Flowmaster Installed

rikhek · April 12, 2002

For what it's worth...had a Flowmaster 50 Series (not the SUV 50) installed yesterday with 3" in and dual 2.25" out dumping behind the rear wheels.

With this system I lost significant low end power. Used to easily break both the tires loose off the line pre-install. Now they don't even come close to breaking loose. Much slower out of the hole.

The loss is big enough that I'm thinking of throwing my stock system back on. Might have a Flowmaster for sale soon. Anyone have a better idea/comment?

P.S. Yes, I read the threads commenting on a loss of low end w/a Flowmaster before the install but didn't dream it would be as noticable as it is. Also, I don't think I've picked up anything in the mid or high range as a trade off for the low end loss.

chevy4x4trucks · April 12, 2002

I've got a similar set up, just a 40 series instead of 50 and I didn't feel any loss at low or high rpm's. It was about the same at the low end and at high rpm's it was more peppy than before. W/ the addition of the FIPK I really noticed a significant power increase.

Do they have something to stick in the pipe to create more backpressure? I thought I remembered reading something about that. I'd hate to see you waste all that money on an exhaust system that robs you of power.

Big Boy · April 12, 2002

Do you have an aftermarked air intake. I think the upgraded guzout works better with an upgraded guzin too.

rikhek · April 12, 2002

No aftermarket intake kit. I imagine it would help a little but if i went that route I feel like I'd be chasing to get back to where I started. ???

Rick

copper99z71 · April 14, 2002

just added new exhaust on my 02 1500hd w/6.0

installed a 2-1/2 magnaflow x-pipe then (2) 50 series flowmasters w/ 2-1/2" out the back w/3"" slash cuts.the sound is awesome, runs a lot better. has a deep sound,sounds good through the gears a little noisey in the cab. at 70mph little are no noise. I plan on spraying the bed soon, that will muffle the low end somewhat. I think the x-pipe made the difference.

LeeS · April 14, 2002

Just give your truck about 2 weeks and the computer will adjust to the Flowmaster system. Trust me I know I had the cats removed using O2 Simms and I had a FLowmaster 40 Series muffler with 3inch in and dual 2.25" outs. The pipes come out under my back bumper with 5inch tips. I had the same problem but after about 2 weeks it all came back. Just give it some time.!!!

SoCalZ71 · April 14, 2002

Have you tried resetting the computer by disconnecting the battery for about 20 minutes? I know that if you change your intake, its recommended you do so so maybe the same will be true for your exhaust.

TheScaryGuy · April 14, 2002

Honestly, I don't think you can feel the difference in torque/hp n such. Less you've timed yourself in some 0-60's.

The only way to know if you exhaust was a detriment is if it was dynoed.

just my .02

rikhek · April 16, 2002

I think my observation is a pretty good qualitative analysis of the before and after performance:

Before - easily spin both rear tires from a stop by pushing the accelerator to the floor.

After - not close to spinning both rear tires from a stop by pushing the accelerator to the floor.

My point being this is not a "feeling" but a "real" qualitative performance function which is not subjective.

BDBWTE · April 30, 2002

I had straight pipes on my 99 Silverado and I noticed a little loss in power at low-end. I also installed 305x70x16's on the truck so that has something to say from the power loss I don't know how you could have lost that much low end grunt.

Nick99Chevy · May 1, 2002

Just give your truck about 2 weeks and the computer will adjust to the Flowmaster system. Trust me I know I had the cats removed using O2 Simms and I had a FLowmaster 40 Series muffler with 3inch in and dual 2.25" outs. The pipes come out under my back bumper with 5inch tips. I had the same problem but after about 2 weeks it all came back. Just give it some time.!!!