so i was thinking about doint just the up and down pipe but leaving the stock cat back in. what are some facts i should know and has anyone done it? does it sound good?

i remember that there can be an exhaust leak were the dp meets the catback, is there any solution other than new cat back?

thankx in advance.
-rebbaz

 

you get a lil power gain and a loud turbo spool (it will still sound stock, but i lil bit louder). . . you will be losing a lot of power if you dont run a aftermarket catback. there will most likely be a leak from the dp to catback if you dont put new gaskets in. my 2 cents is to just get a aftermarket catback thats quiet like a borla hush.

 

yeah, i guess thats the route then. is the sti catback kinda quiet, or quieter than the hush? that is considering the same factors on exhaust, yadda yadda...?

 

all stock components will sound quiet. The hush will be louder than the stock sti catback.

 

okay, thankx. and how about fitament with a stock sti cat back, does anyone know if there would be an exhaust leak between dp and cat back like there is on that of the wrx catback and aftermarket dp?

thankx for all the info.

 

You will get some great gains from those even with the stock cat-back. With those two pipes you will have deleted 3 cats. If you plan on getting the up-pipe done by someone it can get $$$. I say get a downpipe and a cat-back if anything.

 

cool, thankx for the info.

 

Sorry for the hijack, but this question is along those lines. I'm picking up a crucial dp and race pipe to match my STi up pipe on my 2.0L WRX. What precautions should i take during the install? Will i get boost creep?

 

thats not true, the power gains from a catback are minimal....now if you are talking about leaving a stock catalytic converter in there, then yes the blocked airflow will reduce power.

 

i have up/dp, and was running a full 3" catback. im back on my stock exhaust now. the power loss is very minimal, only top-end seemed to have suffered a tiny bit. low end feels better!

 

Many people run the stealth back. i think its three inches back, up pipe down pipe to a stock axle back. do u get the loud turbo spool from the hks downpipe?

 

I'm going to run a 3inch dp to a 2.5inch opening. anyone know where i can get a high flow cat that will fit onto the stock exhaust?

 

good info, keep it comming, more hijacking is recomended if it comes with more info. yay!

 

the hks downpipe is not the best for a subie, because it blocks the wastegate just like the stock piece. I would just go with a bellmouth or divorce pipe.

 

up pipes are basically all the same, right? except for the flex section, not like the dp where there is a significant difference with the bell mouth and the actual diameter of piping, right?