rosssti

iTrader: (1)

Hi, my 5 speed has just stripped 3rd gear at 400bhp, so I'm after a 6 speed, will a UK 6 speed box fit my UK300 2001 diff? What other bits will I need to fit this?

Thanx guys.

Paulo P

iTrader: (42)

You will also need the cradle and linkage. You need to check the rear diff ratios for the UK300 box because I don't know what it is, the UK sti 6 speed runs a 3.54 rear diff. You don't need to change the clutch, flywheel and starter if you want to continue running the 5 speed clutch.

rosssti

iTrader: (1)

will my car still be as quick as it is now with a 6 speed box? do i loose any performance? what 6 speed is best, 2.0 or 2.5 box? will this box increase my top end?

sorry for all the questions but need to be sure what to buy.

thanx

Ian

iTrader: (10)

if you have lost 3rd gear, then the 6 speed will be faster :-)

dunx

iTrader: (3)

Hawkeye box gives 80 mph at 3000 rpm, or 200 mph at 7500 rpm....

UK STI will be at 80 mph around 3300 rpm.

HTH

dunx

P.S. The extra weight and gear shifting may reduce acceleration, but I only swapped to get DCCD into mine.

rosssti

iTrader: (1)

Am I right in thinking both the UK300 and sti 6 speed both use a 3.90 diff?
So I shouldn't notice a power loss then?

dunx

iTrader: (3)

JDM STI rear is 3.9, UK STI is 3.54 but the JDM box has a shorter 5th/6th combo than the UK box.

Good for a track toy.

IMHO

dunx

Midlife......

iTrader: (2)

My Bug lost it's secong gear twice.......and I went six speed but chose a Jap box. In hindsight I should have gotten a UK box as it's a bit short for the motorway LOL

Shaun

rosssti

iTrader: (1)

so, if i go for a uk 6 speed box ill have to replace my rear diff, will my rear shafts fit to the new diff? or will they need changing too?

Kartingsteve

I have a uk six speed in my bugeye wrx and still running the orignal diff , you need sti rear shafts and hubs to use sti diff.

rosssti

iTrader: (1)

im trying to keep the cost down, so im thinking a jdm box now, so i think all ill need is the box with linkage and prop?

Paulo P

iTrader: (42)

Find out what the ratio is of your diff, if it's a 3.54 you don't need to change it as I said.

Midlife......

iTrader: (2)

Jap box needs matching rear diff because of the ratio's (I think that's right.......I had to buy a jap diff and IIRC it was about £400 plus VAT...)

Shaun

Paulo P

iTrader: (42)

Any box requires a matching rear diff lol If you don't want to change your diff find a box to match In this case I think the UK sti 6 speed is his best option providing the rear diff is what I think it is.

Midlife......

iTrader: (2)

It was post 11............"keeping the cost down by going Jap" that I was trying to answer LOL

Shaun

Paulo P

iTrader: (42)

Post 11 makes no sense at all lol because he would definitely need the rear diff

dbrad

iTrader: (26)

Fully rebuilt and upgraded JDM 6 speed available from me, if your interested pm me.

andythejock01wrx

Yeah, 6th on my 2006 Spec C/Type 20 is a bit short geared as a cruising gear on the motorway. Makes motorway drives great fun though, even if it is a bit of a gas guzzler!

rosssti

iTrader: (1)

I'm just trying to find out what diff my car comes with so I can buy what ever 6speed if any will go straight in with a prop.

rosssti

iTrader: (1)

My box number is Ty754vn2aa. Can anyone please tell me what diff I've got and if either the UK or jdm box is a match.

classicgc8

iTrader: (4)

yours is uk box and should have a uk 3.54 rear diff

Paulo P

iTrader: (42)

That code relates to a US MY02 Impreza WRX with a 3.9 rear diff according to the site I use

classicgc8

iTrader: (4)

true i use vn for uk and 3.9 final drive with 1.1 to 1 drop gears so 3.54 rear diff,

Paulo P

iTrader: (42)

I'm a bit confused by that code on the box, is your car a UK or JDM WRX Ross?

ditchmyster

iTrader: (7)

Speak to david at api, he will tell you everything you need to know for definate

rosssti

iTrader: (1)

It's a UK300 bud.

Paulo P

iTrader: (42)

Oh yeah, I forgot you said that in the first post that gearbox code says you have a 3.9 rear diff which is the same as the JDM 6 speed rear diff so you can use the JDM 6 speed box, cradle & linkage

dbrad

iTrader: (26)

My JDM 6 speed has just been fully rebuilt using the later (better) synchros and carbon baulk rings. I also added an AP suretrac centre diff to improve the handling. Box/cradle/linkage/speedo sensor £1700 collected from South London.

(Paul seen your engine build on FB, looking good )

rosssti

iTrader: (1)

Great, that's what I thought. Don't understand why its the jdm box that matches to my UK diff, thought it would of been the UK box really, I've been looking threw some box code charts myself and it does only say US car has that box, but there's not a full list of UK cars that I can find, there all just jdm and US with a couple of UK cars on it but missing loads.

Paulo P

iTrader: (42)

I know, that's what threw me mate and I've searched around and everything points at it being a US box