Thursday, August 31, 2006


swapstar productions
Diffs. - for What is a diff, please go to

Front LSD:

Q: I want a front lsd -

why? unless you are on the gravel (i.e. you own a rally car, not a fanboy car), you need not apply. There are circumstances (SCCA prosolo contenders, 500 awhp), that justify a front LSD, but for the most part its an extra expense that you would be better allocating to your food budget, girlfriend budget, etc.

Q: how much does a front LSD cost:

- $800 or so depending on the diff, then the labor to a transmission shop to pull the gearbox, break it open, and install it. I would budget $1500 or so.

Q: which JDM gearboxes had front LSD / How much will it cost me for one:

version 5/6 sti-RA only, version 7/8 RA, usdm sti as well. budget $3000 for starters for the 5mt JDM gearboxes. quite rare and tought to come by.

Centre LSD -

Q: I want a DCCD, Do i need a dccd?:

no. DCCD only comes in STi-RA models from version 2+. if you are going for the DCCD Look, you can buy the dccd button alone for $45 new. that completes the look. DCCD is not really that useful, many people are slower with DCCD than without it.

If you are looking to make your AWD driveline more rear torque biased, then we can talk. STi 15kg and 20KG centre diff does just that, so do the Cusco and KAAZ centre diff products. I have a dccd in my car, i leave it default rear biased 65/35. its really the same as if i had an aftermarket, but am hampered with an annoying little turny wheel that riceboys like to drool over :P

the car is easier to drive with the stock 50:50 centre diff. if you are overpowering the centre diff, or desire a more rear biased driveline for competition purposes, then the aftermarket parts are good to consider.

rear LSD -

How to fit a rear LSD on my car:

Rear LSD is the one of the 3 diffs that is arguably useful. on a Low power NA car - ej25/22/18, you may have more fun with an open rear diff, unless you are planning on loosing time in corners by sliding the car too much. Sliding is fun.

you can AWD lift-off drift a Ej18 with open diffs at 80mph. Just turn in hot and lift off to unweigh the rear end, then WOT to exit.

rear LSD will make your car want to go straight. On snow or dirt its quite useful, same for rain. Dry traction with good tires, you quite possibly might not notice it at all.

Q: Viscous LSD: worth the trouble?

If i was in a snowstorm, I'd rather have a VLSD than no lsd. If given the choice however, VLSD is almost a waste of time to instal. unless bought for very very cheap, I'd pass and wait it out for a JDM Mechanical R160 unit.

Q: Mechanical R160- which cars had it?

JDM sti's tend to come with Mechanical R160's. Subaru and part spec is quite a random game though, so JDM WRX's have been known to come with them somtimes as well.

Q: What parts do I need to fit a rear Mechanical LSD?

- R160 LSD unit - ideally complete pumpkin with proper Final drive ring and pinion to fit your gearbox.
- R160 LSD axels for mechanical LSD - differnt from open and viscous
- all AWD R160 rear hubs are compatable with R160 axels. you will NOT have an r180 in your car unless you have a 2004+ GDB sti, or a JDM GC8-STi RA v3+ complete car.

* some of the early impreza L models came with tiny diffs smaller than R160, and a dogbone style mounting X member like the legacy and GDA wrx. Just swap the studs over from the diff cover and it goes right in.

R160, R180, R200-

what do these things mean?

r160- all subaru diffs are R160 - for the most part, all usdm subaru's came with R160 diffs. Dating back to the datsun 510, its about the oldest thing on the block. Very simple dissasembly, a beginner can swap ring and pinion gears in about an hour or so.

R180 - the same diff as some of the datsun Z cars and the S12 200sx, the R180 rear diff in subarus has a 180mm (or so) diameter ring gear. Very creative name, the R180 is a direct fit onto any AWD subaru X member, just need to have the proper axels and driveshaft (or custom drill small pattern R160 driveshaft bolt pattern into the R180 flange- easy to do).

R200 - rear diff from a nissan Silvia, Skyline, 300ZX. its big, dosnt fit in your subaru without a guy+welder+metal fab shop. Useful for drifting, and people who like to destroy things, we do not put R200's in subarus.
Gearbox FAQ.

5 speed:

everyone asks about 6mt conversion. if you have a spare $7000 that you're dying to throw away, stop reading and go directly to the 6mt section.


