2.48 or 2.29 1st

[waynemk2]

Hi
Just looking for advice
Going to run a 2.2 Pinto on 48's
13" wheels
4.6 cwp

Not sure on what 1st is best 2.48 or 2.29

Whats your thoughts?
Cheers

[rallyrob]

2.48, Im not 100% sure but Im pretty sure that's what the 1st gear is in my Tran x..
Mine's 13" rims and a 4.6 cwp.

[Erikmex]

Depends, what you're using it for, where your power band is and how fast you want to go in first, use a speed calculator work it out.

[rallyrob]

True enough I suppose..

[Erikmex]

If its for rallying and your more concerned with a long first for hairpins etc, go for a 2.29....if you're wanting quicker starts off the line...go for 2.48, both will be ok with a 4.6. I run a 2.48 with 4.4 for hillclimbs with a similar spec of Pinto and its good for tarmac launches. Alot also depends on what your 2nd gear ratio is and so on!

[waynemk2]

Thanks so far guys

The ratio options i have are:-

Running 185/60/13 @ 4500rpm

1st - 2.29 27mph or 2.48 25mph
2nd - 1.61 38 mph
3rd - 1.225 50mph
4th - 1.1 56mph
5th - .82 74mph

I would be using for mainly hillclimbs, sprints, and the odd tour.
Cheers

[Erikmex]

Why would you be only revving to 4500 doing competition? you need to look at the speed at your shift point revs, either will work well but personally id choose a 2.48.

[Mkdu]

I had a 2.48, then move to 2.24 with new box, now 4.9cwp but will change for 5.1 with new axle.
I used a calculator to see what's going on with cwp and ratio. As reference a zf 5 speed gear ratio in mind

happy with that 1st gear
The problem is the drop between 1st and 2. I pay attention to that.