Calipers expanding when hot? How much?

[crobaa]

Hi guys, I've just installed spoon monoblock calipers on my car with sw388 wheels, the clearance between caliper & spoke is max 1mm. The wheel currently spins freely and doesn't hit the caliper at all, I'm concerned at a track day/aggressive driving the caliper will expand and touch the wheel. Anybody have any experience with this? I was thinking the wheel would also expand considering its bolted to this disc which is the hottest part

[bennjamin]

I dont think this is ever an issue in the real world mate. Ive only ever heard of brake discs or pads being effected by excessive heat - and this is to material build up. If you are worried - i would definitely run a thin spacer say 2-3mm

Try these


Linear expansion

To a first approximation, the change in length measurements of an object ("linear dimension" as opposed to, e.g., volumetric dimension) due to thermal expansion is related to temperature change by a "linear expansion coefficient". It is the fractional change in length per degree of temperature change. Assuming negligible effect of pressure, we may write:
http://upload.wikimedia.org/math/d/9/f/d9fccb57e55a18e03c4c51b7d68280fb.png where http://upload.wikimedia.org/math/d/2/0/d20caec3b48a1eef164cb4ca81ba2587.png is a particular length measurement and http://upload.wikimedia.org/math/6/2/0/62002234e0458ec4ade2d18c4bf1693c.png is the rate of change of that linear dimension per unit change in temperature.
The change in the linear dimension can be estimated to be:
http://upload.wikimedia.org/math/8/1/2/8129cc34d97c8cc97260d9fd7d04fb9d.png This equation works well as long as the linear-expansion coefficient does not change much over the change in temperature http://upload.wikimedia.org/math/3/e/c/3ecdbbc9a64a9bfc57883ae306bf51cd.png. If it does, the equation must be integrated.

[crobaa]

^ good work on reminding me that I'm not a scientist lol. I know alloy does expand at high temps, but in theory the wheels should also expand, normally I wouldn't be concerned but the wheels and calipers are expensive the clearance is very tight. Ideally I'd like to run no spacer if I could get away with it.

http://i195.photobucket.com/albums/z233/crobaa/null-58.jpg

[curtis265]

the wheels will expand as well dude, although at a slower rate

still though, a 1mm differential is a lot

[crobaa]

Would you be concerned based on the above photo?

[crobaa]

Actually on second thought, wouldn't the wheels just expand in every direction? There's nothing to say they'd expand away from the calipers is there? So in theory if they both expanded .5mm I'd be in trouble? The question now is .5mm a realistic possibility of expanding?

[mocchi]

i rkn will be far less than 1mm.

engine piston is an example maybe.
cast aluminium with clearance less than 0.05mm in cyl bore.

[crobaa]

So I'm safe? I'll send you the bill if they get messed up Oscar :p

[grifty]

Don't think they will expand by 1mm, like Oscar said, think about the bearings in a motor and piston/cyl bore clearance.

You might be be able to get 1mm expansion by using a oxy torch lol

[trism]

From about 5 minutes of googling, seems like most brake places recomend a minimum of 2mm

[mocchi]

So I'm safe? I'll send you the bill if they get messed up Oscar :p

inb4lawsuit

byp told me, not my fault

[crobaa]

Lol Oscar!

Is there such a thing as 1mm spacer? I really dislike running spacers so would prefer the smallest one possible. I actually test fitted with one washer on each stud yesterday and the center of the rim was still able to seat on the hub. Opinions on 1 washer spacer?

[curtis265]

i think the bigger problem is actually wheel spoke flex

anyway if u get spacers make sure they're hubcentric and get the studs extended too. Should be fine #yolo

[Rage King]

OP if your that worried - just buy then spacers to be safe. otherwise dem bbc will expand when hot mate!

