Baselined my car today (just brought it a few weeks ago and run in a spec class).
Car has a LPE cold air with the ram air bottom piece, Lt4 knock, tb bypass, and gutted cat and flowmaster muffler welded in.
Also 3.73 gears so figure a little less power due to gearing.

As above
273rwhp 5,200rpm
313trq 4,000rpm (but within 5 trq from 2,300-4,000)

Makes me wonder why he put 3.73's in with this flat torque curve I might even change to 3.23's for road racing.

then we disconnected from gutted cat back. So wide open after cat.
286rwhp
329trq

so 14rwhp and 15trq at literally 2,000-6,000rpm.

Car was model of consistency as all similar setup runs were within 1rwhp.

So key is now cutout or better catback?? It was loud as hell open.

Also how much will headers really gain??
Y-Pipe doesn't look that bad so figure is there really 20rwhp above the cutout left in the headers??
I would go MAC's coated or ASM's.

 

If you have the cash-go with AS&M,if not, I have heard good and bad on the Macs.If ground clearance/emissions aren't a problem,go with the Hooker LT's.You will gain power with any of the 3 mentioned.

 

Now I debate if the best cost answer is a y-pipe with cut out or a y-pipe with random tech catback or something.
The key is headers need to be worth about 20rwhp or more over cutout for the $1k price installed.

 

Do you even have a catback now? It sounds like you just have a welded in muffler. Also what style Flowmaster? People always seem to rag on flowmasters around this site but half of them don't even have the catback setup. My intermidate pipe was way larger than the stock one not to mention it was mandrel bent, which would flow way better than stock. You could have the best flowing exhaust out there but if the pipe getting to it is holding back flow it really won't benefit you.

A cutout is always going to be a little better but not 14rwhp that sounds odd, some people swear by the cutout but I can't stand how it sounds. I had no exhaust after the cat for about 15min's while I took it for spin before I installed my exhaust, I thought it was horrible. Maybe if the car has a good lumpy cam and long tubes than it sounds good without an exhaust.

I'm getting mine dyno'd here in the next few weeks maybe I will try and disconnect it at the cat to see if it makes a big difference. I still wouldn't change my exhaust because nothing I have heard sounds any better than a flowmaster.

More or less, if you just want horsepower go with the cutout otherwise find an exhaust sound you like and buy that.

 

i have some friends that don't buy a cut-out, they just take off the muffler and tail pipes at the track. HP gain and less weight

 

CUTOUT is byfar the cheapest HP mod

 

If you don't mind the loudness go with a cutout, otherwise spend the extra for a catback. I had a cutout for a while and it was just too loud after I got headers, now I'm just running an SLP catback I picked up for $200 used.

 

Might do random tech catback and a borla y-pipe with a straight off road pipe instead of gutted cat.
Should get me to 290rwhp which isn't to bad for little money spent.

 

How loud is the loudmouth??
Is it much lighter than stock catback??

 

95blueformula:

Look at my sig. That AZ Header/RT cat and cat-back setup got me a SOLID .5/5mph in the 1/4. WELL worth it.