SpeedRacer

I have a quick question. I am planning on buying an exhaust upgrade and have been going back and forth between buying a x-pipe w/ high flow cats or just buying the x-pipe piece that uses the existing stock cats. I have been reading on the forum that our cats are pretty much high flow from the factory, so would there be any advantage in replacing those? I am more looking for a little louder exhaust that looking for extra ponies, although a few extra ponies never hurt either. Any and all opinions/comments would be appreciated!! As a side note, the x-pipe combo that I am looking at is the SLP with high flow cats. I am currently running Flowmaster Axle Backs. I have thought about the pypes o/r h, but I want to stay as legal as possible.

don_w

Once you remove the stock cats, forget being "legal". It's like being pregnant... you either are or you're not.

TKEUofM

Go with the bassani x-pipe and their cats. You'll love the sound. Amazing difference.

STANG_IT

I'm gonna be welding in a set of 2.5 " ID 300 cell density Metallic Substrate Universal Catalytic Converters from Magnaflow to my off road x pipe. I've been running my FRPP stingers with an off road h pipe and I still get trumpeting. I'm hoping I'll like how they'll sound with the x pipe with the new high flow cats. If not, then I just wasted money yet again on exhaust.

RACING GT

Most people who have the High flow cats still have the trumpetting. Because they flow as much as straight pipe.

SpeedRacer

OK, so if I understand properly, if you replace the stock system with the high flow cat system, you will not be legal anymore? Will it still pass the emissions test? That is my major concern as I have never had anyone that is doing a smog cert actually crawl/look under any of my cars. Does anyone have/heard the x-pipe with the stock cats?Thanks for the feedback for far!!

STANG_IT

Well, you're legal to an extent. You're still running cats but they probably won't pass emissions.

SpeedRacer

Thanks for the info. It looks like I will have to go with the short x-pipe that connects to the stock cats in order to stay 50 state legal. Now it will be just deciding if I want to go with the Ford Racing version( I believe the Shelby Hertz and the GT500 are running it) or pony up the money and go with the Bassani version. Does anyone know if there is a sound difference between the x-pipes or do they all have pretty much the same sound?Thanks for the help.

don_w

In California, you don't need to worry about a smog test for 6 years. Since you have a 2006 car, you have until 2012.


http://www.smogcheck.ca.gov/StdPage....ck/doineed.htm

FireFighterHill

go with hi flow cats.

Error404

how much of a sound difference is there from stock H with stock cats, to an aftermarket X with aftermarket cats?

PIKE2244

I am wondering the same thing?

Mustang Buster

I installed the FRPP X-Pipe that is used on the GT-H, and I am very happy with it. The install was very easy, and the X-Pipe itself is available for $129 from FRPP dealers. I also ordered the axleback mufflers from the GT-H, (around $270 from FRPP dealers) but they are on back order until mid-September, but even with the stock exhaust, the X-Pipe made the exhaust note a little more agressive, but not offensive. Oh, and the X-Pipe that is used on the GT500 is different, it has more of an X chamber vs the X-pipe, so it is not the same as the one on the GT-H.

traffic142

If you are going to mod it that much, spend an additional 600 bucks and get a LT header set up.

SpeedRacer

Thanks for the info. By more agressive, I take it to mean louder? If so, then that is exactly what I am looking for(louder but not offensive) and without a big price either. Also, where you able to notice any performance gain?

WERKED 66

check out my post...this will help answer your questions........

http://forums.bradbarnett.net/showthread.php?t=51300

Mustang Buster

Yes, it is slightly louder, but there is no resonance or drone. Sound is a very subjective thing however, so it is very hard to quantify. I like it, as I thought the stock sound was pretty good, and the x-pipe just made it sound even better. The x-pipe is supposedly good for an additional 5hp, and it does feel a little quicker, but I am sure most of that is just because it sounds faster. I don't think anybody is going to be able to feel just a 5hp increase. I recommend it, and if it is good enough for Carol Shelby to use, then it is certainly good enough for me.

SlamMan02

so you wouldn't recommend going with an off road H pipe with FRPP Stingers?

Mustang Buster

No I wouldn't, because the power gains would be minimal, it won't be smog legal anymore, the Stingers have resonance at certain RPM's, and you may notice more fuel smell without the cats. I have been down that road with my last Corvette. I went with the 3" exhaust with x-pipe and no cats, and all of the above problems manifested themselves. It was not worth it in my opinion, but if you are looking to get every last bit of performance out of your exhaust it may be for you. That is why this time I am leaving the cats alone, and just replaced the H-Pipe with the X-Pipe, and have the slightly more aggressive GT-H mufflers on order, because they don't resonant. Good luck with whatever you choose