ok i have a dual custom exhaust but i recently purchased an 05 or 06 (cant remember) stock coupe exhaust and im wondering what you guys think...just put the oem back on...or leave my dual and have an xpipe custom welded?..if you look at my sig you can see what i got..i also have kinetix hfc and unorthodox pulley on the way...let me know what you guys think..by the way i want to gain my torque back w/out sacrificing too much up top power..thanks!

 

Can u really feel the low end power loss? I would say stay with true dual with X-pipe after the cats.

 

yup i can feel it

 

You have no cross-over pipe at all on your dual now? If not, then that is your main problem. Also, what pipe size do you have from the cats back?

 

can u describe how u did ur exhuast which u have right now?

 

Maybe a H pipe.

 

sorry forgot to mention that i do have an h pipe..but its rather small..just did it to help with the sound..and the pipe diameter is 2.25 if i remember correctly..basically where the ypipe used to combine after the two flex flanges..i got te oem exhaust cut there and then two pipes run to the back with 2 resonators and an h pipe through two magnaflow mufflers...i just want the most performance i can get and i feel that the dual exhaust is hurting me and ive heard that the oem is perfect if im not going FI..and plus that stock sound is so nice!...i also have one more question..after the hfc and pulley install and along with the other mods...will i still need an a/f tune if i use the stock exhaust??..thanks for all the help guys!

 

Whether its an X or an H, it should be located as close to the cats as possible to help pulse scavenge and flatten the torque curve. If you have your H way back at the entrance of the magnaflows = no good. Sounds like going back to OEM is the best deal for you now. With the headers and HFC, it should help maintain most of the low end and gain a bit up top. Re-Tune? Only a A/F measure on a dyno will tell for sure. Just give the ECU a week or so before the dyno to get itself adjusted to the new stuff.

 

The only true dual I thought yielded decent result was the borla and it had a H pipe I think. But if you already have HFC and headers you might want to keep the stock exhaust for backpressure and low end torque. It's hard to keep that balance between flow and backpressure...

 

On the 6 bangers - the X pipes work best. H pipes are really best for V8's. the sound change for x-pipes is also smoother on the v6 - H's tend to increase drone.

Magnaflow makes one of the best flowing x-pipes out here - so an easy weld on and dual balance control.

As far as the tune goes - you will need to adjust AF via dyno and piggy back. Once the CATS and headers go on, with a spacer, the car leans out more than normal and the curve in the high band leans out more as well. You want to shoot for a pretty flat 12.8 - 13 AF on the dyno to redline.

The 2 1/4 pipe should have retained your bottom end, but I'm concerned about the mix you have with the headers and CATS. You may have unmatched the system and really need 2 1/2" pipe for the catback - which is the optimal diameter for these cars.

Doing exhaust on these cars is not as simple as just cutting, tweaking mufflers in place and welding. These cars are very well refined and need systems that are designed and tuned to work properly for the best result to be achieved.


Rick

 

y pipe

 

The x-pipe works great in my car.

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^^^u have very nice setup.

 

i think im going back to oem and seeing how that works for me..i already bought it so might as well try it...but ill just keep my other set of mufflers and if i decide to go back ill use an x pipe as well as 2.5 piping..but im gonna get the other stuff installed first..thanks for all the help!

 

That's basically a copy of the Stillen...I did that a few times with different components too. It's real easy to make a much better system than Stillen did...

Rick