BFK86

iTrader: (1)

Anyone ever done any back to back tests of a typical 3" Y pipe and catback setup on a 98-02 fbody versus a 3" true dual to the bumper (kooks, speed engineering or TSP)? Just curious how much of a restriction my Y pipe and magnaflow catback is. I've got an 02 formula with a 383, PRC 225s with 11:1 compression, BTR stage 3 NA cam, ported fast 102/NW 102 and ftp lid, 1 7/8" headers, TSP catless Y pipe and magnaflow catback. Made 440 through unlocked converter (4l60e and yank PT4000). I've wanted to change up the exhaust for a while but if there isn't much to gain with a true dual or 4" mufflex style, I'd prefer the quieter magnaflow catback.

99 Black Bird T/A

iTrader: (4)

Not exactly what you're asking about but in the ball park.

1) My 91 RS w/LS1 383 Stroker made 445whp through 3 inch Y pipe to SLP Dual/Dual cat back.

2) With the electric cut outs open off of rhe headers bypassing the Y pipe & catback but otherwise exactly the same, the car made 465 whp.

Hope that helps.

BFK86

iTrader: (1)

I've got a cutout in the I pipe but it's not an electric one so I never mess with it. I figured the restriction would be the 2 3/4" section after the Y pipe thats meant to hook up to a factory catback but thats a pretty impressive gain eitherway. I should have told my tuner to pop the cap off when he had it on the dyno to see what it would do.

Ls1Rx-7

iTrader: (4)

If you search you’ll find even tbe best y pipe (4” y to cutout then step down to 3”) setups fall far behind the x pipe true dual setup.

BFK86

iTrader: (1)

yeah I've always heard this..and i don't doubt it, but would just be nice if someone had any dyno numbers to share between 2 exhaust setups.

cujo18

I had the TSP Y-pipe on my 427 and switched to the SE true dual out to the rear, and it made 30hp more when i got it back on the dyno.

BFK86

iTrader: (1)

Nice, what kind of power was it making?

cujo18

544hp, 560tq on a mustang dyno

LilJayV10

iTrader: (39)

Engine Masters did a y pipe vs true dual episode several years ago that was pretty good.