LS1TECH - View Single Post - How much HP will a 4" mufflex with Flowmaster muffler support?

MBC Racing · 06-29-2009, 05:20 PM

I have been searching and can't find any results...... I have heard that the flowmaster used in the 4" mufflex flows like crap. Some reports of picking up 28 rwhp by switching to a borla xr-1 in place of the flowmaster???

I had it on my car and LOVED the way it sounded. I took it off due to being heavy and trying a true dual set up with bullets. Well, the duals are going on another car and I am contemplating putting the mufflex back on this car. It will be a 6.0L heads cam motor with A4 and SS4000 yank. Hoping for 450-470 rwhp.

Question is..... how much hp can the flowmaster muffler support effeciently?? Would I pick up 25 hp with a different muffler or another true dual setup??? I don't care about 5 rwhp... however 25rwhp is a BIG deal. Anybody have a before/after dyno result?

Thanks

06-29-2009, 05:20 PM	#1
MBC Racing Launching! Trader Rating: 2 Join Date: Jan 2002 Location: St. Charles, IL Posts: 250	How much HP will a 4" mufflex with Flowmaster muffler support? I have been searching and can't find any results...... I have heard that the flowmaster used in the 4" mufflex flows like crap. Some reports of picking up 28 rwhp by switching to a borla xr-1 in place of the flowmaster??? I had it on my car and LOVED the way it sounded. I took it off due to being heavy and trying a true dual set up with bullets. Well, the duals are going on another car and I am contemplating putting the mufflex back on this car. It will be a 6.0L heads cam motor with A4 and SS4000 yank. Hoping for 450-470 rwhp. Question is..... how much hp can the flowmaster muffler support effeciently?? Would I pick up 25 hp with a different muffler or another true dual setup??? I don't care about 5 rwhp... however 25rwhp is a BIG deal. Anybody have a before/after dyno result? Thanks __________________ 00' M6 Z28 (461 RWHP, 434 RWTQ) 11.37@121--KABOOOOM! Auto Cross car...Going back to A4 and 6.0L LQ9 with Heads/Cam will now be street/strip car! 00 SS A4 to M6 conversion AX/road racing Track Whore bolt on car..359 rwhp/357 rwtq w/ 108k miles!---Finially finished 06 GTO, 12.5@113 TR224 cam,hdrs,exhaust,CAI,Tune 95 Imp, 13.28@101 cam,hdrs,exhaust,3.73,CAI,Stall, Tune