USDM WRX gearbox is not weak. its just geared terrible to pass emissions stateside, and make the 0-60mph test a 1 shift deal. 100 mph capable 3rd gear is nobody's friend unless you've watched wangan midnight too many times, or live in houston texas - the land of the everyday wangan commute.

many people come to us for our JDM 4.11 5mt gearboxes. similar to a usdm NA 2.5RS gearbox, they are geared for ej20 turbo engine powerband, and are short ratio. 1 and 2 are longer, 3/4/5 closely spaced to keep you in turbo powerband. it is niice. many 12 second cars that run these with GDB ej207 setups.

for the average human being, you will want a plane jane WRX 4.11 5mt. Easy on the wallet at the gas pump, good ratios to keep you happy in turboland on the track or mountain pass.

4.44 vs 4.11 vs 3.9.

in the 5mt world (refering to REAL gearboxes), there is only 1 3.9 fd gearbox. 1995 sti-RA version 2. very rare - it is my very most favorite gearbox, but extremely expensive and very hard to come by.

4.44 vs 4.11

in the 2.5RS fanboy world, everyone wants a 4.44. why? because the number is impressive. the shortest geared subaru gearbox is a 4.11. 1993-1995 WRX-RA (non-sti) for gravel competition is utterly short. to run on tarmac, you better have a 9,000 rpm motor or be running on a low speed track. not useful for streetcars, it causes all the poseur fanboys to run out of gas money quickly.

the later version 5/6 cars and sti version 3-6 had 4.44 final drives. gearing was slightly LONGER than the 4.11 cars (version 1-2) in some circumstances. shorter final drive + longer gears = longer final drive + shorter gears. No differance.

the 95 3.9 FD sti-ra box I drive personally is shorter than the version 5/6 4.44 sti-ra box. Again, the differance is in the overal gearing, not just the final drive.

if you would like to build a version 5/6 clone car, perhaps think about making it RHD first. There are no LHD JDM cars.

We are all about the best bang for the buck, if you want a 4.44 box for the bragging rights we're happy to take your money, but the same results can be hand with a 4.11 box for half the price.

6MT swap.

6mt+cheap = NO.

lets break down a 6mt conversion price matrix;

ghetto style 6mt conversion:

most inexpensive 6mt gearbox - $3000
use 5mt clutch - $0
automatic R160 driveshaft - $100
3.9 FD r160 rear diff - no lsd (assuming you already have one) - $0
shiping $200, misc fluids $50, labor is free (DIY)

$3350 bux.

proper 6mt conversion -

DCCD 6mt gearbox - $4500
6mt clutch and light flywheel $750
R180 6mt driveshaft - $200
R180 rear diff- suretrack LSD - $600
R180 rear axels $300
R180 brembo big hubs $400
brembo rear brakes $350
shiping $200, misc fluids $50, labor is free (DIY)

$7350 - Properly done.

the differance is in the good parts, the best part of the 6MT parts is not the ability to brag about having 1 more gear, or the ability to stupidly do awd clutch kicks (untill your axels break). The best part of the 6mt conversion is the R180 suretrack LSD, the big strong hubs and axels, and the 12.8" rear brembos that make you stop good. Those parts are so nice that we run them with JDM 5MT's on our own cars.
2.5RS vs impreza L

2.5RS is garbage. Yes, your beloved 2.5RS is only worth having for the shell. the only part of the exterior worth keeping is the headlights, fenders, doors and trunklid, the only part interior is the dash it self. In some senarios, its worth the cost spent to have a nice clean shiny shell :). Othertimes, its a waste of money.

Many people with 2.5RS's end up modding them up to stop and sell it to buy an impreza L - Why? lets discuss.

Impreza L - buy in ~ $2500 bux for a good clean one
impreza RS - $9000 for a decent one

L - avail in OBD1, easier to pass emissions
RS - OBD2 only

L - i want the 2.5Rs look - spend $1200 on JDM lightweight bumper/aluminum sti hood/headlights/sideskirts conversion and you are there. Direct EASY bolt on.
RS - it looks good, but the hood is a brick and the bumper is heavy. $500 bux to spend

L- my rear bumper has an ugly stripe, so im buying the JDM version 3/4/5/6 bumper - $300
RS - my bumper has the ugly stripe, its just painted - $300 for the good looking bumper

L- EJ18 dosnt make any power, so im going to JDM ej20 swap. - $1500-4500
RS- my EJ25 has bad head gaskets and dosnt make any power either - $2500+ because i have to do OBD2, if no need for smog its same as an L

L- i want a real gearbox - $1050 + $150 for hydro pedal box conversion
RS - my NA gearbox isnt that great either - $1050

L- i have no LSD - $350
RS- my VLSD is same as no LSD (i just paid extra for it with the price of the car) - $350

l- i need suspension - $800
RS - i need suspension too - $800.

