Thought i would post my experience to aid anyone wanting to upgrade their front brakes in the future. I went for Lotus supplied 4 piston AP calipers, AP discs, Custom bells. Now for the interesting stuff:
You need to drill 2 holes 10mm X 10mm, on virtually the opposite side of the hub if i could describe it that way, same centre as ol holes just a few cm’s inboard. This is not something which should be attemoted with a hand drill, as you will inevetably break a drill bit and if you can’t get it out you will not be able to drill the hole properly. Also please bear in mind that you only have one shot at these holes being perfect because there is very little clearance between caliper and disc and no space for another attemp… I was lucky in the sense that one of the companies that rents some of our properties engineer to spec, so i got them to do it for me, and getting the centres as per lotus drawing is not easy.
Before marking the holes working off the lotus drawing please check clearance as it seems the bottom hole which is specced at 18.25mm as per the top should be +/- 18.75 as the caliper shears at this spec, but more of this later. The engineering shop after removing one of the old caliper bolts and seeing how much of the alloy came out with, offered to make a metal plug whcih they would tap and give it a bit of extra height so negating the need to shim with washers, i graceously accepted. and am pleased i did as i have had to remove them several times during the fitting process and don’t know how well the tapped alloy would have held up.
The calipers are now scraping the edge of the disc as the bottom hole we now know should have been slighly more outboard, but we are just going to remove the offending bit as there is now way we can move the hole now.
I also fitted the lotus master cylinder upgrade and for this you wil require fittings that screw into the mastercylinder properly as the current steel lines do not, they do not have enough thread. I replaced the whole front brake line system with goodridge hoses and aeoquip fittings what a pleasure, and the rear with an aeroquip adaptor from the master cylinder to the steel line. Will eventually replace the whole line when i tackle the rears The master cylinder is by far the worst job as there is just no access to get it tightened up in the pedal box. You will also require a fluid reservoir for your clutch as the master cylinder no longer has an outlet. Simple to fit and no longer boiling clutch fluid as it has it’s own system, personally i think its much better
Hope i don’t bore you guys with these, i just think it would be nice to search for motorsport brake caonversions and find out all the little things involved and plan for them before your parts arrive, unlike me who was only informed after i though they had sent me the wrong stuff.
And so concludes my thesis on 4 pot brakes for the exige. Please mark fairly and remember it was my first time