six speed st gearbox in mk1 fiesta 957

[J-dog-ov-s6]

im currently in the process of converting my 957 mk1 fiesta into a zvh turbo, im havvin no problem building an fittin the engine, however i am going to use a six speed gearbox out of a focus st 170, just wondering if anyone has attempted or actually done this before? iv figured out what im doin about the clutch and flywheel just need a little info about what driveshafts to use an what hubs il be needin? Appreciate any help thanks!

[xrt_si]

There's a Mk1 Fiesta in this month's Classic Ford with a six speed from an ST170 fitted.

 

I spoke to the owner and know a couple of people or have performed this conversion in other Fords.

 

The gearboxes are smaller than the original Fiesta four speed unit so they require no modification to the inner wing for clearance which is good. They are a lot deeper though which creates problems with clearance for the original brake servo/master cylinder set up, so normally you have to go for a bias pedal box instead, which helps as the clutch needs to be converted to hydraulic, too.

 

No shafts fit straight up, you need custom ones made up that use an inner from a n ST170 and the outer to a Mk1 Fiesta. It's best to get hold of both sets of shafts to use as a starting point to work out how long to make them etc...

 

A mount needs to be made for the top and back of the 'box and you need the cable change mechanism from an ST170 as well, which needs to be welded in place.

 

Flywheel and clutch is normally a big problem, too - what have you got in mind?

 

You also need the starter motor from an ST170 as they are specific.

 

Hope that helps!

[J-dog-ov-s6]

yeh iv done some measuring up an think i can get away without choppin the neerside of the engine bay, maybe a small amount for the engine? there is no brake servo fitted to my car wich will probably help as i can just fit one around the box an engine when its done, plus im making a custom exhaust manifold and plan to use quite a large turbo fitted to the side of the engine above the gearbox so wud have to modify the servo anyway.

 

im thinking of using a clutch master cylinder off a land rover as i can just bolt this from the engine bay to the back of where the pedal is, making some kind of push lever system to operate it.

 

im using a rst flywheel and either an uprated rst or zetec clutch and pressure plate modified, by a company we use at work, to fit the large getrag splines on the st box.

 

do you know the differences between a mk2 xr2 hub and a mk1 hub? i know the driveshaft splines are actually smaller to accommodate larger bearings but will my steering rack fit an also the bottom ball joints? iv actually got mk2 xr2 disks pads and callipers and attempted to fit to my standard hubs but could not do this without modifying the hubs and carriers,iv already got the st driveshafts so looks like il be needing a set of mk2 xr2 hubs and driveshafts an making them fit the st box...

 

iv got the gearstick mechanism out of the st but no cables, iv read somewhere that the actual cables from a focus st are too short to fit a mk1 fezzy but dunno how true this is? maybe mondeo ones are longer?

 

Cheers James...

[xrt_si]

Yeah a Zetec and 6 speed should go in with no work to the inner wings on either side if you position it right, but remember it needs to be in the middle as you want equal length shafts, or near enough.

 

Resplining the clutch is handy if you know someone, though the 220mm set up a little small if you're going for big power.

 

For the hubs - I can't remember for definate to be honest, been awhile! The bottom arms are different in a Mk1 and Mk2 but only from where the tie bars bolt up, as far as I remember the ball joints and steering side of things are the same.

 

You've got no choice but to use the Focus cables - they are specific to the six speed gearbox so you can't use anything else. They are plenty long enough though, a mate had them in a Mk6 Fiesta and another mate had them in a Mk3 Escort.

[J-dog-ov-s6]

yeah i thought that about the clutch also but its difficult finding a flywheel that will work, possibly goin to get the guy that mods the clutches to put an extra diaphragm spring in the pressure plate to put double the pressure on the clutch plate to avoid slipping, but then again with it being a light, front wheel drive car the wheels will probably loose traction first...

 

just need to finish porting my head now then can start putting it all together

 

cheers mate youv been very helpful!!