mac10chap

[sm=icon_cheers.gif] haha, no prob man

dukenitro

I will second that. The factory cats flow extremely better than anything they have ever had before. Make sure you reflash properly cause these 05's will lean out ALOT when you flow more air.

fin1

A performance shop I work with dyno tested an 05 GT with an x-pipe and cat back exhaust replacement and the gain was less than 5 rwhp. Given the cost-to-hp gain, it was not worth it IMO.

mac10chap

i believe it with only the x-pipe and exhaust...now throw on some long tube headers and send it back to the dyno...those are actually the only thing behind the exhaust manifold that the new mustang didnt already come with from the factory

SMP

Hey did they retune after installing the new x and catS? or did they just put it on the dyno

fin1

I was told a tune was done after.

F1Fan

A cat back exhaust is just that, it retains the stock cats, simply cutting out the H-pipe to weld in an X-pipe won't make much of a HP difference but typically can improve an engine's torque curve. What brand and model parts were tested? Were the parts all from the same manufacturer or was it some kind of kit that was made up? Was it an exhaust system designed to work together? Did they re-tune the ECU with a canned program or did they custom tune the car on the dyno? Did they tune it at all? Your story while interesting is not very much help to those tring to figure out a setup that works.

In your comment it sounds like they used the stock cats cutting off the stock H-pipe and simply welding in some sort of X-pipe and hanging new cans out back. Based on this description it doesn't surprise me that they didn't see much of a power gain. If you told me that they replaced the stock catted H-pipe with an X-pipe and straight pipe with no cats and they saw no power I'd say their dyno test routines need to be reviewed.

The stock cats are not so much a restrictive design as just placed in a poor location that makes the pipes effectively necked down and the gases exiting the cats have to change directions immediately on exiting the cats, this is bad for flow. The new Magnaflow Tru-X pipe's OBDII compliant cats are located higher up and are slightly shorter to avoid the necking down of the pipe on exit from the cats. Basanni gets around this problem by locating the cats on the long part of the X-pipe under the car just before the X-pipe crossover. This design offers the advantage of allowing easy swaps to a straight through pipe to eliminate the cats completely but also kills your ground clearance. But given the flow of modern high flow or race cats this makes no real difference in power and the distance of the cats from the exhaust ports causes problems with the O2 sensors and ECU's OBDII programing. IMO Magnaflow's design is much better being so much closer to stock retaining all of the stock location O2 sensors with all of the advnatages of lower restriction and the added X-pipe torque advantage. This is why the Tru-X pipe will work better. I'll know more next week once I get it installed and tune it a bit before working it up on the chassis dyno a few weeks later.

F1Fan

Dave,

JBA told me the same thing when Icalled and asked about an X-pipe. Of course they would be happy to sell me one of their off-road H pipes if I wanted it installed. BUT, you gotta understand that JBA has a vested interest in this area as they develop and sell their own exhaust systems with great sucess.

JBA's reputation is sterling in the area of product knowledge and development of Ford products but they seem to have a conflict of interest here. They refused to sell or install the Magnaflow Tru-X pipe w/high flow cats to me even though they had agreed to and are a dealer! I think that JBA is going to be coming out with their own catted X-pipe and did not want to install a competitor's product. I'm just going to pick up a Tru-X pipe from Brother's Performance on the way back from San Diego or order it on-line if I'm too late on the way back.

I too was just about to jump to the Basanni X-pipe with race cats until I saw Maganflow's Tru-X pipe with high flow cats. It is a MUCH better design and will deliver more power AND avoid the OBDII check engine errors because the O2 sensors are in the stock locations with Magnaflow's OBDII compliant high flow cats! Magnaflow is the first to produce OBDII compliant cats on a solid X-pipe design for the '05 GT and I hear that Kook's Custom Headers will be using these X-pipes in their '05 GT header and X-pipe system too.

Before you jump on the Basanni train check out Magnaflow's Tru-X pipe with high flow cats. They should be worth the effort to research, they are just getting out in the supply chain now.

HTH

BradInFl

I am not worried about horsepower. I just like the sound of a nice exhaust system. I would like to just go with a axle- back kit when I get my car!