Upgrading the brakes

[Mecky]

After @JR73 has helped me with the confirmation that his calipers are bigger than mine, I have now ordered the bigger ones for myself, too. This investment will pay off after the 4th new set of pads, which means round about four race weekends.

A few days later, the confirmation from Lotus Supplies came, that the brake pads need to be grinded before fitting into my "old" calipers. Maybe this was a misunderstanding between the technical side (Banks) and the commercial side (Lotus Supplies), but I'm not sure. I have fed the information back to them and they will decide on what to do with it.

[cazman]

I do not know if Nick at Lotus-supplies is overwhelmed, but communication from them has been less than desired. I have had issues with a couple of things I have ordered from them and after much delay, they basically say call Richard. He is great and can be available, but I wonder if Nick has the resources he needs without Richard.

[europa88]

Nick and Dave at Lotus supplies are essentially enthusiasts for the marque and are parts guys. Richard is still the main technical guy, but I find Nick very knowledgeable on his inventory. What they may lack in tech knowledge they seem to make up with an honest desire to help.
Just my experience 

[Mecky]

Hi guys, I have now received the right calipers for my ventilated discs (not from Banks). The wider ones seem to be even lighter than the smaller ones. That's because they are bolted together from a cast aluminium part (which contains the hydraulics) and a cast iron part (which holds the brake pads). If they are equally as strong and also tend not to overheat under high frequent high pressure application, I'm happy.

In addition, I'm going to change my front springs to a stiffer coil. From 180 lbs/inch to 200. The nose dives very much under braking. Of course, dive is normal. But I think, I could do with a little bit less. I hope, that will keep the rear a bit more stable under heavy braking.

[Mecky]

I have now fitted the bigger calipers and I'm happy with the result. I still don't get, why Lotus Supplies did it that way. They should at least have informed the customers about the necessity to grind down the brake pads.

The change of springs on these tiny Protech shocks was a little bit funny. I didn't manage to fit the spring compressor into the tensioned spring. Thus, I used a heap of zip ties to compress it. With the new spring, it was a bit easier and it just worked out with the spring compressor.

[BDA]

Spring compressors for Macpherson struts don't work very well for our springs and shocks. A simple compressor made from some 5/16" threaded rod, some similarly sized j-hooks such as used on battery hold downs, a couple of nuts and washers and threaded unions, and a rod drilled for the threaded rod, and you have something that works much better.

The holes in the rod should be a bit bigger than needed for the rods so they can be angled. The holes in my rod are 3 7/8" apart. You want the angles so the threaded rod doesn't scarf up your springs. I put liquid plastic coating, such as used for plier handles but a piece of tubing would probably work better to protect the springs from the j-hooks.

[GavinT]

In addition, I'm going to change my front springs to a stiffer coil. From 180 lbs/inch to 200. The nose dives very much under braking.

Could you even feel a difference of 20 lbs?
I wonder if Richard Winter's 250 lbs springs would fit your Protech dampers?

EDIT to add:
Stefan, what are your rear spring rates?
As I said somewhere in another thread, that rear 'step-out' incident in the video could probably be countered by hardening the front but I didn't ask what rear spring rates you were currently using.

[BDA]

I currently have Richard's 250# springs on Protech front shocks.

[Mecky]

I put the 200 lbs/inch in and the front rose 30 mm higher after that. Of course, I have now set the height back down to the old level. I'm curious on the effect. With the softer springs, I used to set the sampers to the hardest setting (13 clicks are possible). Now, I'll adjust the dampers a bit softer, maybe by four or five clicks. What do you suggest?

Is the 250 lbs spring for road application? because the difference between the 180 and 200 feels already quite significant. But the next possible step would have been 325 (the store had nothing inbetween in stock) and that is too big of a step, coming from 180. The car was very predictable with the soft springs. Absolutely no tendency to understeer.

[JR73]

I’m running 250lb springs on the front as my ‘road springs’.
When I was racing I generally ran 400/450lb springs on the front with 250/300lb on the rear (different chassis and suspension to yours but just to give you an idea of the rates that you could investigate).

[Mecky]

Hey JR,
that sounds very very stiff. Which ride hide are you running at the lowest point? At my car, it's the leg room just between the front wheels.

I'm running 55 - 60 mm above the road surface at this point. Already the 200 lbs springs can be compressed by just 15 mm through the damper thread. A stiffer coil would definitely mean a higher front height for me. Right now, I'm very pleased with the car's handling, thus I don't want to mess around with the right height.

[Clifton]

I ran a 250 lb front spring for a few years and just put in 300lb springs in along with taller prothane rear bumpstops that will make up the rate difference for the rear mid corner.

[JR73]

I have the ride heights in my notes but I’m away from home this week so will get back to you with the info asap.

Depending on the track and weather etc I ran different springs to suit - even the high rate springs would use the full range of damper movement (sometimes just hitting the stops) and I would start in the middle of the damper adjustment range. - Remember that changing the spring rates at one end can affect the balance/handling overall so if you have a balance that you are happy with then be prepared to increase the rear spring rates by a similar amount.

The higher rate springs are shorter in length so that the same ride heights can be achieved, I buy my springs from here:

http://www.dfaulknersprings.com/

Looking at your on track pictures I suspect that you should also be investigating a bigger anti roll bar along with the stiffer springs.

[Mecky]

Of course, the springs can be chosen shorter. Didn't think about that logical idea.

Regarding the anti-roll bar, I don't have one. Thus, that will be a good point to improve the suspension. To be frank, I don't even know the construction of the stock rear anti-roll bar. I have to do some research on that. The front could be difficult, as my Protech shocks don't have mounting threads for the anti-roll bar like the well-known Spax or Koni shocks.

[SwiftDB4]

Protech does make a single adjustable Europa specific shock with anti roll bar stud. Europas never came with a rear anti roll bar. When I raced my S1 I always used a front one.