Dyno results from Magnaflow R&D shows their catback makes 17 hp..
it was my truck. The Mag sounds big blockish, but nothing like a flowmaster. Chambered mufflers dont sound to good on a Lightning.

 

InS0mNiAc,

What I meant was, are tuners the only ones that have real answers?

We're all just trying to help out. I doubt that is what you meant. Peace...

 

Flying ****,
I know that I'm a real PITA. But... Any sound clips yet? LOL

 

I got my truck and started modding it before I knew about the boards. So, without any other L owners to warn me against them(like some do now), I had 2 40 series mufflers installed. imo they sound great. a good low end rumble and they are as loud as a mother fugger @ WOT. I didnt notice any loss of power but that is not dyno proven. I cant really compare the way my exhaust sounds to any others because I have not heard any aftermarket exhaust on an L (besides mine of course). Basically what I am saying is if I had to start over, I would go with flowmasters again.

 

By no means do I mean that the tuners have the only answers, what I am getting at is whenever I or anyone has asked the tuners about this subject they have not commented.

 

I have duel Flowmasters on my truck. No noticable difference in performance. Love the sound.

 

I dont know why anyone would buy exhaust for their L for lots of money(unless they were doing alot of motor work) Many dynos have proven that alot of these systems hurt and do not help.NO,I do not have anything to back this up at the moment but Ive been on these boards ALONG time....since 99.I re,member positivly someone dynoing Flowmasters and along with the dreaded drone at 2k rpm,you LOSE power.

I took off my muffler ran strait pipes in its place(along with the original remainder and tips) and sounds loud,mean,and I gained 2 tenths.

 

Holy chit, you have to wonder how Flowmaster stays in business.

 

Stay away from the Single dual in / dual out Flowmaster. I had it on my truck for one week and that's all it took. It sounded fine until you gave it 1/2 pedal or more. It sound like air rushing out of a broken air hose after that which is a sure sign of restriction. I could tell the power fell off in the upper rpm range. My truck was basically stock then.

I was one of the first people to use a Magnaflow because that is what the other muffler shop I used had in stock. It was a noticable difference in upper RPM power between the Flow and Magnaflow single mufflers.

The single Flowmaster flowed less than stock and the single Magnaflow flowed slightly more than stock which made it easy to tell the difference between the two.

If you must go with Flows then install dual mufflers.

 

has anybody dyno-tested? tuners???

 

t p

 

I tried the dual 40 series setup on mine first. Burnt them up in 2000 miles. Very restrictive. Wet floppy sound under full throttle. Basically..... they sucked. My fuel mileage went to 10.5 mpg, with the stock exhaust, I was getting 12 under the same driving conditions. I changed to Borla and then to the Silver Bullet, I now get an average of about 13.5 mpg.

For the guys that just have to have the Flowmaster sound, I wonder if you could have the pipes stepped up to 3 inches after the cats, and cut back on the restriction. It might be worth a try.

 

I promise ill do them tomorrow afternoon. Just shoot me another email for a reminder and ill take care of it.

 

why not just get the 1 chamber (10 series) flows. That what im gonna do.

 

bah you wimps. straight pipes all the way baby!!! getting one in a week or so..custom bent 100% stainless steel 2.5" tubing...

credit goes out to speeding bob and his friend from cincy