gear ratio's

[howie p]

how easy/possible is it to change a gear ratio?

i was thinking, whilst driving up the M1, that having a longer 5th gear would mean at any given speed in 5th it would be less than the original gear ratio.

so eg normally at 4000 revs would be 80mph

could this be changed to 3500 at 80 mph?


bad idea? costs?

i understand that the gear would not pull as well but theres always 4th or even 3rd

 

[edde]

Expensive there are ways round it have the 5th gear increased like Algorami had done or chnage the final gear ratio but then all your ratios are longer.
Its not cheap though Algorarmi had it doen as his box was already in pieces as they were putting a LSD and lower ratio's in it for racing but your looking at £1k at least in costs.

 

[howie p]

what about a mk 1 172 box? cost?

 

[haitch]

not sure on mk1 box but its got to be similar, Yasser had his done on his cup at about £1500 i believe.

 

[edde]

what about a mk 1 172 box? cost?

Ratios arn't much longer on the box total cost say £400 to swop boxes plus new clucth (might as well) then £400 for a box maybe but you'd not know what its like quality wise.
A dci 80 box is the way to go but the ratios are massivly to long.
1st gear would go to 35mph
2nd to 77mph
3rd to 110 or so
4th to 150ish
5th to 180ish
But it you wouldn't get to 180mph without way more power at 80mph it would be doing 3k though.