Peter May Type 900 Front Brake Upgrade

[bobwhittaker]

Has anyone fitted or had experience of the front disc upgrade that Peter May supplies.

[Splat]

Sort of......

I originally fitted the Frontline 9" upgrade with the original "Minilites" (and from here on I'll refer to either "steel" or "wire" for the two types of wheel). This consists of two (reproduction) MGB callipers, 9" steel discs, either drilled or not, two aluminium disc carriers and the bolts to connect carrier to disc.

The Frontline kit is for steel wheels only. They don't do a kit for wires. This wasn't a problem when I first converted to wires, with splined-hub converters bolted to the original steel-wheel hubs. But I was deeply dubious of these converters, which was borne out when a rear wheel detached, with its hub converter, thankfully at low speed on a roundabout! This prompted a change to proper splined hubs, front and rear.

Both ends would be a problem, the rear as I had a steel-wheel axle and the front as the Frontline 9" kit can't be fitted to splined hubs. Peter May's products solved both problems. Firstly, he produces hardened half-shafts with splined hubs to fit steel-wheel axles. Handy! Secondly, it turns out that the Frontline kit has been reverse engineered from Peter's original!! But they only purchased a kit for steel-wheel cars, not wires. The difference is purely in the width of the aluminium disc carrier. The steel-wheel carrier is about 2" deep, whilst that for wires is maybe 1.25". Peter was generous enough to provide me with two of his carriers, despite my having bought a kit ripped-off from his original.....

So yes.

I wasn't overly impressed by the original brakes. However, nor was I blown away by the upgrade. Pedal feel was awful and retardation average. It wasn't until I fitted the (mighty pricey) enlarged AP Racing master cylinder that they really worked. But work they now do! Good feel, progressive pedal and more than enough power. The master cylinder is a bespoke item and AP wasn't able to sell it to me direct. They're also made in very small batches, rather infrequently. I had to wait about six months, but reading various forums I did quite well. Some had waited over a year.

Other forums? The master cylinder is made for Caterham, with Westfield taking a tiny number. And it's considerably cheaper from Caterham. Here's a link (and it's out of stock!!)

http://www.caterhamparts.co.uk/product. ... product=29

Edited to add the following:

Firstly, you know what Jan's going to say and he's almost certainly correct. If you go down the MGB calliper route, go for twin master cylinders with a balance bar. I believe that Westfield have the latter and the chassis mounting plate is pre-drilled for the former.

And I note that PM only markets the 900 kit for wire wheels now. If he still uses the same discs then I have a pair of disc carriers for steel wheels that you can have if needed.

[bobwhittaker]

Thanks for the prompt and comprehensive response. My car is on wire wheels and it would be my intention to upgrade
the front only. I only use the car on the road and I am long past the boy racer stage, however even for only semi fast road
use I feel the standard set up is only at best adequate and this considering The Eleven weighs some 190 kg less than the
Midget . This in traffic some 50 years on from my donor's design / build. I am using the 1967 pendant pedals and single line
master cylinder ( All components were new at build ie master cyl / discs / caliper seals pistons / pads drums shoes slaves )
The system bled up OK and pedal is good, however the pedal pressure is high and to give confidence I feel an upgrade is
needed.
I have bog standard pads and wonder if there is a better material available ( Cheap Fix ). From your comments it
needs a deal of thought as it doesn't sound like swopping to the PM kit alone is going to be the answer.
Cheers, BOB.

[jonclancy]

Hi Bob,

As a cheapest starter for ten, try Mintex 1144 pads. A huge difference from stock items, and they work from cold.

Cheers

Jon

[Westfield 129]

I have the same hanging pedal setup on my personal car. using a .75 master cylinder. It's an early chassis, LHD.

My initial problem was poor modulation and feedback, with an inconsistent pedal. Sometimes brakes, sometimes, well, not so much brakes.

The fix, after replacing every other component in the braking system without improvement, was a set of expensive Timken taper wheel bearings and a set of shims so that the torque could be properly set using the center spacer in the front hubs.

Even the engineers from Wilwood came by (they are a few miles down the road in Camarillo) and suggested a new pedal quadrant, but that didn't make much sense to me, as the quadrant was not causing the problem of an inconsistent pedal.

In the end, the problem was "knock back" from the lateral play in the old ball bearings (I had replaced them numerous times, with a small improvement, only to find the problem returning). The taper bearings fixed the problem, and I now have very consistent braking, making my canyon driving far more enjoyable (read: faster, especially down hill). I hammer the brakes. Very consistent. Probably why I have not done disc brakes in the rear (yet... I have to do a trick wheel package to work with the 4.50 and 5.00 Dunlop vintage race tires, first).

Note... If you are going to use 72 spoke, 15" wire wheels, you will have to check the clearance between the hub and the caliper with the small Spridget rotors. You will have to grind (mill, if you have one) some off to get clearance so that the wheels will turn.

I imagine that with a larger rotor and larger calipers, the problem may move out of the way of the wire wheel hub's circumference. Just something to think about, even with proper wire wheel hubs.

I will be looking at Peter May's larger front brake setup.

As for using some of the Spridget rear disc brake setups, there are problems fitting the rear calipers with the hand brake. Appears that it needs to be in the same place as the Panhard Rod mount on the axle... Maybe a change in the brackets? Just a problem that a builder is running into here as he assembles his car.

