4 pot brake system

The Oily Bits S1 Specific Topics
1

Hello

I need your advices about brake on my exige. The previous owner has fitted 4 pot front and rear calipers but kept original lotus disc. Actually the car brake well (should probably be improved with better and larger disc).

Are original lotus discs not dangerous (I’ve read they are poor quality items…)

2

Don’t know about that, I thought they were the old Laguna or something, mainstream and use to stopping something much heavier therefore unlikely to be dangerous. I’ve heard they can crack if too thin though.

Ian

3

I need your advices about brake on my exige. The previous owner has fitted 4 pot front and rear calipers but kept original lotus disc. Actually the car brake well (should probably be improved with better and larger disc).
Are original lotus discs not dangerous (I’ve read they are poor quality items…)

I don’t know about dangerous but I would point you in the direction of my problems, and other peoples experiences on the following SELOC thread:

http://forums.seloc.org/viewthread.php?tid=76349

4

Hello
Are original lotus discs not dangerous (I’ve read they are poor quality items…)

No they are NOT dangerous. Don’t believe everything you read on an internet forum.
There are better discs available but they can be expensive.

5

as Ian says they can crack - mine were just hairline though and starting at the cross drilled holes - in themselves I did not find them too bad, pagids, SRF and steel hoses did make a big difference.

The only reason a swapped them out was to try and stop the hairline cracks.

6

Steve,

Exactly. Depending on useage you can crack most discs. Personally I’ve never cracked std discs but have cracked ally-belled ones once.

7

Hello

I need your advices about brake on my exige. The previous owner has fitted 4 pot front and rear calipers but kept original lotus disc. Actually the car brake well (should probably be improved with better and larger disc).

Are original lotus discs not dangerous (I’ve read they are poor quality items…)

Original Discs are MOST DEFINATELY NOT DANGEROUS… you can make improvements but then so can everyone… but they aren’t dangerous…

8

Thanks a lot for advices!
Today, I bring the exige (my car for one month only) to a race car specialist for an inspection (I need to be confident on my car before fast track days).
Some bad news…
-oil leaks on left front damper (Sachs)
-inner ball joint of a toe link which is twisted
-there’re 2 springs on each dampers and the short one is fully compressed (even without wheel…). So, need to be replaced by others with a higher spring rate

9

I presume the sort spring is a �helper� one. If so, it has to be like this.
By the way, it is a good idea if you replace the rear toe links with the ones using jose joints.

10

Yes, it’s an helper spring.
here, a picture send by the previous owner:
[image]http://img277.imageshack.us/img277/7923/dscn00016xa.th.jpg[/image]

now, what we have seen with the spring fully compressed:
[image]http://img107.imageshack.us/img107/5606/25oj1.th.jpg[/image]

I think the geo had been modified (need to be check now).
(I(m going to search a post on exiges.com about double spring system with nitron to know rates of teh springs)

11

Alex, it’s a helper spring as mentioned.
Its job is twofold:

-to achieve the correct ride height with stiff springs sometimes the spring is a little bit loose in its seats. This will rattle and could potentially unseat itself and locate in a slanted position. This will of course not pass an MOT. A helper spring will keep the spring properly positioned at all times.

-with a single spring rate while cornering you’ll feel the unloading of a wheel very sudden. It works in some cars because all sort of other things have been tweaked as well, but on a normal Exige it could lead to less traction instead of more. A helper spring with a lower rate will take care of the unloaded situation, being softer at the initial travel, with the consequende of a less sudden loss of traction, at the expense of a teeny weeny bit of roll.

From the picture it’s not fully compressed when without load, so it’s doing its job.

Speak to Guy at Nitron, he’ll explain you all (provided you have Nitrons of course )

12

Thanks Uldis

If you look the pictures, you’ll see it’s ok on the first one but the second picture (front damper without load) clearly show the helper spring fully compressed:
[image]http://img243.imageshack.us/img243/1047/211rx.th.jpg[/image]

Could it be due to a too low ride height?

13

I wouldn’t say due to that, maybe it’s just at tad too soft? (the helper)
In that case it’s only functioning as a spacer, and if your ride height is Ok, leave it at that.

Changing to a longer primary spring (same rate as the one you have) could get rid of the helper if you just hate to see it compressed, but will feel the same on the road.

Suggest to consider another longer one only if you want to play with spring rates, otherwise just leave it as it is.

14

Fully compressed helper spring at full rebound has nothing to do with it being too soft as a helper spring should always be a LOT softer than the main spring. As you mentioned above it’s main reason it to keep the spring located at full rebound when the wheel is unloaded.

In Alex’s case, if the helper spring is fully compressed at full rebound (although it looks like it is it may not be) I would just remove the helper spring on the front and turn the spring seat down to the position that gives the same ride height or preload. If it’s fully compressed at full rebound then the main spring must be working, therefore the helper spring will never be anything other than fully compressed at any point in the suspension travel therefore it’s a complete waste of time it being there.

15

Some troubles again with this new exige

AP 4-pot calipers with PAGID RS42 rattle heavily…
There is no spring (I listen “clang-clang” from low to high speed and the aluminium chassis act probably as a resonator… just stop when I brake).
someone Have an adress to find anti-rattle spring

Cheers!