It is said by most WRX owners is to do the Uppipe first as their first mod. Then a boost controller (manual or electronic) then a downpipe. A manual boost controller (MBC) will run you $50. An electronic one would run you $300-$500. Electronic is better but if your gonna stick with the stock turbo for a while, then go for the manual boost controller. So back to your question, yes doing the uppipe and downpipe first would be a great idea. I highly suggest it. Now as for the stock muffler (axle-back) with a stock exhaust, it only robs about 2-5hp, it now discovered by Shiv from Vishnu, if you have a turboback exhaust with a stock muffler, it will rob you 15hp! Anyways I hope I could be of some help. Drive safe

Jason

 

Just like someone said before, he gets rid of one of your cats and it decreases your turbo lag big time. Also they said to do it first so the bolts wont seize. And for the person that asked about boost, no you dont need a boost controller if your not gonna tamper with the boost but seriously man, its so much better with a boost controller.

Jason

P.S. Screw warrenty. Fix your own car Think about it this way. If you break something, buy better one of it

 

the other advantage of doing the up-pipe is that the cat in the UP is like a big cork up stream of ur exhaust. so even if u remove the other two cat, u still have a bottleneck up front....so that's why u wanna get rid of it first.....just to re-iterate, u wanna do it early in ur car's life as bolt will freeze, i had a broken bolt when doing mine, pain in the (_|_).

shiv, over at vishnu did fine that the stock muffler robbed about 15whp, but that was comparing w/o the muffler. he was tuning a customer's car when he found that out....so yeah, that 15whp number is kinda high cuz it was also being tune, ecutek

if u're watching ur budget, the hks UP/DP combo is probably the cheapest u going to find, unless u wanna gut ur UP

stock boost could be anywhere between 13.6-14.7psi, that's the range i've notice on these message boards