Axle ratio for 1.9td estate?

Can you work out what diff ratio the donor vehicle used? That should give you a good start to work from.

3 to 1 would be bottom end of what you need i expect. wheel and tyre diameter will be a massive factor though. i started out with 3.9s in my truck (with 31" tall tyres) and its massively undergeared, as the gearbox ratios are a long way off of what they were supposed to be. I'm going to swap it out for 2.7 shortly.

do you know what your gearbox ratios are? i based my calcs around top gear being 1:1, but it cant be given the speeds I'm getting.

the numbers youve hashed out in your tyre size are the important ones. do you understand how tyres sizing works?

youve got a good headstart with an overdrive top though- what box are you using? lt77?

what power/torque you have don't really matter (as long as there is enough to push the car along obviously) and youll have plenty with that engine. not overrevving the engine is much more important on a derv. my general rule to aim for is 3000 rpm in top at whatever you want your top crusing speed to be (80mph or so). its what our lupo runs, what i was aiming for with the truck, and roughly what my merc runs too (with the correct tyres anyway).


also, what rear axle do you have on there? an english? is they're any ratio better than a 3.54 available for them? not many axle have taller gears available than that.