I drive a 02 WRX, I'm running a cold air intake with full exhaust kit. 3" all the way with catless up pipe, I also have the Cobb accessport v2. I would like to get some knowledge on short blocks and long blocks. I've been looking at some different options out there. I was considering a short block, but then I got to thinking about heads and intake, also, motor size. I hear good things about the 2.5 L, could I use my old heads or would new ones be better? If I went with a long block, could I use my intake, and ether way could I use my stock turbo, would it be able to keep up with the new motor. I say new, but it will probably be rebuilt by a Subaru Performance Shop. A lot of company's I've seen seem to have a better deal on a used motor than a brand new one. My question is pretty broad, what are my options? Thanks for all the help on this one. -William... p.s. the motors I've been looking at are at http://www.vividracing.com/catalog/index.php/cPath/4206_4250 some others are at Cobb. Thanks again
http://www.subaruwrxparts.com/wrx-drivetrain.html http://www.iaperformance.com/index.php?cPath=44_45_90_234 and here is a post about the 2.0 from a jdm sti. http://forums.nasioc.com/forums/showthread.php?t=670037
Please don't buy anything from vividperformance. What are your goals? what do you do with your car? how much do you want to spend on doing all this? if you're going to keep your small dinky turbo i say there's no point in going to a built shortblock or jdm longblock. if you do get a built engine and lots of horsepower do you have the money for a new transmission when it blows? ask yourself all these questions
This brings me to my first point. Say what you want about the TD04 but the bottom line, the way I see it, is they just don't break, ever! That said you can't beat them for reliability, and you certainly can't blame a person for likeing the INSTANT spool up they can give. I have an 06 WRX, which everyone knows has the 2.5 and what everyone should also know is that the 2.5 plus the TD04 equals absolute power in terms of low down torque. And sure the power starts to run out at around 5 grand BUT! Who in thier right mind drives thier car at over those RPM's on a regular basis? The answer is no one because unless you're hauling one hell of a load uphill you DO NOT need those kinds of RPM's. And I know this post is a bit long, but I just want to let people know how happy I am, with my current setup: http://www.wrxatlanta.com/forums/showthread.php?t=6380, and that you too can see what it's like to own an STi (or pretty much any duelie) with the unrivaled, instant torque and a 0-60 time that this particular recipe can give you. In a way I'm playin around... but on a serious note. Ask SS or anyone whose ridden in my shit with my new tune and they'll tell you it's no joke. Not that it's all that but it's definitely not bad at all for the little turbo.
If you really have that much discretionary income, I'd advise you to look into something else. Assuming you visit the brakes first, I would personally keep the 2.0 and build it to around 275WHP using the stock sized turbo. Then I'd put some money into the tranny (you'll need that with a 2.5 anyway). The rest goes into suspension/tires. 2.0 with a small turbo is a lot of fun and will have impressive launch- especially with a built tranny!
I have a thread in the drivetrain section on the tranny. I found a good deal on a stock case with STI R/A gears from a place called ~ www.boxer4racing.com They can sell the case, diffs (front and center) and gears for 32 hundred. This is a little from there site on the gears here, (not my wording). Price is with shipping too... STi Type RA Synchromesh Close Ratio Gear Sets for 5-Speed WRX. Factory Ver.6 STi and STi RA 5-speed close ratio gear sets with special cryogenic stress relieving treatment with micro finish coating. Improved strength and durability over stock WRX components. 1st & 2nd gear width increased by approx. 1mm vs. standard WRX. Gear tooth root thickness also increased substantially on most gears as shown in the picture. Excellent for mildly tuned street and group N competition vehicles. Note: Gear kits come with main shaft, gears, locknuts, case gasket, oil seal, custom speedometer gear, thrust washer, and other special components required to adapt the gear set to the standard MY02-04 WRX. I like the setup and its cheaper than a stoke tranny from SOG. About how much power I want or what I want to do with the car, this is what I want. I would love to pull up next to a EVO, and make the guy wish he had half the shit I have. To not have to worry about the car in the other lane, the numbers that come to mind would have to be 0-60 in maybe the 4+ and quarter mile time in the 11's or low 12's. And whp numbers in the 350+. My question is of course money, I'm not looking at getting to far in the hole. This isn't something I want to through together in a weekend ether, a build would be nice to do, buy the parts out the dealer and put it together in my shop. Sorry for this being so long, and thanks for reading all this. -William...
Those oldschool 5speed gearsets only last to about 300-350whp. If you keep your stock 3.90final drive it's also more likely to break than if you ran them at their 4.11/4.44 fd. Just keep that in mind with your power levels.
A link I found looking for transmission took me to a place were they give the drive lines out in numbers. The finals are not up tho I think what your talking about is the same as what I'm looking at. This is the driveing numbers here~~~STi RA ratios: 3.083 (1st), 2.062 (2nd), 1.545 (3rd), 1.151 (4th), 0.825 (5th) Whats that look like to you? Thanks -William...
If you're installing those gears into your stock wrx transmission case then you're going to be using your stock final drive ratio which i think is 3.9. The lower the final drive ratio the more shock is experienced by the gears as you shift. I'm not an expert at this by any means. But I figure since you're looking for 350+whp and you're using a lower final drive ratio than recommended that you will need a different transmission setup.
I'm lost then, I've allways thought the 5th or 6th gera was the final drive. Check this out tho and let me know what you think. http://www.catherineandken.co.uk/sti/trans.html Thanks -William...
CalmNothing - please elaborate. I have the full set going in and not keeping my stock 4/5 gears as I have heard for keeping the gas mileage from suffering. So is it more strain with or without the full set?
