, AFPR, gears etc. I just got the car and plan to do exhaust for this spring. My problem is I know 4" is too large for stock, but I have a 383 going in next year. So I dont wanna do 3" this yeard then do 4" next year. And I dont just wanna wait...coz. you know...Cars gotta sound good right???
Anyways. I plan on doing 4" Mufflex or Flowmaster. Anyone run these kits? any power LOSS on stock motor? How did they sound?
THANKS GUYS!!!

 

I have a 383 and I use 2.5" duals.

A 3.0" won't really be restrictive on a 383 either.

I would put my money elsewhere.

JMO.

 

Dude....2 1/2" duals flows more than 3". The motor thats going in my car made about 500 rear wheel hp...naturally aspirated. And the car its in had Dual 3". Its hardly going to cost me more to do 4" over 3". single 3" is too restrictive for that motor.

 

There are guys on this board with motors bigger than 396s using a 3" borla.

I have a friend who went from a 3" borla to a 4" mufflex and complained about the decrease in throttle response at low rpms.

 

you can do it...doesnt mean its meant to be done.

 

People usually run a 4-in catback with a big cubed, high boost motor. I am still running a 3-in ATR catback with my blown setup.

 

I went from a 3" Flowmaster to a 4" Mufflex and it was a GREAT move for me. The sound is much better and their was a (more than minor) hp increase, even on my near stock car (for now). Combined with my Hooker LT's I eat LS1's all day and sound a HECK of a lot better.

I respect Gripenfelter's posts on many things, but his sources are all wet when talking about this low-end power loss or whatever urban myth that is supposed to be..

GO WITH THE 4" MUFFLEX!! You will be glad you did!!

Patrick

 

Ya I heard sound clips on all the different exhaust notes. And I honestly think LT1 f-bodies sound horrible. But I heard one with 4" Mufflex and it sounded MINT!. I was overly worried about any loss on the stock mottor unless it was Major.

 

Then you have no worries. You will get nothing but increases. You will love it!

Patrick

 

Some people will state otherwise, but I've personally seen dyno's that have showed 4" Mufflex systems to NOT be overkill on stock or bolt-on LT1's/LS1's. The track #'s also backed this statement up. And the more horsepower you make, the more beneficial the 4" system will become. Do what you want but you'll be fine if you choose to go this route.

Mike

2002 M6 Z28

 

There a formula you can use to figure out which is more efficent, but hey, just dont sell your GTA.