I have a 9a 2lt 16v on TB's with a good bit of work done to it. It is going into a mk1 golf. What gearbox would be best suited? Car will be used for track days, sprints and sum sunday driving to shows etc. Im not too worried about top speed. (don't want any points on my licence) Id like her to be quick up to 4th and possibly longer 5th for motorways etc. I was thinking of a shortish ratio box and then change 5th gear for a longer one. Also which diff should i get?? ATB, LSD?? Any suggestions?
possibly just a standard valver box with a different final drive to shorten the gears a bit? not had much experience with diffs, but two of my friends have had quaife atbs, one in a civic, the otherr in his turbo integra, both have given amazing results, and the integra doesn`t really have any trouble putting down 250bhp....
8v gti ACD box has identical 1-4 ratios as a 2y box, but with a taller 5th for better cruising. The input shaft on an 8v box is smaller tho, so you'll need an 8v clutch friction disc Check out GVKs website, theres a handy dandy gear ratio calculator.
I used a 3.94 FD in a 2Y ratio'd box with a Quaife diff. Likewise Bill B did with his Jetta, and RobT with his Ibiza + others. No need for a plate diff since Quaife's are maintenance free, whereas plates wear out. Leaves you with a cruiseable 5th, but far more useable, and closer gears 1-4. 4.2 FDs are out there, but rare, and 5th will be buzzy! Make all the decisions beforehand on the FD, then buy the Quaife, since there is some mixing and matching of 8V & 16V components IIRC. Main point of this is the Quaife 8V and 16V diffs have an outer diameter 2mm different, to suit different IDs of 8V and 16V crownwheels. You can't grind the Quaife's to get them inside the wrong crownwheel, though you can lathe out the crownwheels. Best to talk to someone who knows this inside out, unless you're doing the build yourself. Budget for 900-1.2k, with the Quaife, CWP bolts, bearings, labour etc
