1330cc Engine spec help - Gearbox
Turbo Mini Forums

Yeah go for a 3.1 (if your runnings 10 inch whels), as a turbo engine is naturally more torquey it pulls through the gears really nicely. On 13s a 3.44 may be fine but ive never had 13s so I couldn't say.

If you can afford a straight cut box and drops then go for it, but if you can't then a helical box and drops can last. As long as you have some mechanical sympathy and your not constantly thrashing it from a standstill they are pretty robust.

I drove mine as a daily for a year (covering 10k +) with helical drops and box running about 130bhp, and it was fine. But I drove it like a daily and didn't have my foot planted all of the time.

If your building the car to be thrashed around a track etc... then straight cuts are a must. If its mainly used for commuting with the odd emergency start etc.. then helicals can last.

https://www.facebook.com/pages/Fusion-Fabri..._homepage_panel

www.fusionfabs.co.uk



1/4mile in 13.2sec @ 111 terminal on 15psi

That ratio calculator is quite wierd to get used to!

So matty, you reccommend a 3.1 final drive? I'm going 10's in the next few weeks so ill defo have 10's when the lump goes in.

It will be used as a show car, weekend, basically my toy.

I was looking to get about 150BHP, however, looking at some people's builds with the same spec I had in mind I think I'll be looking at a bit more to be honest!

If your going for 10s then a 3.44 will be way to low, definitely go for a 3.1.

From the power you want and description of a toy (weekend warrior) your best going for straight cut, because if you haven't got the worry of needing the car for work the next day, your going to want to give it some stick. lol

https://www.facebook.com/pages/Fusion-Fabri..._homepage_panel

www.fusionfabs.co.uk



1/4mile in 13.2sec @ 111 terminal on 15psi

So your saying if i use the helical gears with straight cut drops, the gearbox wont last if I give it a little here and there but not proper ragging it?

Why does everyone keep on suggesting different diff ratios for 10s and 13s??

16.51mph/1000 rpm 3.44 on 10's 107 mph =6500rpm 165/70 10

17.2 mph /1000rpm ,3.44on 13's 112 mph =6500rpm 175/50 13

18.32 mph/1000 rpm 3.1 on 10's 119 mph =6500 rpm

19.09 mph/1000rpm ,3.1 on 13's =124 mph 6500 rpm

thats not allowing for tyre growth ,which on my 12's was 3.22%

editted for tyre sizes ,this was done using gearcalc software.

Edited by robert on 29th Nov, 2011.

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

Which 10s, which 13s?? My A032R(Which most of us use) tyres are bigger than most of the 175/50-13" ones. I don't care about theoretical sizes, go and have a look.

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will