R34GTR

Hello

I have a few Questions about The TY856WG7KA gearbox as fitted in the STI TYPE UK MY06 ( I believe this might be the exact same gearbox as fitted to the JDM Subaru STI forester) and would appreciate some input from Experienced individuals

1.How much power and torque can the Stock TY856WG7KA Gearbox take ? what changes were made to strengthen it from the Blobeye STI ?
2.How did the internals change on the UK 2006 STI WRX and the UK 2007 STI WRX ? and the USDM DW-​TY856ww7ma and DW-​TY856ww8ma Gearboxes of the same year
3.Were the Syncros ,input shafts and internals strengthen between these two years and if so how ?
4.i have seen USDM STI MY07 RUN 900+ BHP on stock Gearboxes can the TY856WG7KA handle this much power ? 5. does the TY856WG7KA suffer from High RPM LOCKOUT at 9k RPM + I know the USDM STI Gearbox does not look at this at 12 min 07
The SPECS On this TY856WG7KA Gearbox are btw
1st = 3.636:1
2nd = 2.235
3rd = 1.521
4th = 1.137
5th =0.891
6th = 0.707

Final Drive Ratio 3.900
Thank you

Don Clark

Forester STi gearbox codes

Revision C - TY856WL4CC
Revision D - TY856WL7CC
Revision E - TY856WL7CC
Revision F - TY856WL8CD

Tidgy

US BHP and UK BHP are different things, so bear that in mind.

2pot

iTrader: (3)

Your box was June '05 - June '06 from Impreza STI
The ratios your listing are from the Forester sti and later spec b Legacy's

https://www.rallispec.com/gea_syn_rstf145_t.html

'07 6 speed had carbon coated baulk rings:
https://www.importcarparts.co.uk/par...y=&searchPart=

No internal pump in the '07 six speeds.

R34GTR

Great Info
Thank you to Don Clark ,Tidgy and 2Pot for your Input .
very helpful and thanks for the contacts and references .
We also found this link
https://forums.nasioc.com/forums/sho....php?t=1611975

Having Read the pages It suggests The Following about the 2006 STI 6 Speed Gearboxes

*The 06 Gearbox is better for race applications as it has the Internal oil Pump (as mentioned by 2 pot) as opposed to scrapers, so the 2006 model will greatly reduce the chances of Gearbox lockout Due to heatsoak and having the Oil Pump will also aid Cooling and reduce the chances of damage to the gearbox Syncros caused by the Gearbox oil Overheating and Thinning .

*This Subaru gearbox Was said in the post to be Designed by PORSCHE for SUBARU but this cant be verified
https://forums.nasioc.com/forums/sho...mission+design

*The oil pump for the gearbox was removed in the 2007 Model STI's for cost saving purposes ,although it has been suggested that there was a problem with the earlier(2003-2004) 6 Speed Gearboxes as the oil pump Shaft would break and there was a recall for this item.

*The Gearbox on the 2007 model is meant to have a wider keyway on 3rd gear (Hope its not because the 2006 suffered breakages on the Gear )



Whats the Highest BHP and Torque you have Seen on the 2006 Gearbox as fitted to my car namely The TY856WG7KA gearbox?

There must be some Drag Racers and TOTB Runners in here ?

R34GTR

SUBARU WRX STI 9 MY06 DATA -GEAR RATIOS