Hi all,
So I’ve been doing some research on braking systems, and read that S1 brakes are as good as is needed. Yet the S2 brakes were “ upgraded” with 3 pot calipers, and larger rotors. I believe with the S3 they went even further. So to me the implication is that the factory thought they could improve the S1 brakes.
Thoughts?
I upgraded my S1 to S2 brakes. Much improved feel and stopping power. Jaguar didn’t make the change for no reason. Best upgrade I’ve made after changing out the 3.54 diff.
in my experience S1 brakes in perfect condition give adequate braking performance. The later brakes have a better seal system and their braking performance doesn’t deteriorate as quickly as the later ones
They changed to radial on S2 so were able to increase stopping power without risking more frequent lock-up. When you say larger rotors are you just referring to thickness rsised to 1/2 from 3/8”?
Yes a thicker rotor along with 3 pots and larger pads
What is it you hope to improve? The fact is, for all three E-Type brake systems, and “upgrade” will NOT stop the car any faster than the system the car left the factory with. ALL are more than capable, when properly maintained, of locking all 4 wheels. There are only two things that can be improved:
Pedal “feel”. The S1 Dunlop brakes work well, but pedal effort is highly non-linear. Making a maximum effort “panic” stop takes a LOT of pedal effort. The later systems reduce this effort through a combination of larger pad area, and a much greater vacuum assist. Simply swapping the stock front calipers for something like the Wilwood calipers will give the same result.
Brake “fade” can be reduced by using vented rotors. However, there are two problems here. First, I STRONGLY maintain that ANYONE who experiences brake fade when driving on the street, even with the stock Dunlop system, seriously needs to modify their driving style. Second, the rear brakes ALWAYS fade first, due to the inadequate cooling caused by their in-board location. Adding vented rotors to the rear is non-trivial.
So, my advice: If you have the stock Girling brakes used on the later 4.2s and V-12s, change NOTHING. If you have the earlier Dunlop system, and find the pedal effort a problem, install Wilwood calipers on the front, move the old front cylinders to the rear. In either case, maintain the system properly, with good quality pads, and regular bi-annual fluid changes, and you’ll have about the best brakes you can have. Anything else is a purely cosmetic change that will have no practical benefit in the real world.
If you’re driving on the track or other competition setting, any solution that does not START with adding vented rotors to the rear, and forced cooling air supply is a complete waste of time and money.
Regards,
Ray L.
Ray. Do you know if 4 bolt Dunlops 1 3/4 solo piston will fit on 4 bolt solo piston Girling rear Girling caliper casing ? I ask as my late '66 build fhc has Dunlop up front but 4 bolt factory Girling on rear. Are the piston flanges same location between Dunlop and Girling (solo pot type).
Patrick
'66 fhc
To me, the ability to lock up all four wheels in a panic stop is not the measure of an adequate braking system. You should be able to bring the car to a smooth, sure stop from any speed without having to stand on the pedal.
The S1 4.2 system is good, but the S2 setup with thicker rotors, 3-pot front calipers, and almost double the swept area is a big improvement.
Ray, Thanks for the detailed reply. I have the Dunlop’s (which seem almost identical to the 1959 MK IX I drove through college many, many years ago.)
My car came out of an estate, where the 94 yo PO didn’t drive the car much at all. So I’m not feeling confident about the brakes, and I they do stick on for about 2 or 3 seconds at a stop light. Not sure that is normal… or what it indicates. I’m guessing maybe pistons sticking in their bores.
So I always like a car that stops as good or better than it runs, and it might be cheap insurance to go through them.
I just picked up a new set of Wilwood calipers and vented rotors at a great price, so I’m thinking I should go down that path, although there is a part of me that likes the original. Perhaps I’m sentimental
Do you have an opinion about Wilwood vs the alternate conversion set that SNG Barratt sells? This is the vented option with Aluminum calipers.
https://www.sngbarratt.com/us/#!/English/parts/b9397906-2682-4db4-b8f6-9fcfa32b760d
Seconded…
The standard S2 brakes are excellent. I am in the process of upgrading an S1 to a complete S2 braking system as a drivers car.
Last year on the Nurburgring, I had to do what in effect was an emergency stop at 137 mph to zero in the coupe. The S2 brakes coped no problems, although we had a fair bit of smoke in the pits afterwards!
Just amazing for a 50 year old car.
Afterwards, the brakes recovered just fine. No warped discs, no funny pedal, not even a squeal. I have Greenstuff front pads.
Anymore braking power and I think I would worry about the strength of my wire wheels!
I have no experience with that kit, but I’m sure it works just as well as any other solution. Remember, the rears will ALWAYS fade first, so why bother with vented rotors on the front only?
Regards,
Ray L.
And whether any particular system meets your criteria is purely subjective. The fact is, NO system will stop the car any after than the stock system, unless other modifications are made to increase tire traction.
A “big improvement” in feel only. NOT in actual reduced stopping distance.
Regards,
Ray L.
I know this is an old debate, but if anyone is watching, I have a S1 3.8 and got terrible brake fade on track days. I upgraded the front to a 4 pot ventilated disc system and the behaviour on track days was transformed.
If anyone is interested, I managed the conversion quite cheaply and with no modifications to the car. The discs were from a BMW. They were the right diameter but need honing out a little to fit on the hubs. The callipers were Girling from a Volvo and fitted the existing bolt pattern.