I will be working on another disc brake setup in the near future, I will let you know how it works out.

Anyway, back to the ftont brakes... I am running R4S pads from Porterfield Brakes, a local company. They are carbon based, and quite good. Lots of adhesion, light pedal pressure, extreme fade resistance.

However, the Mintex (my previous pad, came in a box with the car) proved to be quite reliable, and gave excellent feel and pedal pressure. I only switched to Porterfield as it is my preference, and I ordered a set for my RHD build). The Mintex may be your best bet to getting your brake pedal pressure and feel under control if that is your only problem. You may consider replacing the front rotors when you replace the pads, as they may be glazed. You could also turn the torots, but I don't think that the cost of turning makes sense since the rotors are actually quite inexpensive to replace.

When making changes to the braking system, especially when adding larger front brakes or disc rear brakes, the master cylinder size must be considered. Some of the systems will have recommendations, while others will use the pieces that you already have. I make my choice by feel. Bigger if the pedal throw is too far and too soft, smaller if the pressure is too high.

The tandem master cylinder used by Westfield for its Spridget brakes is not an ideal combination (not really a good match for the calipers and rear cylinders), and I have found that the feel and modulation is not up to that of my old single master system, let alone my RHD car's Twin Master Cylinders (.75"). which give perfect feel and pressure, along with excellent front to rear balance with the adjustable bias bar (supplied by Westfield).

Amd, if an inconsistent pedal is the problem, a set of taper wheel bearings is the permanent fix.

[bobwhittaker]

I now have a lot more information than previous to consider and I will work my way through starting with " The Cheap Fix "
of different pads. Considering the use I give the car and my driving style I do not need to extend to disc rear brakes and
a progressive fix will be adequate rather than an " Ultimate Fix ".

Thanks for the feedback. Bob Whittaker

[bobwhittaker]

Have now fitted and " bedded in " Mintex 1144 pads on the front. There is a noticeable improvement over the previous pads
and considering the type of use the car gets I now feel that the system is more than adequate.

Regards a " cheap fix " these pads were some £51.00 from a well known Midget specialist, whereas the MGOC catalogue shows
Mintex pads for a midget at £9.95, however the catalogue doesn't quote a grade and I only discovered the price difference
after fitting. At over 5 times the price of what I presume to be standard pads I would expect there to be an improvement.

[jonclancy]

Yep, Mintex do standard items, too.

1144 and 1155 are the go to pads. A friend gets good results from EBC Greenstuff in his B, but I have used 1144 on a couple of trackdays and they were great. Unlike me......

[erictharg]

Having raced my Eleven for 4 seasons now I believe the most essential improvement in brake performance for "fast" use is first the pads. I initially did some track days and found the stock pads fried very quickly (no surprise there...). Mintex 1144's were great for the road and track days but still not up to full on racing. The biggest improvement in feel was going to dual cylinders and a balance bar (used the Westfield kit). Pedal is much heavier but almost zero slack. You just need to get used to pushing harder than in your servo'ed daily driver! Brake force then feels proportional to force, rather than travel at the pedal. For a fast road car I'd recommend stock discs & calipers with 1144 pads and a dual master cylinder set up. Will also handle all but the most brutal track days. I'm still running Midget brakes but with 1155 pads on the front (still fine on the road), dual master cylinders and Minisport uprated Mini shoes at the rear (not essential for the road). I use the best quality Brembo branded discs (still very cheap!) and get two seasons plus from pads and discs. Rear shoes do tend to wear - maybe two sets a season, but again, for the road this won't be an issue. I plan in the future to use a similar set up to the Peter May 900 kit but it doesn't accommodate taper roller bearings, which I'd like to move to. Not because of any running problems with the stock bearings, but to improve serviceability. Every time you remove the hub with the stock bearings you run the risk of damaging them as they usually come apart and need "popping" back together on re-assembly. If you are happy running stock wheel bearings on the road (and I would be) the Peter May kit is a good value route to more stopping power. But I can't think of any time of the roads when you'd need that much braking.

[Westfield 129]

I once did a huge improvement to the brake pads on my Mustang racer. The car already had the bigger brakes from a Lincoln coupe (the hot setup back in '90}, and adding the Porgterfield R4 race pads reduced the fade problem, but caused another problem on the tighter tracks that were more demanding on the brakes. The discs would heat up so much that the grease in the bearings would melt, and the little hub bearings would fail. While the brake pads could stand the heat, the wheel bearings could not. I had to replace the front hub bearings after every event... Well, they were cheap... Eventually Ford had much larger rotors, bigger PBR calipers and sealed wheel bearings, that would last about 9 hours...

As for the harder pedal pressure with your dual master cylinder setup, what size master cylinders are you using?

I had started with 5/8" and ended up with 3/4" (same as the single brake master cylinder that I use on my early car). The brake pressure is not excessive, and with the Porterfield R4S (street or vintage race type), the pedal pressure is about the same as the single cylinder setup on my early car. The braking is really precise with the dual master. This is far better than the "stepping on a dead animal" feel of the tandem master cylinder that is supplied with the current LHD and RHD kits.

.7" master cylinders are also available, and will incrementally reduce the pedal pressure with only a very small amount of additional travel. The beauty of a twin master cylinder system is that the master cylinders are inexpensive, and can be changed out to get precisely the feel you are looking for.