Tuning diy big brake conversion

sussexa · Apr 12, 2013

hi guys looking at big brakes for the summer, full 330mm.
now ive searched for big brake conversions and seem to be fiat coupe(305mm)calipers or full race stuff (new)
so looking at creating a fairly cheaper version, so far I have some discs sorted
lancia delta 111 (2008 - 2013) 1.8 turbo
ebc EBC Brakes Standard Vented Discs D1765
Vented Disc; 4 Bolt Holes; 330mm Diameter; 45mm Height; 28mm Thick; 26mm Minimum Thickness
found the brembos discs now also
09.A500.11 approx.£115-£130
http://bremboaftermarket.com/En/Car_...1-6973e7fa3a03

now does anyone have any info on the bolt holes for the brake calipers?
if it makes a difference to mounting lugs, my car has 281mmx 26mm sd brakes
hole size ?
threads, pitch?
hole centers on calipers/hubs?
hole distance from center of hub to design adaptor plates ?

had a look in eper and no details of stuff above

early days yet may all depend on finding cheap good calipers .

basically plan is to fit delta discs, most probably lug mounted 4pot calipers mounted to an adaptor plate to convert hole centers and also space to suit the 330mm discs.

I have std 17" blade alloys(although I will need a full size spare as spacesaver /steelie) probably wont fit over larger calipers.

I also already run with 15mm hubcentric spacers so have quite a bit of clearance from caliper to back face of alloy.

any info welcome otherwise I will need to strip and measure up one weekend.

edit on a side thought I could just go with the delta discs and space out further my oe calipers? not sure on clearance inside caliper for a disc 2mm thicker.
should order the discs really then no going back.

sussexa · Apr 13, 2013

heres a paint of brembo drwgs of both discs to compare size on size

sussexa · Apr 23, 2013

sussexa · Apr 24, 2013

i'll stick this link up on brake forces and balance examples and formulas looks like a good demonstration of increase in braking forces for increased rotor size but also shows how it reduces rear braking and throws balance out a lot if just fronts are increased.
TurnFast! Race Driving Techniques for Heel Toe Downshift, Driving Line, Cornering, Braking, and More • Balancing Brakes Upgrades 2
I may have to do rears aswell and just machine down those 278 x 12mm discs to 11mm or 10mm to fit in rear calipers, although looking at those examples I could do with approx. 290mm to keep balance closer to std

fingers99 · Apr 24, 2013

Logical flaw is that it doesn't take into account weight transfer (to the front wheels) under braking but just treats it as static. Just as "stoppies" are possible on a bike, under maximum breaking, the rear wheels of a car will almost be off the ground -- maybe carrying 10% of the weight.

For a road car, I'd bet that the front only conversion will be just fine. For a track day or circuit car where the driver employs trail braking (which you can't really do on an unknown road) upgrading the rears may help.

sussexa · Apr 30, 2013

bit more planning only as discs are on back order may be weeks?
http://imageshack.us/a/img834/9084/imageapol.jpg
http://imageshack.us/a/img854/3443/imageibtv.jpg
now the rear doesn't look doable due to closeness of the holes not leaving space for bolt heads and spacers.
so this shape bracket would be needed(no sizes yet will need to measure up yet, so used example spacing between holes 100mm)
http://imageshack.us/a/img9/3889/imagebnzr.jpg
http://imageshack.us/a/img541/3350/imageyvo.jpg
http://imageshack.us/a/img541/9205/imagetqqm.jpg

anyone see an obvious flaw? with caliper sitting higher up at different angle?

sussexa · Aug 2, 2013

bit of update, discs arrived and plate needed remaking due to clearance on the outer rim of disc fouling the caliper
heres discs together
http://www.imageshack.com/i/0k8er8j
heres on the hub
http://www.imageshack.com/i/2ot319j
and heres with the wheel back on (17" blades)
http://www.imageshack.com/i/nd6cpkj
here was final spacing of holes in plate(added 3mm for extra diameter to clear radius change)
http://www.imageshack.com/i/1qxawlj
the other holes are for these calipers at a later date(were supposed to be off a 166 and would have had bigger pads but too late now these will still do (off a gtv alledgedly)
http://www.imageshack.com/i/g16uqyj
http://www.imageshack.com/i/b6udxcj
brakes still bedding back in before i go to mot station to get the ok and some braking force figures.

sussexa · Sep 14, 2013

Finished the rears and theyve been bedding in for a few weeks now
Just had mot so videod the brake test again
I was expecting higher figures
Anyway heres the rears

Mot brake test 2013 - YouTube
Small discs left=130 right= 150
Big discs. Left=126 right= 152

http://youtu.be/K_fwx80Dgak

(Plus a change feom green stuff pads to red stuff pads)

Heres the fronts

Mot brake test 2013 - YouTube
Small discs left=324 right= 333
Big discs. Left=308 right= 322

http://youtu.be/7CAe4aDTdso

(Same set of red stuff pads)

Unless they havnt fully bedded in yet.

