Jump to content
LegacyGT.com

6MT Master Swap Thread


HAMMER DOWN

Recommended Posts

Think I compared the FSTI 6MT gearing to the Spec B 6MT and they were the same. FSTI has the lube pump as well, unlike the 08-09 Spec B
- Pro amore Dei et patriam et populum -
Link to comment
Share on other sites

Comparison

 

 

 

JDM FSTI 04-07 Gearing

1-6: 3.64 / 2.24 / 1.52 / 1.14 / 0.89 / 0.71 Rev is: 3.55 TR is: 1.0 and the FD is: 3.9. Wonderful AP SureTrac front diff, and the rear is an R180 Suretrac, but the center diff (38913AA112) is a VLSD.

 

 

07 Spec B Gearing

1-6: 3.64 / 2.24 / 1.52 / 1.14 / 0.89 / 0.71 Rev is: 3.55 TR is: 1.1:1 and the FD is 3.54 (Similar to 06-07 STI). Open front diff, rear is R180 Torsen, and Center Diff (38913AA112) is VLSD

 

 

 

08-09 Spec B

1-6: 3.64 / 2.24 / 1.52 / 1.14 / 0.89 / 0.71 Rev is: 3.55 TR is: 1.1 and FD is: 3.9 Open front diff, rear is R180 Torsen, and Center Diff (38913AA200) is VLSD

 

 

Not sure what the difference is between the AA112 and the AA200 Center Diff, but would really like to change out the Spec B setup for the FSTI version. VLSD center diff is fine with me.

- Pro amore Dei et patriam et populum -
Link to comment
Share on other sites

Comparison

 

 

 

JDM FSTI 04-07 Gearing

1-6: 3.64 / 2.24 / 1.52 / 1.14 / 0.89 / 0.71 Rev is: 3.55 TR is: 1.0 and the FD is: 3.9. Wonderful AP SureTrac front diff, and the rear is an R180 Suretrac, but the center diff (38913AA112) is a VLSD.

 

 

07 Spec B Gearing

1-6: 3.64 / 2.24 / 1.52 / 1.14 / 0.89 / 0.71 Rev is: 3.55 TR is: 1.1:1 and the FD is 3.54 (Similar to 06-07 STI). Open front diff, rear is R180 Torsen, and Center Diff (38913AA112) is VLSD

 

 

 

08-09 Spec B

1-6: 3.64 / 2.24 / 1.52 / 1.14 / 0.89 / 0.71 Rev is: 3.55 TR is: 1.1 and FD is: 3.9 Open front diff, rear is R180 Torsen, and Center Diff (38913AA200) is VLSD

 

 

Not sure what the difference is between the AA112 and the AA200 Center Diff, but would really like to change out the Spec B setup for the FSTI version. VLSD center diff is fine with me.

 

Are you just wanting the flsd?

Link to comment
Share on other sites

Front and Rear LSD are "must have". Not just fancy stuff but actually transform car totally!

Hence Spec B transmission doesn't make sense (to me and many others)

 

Reading how many ran DCCD in open position pushed me to to FSTI instead of considering (costly) build of DCCD trans in to tall gear option.

Link to comment
Share on other sites

Not sure what the difference is between the AA112 and the AA200 Center Diff, but would really like to change out the Spec B setup for the FSTI version. VLSD center diff is fine with me.

 

It might be the front/rear torque split. Some cars were 35/65, others were 40/60, and if I remember right the rear diffs had different ratios that went hand-in-hand with that. So if you swap the center diff you'd also want to swap the rear diff at the same time.

Link to comment
Share on other sites

From everything I've found the AA112 and AA200 are both 50/50 VLSD CD's.

 

The transfer ratio (T.R.), which is box dependent, does effect which ratio you need for a rear differential.

 

07 Spec B 6MT TR is 1.1:1 which requires a 3.54 rear diff (like the 06-07 STI)

 

FSTI and 08-09 Spec B 6MT TR is 1:1 so these boxes require a 3.90 rear diff.

 

FSTI and 07 Spec B use the same 38913AA112 CD

 

08-09 Spec B 6MT uses the 38913AA200 CD, but the 38913AA112 CD is also compatible.

 

Difference in price though - AA112 is $626.00; AA200 is $493.00

 

May have more to do with the internal differences/space-fit between a pressurized and a non-pressurized box. But it appears that both work for 07-09 Spec Bs, so presume they'll both work for 04-07 FSTI.

- Pro amore Dei et patriam et populum -
Link to comment
Share on other sites

A couple of thoughts that really only pertain to using a 6MT in a race car, not applicable to a street car:

 

The 6MTs with a VLSD I suspect are a heat problem. After I swapped in the JDM Forester STI 6MT in the Silver Eagle I was never happy with my tranny temps even with an external cooler setup. I think the problem is the VLSD is creating a lot of heat when you keep it working hard for an hour. Maybe with a larger cooler and more airflow from a higher pressure source would mitigate it.

