I've got a 2004 automatic GT with a UPR x pipe. today I had 40 series flows welded in and now it feels like I lost low end power. Top end it seems a little stronger, but it feels like I lost ALOT of low end. I didn't expect ANY power change from mufflers, just sound... but this sucks. Do you think it might be an exhaust leak? should i reset the ecu?
Got flowmasters, LOST power.
- Thread starter jas142
- Start date
Betrayer00GT
Member
Oh no, here we go again...
But seriously, I do not see how reseting the ECU could help.
I really think that this is in your head, tho. Sorry, but I do.
But seriously, I do not see how reseting the ECU could help.
I really think that this is in your head, tho. Sorry, but I do.
Teen'93stang5.0
Founding Member
ditto, you may have lose 2ftlbs or so by reducing backpressure significantly, my o/r h pipe did that and it was noticable only when i changed the mufflers
padge
New Member
Hows it sound? I've got Dynomax Ultraflows with an offroad X-pipe, but I'm kinda sick of the sound. They drone a lot around 2000 rpm.. which is weird because its a straight through muffler... How are the flows for droning with the X-pipe?
BigHairyMonkey
Founding Member
crazynorwegian
20+ Year Stangneter 
when I got my flows welded in, the installed one backwards. I didn't notice it till I got my side exhaust put in.
You may have lost low end. I have argued with many people on here that you do loose low end when installing flows and off road pipes. If you know your car and know how it drives you will feel it. I just simply put 4.10 gears in and it runs better than ever and sounds meaner than hell.
wms004
Founding Member
having a high flowing midpipe with mufflers that have some backpressure is a good combo to have gains in the high end without killing low end in my opinion. It would have less low end power with straight thru mufflers.Teen'93stang5.0 said:
Ryan02Stang
Active Member
kirkyg
Founding Member
You typically lose a little low end power when reducing backpressure. There shouldn't be much of a change in hp / tq curve if you just change mufflers. However, you might lose some lowend tq if you remove the cats.
kirkyg
kirkyg
I still have my stock H pipe but I got the AT catback installed last week. It felt to me that someone pulled the cork out of my stang's a$$...the car didn't seem to be nearly as strained in hard acceleration and it seemed like I could run the tach up a lot faster. One thing I did notice is that Saturday it was nice and the air was dry, the car was running awesome...Sunday, it was hot as hell and very humid, the car seemed really bogged down. Weather???
kirkyg
Founding Member
weather affects performance quite a bit from day to day. I love when the first big cold front comes through in the fall and things dry out after the front its like 15 hp just came out of nowhere 
kirkyg
kirkyg
Bierbelly lost 8rwhp (peak) from having those Flowmasters welded in. Shoot him a PM if you need the dyno specifics.
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