Silver4.6

a little off topic, but correct me if I am wrong but stangtvert you wouldnt happen to be the old N02junkie are you? from a long while back?

andy98gt

Get the K&N Cold air and your talking 12. That is dyno droven 10 RWHP on a stock 4.6

03GTType

Hahahahahaha, yeah right... and put the K&N stickers on to give you another 5hp..

nanaki

tell that to my old K&N. i got like half that.

94Cbra

Flowmasters flow better than stock mufflers so how would you loose HP? Looks like you need some education too...

Results based on 5.0 Mustang Magazine December 2002 issue (page 55). The mule is a 1990 Coupe with 370 HP and easy 11 second potential. A number of 66 pulls were made to compile this information.

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

Sound Off in Quietest to Loudest (Decibels):

1.Borla XS, 80db at idle, 90db at 2,000 rpm, 110db at WOT.
2.Hooker Maxflow, 80db at idle, 90db at 2,000 rpm, 120db at WOT.
3.Magnaflow, 82db at idle, 91 at 2,000 rpm, 114db at WOT.
4.Flowmaster, 82db at idle, 93 at 2,000 rpm, 115db at WOT.
5.Flowtech Warlock, 83db at idle, 92 at 2,000 rpm, 112db at WOT.
6.Dynomax UltraFlo, 83db at idle, 94 at 2,000 rpm, 113db at WOT.
7.Borla XR1, 83db at idle, 96db at 2,000 rpm, 118db at WOT.
8.Bassani Street, 83db at idle, 96db at 2,000 rpm, 120db at WOT.
9.Edelbrock RPM, 84db at idle, 93db at 2,000 rpm, 118db at WOT.
10.Bassani Real Street, 84db at idle, 96db at 2,000 rpm, MAX. (120+db).
11.Flowtech Afterburner, 86db at idle, 94db at 2,000 rpm, 115db at WOT.
12.Flowtech Terminator, 86db at idle, 94db at 2,000 rpm, 119db at WOT.
13.Hooker Aerochamber, 87db at idle, 94db at 2,000 rpm, 114db at WOT.
14.SpinTech, 87db at idle, 97db at 2,000 rpm, 116db at WOT.
15.MAC, 87db at idle, 98db at 2,000 rpm, 119db at WOT.
16.No Muffler, 91db at idle, 103db at 2,000 rpm, MAX. (120+db).

Flowmasters made a peak HP of 369.4, the highest flowing muffler on the shoot out made (open Warlocks) 374.2 HP. Difference is 4.8 HP. If you think a muffler is going to make your HP then your sadly mistaken. Pick what you think sounds the best, all performance mufflers are quality units. If you wanna compare somthing, compare the price you paid for you exhaust and the price I paid for mine for equal performance. Dont go by advertisments, do some real research.

redass02gt

looks like flowbastards lost some power to me. although I could gain half a horse by lowering my window and farting backwards.

04BlueGT

Ah, but look at the torque. About where most others were.

Let's not forget that NO muffler has the lowest HP. If anything, the Flowmaster's don't generate the correct back pressure that engines require. Especially modern mod motors. Follow the science, not the hype, and never forget that louder does not mean faster.

Like 94Cbra said, get the sound you like. If you want HP, then you'll have to go with headers, an x-pipe, and the cat back. Don't just change the mufflers. Those factory pipes are not mandrel bent.