 

I have no proof the VLSD is causing the heat issue, it's just my guess based on my experience and knowing how a VLSD works.

 

The Blue Sake Bomber STI has no tranny heat issues. I'm running an external cooler off the oem internal oil pump. The tranny is getting notchy so this winter I'll get it rebuilt. I may or may not have the rebuilder add a more sophisticated external cooler system. The gearing seems to be fine, I have yet to hit redline in 6th at any Pacific NW tracks.

 

Of course you have to have a temp sensor to know it's a problem, at least until you go to change your tranny oil and it smells awful burned up!

 

A FF 818R running at the Portland Enduro last fall had a total tranny failure after 2 hours of racing in the 8 hour enduro caused by overheating their Subaru 6 speed. They had no external cooler at all. I don't know if they had a VLSD tranny or a DCCD tranny. But any racing of over 30 minutes should have an external cooler setup, either using the internal 6sp oem oil pump or an external aftermarket one on a 5sp or 6sp.

 

So in general for a race car the DCCD 6MTs are a better option, just for that. Throw in the DCCD doing it's thing and it's even better.

 

I still like the M Factory online calculator for playing with tire size/ max RPM, Final Ratio, and Gearing. To get the graphing function to work in either Chrome or MS Edge you have click on the Get Flash link, then if you already have Flash a box will pop up asking you to allow it to run. The graphs are great for visualizing the differences when comparing trannys or other parameters. One of the predefined gear sets is the Subaru WRX close ratio.

http://www.teammfactory.com/calculator

Edited by Sgt.Gator

Nothing like a race track to find the weak points in man and machine.

"Good Judgement comes from Experience. Experience comes from Bad Judgement"

Link to comment
Share on other sites

I just wanted to add that I finished up my JDM FSTi swap and put in about 300 highway miles this weekend. I am completely satisfied with the swap. Highway speeds under 3000rpm makes cruising so much more pleasant. I haven't been able to take advantage of all the LSD's in the drivetrain yet but the gearing is worth the price of admission for certain. The only issue I need to sort out is that I experienced a sensation when reversing into a parking spot in full turning lock. It felt like the transmission was in "Lock" with a little bit of bucking at low speed. Everything else has been rainbows and unicorns.
Link to comment
Share on other sites

The only issue I need to sort out is that I experienced a sensation when reversing into a parking spot in full turning lock. It felt like the transmission was in "Lock" with a little bit of bucking at low speed. Everything else has been rainbows and unicorns.

 

 

Sounds like a good install.

 

 

 

Bucking and shuddering in reverse, or torque-bind in hard turns on solid surfaces, is usually associated with the CD, and typically on autoboxes, which, in most later models, is electronic. Juddering, OTOH, is typically associated with the clutch... in both directions.

- Pro amore Dei et patriam et populum -
Link to comment
Share on other sites

 

The Blue Sake Bomber STI has no tranny heat issues. I'm running an external cooler off the oem internal oil pump. The tranny is getting notchy so this winter I'll get it rebuilt. I may or may not have the rebuilder add a more sophisticated external cooler system. The gearing seems to be fine, I have yet to hit redline in 6th at any Pacific NW tracks.

 

Of course you have to have a temp sensor to know it's a problem, at least until you go to change your tranny oil and it smells awful burned up!

 

 

So in general for a race car the DCCD 6MTs are a better option, just for that. Throw in the DCCD doing it's thing and it's even better.

 

 

Not to start any argument over this of course, to each his own.

 

I always wanted to have front LSD and SpecB's open diff is the reason I never pursued venue of swapping 6MT from SpecB into my car. Mike HAMMERDOWN's decision to sell the car was the trigger as I followed his build from the beginning and knew he ran STI 6MT with DCCD controller. I know one can buy front LSD unit and have

it installed in non-STI tranny, but that looked like too much hassle with too many uknowns on the way to happiness.

 

now that you mentioned tranny coolers, any you can recommend for 4th gen LGT and STI tranny swap? I will have everything out of the car including engine when I do the swap, so perfect time to run any lines etc. Car does not see any hardcore racing except auto-x but I want to keep it for as long as possible and having tranny cooler will only help with that.

2005 LGT Wagon Limited 6 MT RBP Stage 2 - 248K

2007 B9 Tribeca Limited DGM - 258K

SOLD - 2005 OB Limited 5 MT Silver - 245K

SOLD - 2010 OB 6 MT Silver - 205K

Link to comment
Share on other sites

I just want to confirm - stock LGT front CV axles are compatible with STI 6MT or SpecB 6 MT, so I can keep them for swap?