[mugen_ctr]

3mm wheel spacers is the minimum size or thickness they make atm, its more than enough to give u clearance, imo 3mm isnt going to effect anything, ur wheel nuts will still have enough threads to bite on on studs, rather be safe than sorry with a 4mm gap verses a 1mm gap tolerance on the calipers to wheels lol

[daevilone]

i think the bigger problem is actually wheel spoke flex

anyway if u get spacers make sure they're hubcentric and get the studs extended too. Should be fine #yolo


^ this.

the effects of heat are going to be 0 to negligible. Not even worth considering. However, the wheel WILL flex as you are cornering on track. 1mm isn't much so you may run into issues there. Depends on a lot though, but as someone else mentioned most BBK manufactures ask for 2mm clearance.

[euRo_noob]

i think the bigger problem is actually wheel spoke flex

anyway if u get spacers make sure they're hubcentric and get the studs extended too. Should be fine #yolo


I'm no expert on caliper clearance etc but I thought this would've been the main reason of caution. Not seeing anyone mentioning the spokes flexing when cornering hard on the first page made me think I was a bit of a derp. I think that'd be more of a problem than the calipers expanding.

Not sure about the DC2R but I tried I think a 3mm or a 5mm (can't remember) spacer on my Euro and when I tried to fit the wheel nuts back on, there was definitely not enough thread to hold my wheel back on securely so I took them off.

A 3mm spacer for your piece of mind - definitely.
Willing to buy extended studs to accommodate the spacer - don't know, up to you. I'm not sure how much extended studs cost and the costs to also take off old studs/install new ones.

[curtis265]

extended studs are an easy diy

even I, a guy with hands as skilled as potatoes could do it

[Rage King]

http://t.qkme.me/3p2sut.jpg

[crobaa]

I don't think I'd need extended studs on a 3mm spacer. I still like my 1mm washer idea but nobody has commented on it yet

Wheel still sits on hub center
I have more thread on the standard studs to use
The washers are all same height
The pressure from the wheel nuts should still be evenly distributed


How important is it that there's between the hub and the wheel from stud to stud? From memory the wheel is hollow at the back on that point anyway?

[trism]

whats washer thickness?

[PHO]

The washer isnt machined. So ur gonna have trouble with wheel wobble if its slightly off.

[mugen_ctr]

do not use washer, by using washers, u are creating 4 separate loads on the hub itself from the wheels, even if u torque it up evenly doesn't mean it will work and as pointed out the wheels will be off as washers aint designed for this particular application,

so realistically speaking, having a flat mating surface u spread the load evenly across the hub, so the idea of using washers is rather a odd one LOL

Theres a reason why race cars or show builders dont use washers to space out, even if its 1mm lol

Do it once, do it right and go for the spacer, 3mm isnt going to kill u

[curtis265]

do not use washer, by using washers, u are creating 4 separate loads on the hub itself from the wheels, even if u torque it up evenly doesn't mean it will work and as pointed out the wheels will be off as washers aint designed for this particular application,

so realistically speaking, having a flat mating surface u spread the load evenly across the hub, so the idea of using washers is rather a odd one LOL

Theres a reason why race cars or show builders dont use washers to space out, even if its 1mm lol

Do it once, do it right and go for the spacer, 3mm isnt going to kill u

it's called bearing failure

[mocchi]

3mm isnt a problem on stock studs
5mm too mut m8
8mm fuark beast m8

[stndrd]

it's called bearing failure

Bearing failure wouldnt happen any quicker. If you were running a 10mm spacer or thicker, yes but not from a 3mm spacer

[crobaa]

Yeah just thought maybe nobody had used washers because people never have a need to space out 1mm extra. Will order 3mm now

[curtis265]

Bearing failure wouldnt happen any quicker. If you were running a 10mm spacer or thicker, yes but not from a 3mm spacer

was referring to the washer use, and the failure the hub surface due to bearing stress.

[crobaa]

3mm spacer ordered, correct pcd and centerbore

[Daveho1]

http://images.sodahead.com/polls/0/0/3/6/2/1/8/2/7/4413530658_TrollFaceForm2.png

spoon calipers...




but srs good choice on the hub centric spacers..

[crobaa]

Wish I didn't need them, but for piece of mind it's worth it

[Daveho1]

causericecar

[curtis265]

Studs too?

I would... For maximum mating surface between nut and stud

[crobaa]

Not for 3mm, still a fair bit of thread there, anything bigger id get studs

[trism]

yeah no point extended studs for 3mm.

