Conversation Between Karlos G and andrewow47

Hi Andrew,
RST ratios will not be ideal for a NA powered car for sure, the Sport Ka ratios would be much better suited (loads of acceleration but top out around 120mph in the Ka) but has a hydraulic clutch as you have said, the other alternative would be an Escort GTi gearbox as these are quite close and cable clutch I believe, you could then just drop your RST LSD in and your sorted.

Karl

Hi Karlos

I was advised to message you about the ib5 gearbox.

I am putting a 2.0 silvertop zetec into a mk 3 Fiesta base kit car (Quantum H4) mechanically and suspension wise it is literally identical to a Mk3 Fiesta Si which has a 1.6 zetec engine and a bc box.

In addition to the 2 litre silvertop I want to upgrade to an ib5 box at the same time.

I can get hold of an Escort RS Turbo Series 2 box, but I've been told that the ratios might be too tall, but I like the idea of an LSD.

I have also been told that the Ka Sport box would have good ratios but it doesn't have a LSD and so I don't know which is the best option.

My car has a cable clutch, I don't know if I will need to fit a hydraulic clutch?

By the way I really liked your work on the St170 bottom half with a blacktop top half for the Zetec turbo, I might have a crack at that in a couple of years but I need to walk before I can run! I fancy trying to mate this up with a Jag x type manual 4wd transmission. My understanding is that the Jag has an mtx box, plus a transer box and obviously a propshaft and rear diff. I guess this is a similar set up to the Mk1 Mondeo 4x4?

Ny guidance on the ib5 plus silvertop would be much appreciated.

Andrew