11 replies to this topic

[@stevedamini]

Hi Just wanted your help with a couple of things.
What final drive ratio shall I for I do a bit of motorway miles but mainly round town driving?
I'm thinking of installing a minispares heavy duty gearset but everyone seems to be going for straight cut gearset wanted to know how noisy they are with helical drop gears.

[KTS]

..what engine & camshaft ?

[@stevedamini]

1293 kent 266 cam aiming for 130bhp.

[alex-95]

1293 kent 266 cam aiming for 130bhp.

Is that with a turbo or supercharger? 130BHP will be hard to hit with an NA engine. 

I've got a 1293, kent 266 cam, 1.5 rockers, Kieth calver GT head, HIF44 carb and I'm running a 3.2 Diff which is great for the back roads and pretty good on motorways.

 

EDIT: Just realised its in the forced induction section

Edited by alex-95, 01 October 2022 - 06:42 PM.

[bpirie1000]

How many miles a year.

Straight cut gears are a hoot but they wine....

Alot........

[@stevedamini]

Its a turbo its going to be a daily 6-10k a year

[stoneface]

It's all a matter of personal preference but I wouldn't run SC drops on a daily car unless you like ear plugs and don't want to have a radio.

[nicklouse]

Standard box and pick a final drive to suit the power band and driving environment.

[@stevedamini]

So I shouldn't bother with the gear sets?

[Ethel]

Doesn't look they're available, anyway.

 

If you're wanting to run a taller diff it'll make 1st & 2nd gear even taller on a close ratio box, which are really intended for higher revving competition motors to keep them in their narrower power band. Even with forced induction you could find yourself lacking enough torque just to get moving on a steep hill. A good condition standard box should be fine with 130hp if driven sensibly and you'll have more chance of finding individual parts if you do break any.

[stoneface]

I ran a 3.2 diff with SCCR gears on a NA 132bhp 112lb/ft and it was hard work to get going. Not impossible but clutch slip was required.

Starting on a hill or carpark ramp was a pain.

It's up to you depending on your use, but for a road car around town I wouldn't go that route.

I don't know what its going to be like yet as mines not back on the road, but I've keept the 3.2 diff and gone with a standard A+ gear set.

[KTS]

if you've not seen or used it, the Guessworks gearbox calculator is an excellent tool for showing what the different gearing options give 

 

http://www.guess-wor.../Tech/ratio.htm