I just swapped my Spintech for that Ultra-Flo PN# WLK-17538 muffler on my 4" Mufflex last weekend. Man let me tell you it's like night and day. I had to add more fuel at WOT. I used to have consistant 113-114 mph trap speed in the 1/4. I went to the track last weekend and ran a 11.64 @ 120 mph with a 1.68 60ft on the first pass, I added more fuel at WOT and backed it up with a 11.66 @ 122 mph with a 1.80 60ft. So all you guys thinking about getting a 4" mufflex don't buy it with a spintech or flowmaster. I have proof in my hand what the Ultra-Flo can do. And it sounds pretty good, not to loud but just right IMO. Never got a chance to run the bottle because pressure was to low. So both passes were made on motor. I'm going back this weekend for some bottle passes and I'll post those times.

 

I have seen it also. Me and my friends all replaiced our flows after I swaped out one set and picked up .3 tenths The rest had simular results.

 

I run 2 of these on my race car. Absolutely no restriction of any kind. Open headers I needed to put in ear plugs just to fire the car up. With these mufflers, I don't even need ear plugs going down the track. You can see one of them under the passenger door in my sig picture.

http://www.jegs.com/webapp/wcs/store...10002_74316_-1

 

anyone have any video or sound clips? I have the dynomax bullets, but they are a tad on the loud side to me.

 

i thought that would be hard to believe that spintech or even the flowmaster 4inch mufflers are THAT restrictive. 7mph in the 1/4 is like 60-70hp.....

 

AHHHH CRAP

 

i have the ultraflow too, its soooo unrestrictive it's incredible, i think it lowers the veloity of the exhaust so much its quiter? correct me if im wrong.... i just wanna kno

 

Well it's pretty quite until you hammer down on it. It's money well spent.

 

ive been preaching dynomax for years.
i have tried just about every muffler there is.
for noise and track times, you cannot beat a dynomax!

 

Hehehe. When I bought my Mufflex 3.5" catback system the only choices were the Spintech or the Slowmaster mufflers. I went with the Spintech because of the Slowmaster's reputation.

Anyways after looking at the Spintech I did not like how the air traveled through it and how much that thing weighed. Luckily Magnaflow came out with their very nice 3.5" straight through muffler so I was able to avoid the situation. The Magnaflow flows over 1100cfm which is good for 500 horsepower according to David Vizard's forumlas.

 

I have to say thats sounds pretty odd to me also, my car only loses
.015-.02 with my flowmaster on vs off - most of time at track I drop just the muffler and never lose more that .02 with it on.
I also run 4" mufflex. Car traps 125 ish with out and 123 with.
But I have been looking into swapping to another muffler though, maybe a lighter one with less restriction, but not much louder.

 

wow.. thats just incredible.. i get about the same mph to the 1/8th and your car just takes off.. btw, 122mph is good for near 11.2, maybe 11.1..

i just found my new mufflers.. my semi-crush bent 2.5 true duals aren't cuttin it anymore..

 

zz17iroc, you coming out to play tomorrow at the GaFBA shootout?