I think it really depends on the sti tranny. I believe the 04's required much less than 05+ sti 6 speeds. But I have heard rear end, possibly axles and driveshaft.
6 spd shifter and linkages driveshaft swap the ring and pinion in the r160 to a 3.90 or r180, hubs brakes and axles from an sti Mine was a jdm tranny so it didn't have dccd. If you want to use it on a usdm transmission you'll need a dccd controller. I went the r160 route if that breaks then I'll go with the r180.
So it will be easier to go jdm 6 speed? what version tranny will i need? I know the cryo treat gear set is good up to 400 hp but i will be pass that very soon. my 02 rex has the late model trans but we all know there still glass. I want to cover the trans issue before it comes apart some day.
I don't know how easy it will be to find a jdm tranny. I think I got lucky to find mine. Either way the install is the same with the exception of the dccd. I don't believe you need to hook it up to use the the USDM tranny.
from NASIOC What's involved with swapping from a 5MT to a 6MT? You will need to obtain and install the following components: 1. A complete 6MT transmission. 2. 6MT transmission mount. 3. 6MT shift knob, 6MT shifter linkage, and 6MT shift boot. 4. The drive shaft from a 6MT or the drive shaft from any model automatic transmission equipped Subaru. The stock WRX 5MT drive shaft may also be modified (will need to be shortened) to fit as well. 5. New rear end options: a. New ring and pinion gears to upgrade the stock WRX R160 rear differential to 3.90. b. Convert the 6MT center differential from 1.0:1 to 1.1:1 and use the stock WRX R160 rear differential. c. Swap out the stock WRX R160 rear differential to a stock STi R180 rear differential. The real decision to a 6MT swap is the rear differential, as going with the R180, though the "better" choice, raises the costs significantly as you need to use the entire rear end consisting of the STi driveshaft, STi rear half shafts, Sti rear hubs, and STi rear discs to include the Brembo brakes. This will also require the use of 17" wheels as well to accomidate the bigger brakes, which for some, may be an additional expense. As well, www.gearboxtech.com sells the parts that let you use R180 inner CV joints and the R160 outer CV joints if you want to use the R180 rear end and not swap over to the R180 hubs/brakes.
#2 may not be necessary. I have been using the stock wrx transmission mount for 6 months now. I am not saying its the best idea but it does fit and I have not had any problems.
Contact fourstarmotorsports or jdmspecc4u on nasioc. Jdmspecc4u was selling 6 speeds with the R160 R&P for like $3200 I think at one time.
damn that is really cheap! I have not seen one go for under 4k. Almost makes ya want to do the 6 speed instead of ppg's! Can you use the same front axels with the 6 speed or do those need to be swapped out? Tried looking on nabisco and seems their site is down...the whole thing right now, lol. Try back later and see what they got!
I take back my statement on the tranny mount. I now recommend using the 6 spd sti mount. I had to switch out my stock wrx mount for a group n sti mount today. It was causing fitment issues with the rotated kit. As far as price goes, I got my tranny, rear diff (converted r160) , balanced sti flywheel and rps 6 puck clutch, and shift linkages with everthing but the knob for 4k.
So nobody sells cryo treated 5-speed gears? A rebuild sounds easier, but I have never researched the subject.
So whats the point of going to the 6-speed? The top speed is the same. Most of the gears are shorter. Can't you just make it so the 5-speed is more durable by doing a rebuild to stronger gears? Not trying to change topic, just trying to understand the 6-speed swap.
If you are lucky you can do the 6 speed cheaper than the stronger gear set. As of now the only reputable gear set is the PPG's. PPG's will run you around $4500 installed. 6 speeds with the driveshaft, rear R&P and all can be had for around $3500.
Wow, good info. I did not know that. What does ppg stand for, I want to check their site out? Thanks.
the gears are "tighter" so you don't drop as many rpms when you up shift, thus keeping the car in it's powerband. Also, the 6-speed has a LSD front diff and better center diff.
Pfitzner Performance Gears, PPG is a great gearset from everything I have heard. My goal is more strength than anything in my decision to swap the tranny out. With a new LSD for the front you would be looking at $5500 frm the PPG set up and be good for an unknown HP (I say unknown because to date Andrewtech/gearboxtech has not had a broken set by a customer in theory). Now with the 6 speed you have a transmission that is a little better designed from what I understand...it has a different case design that is no loonger prone to case flex, it has a built in LSD, the gears are pretty dang strong and can survive quite a bit from what I gather, and they have a better lubrication system that adds a fluid pump (Vs the WRX's splash system). In theory you could make a Sti tranny stronger and more reliable than the WRX tranny, but the only currently available gearsets made aftermarket for the Sti is a 1-4 dog engagement set up from ppg. I miss anything? Edit: One downside to the Sti's 6 speed is that for drag racing the 6 gears means more shifts= more time=slower et's. For that reason a lot of drag cars actually go with the 5 speed built.
The new gear ratios for the 07 6 spds are much friendlier for drag racers. If the new gears will fit in the 02 jdm 6 spd case I will be switching mine out.
Also I was told the 07 gears are only different for 2,3, and 4 gear. Same source told me those gears were only $180 which is cheap but I dunno if I believe that.
So it seems that a gruppe-s ra gear set will be the easy fix for the tranny issue? Can the ra gear set put up with 400-500 whp on a every day driver?
probably not but who knows...http://forums.nasioc.com/forums/showthread.php?t=1097052 $3317 + shipping in current exchange pricing.
I was told 350-400 for this set, I would assume the cryo treating will help a bit as well as it sure did in the military. I am sitting just under 350 myself and have not had a problem with this gearset. I would like to find out if any one has ever broken a RA gearset...SS said he heard they were unbreakable.
look through the posts on nasioc....there are quite a few that have broken the RA set. Supposedly the manufacturing process for the RA gears has changed as has the manufacturer (yeah it was outsourced) and they are no longer shot peened and heat treated like they used to be. The cryo is still in debate as to the real gain in strength on these. The only real difference that has been seen on these (big debate still) is a small percentage thicker at the base of the tooth than 03+ wrx regular gears. I guess it is really if you want to go with a sure thing or gamble on them.
You're asking the wrong question. Hp doesn't break gears....tq does the damage. More specifically how you apply that tq breaks stuff. Anyways anything over 350 ft/lb tq is not recommended for the RA set. You start pushing them there. That being said many people with 400 tq/hp still ride on the RA's. I say if you are still concerned....heh better go ahead and get six speed or PPG's.