Hi, Could anyone please suggest me a short ratio gearbox that would fit this engine ? Thank you, Simon
Hi there. There is not a suitable oem box with lower ratios than the 2Y that will fit your car. The early mk1 GTI used the close ratio gearset and a 3.89 FD. However this box does not have the casting lugs to accept the mk2 gearbox mount, or the facility to take your 100mm inner CVs. This being the case you would be looking at a hybrid gearbox build to lower the ratios, either using a 3.94 or 4.25 FD. This would also require a 4th gear and diff change as the ID of the lower ratio crownwheel is smaller than the 2Y 16v box by a couple of mm.
Thank you for the highly technical answer! Ive spent about 3 hrs on internet looking for an answer to this question. Well, never thought it would go as far as building a hybrid box, as Ive heard that 1.3 mk2 g'boxes could fit. Shame (
The mk2 1.3 gearboxes are a different type of gearbox and not compatible. They are the 084 (4 speed) & 085 (5 speed). Where as your gearbox will be an 020 model. They all have separate codes which determines what the ratios are within the box. Of course some people may have built hybrid boxes with them in the past, so the code cannot be used as a 100% sure way of knowing what is in the box.
late 1.6 gti 5speed gearbox as early ones are 4 speed about 1980 they are hard to find as they only made them for a year or two before they went 1.8 im sure code FM is the same as FD
Have a read through the Transmission FAQs at the the top of the section. Imparticular have a read through this link as it is a very good informative site. http://www.brokevw.com/020ratios.html
I'll stick with the 2Y gearbox. Won't make any changes to it either due to lack of time. However, cerips, if you are still interested: The car will be used to learn sports driving skills on gravel/tarmac. Tyres - dunno yet. What's wrong? - Due to lack of knowledge we thought 2Y is not a short ratio gearbox. (Just logically - 1.8 engine will have longer gbox than 1.3) ) I understand now this is not the case with 2Y. Power - Have no idea about power tbh. Mods: engine head skimmed significantly, material taken off combustion chamber (to improve gas flow), lightened flywheel, lightened conrods.
You need to use the 8v 4th gears on the 4.25 output shaft because the output shaft varies on the 16v. No problem as the ratios are the same. Just means stripping a 3rd box to source all the relevant parts. That being the case if you start with an mk1 or 2 GTI box then you only need to strip 2 boxes down, one for the FD and one for the gears. I could launch in 2nd with my 4.25 FD and 2.12 2nd gear, first was all but redundant. The fact 2nd was low enough to take off in, meant that it was too low for certain corners on track. The lower FD does begin to bring in compromises in certain areas.
you could switch to VWMS type side engine and gearbox mountings, these are welded direct to the chassis legs and are basically mk1 golf stuff so you can then fit a short ratio mk1 gti box
Didn`t strip any other `boxes` ... sourced the 8v cog direct from VW - all thanks to Martin (Hotgolf)
It gets a bit pricey that way. Not sure some of the parts are still available from VW these days. The 4.25 FD was never fitted to a gearbox with the close ratio GTI gearset as standard. Therefore it is possible to build the box by using 2 gearboxes if a mk1 or 2 8v GTI box is sourced. As the 4.24 FD was fitted to gearbox casings that allows the use of the mk2 rear gearbox mounting, and 100mm inner CVs it makes sense to use it. I have never heard of anyone snapping a gearbox input shaft, so the need to use the larger 16v 2Y coded gearset as a donor just makes for extra work or cost IMO.
It can be done! the guy i knew who did it was running a syncro with too much power though. plus he also killed an abf which isnt easy
Hi guys I'm planning a 4.25 diff in a ACD mk2 box. ACD have identical ratios as 2Y with a taller 0.85 fifth. All or any input will be appreciated guys!
5th = 0.89 vs 0.91 on AEB/2Y FDR to 4.25 will increase overall axle torque and reduce overall speed in gears. Depending on your engines torque curve the .89 gear will affect the rpm drop you will experience on a 4th to 5th up-shift. Brain and calculation tools offline at the moment but I am sure someone would put some numbers in a gearbox calculator and determine what vehicle speeds or RPMs will occur at shift points for the various diffs and gear sets.
