ponyman

So there, as expect, is usually a lot of discussion on both here and other Mustang forums about X vs. H pipes, etc. And everyone has there opinions and beliefs, but it mainly revovles around off-road systems...well what about those of us that have to go through emissions controls (not CA standards, but emissions none the less)?

So what are some options for H-pipes that have high-flow cats??? And for that matter, I know Bassani has a high-flow cat for there X-pipe, but does anyone else?

spyder7724

muscle mustang and fast ford magazine did an install of the bassani shorties, catted x pipe and axle back system and i found that the results were disgusting. i think they only picked up 10-15 hp and spent $1500+!!!! lidio iacobelli (alternative auto)did the same test with the complete mac system and only picked up 8hp! neither of these tests used a true long tube header so that is why the gains are so small. if you seriously want power and to stay legal try jba they may offer a catted x or h pipe for their long tubes. i know hooker doesn't i asked them. ford did a hell of a job on the exhaust for this car. the stock cats flow great and i would have kept mine on if they had fit with the l/t's.

gt6974a

Well, I'm hoping with the tune turning off the 02 sensors I won't get caught. But if I do I'll just put the stock back on.

That's why I ordered an O/R H-pipe and kept my stock pipe. I'll just put it back on if I have to. We have pretty strict emissions here in Atlanta, every damn year but I wouldn't sweat it. just keep your old H-pipe.

hawgman

JBA does make a catted H-pipe for longtubes
http://www.jbaheaders.com/05mustangnew.asp

2.5" H-pipe with cats PN# 6675SHC

Thump_rrr

I'm running the JBA Longtube headers and the 6675shc catted H-Pipe with great results.
I reduced my 1/4mi. time by 13/100ths on the last day of the season with a slipping clutch.
The problem with longtubes are that they're not C.A.R.B. legal but who checks anyway.
If HP is your only concern then I would go with a MAC Prochamber. It beats the H and X hands down.
An X-Pipe makes more HP than an H-Pipe but an H-Pipe sounds like a musclecar.

NewMexMustang

you might also want to check pypesexhaust.com

spyder7724

our emmisions here in MD must not be as strict. if the vehicle is obd2 they just plug in and check the ecm for codes. if the emmisions are out of range then it will pull a code. so far i haven't gotten any dtc's on this car from changing the exhaust. if it's older they do a sniffer test: you can always use the tricks that got me through with my pro street car... run the tank down to 2-3 gallons put about 10 bottles of dry gas(heet or gas line antifreeze will do) unplug the pcv and crankcase breather tubes from the air inlet and don't plug them so they actually leak vacuum and don't suck that dirty crap from the engine . get the engine as hot as possible before the test(if there is a wait let it run). this was the only way that car would pass since it had no converters and had 12.5:1comp a solid lifter cam and ran usually on vp or cam2. this most likely won't work on efi cars cause the vacuumleaks will send it into limp mode and f-up everything. the dry gas is definitly a must do though for a sniffer type test.