race mufflers??

[JEFF69Z28]

which is the best?
flowmaster outlaw series or dynomax race mufflers? or some other brand.

[chevyfireball]

Best is open headers. I had to put flow masters on my 572 Camaro for a night meeting and it ran like shit.

[ARUSSELL]

When I have to run mufflers I have a set of Spin Tech

[mr950]

I run Dyno-max race magnums, only picked up 2 hundreths ,between mufflers on and open headers.Must flow pretty darn good! Mind you that was on a 10.1-1 compression BBC. I think the more compression, the better the motor will like open headders. I.M.O. under 12.5-1 compression, motors like some back pressure. These ar pretty quiet mufflers till wide open throtle, unlike them noisy Flowmasters

[russ67chevelle]

my homemade bullet mufflers with 1/2" perferated holes in a 3"pipe will be tested on and off car.taking car to chassis dyno on july 19.will keep info posted.....oh the engine is a 10.2:1 compression 572.286 296@ .050 .748" lift-i will take engine north of 7000 rpms :shock:

[shawnp]

Kooks make a killer muffler set up.

[radicalz]

I'm running the old style flowmasters....the originals...they have held up well...flowmasters work well...for racing

[71]

Flowmaster should be taken to court for false advertising. Worst perf. muffler on the market. I use magnaflow race mufflers on my chevelle. 4" straight through stainless mufflers w/ x pipe. 540 w/ 15:1 comp. and haven't been bothered by the cops yet on the street. At the track it runs the same with or without exhaust. Pay a little more now and be happy for years to come!

[OneBadGMC]

http://www.youtube.com/watch?v=QIz2bSo8ScY

Yeah, Flowmasters are junk. :roll: I'm only making about 1600 crank HP through 4.5" Top 10s (probably more than that given the issues on that pass).

[kwkracing]

Are you racing the truck again Gmc?

[mopar1968]

Dynomax, had a set for years now still great shape :!: :!:


''JUST MY TWO CENT'S WORTH''

[OneBadGMC]

Are you racing the truck again Gmc?

Nah, it's parked this year thanks to the economy. Just not enough spare cash to do it.

I did the NHRA chassis updates over the winter, which hosed my old exhaust, so the Flowmasters are now gone.

I'm in the process of building a set of front fender exit headers, with removable collectors, so I can swap them out with some of them junk Flowmaster collector mufflers. You know, those junk power robbers. :roll:

It's for sale here on RJ. http://www.racingjunk.com/category/28/Race_Trucks/post/1549027/1965-Blown-Alky-GMC-Cash-Talks-.html

I want out of racing. It was fun in my 20s, but now in my late 30s I'm getting lazy and life's priorities are changing. I want something that will run low 10s that I can hop into at a moments notice and go have fun with. Not something that takes a 3 man crew to run properly.

[kwkracing]

I always like that truck, thats a real good price, and i hear you, i am starting to feel the same way in life, my dragster is parked and i have a blown street car i can daily drive, its way more fun than having to go to the race track and having to "work" or race as its called.
hmmm...
38k
im thinkn.... lol

[CamBirdRacing]

Mufflers on a racecar is like having sex under the sheets.

[OneBadGMC]

Yeah, nothing like the 'great' sound of a 11 second bracket car with open exhaust... /barf.

[71]

https://www.fordmuscle.com/forums/all-ford-techboard/475567-flow-masters.html
Here's a link to a forum the Joe Sherman talks on. He is a very reputable engine builder and has some really good insight on dyno results with several different mufflers.

[71]

http://www.youtube.com/watch?v=QIz2bSo8ScY

Yeah, Flowmasters are junk. :roll: I'm only making about 1600 crank HP through 4.5" Top 10s (probably more than that given the issues on that pass).
Sounds like they work for you. Are those chambered or straight through? Also what kind of sound reduction do they give you? Also have you dyno'd with open headers in comparison?

[71]

Are you racing the truck again Gmc?

Nah, it's parked this year thanks to the economy. Just not enough spare cash to do it.

I did the NHRA chassis updates over the winter, which hosed my old exhaust, so the Flowmasters are now gone.

I'm in the process of building a set of front fender exit headers, with removable collectors, so I can swap them out with some of them junk Flowmaster collector mufflers. You know, those junk power robbers. :roll:

It's for sale here on RJ. http://www.racingjunk.com/category/28/Race_Trucks/post/1549027/1965-Blown-Alky-GMC-Cash-Talks-.html

I want out of racing. It was fun in my 20s, but now in my late 30s I'm getting lazy and life's priorities are changing. I want something that will run low 10s that I can hop into at a moments notice and go have fun with. Not something that takes a 3 man crew to run properly.
Calm down o touchy one! I've used flowmasters in the past and always had problems with the baffles ending up in the bottom of the case after a few years. Just seems to me the magnaflows have a little better design for longevity. everyone has their own opinions and I am just giving mine. Buy what you like, it's still a free country... I think.

[OneBadGMC]

Sounds like they work for you. Are those chambered or straight through? Also what kind of sound reduction do they give you? Also have you dyno'd with open headers in comparison?

They are chambered.

http://www.summitracing.com/parts/FLO-954540-10/?image=large

http://static.summitracing.com/global/images/prod/large/flo-954540-10_w.jpg

Huge sound reduction over straight pipe on my old blown 462.

462 8-71 With Mufflers: http://www.youtube.com/watch?v=i5v3Xu67QlY

462 8-71 Straight Pipe: http://www.youtube.com/watch?v=uPxqHQOJ3Xw

With or without mufflers, it ran 9.60s at 12 PSI at 3700 lbs. That was with a .648/.669 solid tappet cam and GM049 Oval Port Heads. This was 2 yrs before I had the chassis done. Motor was probably in the 1050-1100 HP range.

I should also mention that those were the 3-chamber 3.5" mufflers in the videos.

My 505 and 568 blower motors both used the 4.5" Top 10s as in the photo above.

No, I've not dyno'd it on an engine or rear wheel dyno with/without mufflers. The drag strip is the best comparison, in which case I saw no difference.

[OneBadGMC]

Flowmaster should be taken to court for false advertising. Worst perf. muffler on the market. I use magnaflow race mufflers on my chevelle. 4" straight through stainless mufflers w/ x pipe. 540 w/ 15:1 comp. and haven't been bothered by the cops yet on the street. At the track it runs the same with or without exhaust. Pay a little more now and be happy for years to come!

Calm down o touchy one! I've used flowmasters in the past and always had problems with the baffles ending up in the bottom of the case after a few years. Just seems to me the magnaflows have a little better design for longevity. everyone has their own opinions and I am just giving mine. Buy what you like, it's still a free country... I think.

If you got a junk set, then state that you did, or state your reasons for not liking them. Making generic statements like your original post doesn't lead to any credibility for yourself.

I've used the 4.5" set that I just sold last winter (due to chassis changes) for 10 yrs in a blown alky motor that was street driven. I can't think of any worse operating conditions other than salt water to test them in.

Did you call Flowmaster and ask them to inspect the mufflers you blew the baffles out of? Did they offer to help? Did they tell you to pack sand? What did your combo run with flowmasters versus open headers?

It's a free country... What's the point of bashing something without detailed information as to why you feel it's bad?

btw... I think all Dodge products are junk. /roll eyes Free country, right? /smirk

[71]

OK we all know dodges are junk, for the most part they all are. That's what makes them fun to modify! :)
Probably jumped a little hard on flowmaster right off the bat but I had 2 sets with baffle problems on a daily driven 71 chevy p.u. At the time I guess I was being dumb and never called them. I have sense called them and they say they have a 3 year warranty so they may have covered them, who knows. Just so you know the magnaflows do have a lifetime warranty and seem to be a better quality product in my opinion, mainly due to the stainless steel constuction. As far as times with and without mufflers, it is just a street truck and ran high 14's through the exhaust. Never ran it without. I did run some one chamber 3" flowmasters on my 68 camaro and it went from 10.80's open to 11.10's through the exhaust. It was just a little 383 pump gas motor so can't really compare that to 1600hp. Just trying to help out the post, not start a sarcastic typing war.

[OneBadGMC]

OK we all know dodges are junk, for the most part they all are. That's what makes them fun to modify! :)
Probably jumped a little hard on flowmaster right off the bat but I had 2 sets with baffle problems on a daily driven 71 chevy p.u. At the time I guess I was being dumb and never called them. I have sense called them and they say they have a 3 year warranty so they may have covered them, who knows. Just so you know the magnaflows do have a lifetime warranty and seem to be a better quality product in my opinion, mainly due to the stainless steel constuction. As far as times with and without mufflers, it is just a street truck and ran high 14's through the exhaust. Never ran it without. I did run some one chamber 3" flowmasters on my 68 camaro and it went from 10.80's open to 11.10's through the exhaust. It was just a little 383 pump gas motor so can't really compare that to 1600hp. Just trying to help out the post, not start a sarcastic typing war.

No war intended. 383 pump gas motor losing 2 tenths is good anecdotal evidence.

It beats the hell out of "flowmasters are junk and should be sued", as it provides your real life results, not some BS hype from a manufacturer or disgruntled customer.

8)

[JEFF69Z28]

Mufflers on a racecar is like having sex under the sheets.1 OF THE CLASSES I RUN REQUIRE YOU TO HAVE MUFFLERS.

[russ67chevelle]

funny azz analogy hahahhaa

[russ67chevelle]

got back from chassis dyno from this guys shop...

http://www.youtube.com/watch?v=_FdF0wgTikM

looks like my homemade jobbers made best of 625 hp@7000 rpms.best open headers run was 650@7000. thats on roughly a 800 hp 572.

on a 260 hit of nitrous it made 854@7000 thru mufflers with air fuel ratio ranging from 10 to 10.5 to 1

i realize i need to relieve pressure and not to dead head regulators even though my pump has a return right off it to fuel cell. when fuel pump is on with 6 pounds flowing fuel, not flowing its like 12 pounds thus telling with the rich condition on spray it wants a return line.......

final answer, 3% power loss with home made mufflers...not bad for 3" id 4" od bullet mufflers with half inch holes swiss cheesed in the 3" pipe.