pro's and con's of six speed box
 

what are the advantages and disadvantages of fitting a 6 into a 94 uk classic
is the acceleration and top speeds altered in anyway?
is mpg altered?
does your insurance get affected by it?
also what would be all the bits needed to do this conversion
may consider it if i can get all the bits cheap enough
i know some have had this done on here maybe get some input from them guys

thx for any help

steve

is the acceleration and top speeds altered in anyway?

Yes, depending on which gearbox you go for, JDM or UK, but you will also probably need the rear diff and some other parts

is mpg altered?

Depends how you drive your car ;)

does your insurance get affected by it?

Yes, you should declare any modification that takes the car out of factory specification, some insurance co's will charge you more.

also what would be all the bits needed to do this conversion

as above, gearbox, diff and some other bits.

may consider it if i can get all the bits cheap enough

Probably cost you around 2k ex fitting

i know some have had this done on here maybe get some input from them guys

John Banks has one in his car, have a chat with him, but tbh, unless your going for big power and torque, your probably better with your 5 speed.

Tony:D

I would only consider a 6 speed box if you are running sufficient power to be continually knackering a stock 5 speed box. By this I mean in excess of 350 brake and 320lbft of torque.

All of the 6 speeds (bar the JDM Forrester Sti box) have lower ratios than the 5 speed box. These ratios are better suited to high reving engines, certainly higher reving than a classic UK.

The Type UK Sti 6 speed has longer 5th and 6th gears than the JDM Sti box, it also has a 1.1:1 final drive so you can use the standard 3.54 ratio rear differential fitted in a classic UK. In which case all you need in the gearbox, linkage and prop shaft, ideally you should also fit a Group N uprated gearbox (or rear engine as it is sometimes called) mount.

If you were to buy a JDM Sti gearbox you would also need a corresponding rear diff as it uses a 1:1 finally drive which will require a 3.9 ratio rear Crown Wheel and Pinion. Here you have two choices, take a CWP from a UK Sport model and fit it to your diff, or buy the rear diff, drive shafts and hubs from the JDM Sti to fit them, the classic UK has an R160 differential, the Newage JDM an R180.

Of the two boxes the Type UK Sti 6 speed is better suited to the UK Classic engine, but it is far from ideal

and it heaver than a 5 speed

i have a JDM 6 speed in mine, but given the recent infomation on the PPG gearsets from this forum i think i would prefer to spend my cash on one of those iif i was in the market for a new gearbox

Only by 25kg Mike...

Tim W , spot on, I had a uk 96 I broke 2 boxes got a uk 6 speed put in , That did not break, !!!! But wish Id gone for a stronger 5 speed, >> Now I have a sti V7 jdm with all the bits >> this box is well suited to the sti , >> its good ?? cheers Alan.

:eek2: the difference between an RA and a normal STI then?

the difference is a fat and a skiny bloke:D:D:D

Yikes, I must have two 6 speeds installed :D

What is the benifit of fitting the group n mount? i nave a 94wrx fitted with a 6speed but the garage only used the standard mounts. where can i get thr group n mount from?

cheers

nathan

Call Mark at Lateral he may have some in stock or Phil at Barretts

The advantage of the Group N mount is that it is heavier duty and takes the additional weight of the 6 speed better.

has anyone the difference in gearbox ratio's for the JDM version and the europe/UK version?

i have these ratio's but as i far as i know these are the JDM ratio's


http://www.2xceler8.nl/guests/Naughty/6bak-ratio.jpg

i believe the UK/europe version has a longer 5 and 6 but can't find the correct ratio. I have a JDM 6speed with DCCD but that has the same ratio i assume

Euro 5th and 6th are these

5 0.971
6 0.756

Tony

thanks mate

There's a load of info on ratios etc on Bob's thread about gearbox options

David Wallis had a spread sheet with all the 6 speed ratios with in gear speeds & top speeds