for those who don't already know... i bought an '07 OBP STI friday, and traded in the prodrive 3 wrx. my initial thought was to transfer the prodrive exhaust over to the STI (as well as the coilovers) - what is the stock STI exhaust diameter? the prodrive setup is 2.5" my short to mid term power plan is this: stock turbo perrin tmic prodrive exhaust cobb ap w/ss tune my goal for the car is 350-375+ whp so, my question is this, how badly will the 2.5" hurt performance gains, and by how much (est)? i can't find a 3" prodrive setup, and i would really hate to get rid of it, but if i MUST get 3" then i'm going to be looking into perrin, any help would be appreciated
I don't think it'll really hurt you at all until you get into the turbo swap area, then you'll want a bigger pipe. Can't give you any numbers, sorry. Also, I don't think your coilovers will work with your sti unless you get new hub ears for them. Oh Yeah.... Congrats on the purchase!!!
Keep the stock TMIC. The muffler makes really no difference until you want over 400 WHP. we need to order your lower mounts for the Teins to fit...
SS chimed in on this topic here: http://www.wrxatlanta.com/forums/showthread.php?t=10106&highlight=prodrive+whp (search n00b )
i'm coming by today with my stock 04 wrx stuff. we can order the tein mounts then if that's cool. moose-thanks for the link
I am running the prodrive on the sti without any issues, as will said, you're not going to notice much of a draw to your power with the 2.5" muffler. In consideration of my ears, I even put the stock restonator piece back in. The car feels virtually no different, there's a little less flow so there's a little less hp going through but I could care less. I can drive on the highway without an annoying drone in my ears (ty invidia).
Looks great bro! Looks like a fun road to have it on as well. Noob question now though..... What are the differences in the 06 & 07?
thanks... when i asked scott if it was worth the extra money, he rattled off a bunch of stuff about gear ratios, injectors, turbo, more em control... he'd have to chime in on it i do know it has direct mp3 player hookup and the stock sound is pretty nice here's what i found on wikipedia... Rev. F/G (2006/2007) In 2007, a number of small changes were made to the US-spec model. Due to Subaru's decision to reduce costs by cutting the amount of aluminum used, the US-spec STI no longer receives the J-spec Spec C control arms. This decision reduces the wheelbase from 100" to 99.4", and the high caster angle is now reduced. The rear swaybar has decreased in size from 20mm to 19mm. The gear ratios of second, third and fourth gears have been made longer (higher ratio) in order to improve fuel economy and driveability, which inadvertently reduces 1/4 miles drag racing times due to the ability to trap 114 mph in 4th gear, without the shift to 5th. The EJ257's cylinder heads have been redesigned to improve cooling, and the sodium-filled exhaust valves have been dropped. The alternator is changed from a 90A rating to 110 amps. The rear LSD is now a Torsen unit, considered an upgrade over the previous model's helical unit. The turbo has also been changed to the VF43. It has a different wastegate opening, slightly larger compressor wheel than the VF39's wheel and more porting done to the exhaust housing. The side cowl braces are stiffer than the 2006MY. The engine mounts are once again the hard rubber mounts used prior to 2006. On the interior, there is an audio jack that replaces the ashtray, a rear center armrest with trunk pass-through and a 120W audio system
THere are several items incorrect on that entry. The 04 to 06 rear LSD was a MECHANICAL LSD....clutch plates were used. It was the worst excuse for a mechanical LSD on the planet. It did not work. Mid-way thru 06, the engine mount brackets were changed back to metal. The early ones had plastic brackets that broke under launch or hard shifting in lower gears. I have no real data on the heads, but...the 07 STi does get the Smog pump like the 06 WRX, Forester and the 07 Legacy. (All EJ257 turbo engines mind you) That unit in its self requires a change in the heads resulting in a new part number. Smog pump FTL. Top Feed injectors FTL. New turbo FTW!!!!!!!!!!!
i thought they were supposed to be side-feed injectors? what does the smog pump do to hurt performance?
Smog pump is an electrical item nowadays. Its not an 83 Ford V8. 04 to 06 were side feed. SUBARU keeps switching back and forth with top feed vs side feed. I imagine that in 4~6 more years, it'll be side feed again.
My mistake oh great one. That is why I said usually. Lots of modern vehicles still have them belt driven. I have seen 99's with them still belt driven.
you guys referring to the turbo? " The turbo has also been changed to the VF43. It has a different wastegate opening, slightly larger compressor wheel than the VF39's wheel and more porting done to the exhaust housing. " that's what i got off wiki, but there's very little data out there on the 43's.
Monk, what kind of sound system are you putting in this thing? I know you're gonna put something good.
i haven't even thought about sound yet lol, i'm trying to manage the cost of power/handling first the stock sti system sounds a LOT better than my old wrx stock system though
Of course it does, its STi I still have my prodrive, and I still love it. It would be nice to throw a different resonator piping in there to get a more throaty sound out of the car.
yeah i'm really trying to keep my prodrive setup, but scott wants me to lose the divorced downpipe, although the new turbo has a better wastegate that was changed speficically to combat spike/creep issues, so mabey i can still talk him into it.