What Brakes

[locosaki 0]

Well after doing lots of thread surfing reading about brakes I need to make a decision now as it's getting near time to get the car on track !

 

I've managed to get someone who will mill me a set of brackets for the Lotus exige(AP 2pot caliper conversion) but I'm unsure if this is worthwhile going down this road as it will be a little more expensive than bolting the GTI6 calipers to the car and also how much better are the 2pot calipers likely to be over the 6 set up ?

 

I also want to keep the weight down(unsprung) but apparantly the 6 set up is the heaviest of all !!

 

This is what keeps bringing me back to standard brakes(although shocking on my car)

 

Would the weight of the Lotus(AP 2 pot) caliper with the 307 disc work out alot heavier than the standard 247mm brakes ??

 

If it is heavier I wonder by how much !! Saying this though,It should still workout lighter than the GTI6 setup but is the extra expense worth it ??!!

 

 

As you can see,I'm undecided on what way to go !!!!

 

Mike

Edited February 16, 2010 by locosaki

[Batfink 201]

Well the AP calipers will be lighter than the gti 6 ones, and the 307 discs too..

You are still going to be a few kilograms heavier than a standard setup.

What pads do you run? If you are worried about unsprung weight have you tried just uprating them to a better compound??

Correct me if I am wrong but the gti-6 caliper is a sliding caliper still rather than a piston each side so the AP will probably give a better pedal feel

K.

Edited February 16, 2010 by Batfink

[locosaki 0]

The pads that are in just now are unknown but the pedal feel inspires no confidence at all,Could pad compound really make that much of a difference ?

 

You are spot on with the caliper setup,The 6 caliper is a sliding unit and the AP is a piston each side.

 

If running the AP calipers(2pot) Would a change in master cylinder still be required ?

[Rob Thomson 6]

For what it's worth I love my standard 1.6 GTi brakes (albeit with Mintex M1155 pads); no fade, more than enough stopping power and great feel. A 205's so light that brake upgrades aren't mandatory unless you've got daft power.

 

The pads that are in just now are unknown but the pedal feel inspires no confidence at all,Could pad compound really make that much of a difference ?

Pads can make the world of difference to feel.

 

If running the AP calipers(2pot) Would a change in master cylinder still be required ?

You need to compare the piston areas of the alternative calipers. Compare the area of the single piston of the sliding caliper with just ONE of the 2-pot pistons (ie. don't double the area because you've got two pistons). The bigger the caliper piston the bigger the master cylinder you need.

[locosaki 0]

Thanks for the input.

 

I believe the AP 2pots have smaller piston so in theory this should retain the feel of a near standard brake pedal(with decent pads) as opossed to the longer travel of gti 6 caliper set up.

[shalmaneser 26]

Aren't the AP brakes run unservo'd on the mk1 Elise? Could be wrong about that. If they are then you'll have power to spare!

 

personally I'd go for the AP brakes, making up a bracket won't be hard, but make sure they fit under the wheel first!

[locosaki 0]

Yep,I'm pretty sure they will require a spacer on the front,Unsure of what size though !!

[mxcrazy 0]

Yep,I'm pretty sure they will require a spacer on the front,Unsure of what size though !!

 

Im going to be using AP 2 pots on the front of my 306, picked up a set of calipers for £60 off ebay. they will not fit behind cyclones, too wide, so im going to have to go to a 15 inch wheel with more spoke clearance, something like team dynamics pro race 1.2 or similar.

 

I think you can use up to 295mm discs with the calipers on Lotus', its just fitting it all behind the wheels, im either going to use 283 or 288 mm discs.

 

If you have brackets made up to take them bare me in mind i 'may' have a set aswell if thats viable, depends what discs i use yet.

[locosaki 0]

What are the 288mm discs from,I was led to believe I would have to go with the 283x26mm discs as these had the greatest offset ??

 

How much are you after for the brackets ? (if you do have a set spare) PM price if you want

 

What size of discs are suited to the brackets you have ?

 

Mike

[welshpug 1,645]

The 288mm ones weigh a ton, a little more than the 283mm ones.

 

I'd be tempted to go for a 266mm later partner or 307 item, I think they have a higher offset than the 306 discs so give a little more clearance to the spokes of the wheel and are a lot lighter.

 

MDC1491 Brake Disc

 

Diameter [mm] 266

Brake Disc Thickness [mm] 22,0

Minimum Thickness [mm] 20

Height [mm] 34

 

5kg

 

 

 

how much do the AP calipers weigh?

