X-pipe or Straight pipe?

[USAF]

Originally Posted by IM6

Hi Guess55: did you gut yuor cats or bought catless headers from Evolve? did you notice any turbulence with out cats, droning? and whats the performance difference? torque? etc

I bet your fuel economy has increased since its running richer.

regards

Running "richer" will actually decrease fuel economy but these cars will adjust to the decrease in backpressure and optimize air to fuel ratio. Fuel economy will increase due to the decreased backpressure and any decrease in backpressure is always a good thing. It is nothing but a "wives tale" that you need some backpressure. If sound was no object, the ideal exhaust system for the most HP/torque would be about a 3 foot long piece of straight pipe after the header collector.

[guess55]

Originally Posted by IM6

Hi Guess55: did you gut yuor cats or bought catless headers from Evolve? did you notice any turbulence with out cats, droning? and whats the performance difference? torque? etc

I bet your fuel economy has increased since its running richer.

regards

yes i changed headers to evolve tublar headers without cat, you can see the dyno char
evolve tublar header dyno today with evolve ecu tune

it has ecu tune, and all other mods too. torque increase from low end all the way to top but more much stronger after 4k rpm.
fuel economy, the mpg average from 14.6 to 14.7 but i dont think it is from headers.

[IM6]

yeah sorry I meant Fuel Eco getting worse.

Originally Posted by USAF

Running "richer" will actually decrease fuel economy but these cars will adjust to the decrease in backpressure and optimize air to fuel ratio. Fuel economy will increase due to the decreased backpressure and any decrease in backpressure is always a good thing. It is nothing but a "wives tale" that you need some backpressure. If sound was no object, the ideal exhaust system for the most HP/torque would be about a 3 foot long piece of straight pipe after the header collector.

[waleed_wales]

my xpipe is the only mod i got on my car and i think there is a difference (performance wise) from stock application. i did upload some vids overhere on one of these X-H pipe debate threads.

btw nice hearing ur back home USAF, hopefully ur next tour will be to the 380th Expeditionary . been working together with them for years and have to say great ppl and very cooperative. enjoy your beast while ur home

[guess55]

Originally Posted by USAF

Yep, I'm changing right now. Gutted one primary cat last night and will gut the other today. Am running the Magnaflow X-Pipe and then these two mufflers: MagnaFlow Exhaust Products - For Trucks, Suv's, American Muscle, Diesel, & Sport Compact Vehicles

Was going to replace my current Magnaflow X Muffler with the Dynomax X-Flo Muffler I already bought but it wouldn't fit in the exhaust system tunnel. The Magnaflow has reflective chambers inside and the Dynomax has a straight-through design which would probably give less back pressure. Went to my local muffler place and we couldn't get it inside the tunnel anywhere along the length of the car. So now I'm going to the X-Pipe and 2 separate straight through mufflers.

Will be loading my Evolve-R tune this week which will also remove the "increased emissions" light on the dash due to the gutted primary cats. I'll get pics loaded once I get the new exhaust system on this week.

what do you think if move the Magnaflow all the way to the end of exhaust system tunnel will reduce the back pressure?

[e///Mpower]

Originally Posted by Lummox

It didn't make it much louder at idle, although it's beautiful note comes alive as you raise the RPM's. It doesn't come close to being as loud as some of the F1 exhaust systems.

How loud would you say it is compared to the Eisenmann Race Exhaust?