To me, a $200 part that fixes a $100 problem is not "cheap".

 

It's only $200 if you go the electric route; I've got a bolt on plate and spent $45 at my local exhaust shop.

 

Hooker LT's, Hooker Y-pipe, Borla catback. Made 420 RWHP N/A, planning on 600+ after the supercharger is installed in about 2 weeks.

 

I don't know why you think the gmmg is restrictive. On motor back to back i went 343 with the cut out closed to 344 with it open. I did pick up about 10rwhp down low but it narrowed down to only 1hp to the tire i picked up by opening up the cut out. On gas i have layed down 489 through the gmmg on a 150 shot.

 

I can't see how the 4 inch system is 200 pounds more than your current system or even 200 pounds total. I have access to a 4 inch system with a Flowmaster muffler and I'll weigh it when I get a chance. Hey... your engine is going to make enough power anyway. Who cares about weight?

Also... I cannot see how removing the Spintech or Flowmaster muffler is going to free up 30 to 40 rwhp.

Maybe the next time my car goes on the dyno, I'll take off the muffler and see for myself. But with 770 rwhp, I am content with what I have.

 

Well I've already explained how my friend's 3rd gen gained a consistent 3 mph by removing his 4" spin-tech.

My personal experience with FlowsMasher: I had a 3rd Gen Firebird with a 360 cid SBC (4.040 x 3.50) with AFR 210 heads, 8.5/1 compression, GM 847 cam (234/242 HR), Victor Jr. intake, Holley 750, and SLP 1 3/4" shorties, no cat, and a 3" cat-back with a 2 chamber Slowmaster. I was hoping for low 12's at 112+, but only got low 13's. After changing the headers and torque converter, I still barely broke into the 12.90's at 108. One day at the dyno, I decided to unhook the exhaust. To my surprise, the power went from 310 through the exhaust to 345 rwhp open. I then installed an SLP muffler (straight through design) and made 350 rwhp. The next trip to the track verified the gain because it ran consistent 12.20's at 113.

Mike

 

You say consistant? I'd like to see all of the information on the runs to prove that claim as 3 mph on the track could be attributed to a number of things. I'm not trying to start an internet battle by any means.

I can see the gain on the 2 series to the straight through SLP.

But we all have to make a compromise. We can be driving around on the street without a muffler (unless you are a redneck) just to pick up some horsepower.

I like the look of the dual outlet Spintech and until someone makes another muffler like it that provides more horsepower, I'll stick with it.

 

We made 3 passes with a cool-down and minor adjustment between each one. The range was 116.6 to 117.3 mph. Then, we removed the 4" Spintech, but left the pipe going over the axle. The next 2 passes were 119.8 and 120.2

But 40 rwhp on a 350 rwhp combo is a bit extreme. 2 performance mufflers shouldn't be that far apart.

Point taken, but some mufflers are WAY better than others. Like I said, removing my 3" Aerochamber off of my old 550 rwhp combo only net'ed 5 rwhp.

What are the inlet and outlet sizes?

Mike

 

I'm with Engineermike on this, for high horsepower apps, use a "straight-through" muffler, no chambered mufflers. Straight throughs such as Borla XR-1, "bullets", etc. should work best.

 

Good information. Way to back up your results with facts. I would like to see how much would be gained on my car.
388 with 22 psi and no muffler.

The Spintech muffler has a 4 inch inlet and dual 3 inch outlets.

 

Check this one out:

http://www.magnaflow.com/02product/s...ne=main&id=491

$136 from Summit.

It's a straight-through design also + stainless steel.

Mike

 

Nice muffler, but the outlets are on the same side. I don't like the "2 on the left" look.

 

You sure are picky. . .

 

Yep.

 

I am thinking about a 3.5 setup Y-pipe stopping at the Axle with a small turn down running a Borla XR-1 muffler. I have a True duel X pipe setup 2.5inch running 2 Bullets right now.