HotBox420

does anyone notice any significant power gains after they add an exhaust to the xb?

Buebie

Yes, but only after full exhaust to the cat. Not just the axle back. The oem mid pipe is only an inch in diameter. So an axle back wont do much if you keep the oem mid pipe in.
I would put in a high flow cat, but dont want to mess with the o2 sensor. I need to do header and downpipe and that should make it better.

HotBox420

After I put the 20's on, I noticed a significant loss of power from a dead stop, and much slower accelleration at low rpms, so im looking for more power. Any suggestions under $500?

HotBox420

i guess not

Jhhnn

The problem lies in the fact that the engine system is already pretty highly tuned and optimized for midrange and lowend torque. Mods to the exhaust and intake give some gains at the highend, often at the expense of the lowend, which is where you have a problem...

The same thing happens with 4WD vehicles and huge mudder tires, usually solved with compensating ratio gear sets in the diffs. Neither cheap nor easy, and likely not available for a scion...

Ghost_1

I don't suggest it but a lightweight crank pulley supposedly helped some people with oversized rims. do a search on lightened crank pulleys. Good luck.

RTon20s

95% of the exhaust systems out there for the xB are "axle-back." You'll probably see a 2-3 hp gain at best. Most of the exhausts out there are chosen for the style and sound more than anything.

The 5% available that are cat-back are from Magnaflow, Borla and Precision Muffler. These typically run from 1.5 to 2 times the price.

If you get an axle-back and want to replace the mid-pipe it is not a bad idea. Just remember, there is really no need to replace the cat. It flows just fine, and buying a "high flow cat" would really be a waste. Just remember is you have a custom mid-pipe fabricated at a local exhaust shop, have them add a resonator as well. The factory exhaust has a resonator, and keeping a resonator helps maintain a clean, lower tone.

Also, if you add a header in the future and good exhaust shop can also fab up a larger diameter down pipe. The only company that currently has a downpipe commercially available is Precision Muffler. Just keep in mind that if you buy one from them, you will still need to have it welded on. So you're probably looking at a trip to the muffler shop anyway.

HotBox420

thats helpful thanks

jones75254

The RSR GT2 is also a cat back

FDKxB

I'd say that Thermal has always been known in the import world for making some of the best performing exhausts. Fujiz.com has the Thermal catback exhaust for $490. Check into that one...I've heard it gives noticeable gains.