Series 2 to Series 3 V12 Brake Upgrade??

[Retroman]

Hi,

I have recently bought a Series 2 with wire wheels and am told that V12 discs and callipers are a straight swap with no mods.

Fitting vented front discs etc seems like a good idea.

Can any of you pundits confirm whether this is a simple job or is what I am told yet another mechanical myth?

Certainly appear to be a reasonably priced conversion compared to the 'specialist conversions' available.

Thanks,

Nigel.

[MarekH]

The s3 has the same front calipers but with a spacer between the halves to accommodate the vented discs.

It may be a "simple" job but that is not the only difference between the two.

The brake servo is a wider diameter servo to provide more vacuum assist than the s2.
The s3 has no rear anti roll bar.
The s3 has power steering.
The s3 may have different width tyres to balance all of those effects against each other.
I suspect the s3 is a heavier engined car, so the weight balance may be further forward than on a s2.
You can also check whether your servo feeds the front or rear brake circuits first as this changed during production.

Combine all of the above and the brake effort and "feel" will no doubt be different. It isn't obvious whether just altering one item in that list effects an improvement or merely unbalances the whole.

If you are capable of locking the front discs, then you don't actually need more powerful brakes.

kind regards
Marek

[abowie]

If you are capable of locking the front discs, then you don't actually need more powerful brakes.

kind regards
Marek

[angelw]

Nigel Wrote:

I have recently bought a Series 2 with wire wheels and am told that V12 discs and callipers are a straight swap with no mods.

Hello Nigel
As Marek states, the S3 front calipers are the same as the S2 counterparts, but with spacers to accommodate thicker, ventilated Rotor. However, I can tell you for sure that the S3 Caliper/Rotor will not fit directly to an S2. The Caliper will, but the Rotor will foul to the point where it can't be fitted at all. The reason is that the offset of the brim of the S3 hat (look at the profile of the rotor as being a Top Hat) is greater than that of the S2.

I do this conversion a lot and I have supplied to me a Rotor Blank that has the correct Offset but without the attachment holes, which I machine in-house; I also make the spacers that fit between the two halves of the caliper.

You will get absolutely no initial braking improvement compared to the S2 Front Brakes, as the diameter of the Rotor and the Radial positioning of the S3 and S2 caliper is the same. Accordingly, Front Brake conversion on its own has no effect on the balance of the braking. The only improvement would be if you were hunting the car along and using the brakes hard, a lot, then the ventilated rotor would tend to prevent brake fade compared to the stock S2 rotor.

Regards,

Bill

[Retroman]

Gentlemen,
Many thanks for your advice.
I will keep them as standard check the callipers function, fit new pads and change the brake fluid.
Best wishes,
Nigel.