Muffler types and the effect on power

[hotrod 80]

I wanted to open a discussion about this . I currently have Flowmaster 80 series SUV mufflers with cutouts . My machinist told me i could pick up 2 numbers by swapping to a Borla XR1 . I have bought the muffler , but im worried about the noise level . I work on the truck at the house alot and dont want to be a menice to the neighbors . They tolerate alot already . Anyway mufflers and power , open discussion .

[GMR-PERFORMANCE]

Until you put it on a drum to test that its just another opinion in the sea of opinions.. Straight through is straight through very loud and you may gain HP however Tq most likely will drop or move to the right ( more rpm to have the same numbers) So that may in turn effect how the convertor is acting as well.

[Super73]

If your cut outs are before the muffler, who cares if the muffler looses you power.

I run my electric cut outs after the X-pipe but before the 3" turbo mufflers to keep it quiet. When I am racing or want it loud, open go the cut outs.

[hotrod 80]

Originally Posted by Super73

If your cut outs are before the muffler, who cares if the muffler looses you power.

I run my electric cut outs after the X-pipe but before the 3" turbo mufflers to keep it quiet. When I am racing or want it loud, open go the cut outs.

I run capped , He want the cutouts taken out and dyno tuno it to the XR1 's I dont care . I hate the open header sound anyway . I am busy down there driving and i want to hear what is going on . I do need the extra power as 6.80's wont allow me to run the new 6.50 index unless i put the plate on a timer . I also change to a 26" front tire for this weekend and i plan to uncork it and leave at 4500 on the 2 step . there are 3 really big 6.50 races before we go back to nhra bracket racing .

[regan wilson]

I used to have 4.5" Flowmasters on a 4.5" pipe. I went to a 5" Dynomax Bullet (welded) muffler. It helped mine and I cant remember how much. But anyhow my monster is probably quieter at idle than a hot small block with open headers at idle. I dont think the Borlas should be an issue with your concerns with your neighbors. Those have always been the quietest mufflers Ive ever heard at the dragstrip. You are like me I dont like open headers! I want to hear whats going on.

[hotrod 80]

I try to have as much fun as i can without being a menaic to socity .

While we are talking about sound . With my helmet on i can really hear the valve train . Helmet must muffle everything but the valvetrain noise .

Also thinking about having the pipe ran with an easy bend out the side . Like say a 45 to behind the cab , but in front of the caltracs vs being dumped under the truck . Everything from where the exhaust is dumped back is filthy from exhaust . Rear center , shock knobs , u joints . Need to stop by the coin op and pressure wash it underneath .

[GMR-PERFORMANCE]

hyd roller cam I cannot hear the valve train at all I run corked hookers...........





( thats funny) hooker mufflers that is.. I am not a fan of the sound but they do not drone.

[vin63]

My Super Gas car with Borla Shootouts many years ago. I tried on many different occasions running with and without the Borlas and saw no difference in incremental ETs nor MPH, even when running all out (no delay), which confirmed to me their claim of some of the most sound attenuation to highest flow ratio.

http://www.youtube.com/watch?v=jqCVYSnT2Hk&list=UU...

[GMR-PERFORMANCE]

Vin been awhile .. How are things ?? As do the mufflers drone ha ha .. I still am not happy with mine.

[hotrod 80]

Originally Posted by vin63

My Super Gas car with Borla Shootouts many years ago. I tried on many different occasions running with and without the Borlas and saw no difference in incremental ETs nor MPH, even when running all out (no delay), which confirmed to me their claim of some of the most sound attenuation to highest flow ratio.

http://www.youtube.com/watch?v=jqCVY...=share&index=6

This is the impression im under also .

[vin63]

I run the newer model ProXS Borlas on my truck, and they are a little nicer than the older Shootouts. The key to minimizing the in-cab noise (drone, etc.) is to mount the muffler as far back from the cab as possible, and isolate the exhaust/muffler with rubber/poly hangers.

Originally Posted by GMR-PERFORMANCE

Vin been awhile .. How are things ?? As do the mufflers drone ha ha .. I still am not happy with mine.

Good…how have you been? Sorry to hear about your mufflers. Where and how are they mounted?

[hotrod 80]

Was told to have the muffler around 18-24" from the collector and as short as possible after that . I want the pipe to exit out from under the cab similar to yours .

[vin63]

Originally Posted by hotrod 80

Was told to have the muffler around 18-24" from the collector and as short as possible after that . I want the pipe to exit out from under the cab similar to yours .

It'll be a little louder with the mufflers under the cab (one of the reasons newer cars have the muffler(s) mounted at the very back of the chassis these days).

I wanted to mount the mufflers behind the rear axle, but I have an under bed gas tank, and I hung my battery and air compressor to the outside of the frame at the very back. I did manage to position the muffler under the bed just behind the cab. It is quieter with my Pontiac than the Flowmasters the previous owner had mounted under the cab with a small block Chevy.

[BigSingleBoost]

One thing I have learned over the years is that straight threw mufflers "usually make more power. I gained 7rwhp on a dyno switching from 40 series flow master to a 24" 3"in 3"out straight threw manga flow. I've ran nothing else since.

[Wasted Income]

I hate mufflers that rob power. My borg-warner muffler adds about 200 hp

[BigSingleBoost]

Originally Posted by Wasted Income

I hate mufflers that rob power. My borg-warner muffler adds about 200 hp

I also prefer snails I've been cruising your build thread very impressive. I'm building a system for the truck I have now. it'll be my 4th turbo build.

[hotrod 80]

Finally got this done . Did see maybe .05 improvement . Biggest improvement was weight savings . I have been shaving weight lately in everyway I can

[moggey01]

Turn downs at the end of exhaust help noise some. Crossover pipe can help also. Hard to do with exhaust outside of the frame .
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