+11whp (compared to 2.25"), 3" s back exhaust
 

In preparation for cranking up the boost, I fabricated a 3" exhaust for my xA. It is not a full turbo-back but most likely consisdered a "s" back. When I do my new turbo set-up this winter, the new down pipe will complete the exhaust to a full 3".

Last week after I stayed late at work wrenching on the tC, I did a highway pull... I overboosted to 14psi:doh: The boost controller duty cycle was set to produce around 9psi. Luckily I had told Toan (our tuner) during the last tune to dramatically retard the timing and dump fuel at anything over 11psi. That saved my motor.

Lesson learned, a 3" exhaust dramatically improves efficiency on any turbo'd car even on low boost with a 1.5l!

We got my car on the dyno a few days later and just on wastegate, my car was producing numbers which were suprising. On our dyno the Greddy kit out of the box produces around 114-120whp, tuned with tc injectors usually 120-130whp. This is based on the cars we have had come through. Just on wastgate I punched through with 141whp, with previous 2.25" turbo-back exhaust on wastegate I was around 130whp.

If anyone in the area is interested, I can fabricate the same exhaust for them. I dont see us producing this exhaust because I don't see the demand for it. But we can offer to make it.:icon_biggrin:

Before the time attack on the 29th in NJ, we will finally be dropping in my built motor. I imagine that having a 3" exhaust will rely better results running higher boost. Right now signs are good because my car is actually experiencing boost creep, which is totally the opposite of what a Greddy boost curve usually portrays... usually it spikes and drops off toward redline. I will post the results of maxing out the Greddy kit. I imagine not being able to exceed 180whp, but we shall see.

you have a tc now? or is that just a typo?

but yeah, since the best turbo exhaust is no exhaust, than less restrictive bigger exhaust piping is always better. the real question is...are you able to live with it? been driving with 3 inch exhaust just under a year now, and i am just a spectacle everywhere i go. especially since i'm supercharged with a racing header.

where have you been by the way? haven't seen you at autocross, or at the scion show of champions! you shoulda been there, some other owners wanted to hear me rev the engine with the supercharger to see what it hears like, and when i told people to step back from behind my car, they laughed saying stuff like "what are you afraid a part is going to fly off?" well...i revved, they were blown away! friggan epically loud exhaust!

i can't wait for my turbo, so i imagine your xa has better exhaust tone than my tc.

not a typo, to clarify i meant our time attack tC.

I do many auto-x's, mostly NASA. I enjoy NASA auto-x's because you get a lot of runs and it is very organized. Plus they are on Sundays. CDC tends to fall on a saturday which is super busy at work. I only did 1 cdc this year and it was alright. Those tend to be really tiny coarses which you would think i like( because of the car i drive) lol, but i like the venues NASA picks better. They even use road coarses , circuitcross.

I usually kick some serious assage in auto-x, but I still like time attack so much more

alrighty then.

so when you say you can make another xa exhaust, do you have like a jigg saved so you can make it fairly quick?

thats how i got my exhaust, the shop i got it from had a jigg from an exhaust they did for another tc that let them quickly fabricate up another one for me.

yea the jig will be the customers Scion xA or xB :) But if requests become evident we can make a jig

While this might be off topic...I saw your car on I-66 today...you were going East (i was going west to manassas airport) around 5-6pm?

Looks real good at 65-70mph haha.

If it wasnt you...i don't know anyone else in this area with black rims and red stripe with your color paint.

I'm glad you did the 3inch exhaust to see if it did anything. Did you loose any bottom end? Glad to hear about the boost creep as well, that is what everyone likes to hear haha.

Have fun in NJ and spank some ho's

if it was Saturday it was probably me on the way home yes. Thank man, and i do plan to spank some hos.

to answer your other question, no bottom end power was lost. for the boost it was running there were only gains