There is a ring and pinion that determines the final drive ratio. From reading various sites a lower final drive means more shock to the transmission because when the rpms drop so suddenly when you shift. With a higher final drive when you shift the rpms stay higher and cause less shock. Kind of the same principle behind rev matching. Anyways to the original point, the gears are only good to about 350whp or so. I have read a few guys go past that, but not too far past it, and not too reliably either. If your goal is to go above that then I would suggest to look elsewhere for reliability.
another question I got a nut and stud on the turbo thats stuck so to say. I've ran in to this before on the exhaust bolts, 1 on the cross manifold and 1 on the uppipe to manifold. Its like they just get welded together and will not break lose, if I try and man handle it off I know it will break, and then I got to have the turbo drilled and taped. Has anyone ran into this before, and is there some great penetrating oil I can use to get it out? I would like to get the stud out as well as taking the nut off it, but I'm scared of it breaking and then I'm f#@ked. -William...
Yeah cool, I'll try that but I wanted to add to the problem I'm having here. The nut will start to come off for about 1.5 turns and then get tight again, on the ones before, it looks like the bolt(s) are bent ever so slightly and the nut can't come off with any ease. The said stud and nut would be the one on the passenger side of the turbo, but for sure the one on the side. Given the fact that I think on all stock turbo and some after market turbo there are two on top, one on driver side and one on the bottom, and then the one I'm having such a problem with now is the one on the passenger side. I know this probably isn't the best question I'll ask here, but if I should break it, what will happen while its broke and not having a stud and nut in there, with the other 4 nuts holding tight? -William...
Ok, got it off with out any problems. But now I got nothing to put back in it. Got to go looking through my nut and bolt box for a fixer upper. -William...
I have not heard good things from Vivid. A stock STi shortblock, you can find those on ebay from time to time at $1550, brand new. If we, at SOG, install it and SS tunes it...as long as you dont do anything dumb to your car, we carry a 12month/12k mile service warranty on all the work we have done, and the parts. However, if you install it yourself, sorry, theres no warrant as the shortblock is not going into the vehicle it was sold for. :-\ If your car is still running strong, we will reuse your stock heads, oil pump and pretty much anything else. If you have over 60k miles on your engine, I would recommend a new waterpump and timing belt...but either way, you will be getting all the seals and gaskets replaced regardless of mileage. The stock heads and cams max out around 380 wheel hp on pump or race gas...with or without Methanol injection....regardless of what turbo you use. Cams will make more power.... Swapping the AVCS heads is just alot more work, I dont recommend it unless you are willing to spend over $20k on upgrading the car...at that point, buy a wrecked STi or other wrecked 2.5 turbo car and swap it all. As for turbo choices...the stock td04 with the 205 heads and 257 shortblock will make insta-power and die around 5k. Otherwise, its similar to what an sti will do. You'll just loose a little of the initial spool, and a decent bit of top end...if you want instant power and good midrange and top end, the deadbolt TD06H-18G internally gated will do the job. As for transmissions: You stock final drive is 3.70 in the front, and 3.545 in the rear due to the 1.1:1 reduction in the rear output shaft stepper gears. 06+ is 3.70 front and rear. Early 02 WRX has the weakest gears. The latter half of 02's may have the stronger RA thickness gears. Its also a little random in the early 03's as well. Definatly all later 2003+ have the RA thickness gears. However, even with RA gears, or RA thickness gears, they will still break due to the screwy finial drive ratios....it just sucks. The intention of the RA set is to go with the 4.444 final drive for off road rally use. EXTREMELY close gearing, and about 130mph or so top speed at 8k RPM on those Type R/RA EJ207's. I would HIGHLY recommend changing the final drive and the stepper gears, and using the PPG gears....that combination will ensure an unkillable 5MT. But, thats about a $6k job...you can get a 6MT for that. That brings me to the ultimate choice...the 6 Speed. However, there are several choices of 6 speeds. The JDM 6 speeds are super short-close ratio...great for rally use, but not for drag racing or road course...could be good for narrow powerband engines on autox courses. Version 7 Wagon 6MT's have an open front diff and normal VLSD center diff. The Sedans get VLSD center and SureTrac front LSD. IIRC all Version 8's 35/65 center with adjustable lockup (refered to as DCCD from now on) and SureTrac front LSD. Version 8.5 have Helical front, and DCCD...same with version 9 and up. The US Spec 2004~2006 is a good choice...nice LSD front and a planetary center diff with DCCD. 06 changed to 41/59 split and static LSD plates instead of being open as default. 2004-2005 is 3.90 front and rear. 2006 changes to 3.545 rear. The US Spec 07 STi trans has a longer 2nd, 3rd and 4th gear, effectively making 5th useless. Has the helical front lsd, and the same center as the 06. 5th and 6th gears are the same as the 04~06. 3.90 front/3.545 rear The 2007 Legacy GT-Spec B 6MT has longer 2nd-6th ratios. VLSD center, but open front diff. This transmission requires the Impreza 6MT front case in order to have a working speedometer. The center diff output has a reduction, requiring a 3.545 rear diff. Front is 3.90. For a total cost of $9,000...SOG can install your Spec B transmission in your WRX...this package includes an STi Helical front diff, Impreza front housing, and all new components. Driveshaft, clutch/flywheel set, shift linkages, front axle adapter kit, Group N 6MT transmission mount, and all the other little parts. Again, all peices are NEW and OE from SUBARU...and installed by SOG, this means there is a 12 month/12k mile warranty on it that we carry on it. So....yeah...there's some info for ya'll to check out.
Wow, that is still pretty high in price, $9k. I like the warranty being on it, but thats a lot of cake to come off. That was a very helpful post you put up on this subject, thanks for that. How hard would it be to swap out the final drive gear, and the stepper gear? And what is this stepper gear? -William... I would assume you work for SOG, by your wording in the post, do you know of any payment option on the package you mentioned last in you post? :banana: