What kind of power differences(at dyno or track) do you have had when you have replace Flowmaster muffler to some other brand at single 3" exhaust system?I'm asking becauce I have now 50 series Flowmaster at 3" single system without cat,and I'd like to know is it worth to change it to some other brand?

 

It depends a lot on the engine. 2 1/2" duals with high flow mufflers can actually support around 750 hp. Some backpressure can actually be a good thing, but not too much. If you like the sound i would keep it.

 

The results in HP order:
1.Flowtech Warlock (open) 374.2 hp/ 333.1 tq
2.Bassani Real Street 373.7 hp/ 333.8 tq
3.Hooker Maxflow 373.5 hp/ 333 tq
4.Borla XS 373.3 hp/ 332.6 tq
5.Magnaflow 372.8 / 332.5 tq
6.MAC 372.3 hp / 331.5 tq
7.Flowtech Afterburner 372.3 hp/ 330.1 tq
8.Hooker Aerochamber 372.1 hp/ 330.4 tq
9.Bassani 372 hp/ 333.5 tq
10.Spintech 371.6 hp/ 332.2 tq
11.Edelbrock Performer RPM 370.9 hp / 331.3 tq
12.Borla XR1 370 hp/ 334 tq
13.Flowtech Terminator 369.5 hp / 331.3 tq
14.Dynomax Ultra Flo 369.4 / 333.2 tq
15.Flowmaster 369.4 hp / 331.8 tq
16.Flowtech Warlock 366.3 hp / 325.3 tq
17.No muffs 365.2 hp / 330.1 tq

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http://www.ls1tech.com/forums/showthread.php?t=113572 this one too

 

doc221978:my current engine is ~400hp crank level,and I read that 3" pipe can support ~370hp with zero loss,so it's close at limit.

89formula350b2l:Thats good thread.Any ideas is that hp test made at duals,or singlepipe?If that test is made at dual's,then it make sense muffler flow cfm vs. horsepower.And if it is made at sigle pipe,then hp vs.flow doesn't match.

-Jari-

 

my experience with my bolt on L98 was this:

i had a flowmaster 80 series and it ran ok. I changed it out for a chambered tube by classic chambered...the powerstick its called and loved the sound but noticed very little at the track. maybe 10hp if that. hard to say since the weather difference could explain the .5mph difference

 

When my car still had the stock engine with just bolt ons, it ran pretty consistant 13.80's @ 97-98. At that time it had the Flowmaster Force II on it. I switched to a Hooker Aerochamber Catback (both the FM and HA were 3" pipe) and the car started running consistant 13.70's @ 99-100.

 

According to David Vizard at the 400 horsepower level you need an exhaust system that flows a minimum of 880 cfm. So if that is a single muffler it need to flow 880 cfm. If you have two mufflers they would need to flow 440 cfm each.

Here are some some things to help you out. On square inch of exhaust tubing will flow 115 cfm. You need 2.2 cfm per horsepower. If you have a muffler of the straight through design such as a Magnaflow or a Dynomax you can most likely figure out the cfm flow through it using the above formulas. Sometimes the cfm of the mufflers are published so you don't have to guess.

 

The "1 thru 17" data came from a series of chassis dyno tests on a 5.0 'Stang, dual 3" mufflers, pipes to the side (not over axle and to rear bumper). "No muffs" was long tube headers open at the collector (no "torque tube").

 

Ok,that makes sense those numbers.
I have trying to find straighttrough muffler that has similar inlet and outlet pipe locations(3" offset inlet and opposite side of muffler 2x2.5" outlet) as my current 50 series Flowmaster(430512).Not find yet,any ideas which manufacturer has thatkind of muffler?

-Jari-

 

From www.summitracing.com , using 1990 350 as the search criteria:

MagnaFlow MPE-14267, $133.95
Hooker HOK-21729HKR, $85.95
Flowtech BIG-50363FLT, $59.95

I'm making arrangements to have a 3" single-in/-out MagnaFlow installed on the Camaro. I'm expecting quieter operation and quicker times. I'll let you know.

 

No meaning hijack this thread,but how many cfm does that Magnaflow #14267 flow(at 20.3"H2O)?
Also I be surpriced at Dynomax ultraflow #17227 flowcapasity(3"in 2x2.5"out crossflow).Dynomax catalog says 1400cfm (at 20.3"H2O preccure).Is there missprint at catalog or does it flow so much?

-Jari-