I currently have the 4" Mufflex system with the Flowmaster muffler. The car has run a best of:

60' 1.56
1/4 11.85
MPH 118

The motor is a 406 and winds up to about 7000.

Does anyone have experience with the 4" mufflers and would I see a gain/loss/no difference in performance switching from Flowmaster to Spintech or others?

I am looking to swap out directly from what I have and preferribly not fabricate anything. Also I am not interested in sound quality, only power.

Thanks!

 

Best performance would be achieved by a straight through style muffler like a Dynomax bullet muffler.

 

What flowmaster muffler? I know and seen a guy here with a 10 second fbody run the same exact times with duals and no muffler, and duals with flowmaster 40 series on it.

As long as you don't have like an 80 series on it, I doubt you're going to see any gains.

 

I have a friend with an 11 second car that runs 2 tenths faster with no exhaust than with mandrel bent 3" with 40 series flowmasters. It all depends on the car, in a single 4" application with a car that fast he needs a muffler that will flow quite a bit.

 

Though many people like the 40 sound, they don't flow very good.
I would say the flow through (Flowmaster Hushpower or other brand), but not sure if it comes in 4"

They do make a 30 series in 4" and if flows much better than the 40.
Also, 1 in 1 out flows better...

Rafael

 

I currently have the Flowmaster 30 series.

Thanks for the replies. With a race type muffler, not too sure either one will make more power but I figured I would throw the question out there.

 

what heads do you have on the 406? is your formula red?

 

Go to Dynomax's website and see the flow numbers and power potential of their mufflers. It really suprised me how little power some mufflers will support. Hooker aerochambers outflow flowmaster 40 series mufflers, and Dynomax super turbo mufflers flow similar to the hookers. Look how little power the super turbo muffler will support. 2 small case 3" mufflers only support 390 hp! I can tell you for a fact that on a car like that you need a single in single out straight through race type muffler. The single exhaust is fine, but you need something better than some piece of crap flowmaster on there. Go with a Dynomax ultra-flo or another similar muffler, I'll bet you drop a tenth or two.

 

[edit] Nevermind.

 

my car is blue and I have AFR 210 heads