I need to look at options avaliable to me to upgrade the internals of an IB5 box from a ka.

The car has the rs turbo conversion and the standard 1300 box has started to give up.

Has anyone had any experience with these boxes? What are the weak links? by fitting a quiafe atb slip diff, with a new set of bearings and fiesta rs turbo 3rd 4th and 5th gears be enough to cope with an engine producing around 210 bhp with a torque figure similar?

I want to keep 1st and 2nd as this gives me quick acceleration. Is there anything i have overlooked in regards to weak links that need to be addressed in order to build a box that will last.

Any help much appreciated

Dan

 

what exacttly is breaking down on it?

A CTS stage 1 box has IB5 internals i believe, so i'm surprised you've killed it

 

i am told its the bearings on the differential, im not entirley sure but they are sprung loaded and this is what wears which cuases them to be mis-aligned and therefore give you the whinning.

I know the IB5 internals are strong but this part with the sprung loaded bearings is a weakness.

I may be getting confused but if i changed this for a quiafe atb diff would that remove this problem ?

 

Well the differential has always been common to drop out even on the BC type boxes.

Having an LSD in there should help greatly as its not weak like a standard differential

 

im guessing then if my standard differential bearings have given up then by adding the quaife lsd this should solve that problem?

 

well...........it depends what exactly has gone, the bearings a standard differential run on are the same as the bearings an LSD runs on.....and they aren't sprung loaded

 

this is gonna be a case of buying the lsd and then opening the box up and finding out exactly what has gone and replacing, its guess otherwise really.

 

It'd be helpful to fully identify whats gone yeah

 

how much power have you got from ur car? and how much u spend? cos everyone at ford focus owners club reackons i cant get anywhere near 200bhp with a 1.6 zetec s, i feel thats terrible....

adz

 

My Zetec-SE shouldn't be too far off 200bhp.


As for the box, I use a standard Zetec-S box with a Bara uprated VC from an RS turbo.

 

I like this topic, as I'll be considering this in the future too.

Are you sure you want to keep 1st gear? I find it useless! its far too short and if I boot it in first all the way to the redline the engine moves so much it knocks the intake pipe off. Personally first is the gear I'd change. 2nd is fun though

IS it just a case of using any diff that will fit the IB5 box?

Adam01 - what do you mean you cant get anywhere near 200? the box wont take it or the engine wont produce it? if its the latter, i tend to agree.

JAmes.

 

The engine won't produce it - yet the super1600 engine in the JWRC fiesta does 215+ on a single inlet?

With standard valves.

 

Surely its some kind of high compression jobbie though?

JAmes.

 

14.5:1

But that's not the point - the engine can produce the power as shown?

 

I don't know if he's on here, but joey off my ka, put over 300bhp through a ka box and it held its own!!

 

not a standard one, as regards your box it should be fine, mines totlay standard apart from a rs turbo lsd in it, ive done 6k hard miles in it, i have nearley 180 bhp but less torque than you, but i do have biggers wheels and tyres, and as said above the cts units are basicley ib5 internals in bc housings, if your that worried then quaife do a gearset for it, but its £1500 and around £400 for the diff and a couple of hundred to get it all sorted and fitted, i would keep it standard and buy a spare box

 

14.5:1 hahaha, how's that not the point? You do know that the CR is very closely linked to torque and thus power?

JAmes.

 

Listen, you've just claimed the engine won't do 200bhp yet I've just given you an example of the engine running more than that power?

So back up your claims.

 

The engine will do that, with that compression ratio, but it wont be cheap and not suited to a road car. If your setup is the same as it, then it should be possible that your at 200.

JAmes.

 

Does the bc box lsd from the s2 turbo fit inthe ka box ok?? I got offered one last year but i didn't know if it was worth 50 quid, finding out if it didn't fit.

Cheers

 

i run a fiesta xr2i 1600 cvh in the boss and the welsh saloons i took apart a rs 1800 zetec fiesta box used the gear set onto the xr2i cvh shaft so close ratio then fitted the 4.06 crown wheel to match the shaft chucked in a quaife atb diff then fitted the 5th gear off the cvh xr2i gives alot top end oh and done all the bearings and seals any one intrested i can give you the gear ratios if you want on paper at 6000rmp should top out at 134 mph but 1st 2nd 3rd and 4th are close ratio from the rs1800 zetec been in all season and no problems ues a good oil top tip

 

The differential bearings are spring loaded, but thay can be shimmed to any spec you like.