Hi,

I've jus had a ZZR1400 put into my formula 27, but the diff is doing my head in. It had an English axle with a 4.1 diff. Unfortunately the lowest I can get with my axle is 3.54 where ideally I want a 3.14.

The garage that do the work on my car have asked me to look into how easy it would be to swap the rear axle for something that would be compatible with a 3.14 diff.

Has anyone done this or got any idea how easy / hard it would be to do? I have put a lot of time effort and money into the car and this is spoiling it somewhat.

Thanks

Before you go down this route, I would suggest you are able to say with certainty that the ratio is incorrect for your engine. From your other thread, I think that was questionable....

The escort mk1/2 boys do this all of the time but so from that I can tell you will need brackets welding on to replicate your English axle trailing arm and shock pick up points. The other thing to check is the overall hub to hub width as I think the English has at least three width and I suspect the atlas does as well. Finally, if you have had the English converted to disc then check the atlas will need brackets (bolt on or weld on) and possibly hub mods to take your calipers.

So, I would not think it was impossibly if you can get the right width, the bracketry should be possible to sort out after that.

You would need a baby (narrow) Atlas. But, and it is a big but, they weigh a ton compared to an English Axle.

Can you not use a 3.54?

A quick google provided the following -

English axle widths flange to flange (not hub face to hub face)

capri mk1 (4 cylinder); 49.5"
escort mk1/s; 48.5"
anglia 105e; 44"
anglia 307e (van); 46"
cortina mk1; 47.25"

Atlas widths

52" capri mk3
50" capri mk1/2
48.5" European escort mk1 (often called baby atlas and sometime can be a cut down version of the capri ones)


This may also help - http://www.classicfordmag.co.uk/files/2012/01/CLF176.definitive.pdf

lets also not forget that a baby atlas will cost you a fortune as this is the one all the escort boys want.

I just realised why do you want a 3.14 diff ratio? how fast do you want to go? Jeffs pulls 150mph at 7-8000 revs with a 3.54.

What is your max revs?

[Edited on 26/8/15 by Dopdog]

As mentioned above (and in your other post) - you need to establish what rpm you are actually seeing.

I put the figures into my gearing calculator with a 3.89 diff and 9800rpm, that gives only 108mph in 6th gear which is about what you claim to be seeing.

I suspect that you have the lower (9800) rev limit imposed because the ECU is not seeing a speed sensor reading.

If you were getting the full 11500 rev limit then your theoretical to speed should be about 127mph

quote:

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Originally posted by Dopdog
I just realised why do you want a 3.14 diff ratio? how fast do you want to go? Jeffs pulls 150mph at 7-8000 revs with a 3.54.

What is your max revs?

[Edited on 26/8/15 by Dopdog]

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To fit a Capri atlas axle to a locost is simple.

The back of the tunnel needs a little modification to clear the nose. You then weld on new brackets with the same spacing as your current axle and fit some wider arches.

You could increase the front track with new wishbones and you could shorten the axle to baby atlas spec.



Rescued attachment CapriAxle3.JPG This is Mark's but I just copied his

Thanks for all the replies and info. It's really a last resort, and I probably won't need to do it but just wanted to know.

First I'm going to try getting the 3.54 diff internals and maybe try bigger rear tyres which should help gear it up.

Looking at bike clocks the ZZR revs to 11,000 with peak power at 9500. I am unsure if mine is revving to the redline as the Rev counter isn't working properly so I'll do some testing this weekend. I wish I'd just got a set of original bike clocks... If not then I might need to look at how to get rid of the limiter (speedohealer?)

Thanks again