2005 LGT Wagon Limited 6 MT RBP Stage 2 - 248K

2007 B9 Tribeca Limited DGM - 258K

SOLD - 2005 OB Limited 5 MT Silver - 245K

SOLD - 2010 OB 6 MT Silver - 205K

Link to comment
Share on other sites

now that you mentioned tranny coolers, any you can recommend for 4th gen LGT and STI tranny swap? I will have everything out of the car including engine when I do the swap, so perfect time to run any lines etc. Car does not see any hardcore racing except auto-x but I want to keep it for as long as possible and having tranny cooler will only help with that.

 

If you have the STI tranny with an internal oil pump and the external oil line on the driver's side it's possible to connect there and let the internal pump push the oil thru the lines to a cooler mounted whever it fits for you.

However I wouldn't do it to a street/autox car. It's another thing that can fail, leak and otherwise cause a problem when the benefit is so limited on a street car. Maybe if you are regularly towing a trailer.

 

No one makes a kit, you have to piece together what you want as a custom setup. I ran -6AN lines. I would use nothing smaller, but not bigger than -8AN. I generally like to use Earl's Coolers (Holley) and Derale. The Earl's are nice because you can swap around the inlet and outlet fitting sizes, they aren't permanent. So you could use it now as a -6AN, and in the future use it somewhere else as a -12AN. I use the Derale where I want a fan attached and shrouded. I also sell both brands if you decide you want to buy one. Some of the Derale also have swappable fittings.

 

http://derale.com/products/fluid-coolers/engine/remote-mount

 

https://www.holley.com/products/cooling/oil_and_transmission_coolers/

Edited by Sgt.Gator

Nothing like a race track to find the weak points in man and machine.

"Good Judgement comes from Experience. Experience comes from Bad Judgement"

Link to comment
Share on other sites

For 05 STI 6 speed install, do I just need 05 STI stock flywheel, clutch disk and pressure plate?

2005 LGT Wagon Limited 6 MT RBP Stage 2 - 248K

2007 B9 Tribeca Limited DGM - 258K

SOLD - 2005 OB Limited 5 MT Silver - 245K

SOLD - 2010 OB 6 MT Silver - 205K

Link to comment
Share on other sites

For 05 STI 6 speed install, do I just need 05 STI stock flywheel, clutch disk and pressure plate?

Yes, that all I ever ran with that swap. 05 STi fly wheel, pressure plate, throwout bearing, clutch & pilot bearing. FYL, I avg. 100k on OEM STi clutch setup.

Mileage:331487 Retired/Sold

Link to comment
Share on other sites

You should also be able to run the 07-09 Spec B clutch setup

 

IIRC the 07 Spec B is the STI setup. 08-09 Spec B is specific to those years, but would still work with the USDM 85mm 6MTs.

- Pro amore Dei et patriam et populum -
Link to comment
Share on other sites

Yes, that all I ever ran with that swap. 05 STi fly wheel, pressure plate, throwout bearing, clutch & pilot bearing. FYL, I avg. 100k on OEM STi clutch setup.

 

You should also be able to run the 07-09 Spec B clutch setup

 

IIRC the 07 Spec B is the STI setup. 08-09 Spec B is specific to those years, but would still work with the USDM 85mm 6MTs.

 

Thanks guys. I didn't read through all 154 pages of this thread so actual part ## I will pull from online stores. Trying to place order today to take advantage of 4th of July sale.

 

I replaced my 5 speed OEM clutch at ~120K and my current setup is ClutchMaster 250. At 214K now and it's still fine but feeling a bit high, so probably coming to same mark of 100K.

 

Mike good note on pilot bearing, I would have forgotten about it, but yes some flywheels come with it, some without. I'll make sure I order it.

 

Another mystery is which 6MT tranny mount to use. From 05 STI as well, or 07 SpecB? I didn't find any clear reference to which year or part# it is but 08STI 6MT mount sold online is flagged as not compatible with 05STI so I am confused there.

 

Also Mike thanks for using antiseize on many bolts and CV axles, that sure made disassembly way easier and hept parts intact.

 

Paid RalliSpec's invoice so now waiting for them to complete the refresh and collecting parts at the same time.

2005 LGT Wagon Limited 6 MT RBP Stage 2 - 248K

2007 B9 Tribeca Limited DGM - 258K

SOLD - 2005 OB Limited 5 MT Silver - 245K

SOLD - 2010 OB 6 MT Silver - 205K

Link to comment
Share on other sites

I ordered an STI transmount for my install. Perfect fit and slightly stiffer than the Spec B version.
- Pro amore Dei et patriam et populum -
Link to comment
Share on other sites

I ordered an STI transmount for my install. Perfect fit and slightly stiffer than the Spec B version.

 

 

Ordered 05 STI OEM 6mt mount, part # 41022FE010.

2005 LGT Wagon Limited 6 MT RBP Stage 2 - 248K

2007 B9 Tribeca Limited DGM - 258K

SOLD - 2005 OB Limited 5 MT Silver - 245K

SOLD - 2010 OB 6 MT Silver - 205K

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...

Important Information

Terms of Use