Like new car braking

[Chris Hawes]

The most recent DeLorean I have driven other than mine was Dan Shane's (now sold) and this showed how when set up correctly you can have a brake pedal that is as responsive as a modern car.

My car brakes very well but I have around an inch of travel before anything happens. After that the communication from the brakes to your foot is spot on from a responsiveness point of view.

This is my current setup:-
- I have Ed Uding's vented disc's and Kevlar pads on the front (the rears are stock)
- DMC Ltd re-manufactured front Callipers (silver finish opposed to the now defunct Cadmium finish still showing on the website) cured the brake judder that had gradually appeared over recent months.
- DMC Ltd Stainless brake hoses. Stainless versions are supposed to cure the swelling as per the OEM's although I have never experienced any swelling from the OEM's they were 25 years old and would affect my braking performance at some point so I felt it would be worth while to update whilst the system was re-bled from the previous weeks fitting of new callipers. So far I can feel no difference, but sometimes until you replace something you cannot tell if the old part was still spot on or not.

The Brake Master Cylinder and servo have not been changed in my near 5 years of ownership (could be original). I am guessing that the rod from the Brake Master cylinder to the brake pedal could do with adjustment. Otherwise apart from changing the two afore mentioned parts I am fresh out of ideas (and cash).
The system is completely air-free and the BMC is not leaking. I have good continuous travel to the carpet and when sat at rest the brake pedal is flush with the clutch pedal.
To recap, although braking is spot on I am looking for instantaneous braking when I first depress the pedal not after it has travelled an inch... I guess this can be described as spongy. As these cars have no ABS, that extra 1" delay time could cost me when it matters most...

[MikeH]

i would also like to know how to get such good braking for once i get my car i would like to have that spot on.

[stunned_monkey]

What you're looking for is as little pedal travel as possible. The servo does not affect this so although that can help improve things, we can ignore it for now.

You need to change the master cylinder if you want the system to be the best it can be. You want "new" braking, but not all the somponents are new. There're good solid reasons why an old cylinder will still work perfectly well but require a small amount of travel before doing anything. Put simply, the older it gets, the more you have to push it to get it to do anything because the cylinder will wear slowly along its length roughly conically. This makes for travel and/or sponginess.

Unfortunately ANY work on the brake system always results in an extended mission to get all the air out. Our usual approach is to get them working and safe, then a re-bleed after a few hundred miles and at least a few days.

You needed a re-bleed after the new calipers but you've also now had the hoses fitted which means in another weeks time or so you'll need another re-bleed...... you WILL have air in the system again. So you haven't felt any difference.... yet.

Dan did not have the same kevlar pads that you have, and his were all round with a 50/50 master cylinder. You have an original 68/32 (?) with kevlars on the front only.

Once you're happy with the pedal and that all the air is out, you can adjust the travel before takeup. The adjuster is part of the servo behind the master cylinder.

We've done a *LOT* of caliper/hose/master cylinder sets, including on my own cars. Kevlar pads are only really needed if you drive like Dan, or you for that matter I will be fitting a set to mine before too long because I did succeed in overheating mine recently on a 3 mile stretch of country lanes that I know well, and I wasn't trying particularly hard.

[Chris Hawes]

I will check how much pad is left...

Martin, having seen the green stuff on mine would the red you sell be better or because I have vented fronts stick with more green.

[stunned_monkey]

Greens are meant to act like regular pads from cold. Reds get better as they heat up, but Dan's experience is they're better than greens from cold as well. You drove his car.....

[Chris Hawes]

I just read the post Dan listed in the 'Lotus weekend 2006, Caley Hall' section of the 'Events, Car Shows, Meetups' section and didn't realise that his 'new' brake master cylinder was not stock i.e. 50:50 rather than the stock 68:32!!!

Dan's car from a braking point of view felt ultra modern when I last drove it. I knew when driving it that it had kevlars. I did not know that the new brake master cylinder was of a different configuration (50:50) and there was not at ounce of play in the push rod (where the brake medal travels to the BMC?) because this had been setup properly. Do you think they had no play leaving the factory and just get loose with age and wear?

My car has always felt like it brakes too much up front. So my BMC is applying more braking on the lighter end of the car with the smaller wheels.

I see what Martin is getting at:-
"This is the "argument" for going with the 50.50 master cylinder as it applies more to the rear, yet still locks the fronts when pushed. Any car should lock the fronts first"

but why did Lotus not go this way?

Dan, do you know what the configuration is on the Esprit? Has it changed over the years? as this could give some clues.

[stunned_monkey]

Why didn't lotus go this way? Who knows, but the original m/c's aren't available except from DMCH but I think eve Rob Grady has gone on record that the readily available 50/50 ones are better. I have a 50.50 in mine too and you do need to adjust the pin on a new one to get the feel right.

[Daniel Shane]

Chris trust me it took a few goes to get all of the play out of the push rod.

Infact on the way to a wedding I had adjusted it a little to much and down the road smoke was coming out of the rear wheels. I had to remove the BMC and adjust it on the side of the road. As vacuum builds the servo moves the rod out and slightly applied the rear brakes.

I'll have a look for info on the esprit setup, but Lotus went through LOADS of brake systems and setups and to the very last year of production were still playing with the setup of the brakes as they were not 100% happy.

[Chris Hawes]

Dan, did you have a chance to look at what the Lotus is?

If you were ever to buy another DeLorean would you change the brake master cylinder to the Saab 50/50 unit?

[Daniel Shane]

Chris Hawes Wrote:If you were ever to buy another DeLorean would you change the brake master cylinder to the Saab 50/50 unit?

:lol: :lol: :lol: Not gonna happen I'm afraid. However I ran the 50/50 split and I was very happy with it.

Lotus has used a 50/50 a 32/68 and a variable ABS system.

Dan

[Chris Hawes]

Do you know if the ABS system was thrid party and if so could it be integrated into a DMC brake system?

[Daniel Shane]

The Sport 300, S4, S4S, Early V8's and the first 50 GT3's had a Delco Power Master system. Not a bad system but the pedal feel is a bit, well, odd as it pushes back against you.

The Later GT3's (Mr Sprartt's) and the V8 GT's had a Kelsey-Hates system. Better first bite but not as progressive as the Delco.

The problem fitting ABS is that all for wheels have to have speed sensors on them so that the ABS computer knows what's going on. So this would have to be plumbed in.

To be honest I would love to remove the ABS on my Esprit. I find ABS very intrusive and you can learn to brake better and in a shorter distance than ABS can ever stop you.

Dan

[Chris Hawes]

Very interesting! I always leave a safe distance between myself and the car in front. The only trick I know is under heavy braking to pump the brake instead of freezing when/if the brakes lock up. Are there other techniques you know?

[Daniel Shane]

Hi Chris,

What your doing is Cadence braking, a system of manual ABS if you like.

However there is threshold braking which is hitting the brakes hard and backing off enough to stop the wheels locking up. This requires a feel through the brake peddle and some practice and skill to do.

However the effect of threshold braking is unbelievable. On average around half the stopping distance of ABS or Cadence.

Dan

[Guinney1971]

Daniel Shane Wrote:However the effect of threshold braking is unbelievable. On average around half the stopping distance of ABS or Cadence.
Dan

......... and a runway to practice on to avoid any mishaps? :wink: