Will be changing the gearbox for next year and probably will look at the 6 speed box, but have a few questions that i,m hoping some of you can answer...

My car is equipped with a Helical front diff.....can i use this with a 6 speed ..?

It also has an R180 rear diff which does not work since i upgraded rear rollbar. Basically unless the dccd is fully locked if cornering hard all the power is going to the inside wheel, which in turn means i cant get the power down out of the corner.....so do i need to purchase a box with diffs or can it be repaired??? I assume its worn in some way....???

The car also has an Exedy twin plate clutch which is for the 5 speed box.....can this be used with the 6 speed or do i need one specifically for the 6 speed box...???

Also would like to know what the original 5 speed box is worth, even though it is on last legs and also the front helical diff....which i believe is quite rare and only fitted to the sti ra limited and 22b...???

And also know someone who has a dog box from a rally car....would this be any good for me.....

Car is fully caged and only used for track....

Thanks in advance....

 

I think the 6 speed comes with the front diff in it already.

 

The front diffs are not interchangeable between the 5 and 6 speed. The non dccd 6 speed has an open front diff but the dccd 6 speed has a AP suretrac front or a helical lsd for the my05 spec c.

If you are using the jdm 6 speed you will need a 3.9 final drive R180 or for the uk box a 3.545 R180, yes the 5 speed twin plate will fit into a 6 speed box no problem.

Not used a dog box but would imagine it is quite aggressive and you will have to be brutal with the gearchanges.

Banny

 

Thanks Banny........i will definately be going with a dccd box(hopefully the jdm version) and doubt a spec c box is going to turn up for sale......Is the Ap suretrac diff an upgrade from the helical diff fitted in my car????

And what is the Helical front diff worth second hand....??

Thanks again....

 

The front diffs can be machined to fit a 5 speed box

 

S'funny

My 2002STI has a Suretrac in the front.....

dunx

 

dog boxes are NOT aggressive, you just need a positive throw with the gearstick to ensure the dogs connect between the gear and the slipring. changing gear is just as smooth as a syncro box when done correctly

Rooferman
if you go for the dog box option make sure you see the internals of the box before you buy it or at least know its history and where you can get replacements. I'm assuming it is a 5 speed dogbox so make sure it is ftted with proper selector forks (not the std subaru ones) and that it has been modified so you can't select two gears at the same time.

for a dogbox be prepared to change the gears / slipring more often than a syncro box as the dog teeth edges tend to get knocked off and eventually the gear will slip out on a closed throttle

From the reports a 6 speed is perfectly up to the job with a 3.9 ratio


I have the Helical front diff in My STi RA and I love the feedback through the steering wheel when pressing on.

 

most 6 speeds have an LSD in the front. Mostly it's the early JDM sti non DCCD, forrester STi and legacy 6 speeds that have open diffs.

 

Paul my 2003 JDM was listed as having an open diff, does that sound correct?

Banny

 

Paul, is there a service kit for them ?

Mine has lost it's savage (when new) bite, and is a bit tame these days....

dunx

 

Thanks for the replies guys.........So what is the value of the current set up in my car.....basically i have been offered £250 for gearbox in its current state....Is this a fair figure..???