Lotus Elan and Lotus Elan Plus 2 Forums

I'm planning on fitting Plus 2 calipers on the S1 GTS car currently at the very early stages of build.

Found these on ebay at a good price- they arrived today and look great:-

http://www.ebay.co.uk/itm/x1-LOTUS-Elan ... Swo4pYOhVq

Just got to work out how to fit them and whether they require any other mods (discs, master cylinder etc) - advice welcomed!!

David

David,
My experience with this task (on an S2) is in this thread. I used the original S2 MC. Once I got all the caliper pistons properly lubricated to eliminate pad retraction, pedal feel was fine. Good luck!

I have Plus 2 Calipers on my Spyder built 71 Elan S3/S4 combo. All I can think of is that when I replaced the discs, I had to order Plus 2 discs.

Tony V

I guess you are aware of the various types of calipers on the plus2 (16P, 16PB, 16M from memory, variations being essentially in the fittings required, metric for the later models) - I did the change on my street S4, and used alloy caliper brackets then, but you may need to source plus2 (or Triumph GT6 etc) caliper holders to suit, cf. former thread :

lotus-suspension-f42/plus-front-brake-conversion-t26324.html

I did not change the hydraulics, not many people do, but proper pad selection is relevant for a given application.

I fitted +2 calipers and disks on my Elan Sprint.
Very pleased with result
Alan

When you go to +2 calipers you should also use the +2 (GT 6) larger, stronger spindles, hubs and uprights. I believe the 26R used them.They will increase front track slightly. The stock spindles Will fail with modern race rubber.
Be sure to magna flux the spindles. I once had a bunch of new ones fail.

Thanks for the ideas and feedback - until the post by ecamiel I was working on the basis of just needing some different mounting brackets and a little fettling...

No, you need the +2 mounting plates, also do the other things Eric suggested.

I put +2 brakes on my Sprint some years ago it works very well, however the weight is unbelievable.

Try Spyder as a source of the mounting plates etc; they have stuff surplus from their upgrades sometimes.

I believe the AP caliper CP2577 will fit identically to the Plus2/GT6 caliper-but it is aluminium! Lighter. And more expensive:

https://www.apracing.com/drawings/CP2577-1CD.pdf

https://www.gartrac.com/shop/ap-racing- ... p2577.html

These calipers are fitted to some Formula Fords front and rear. They are often removed from the cars to have iron calipers installed to meet rules in the UK I understand. If so, there should be a number of them 'under the bench' ...

Edit:
Also Alcon Type-R should swap onto Plus2 mountings-these are also racing alloy calipers.

With all these calipers the dimensions should be checked before purchasing! I have not personally fitted either.

There is also some very good information here-perhaps the people who commented on this thread could update it:
elan-mods-f31/has-anyone-done-caliper-other-brake-conversion-t20388.html

It is my understanding that to use +2 calipers and discs on an S1 you need:

1. Pair of +2 or GT6 caliper adapters
2. pair of +2 or GT6 calipers
3. Stronger Lotus KO or GT6 front axles
4. Lotus standard KO hubs, not the +2 hubs which increase the track width

It is also possible to use:

5. Pair of special adapters
6. pair of AR calipers
7. Stronger Lotus KO or GT6 front axles
8. Lotus standard KO hubs

I will be using items 5-8 on my 26S

Bill

Davidb wrote:I believe the AP caliper CP2577 will fit identically to the Plus2/GT6 caliper-but it is aluminium!

The AP CP2577 calipers have 1.75" diameter pistons, giving substantially less piston area than the +2 calipers which have 2.13" diameter pistons.

So that would mean less clamping pressure wouldn't it?
I have heard of these calipers being used to replace GT6 calipers with good results. I wonder if there is a version with larger pistons? I will find out.

It is interesting to see the size of caliper pistons used historically in Girling calipers. According to this the brake pistons in the GT6/Plus 2 calipers are the same size as the pistons in the calipers used on the Lola T70-so I bet they do stop nicely!

http://www.bgdevelopments.co.uk/product ... e-calipers

I've got a different view of the larger iron Girling calipers and discs. I've thought about it quite bit in the past and I don't think they're a good choice because the weight penalty is massive and it's all unsprung weight - and I don't think you really need more brakes....

I'm lucky enough to have successfully raced an Elan S1 using standard calipers and discs, shod with A048 Yokohama tyres and powered by a 175 bhp full race engine (albeit on 40 DCOE carbs). I paid a lot of attention to my brakes, but never once did I feel like I needed more brakes on the front (less on the rear at times). I'm happy to share what I did to get to that point (but mainly fresh kit, the right pads and top quality brake fluid).

I now have a 26R type racer which has the Girling AR front callipers. It's really good - the unsprung weight is reduced compared to the standard set up, and because they have large pistons and bigger (but thinner) discs the brakes do not get as hot and so pads last a lot longer than they did on the S1 race car with standard calipers. The downside is that they cost a lot (best part of ?1500 inc vat), and you don't have dust covers on the pistons so they're at risk of corrosion if you don't pay them attention.

I also have a road car (an Elan Sprint) which I run on Michelin XAS tyres. The standard brakes with modern pads seem to me to be more than adequate.

Paul