Well I am trying to decide if i should spend the extra dough on the mufflex 4" exhaust. What do u guys think? Here is my engine set-up:

406ci
10.5 compression
AFR 195cc heads
solid roller cam 242/248 5.71/.577 @ 0.50
Hooker LT's
T-56
12-bolt with 4.10's

In the very close future i am going to put a 150/175 shot of nitrous on it. Is the 4" going to be worth is to me? Or should i get one of the better 3" kits like that one that says it flows with-in 99.9% of a straight pipe? The car is a week-end car with some track duty too. But just for fun. thank you


Shawn


Edit: The 99.9% exhaust i am talking about is the ATR catback

 

From what I hear, that ATR catbacks are really nice. I was considering one myself but had never heard one before. The 4 inch flows really well and would suit your needs but I think that the 3 inch ATR would be just fine also. You could also consider a 3 1/2 inch catback also.

 

I saw the Mufflex 4" support over 1,000HP on a blown 383 in a 30th SS. When he removed the Mufflex to reduce weight, running only collector mufflers on the LT's, he saw no improvement in HP, as measured on the dyno. I also used the Mufflex 4" on my 800HP setup.

 

I am still lost as to what to do. I wish there was someone out that that went from a 3" to a 4" and has some sort of comparison. i know that the ATR is one of the best one u can get for a 3".

 

I vote for doing the 4" now instead of doing the 3" and wishing you had done the 4. I am getting ready to do a 4 on mine as my tuner says that the 3 is now limiting the potential of my setup.

 

My other question is is mufflex the only company that makes 4" exhausts for our cars?

 

They are the only ones that I have heard of. I know that Mufflex and Stainless Works also makes 3 1/2 inch systems, though the Stainless works is very expensive. I have heard the mufflex 4 inch system. A friend of mine had the Mufflex 4 inch with the Spintech dual 3 inch outlets on his built and blown 355 LT1 Z and it sounded really nice. I just don't know if it would really be worth it. He ended up switching his Mufflex for a Magnaflow 3 inch cat back because he wanted a stainless system and he had a cut-out installed. When we went to have it dyno tuned, after all the tuning was done, he ran it with the cut-out open and he didn't pick up any rear wheel HP for some reason. Also, his car was at 574 RWHP. Just food for thought, maybe it was a fluke.

 

The plot thickens............................

 

I would like to do a 4" set up. Just don't have the money right now. I would say yes on your set up...