Anyway discs should last forever now

As always with my mods stick to the facts and Overall id say not worth the effort unless you keep warping the standard size discs(ive done 3 front sets in 35,000 miles)

fingers99 · Sep 15, 2013

As always with my mods stick to the facts and Overall id say not worth the effort unless you keep warping the standard size discs(ive done 3 front sets in 35,000 miles)

But presumably only the fronts?

sussexa · Sep 15, 2013

idid eventually do the rears as well from 251mm to 278mm
here are some pics of whats required spacerwise etc
fronts on and spaced to give 1mm clearance either side of caliper
http://imageshack.us/a/img51/7380/4y3u.jpg
http://imageshack.us/a/img708/9674/qsco.jpg
caution these will only fit under a 17"alloy and ive had to get a full size spare sorted and get rid of the space saver.also I have hubcentric spacers not sure if caliper would still clear spokes on std set up.
http://imageshack.us/a/img9/4199/o4u6.jpg

the rears also needed some adjs to the stone guard and the fact that the spacing of holes required an offset caliper position so no longer at 90deg more like gone from 3 o'clock to 2o'clock position
http://imageshack.us/a/img690/9045/buhv.jpg
http://imageshack.us/a/img707/8315/ttuc.jpg
this was final layout of rear plate and spacers
http://imageshack.us/a/img11/4843/wodb.jpg
the rear disc is originally 12mm thick and needed machining to 10mm thick as caliper has no clearance for bigger disc
I took 2mm off the front face here
http://imageshack.us/a/img16/999/c1xg.jpg
this takes the disc down to manufactures min width for wear!

http://imageshack.us/a/img716/5898/f2j9.jpg

http://imageshack.us/a/img801/6359/4qdt.jpg

http://imageshack.us/a/img600/3610/eigb.jpg

as a disclaimer can I say I searched the net and most users who did brake caliper spacers used 10mm steel but I used 12mm steel plate.
also it seems to be recommended to use at least high tensile bolts of 10.9 spec , which I couldn't get hold of so I have 8.8spec high tensile bolts.
also I have tapped the plates and fitted nuts also as a belt and braces.
again this can only be done if your original caliper is at least 30mm wide to take the 28mm disc and have clearance thers not much.
I only did the rears to try to keep the brake balance between front and back close to the original as possible, do not do just the rears only it will throw too much balance to the back and as proved on the vids did nothing for brake performance anyway.
I had ebc slotted and dimpled rears for 20,000 miles +(on ebc greenstuff pads) and when measured they had lost next to nothing from original 10mm and still measured 9.8-9.9mm so also proof the rears do very little breaking.
also be aware the delta discs obviously use a larger surface area pad and the stilo pads don't sweep the whole face area of the discs
I will update with some pics when I have a nice wear line to show unswept area.

rat20v · Sep 16, 2013

really good read and interesting too buddy

Yellow Peril · Sep 16, 2013

Erm from the last pic you seem to have a massive area of the rear disc that the pads will never come in contact with..?

sussexa · Sep 16, 2013

Yep fraid so, i even said so at end of last post.( the fronts will have it also)
It was to see what could be gained from using larger diameter discs only still using original calipers/pads, the maths says an increase in breaking torque is achieved from moving pads further out even with same contact area.
To cover these discs fully youd need some very big calipers and pads the swept area is massive
Also i spaced the caliper to put the pads right on the very edge of the disc to avoid a nasty rust lip.
Also im not sure if i mentioned the disc weight difference is so much i could feel the difference through the steering wheel when turning at speed.
Like i said i wouldnt recommend this mod.

Studentas · Sep 17, 2013

This whole thing, is really interesting. Keep it going

About calipers, i know some Alfa's has massive calipers, can't you fit them?

sussexa · Sep 17, 2013

Yep i got these for next summer may be( still have 1 to rebuild)
http://imageshack.us/a/img577/5518/6uqy.jpg
Unfortunately due to wrong description on ebay they will fit but still wont fully sweep the disc face.
http://imageshack.us/a/img402/8756/udxc.jpg
Also i think they definately need spacers to clear alloy spoke inner face.

Studentas · Sep 17, 2013

sussexa said:
Yep i got these for next summer may be( still have 1 to rebuild)
http://imageshack.us/a/img577/5518/6uqy.jpg
Unfortunately due to wrong description on ebay they will fit but still wont fully sweep the disc face.
http://imageshack.us/a/img402/8756/udxc.jpg
Also i think they definately need spacers to clear alloy spoke inner face.

Oh, yes, i actually saw those pics, on your thread, i just forgot i saw them

Sorry.

fingers99 · Sep 19, 2013

sussexa said:
Also im not sure if i mentioned the disc weight difference is so much i could feel the difference through the steering wheel when turning at speed.

I wonder, though, if this is caused by the weight difference, or by the difference in wheel offset caused by the spacers?

I say this because I can't feel any difference running stock, unvented front disks and larger (and heavier) Punto GT/Marea vented disks on Centos, as far as the steering is concerned. In those cases, no spacer is required.

sussexa · Sep 19, 2013

Ive had the spacers on for a year or 2 not that.
Difference in disc weight was large something like 6kg bs 9.5kgs.

sussexa · Sep 16, 2014

mot time here are updated figures with a change to yellowstuff front pads and they've been in a while so should be fully bedded.
rears
2012 Small discs left=130 right= 150 (green stuff)
2013 Big discs. Left=126 right= 152 (red stuff)(not fully bedded?)
2014 big discs left = 134 right 151 red stuff)
fronts
2012 Small discs left=324 right= 333(red stuff)
2013 Big discs. Left=308 right= 322 (red stuff)(not fully bedded?)
2014 big discs left = 327 right = 331(yellow stuff)

I gave up on the brembo calipers so still on the original stilo calipers

Tuning diy big brake conversion

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