L- convert to rear disc brakes - $350 for rear hubs + JDM vented rear brake setup
RS - change rear brakes to JDM vented rear -$150

L - my seats suck - $800 for some RECARO SRD's or JDM sti seats
RS- my seats arnt that great either - $800 for the same

When all is said and done, the L owner has spent ~$1500 or so more on modifications than the RS owner, but spent $6500 LESS on buying the car. Saved money on insurance is also significant, Which route seems better to you?
my notes on ej20 wrx transplants.-

ej257 (usdm 2.5L sti). long-block is good to 530 awhp, probably would live all day at 400 chp. i dont like it because it dosnt rev high and isn't constructed to the level of the JDM 2.0L blocks. heads are crappier too. if you want to build your own torque beasty, just get the short-block ($1400 new) and throw some 2.0 l heads on it and make custom frankenstein. works very well. kinda pricey for me

USDM ej205. i wouldn't bother with it, but if you goal is 300 chp and a max usable power rpm of 6500 or so, its easy to find for cheap. wiring is a bizzle, but the parts are plentiful. full motor conversion ranges from $1500 on the dirt to $4K installed. Toys are always extra, so you probably looking at an up pipe and a full turbo back exhaust with a upgraded ECU (accesport,ecutek etc). 300 chp is be easy with stock ecu td04, td04 and IC. its not bad, but JDM is better. the EJ205 is hampered with stupid things like TGV, low compression, and a terrible gearbox.

JDM EJ207 (v7/8/9). the best thing money can buy. but it costs alot of money to buy. power is all in the heads, open deck (technically semi-closed) but it'll handle 30 psi ++ no problem. problem is the price tag. whole drivetrain will cost you about 8K, just motor a nasty $4500 or so. Varients like Spec-C, RA are pricy. very very good though. with the proper setup you can make 400 AWHP daily on a stock motor. the heads are where the power is. Also it benefits from interchangability for sensors with usdm wrx ej205.

- subaru dosnt have a problem with open deck motor breaking, the idiots in the US just tune it bad and crack piston ring-lands. even a EJ205 is good for a reasonably reliable 400 chp if tuned very well on a bigger turbine. longevity is a different story.

JDM ej207 (v5/6) almost a 7/8 motor, but with smaller valves than v8 and no AVCS heads. obviously a good motor, but pretty expensive. $2500 or so just for the motor, $3200+ for a sti-RA engine only. $6500-7500 for the front clip. spendy and not good deal in my opion. obviously the sti-RA models will be faster than hell. trick stuff like sodium filled valves. my buddy has one in his 98, its not any faster than my 95 ej20G sti-RA.

EJ20K. v3/4. a good deal. clip will cost you 4.5-5.5kK with everything complete , the plane jane WRX is a better deal than the STi. wrx comes with a VF22 turbine, STi has a faster spooling but smaller vf23. pick up the normal WRX and give it an exhaust, then go walk sti's all day... u can run high 11's with a VF22. no joke.

EJ20G. the OG of the crew. 1992-1995, they are all the same. Td04 and Td05 turbines flow more CFM's than any of the other GC8 OEM turbines, older design could use a revamp (aka centre baller bearing conversion like EVO td05). if you want to be able to brag that you have a closed deck, EJ20G is the only closed deck. EJ20g also has the most spare parts support of any of the GC8 drivelines. Swapstar productions stocks all standard replacement parts, all sensors, coilpacks, ignitors, maf's. You will be hard pressed to find replacement spares for all other JDM GC8 drivelines stateside. there are "240ps", "260ps", and "275ps". Same size valves from EJ20g to GDB ver7 early. all EJ20G motor internals are identical. Plane jane WRX and WRX sti and WRX sti-RA will all make the same power on the same ecu. the differance is the ECU and turbine, but theres always power FC's to take care of ecu side and turbine upgrades are easy. easily the best bang for the buck, any WRX EJ20G will rev to 8K all day and do 300 crank on 91 octane. my personal one in bone stock setup did 238 awhp on 91 octane. stock turbine, stock ecu, stock intercooler, stock boost, and an aftermarket exhaust. the Td04 small turbine will spool quite a bit faster, so if you're building an autoX monster, or togue pass king car, you might want to do that instead. TD04 will do 300 CHP as well, there are lots of usdm WRX's as thus. High end power or lower end power, you pick.

any turbine and exhaust from ANY ej motor is compatible. you can fit a twin scroll on a EJ20G, or a TD05 single scroll setup on a GDB EJ207 2005. up pipe, downpipe, header, its all compatible.

Wednesday, August 16, 2006