Edited February 17, 2010 by welshpug

[locosaki 0]

I'm not to sure about the weight of the caliper !!

 

I would be more than happy to go with the smaller disc but I was under the understanding that I would have to use 26mm thick discs to suit this caliper ?!

[craig_007 1]

307 discs are 2 kg heavier than the 266 discs.

[mxcrazy 0]

What are the 288mm discs from,I was led to believe I would have to go with the 283x26mm discs as these had the greatest offset ??

 

How much are you after for the brackets ? (if you do have a set spare) PM price if you want

 

What size of discs are suited to the brackets you have ?

 

Mike

 

 

I should have made it clearer, i was saying that if you have some made up i might be interested in buying a set too, sorry.

[locosaki 0]

Sorry buddy,Likely my misinterpitation.

 

To be fair there costing quite a bit to get fabricated but I dare say once I have my setup working I should be able to get a few more done.

[craig_007 1]

Did you find out if the 266mm calipers will work with these calipers??

[locosaki 0]

Yep,The 266mm won't work.

 

I'm not going down the AP route,I've done a bit of reading and also had a few opinions and decided that I won't really gain much from the brakes as the discs are so heavy just seems to a waste of money in my eyes,All the expense of light weight calipers and then throwing on big heavy discs !! Seems pointless.

 

I'm going stick with my standard setup with good pads.

[craig_007 1]

Ok,thanks for that.

 

I just weighed my AP calipers,Pads and brackets and they come in a 2.5kg per side,So with the 288x26 discs(7kg) thats 9.5kg per side(19kg total) So basically 6kg lighter than a GTI6 set of brakes and much the same weight as the 1900 brakes !!

 

Not to bad I think.

 

Also,surely this has got to be better than standard brakes with mintex 1155 pads ??

[DRTDVL 4 1 Cars]

you could run two piece discs.

 

 

Alloy bellhousing with cast pad surface, wonder what the weight differance would be...

[benlilly 0]

I've done this conversion using the Lotus AP 2 pots, custom bells and brackets and discs from Elise Parts. The large discs are quite heavy. I haven't compared the weight to standard or finished the fitting yet so will post the results up here shortly.

Also, happy to share the drawings of the parts I had made and can recommend B. G. Developments for any brake part machining/engineering.

Ben

Edited February 23, 2010 by benlilly

[benlilly 0]

Weights as follows:

Std 1.9 Caliper: 3.75kg

Std 1.9 Disc: 4kg

Total: 7.75kg

 

Elise Parts Disc (288mm) + Custom Alloy Bell: 5.5kg

Lotus AP 2-Pot + Custom Bracket: 2kg

Total: 7.5kg

 

So a little wight saving but not really worth mentioning. To really take advantage of the light calipers you would need to use discs from AP or Alcons and they are very expensive. About £160 each from memory.

Edited February 23, 2010 by benlilly

[Rippthrough 98]

you could run two piece discs.

 

Alloy bellhousing with cast pad surface, wonder what the weight differance would be...

 

On 288mm discs, the alloy centre saves just under 1.1kg per side on the ones I did.

Think the stock disc was ~7kg, wavy discs were a touch under 5kg, with ally centres they dropped to about 3.9kg

[craig_007 1]

What brake hoses have you uses with the AP calipers,I've still to get brake lines yet.

[benlilly 0]

What brake hoses have you uses with the AP calipers,I've still to get brake lines yet.

 

I haven't sourced brake lines yet. The lines on the calipers in the photo came with them and are off the Elise they were removed from.

Best bet is probably ring Goodridge. They will know the hardline-to-flexi hose fitting from the std 205 hoses they make and you can get the fitting for the other end from AP Racing.

Ben

 

Edit. Just checked the AP website and I hink the caliper fitting is M10x1.0.

Edited February 24, 2010 by benlilly

[allanallen 528 2 Cars]

Edit. Just checked the AP website and I hink the caliper fitting is M10x1.0.

 

standard hose may fit then if its long enough.

 

Benilly,your set up looks excellent, are those standard type discs with the centres removed or proper rotors? al

Edited February 24, 2010 by allanallen

[craig_007 1]

Ideal,Cheers guys.

 

I've already got GTI6 calipers so hopefully the lines from there should be long enough for the AP calipers.