[bennjamin]

Wish I didn't need them, but for piece of mind it's worth it

sorry but why do u need spoon calipers ? The name ? Or the design ?



Because im certain - unless your car is making 400kw atw - that standard OEM brakes are sufficient :)

For the money i definitely would of invested in a 2 piece rotor design and or BBK setup such as racingbrake , willwood etc

[crobaa]

My goals with my car were always to go all out on brakes and suspension first before touching the engine, the car is going to be tracked so the brakes are an important factor. The choice of spoon specifically is for 2 reasons.

Spoon dc2r is one of my all time favourite cars and I'm basically trying to build mine pretty close to that

Secondly, I've always loved spoons work in conjunction with Honda, using oem parts manufacturers and their years above experience, research and development over most other companies (especially Honda specific). I needed new rotors and pads anyway so the only real splurge were the calipers themselves. I was initially going to get twin blocks but after some persuading from friends and more investigating the monoblocks are a better caliper for almost the same money.

[curtis265]

sorry but why do u need spoon calipers ? The name ? Or the design ?



Because im certain - unless your car is making 400kw atw - that standard OEM brakes are sufficient :)

For the money i definitely would of invested in a 2 piece rotor design and or BBK setup such as racingbrake , willwood etc

JDM is best

[crobaa]

Also ask anybody reputable, wilwood is garbage. They are well priced tbough, there's a reason for that

[PHO]

Endless pls.

btw billy, are you coming along on saturday?

[crobaa]

Yep I'm coming on Saturday, relying on you boys to lure the cops away from me lol

[PHO]

Do you have any idea of how stock I look? I'm just a normal silver ek civic. Same with ari. You're the yellow one. LOL

[crobaa]

Function 7 is cop bait buddy! I got no illegal mods anyways lol. Ari can lure them away with the 3" exhaust lol. I got stock exhaust fitted today it's quiet as a mouse I love it

[PHO]

He'll just turn on the varex. Haha.

We gonna take east link or getting off at blackburn road > westall > cheltenham rd?

[cbauto]

Endless pls.

btw billy, are you coming along on saturday?
+1 endless more wank factor.

that's just me.

I'm happy OP is sticking to his guns and building the vehicle the way he wants it.

[crobaa]

I'm not fussed on the route, quickest way possible is best for me though

Cbauto thanks for sticking by me!

[Daveho1]

not having a dig fella.... so are you using stock master,booster and lines?

[crobaa]

Yes, they are designed to work with stock system. Might upgrade the lines at a later date but I don't like the loss of modulation with braided lines.

[VTI-RRR]

Billy dw what people say its your car build it the way you want.

Davevo1: why would he need master and booster? Draided lines is good for a piece of mind if you do alot of track days for 2 or so track days a year its not massively needed aslong as your lines are in good condition.

[curtis265]

Function 7 is cop bait buddy! I got no illegal mods anyways lol. Ari can lure them away with the 3" exhaust lol. I got stock exhaust fitted today it's quiet as a mouse I love it

come back to WA mun

it was fun chasing u on cruises

[crobaa]

Aren't you the guy with the euro? I seem to recall chasing you! Might be able to keep up with the lead pack now the car is in better shape than when I bought it

[curtis265]

nah prelude bbc.
was always behiind u lol

by a lot

but could hear ur vtak when we were leaving an intersection

[crobaa]

Prelude big black ****? I remember now. But I don't recall ever using vtec on public roads. Must have been somebody else

[Daveho1]

i was just wondering if the only upgrade was the spoon calipers.. no judgment

[crobaa]

It's also the rotors up to 300mm because stock ones are 282mm, and the spoon pads

[Daveho1]

on the stock 13/16 master?

[crobaa]

Cant remember what stock dc2r master size is but yes the stock one

[VTI-RRR]

ITR master cylinder is 1" hence why its not needed to upgrade

[u mad?]

1 inch master

so you can run 300mm disc with spoon calipers?

im guessing ud need at least a 16'' rim.

[crobaa]

Yes I have 16's. See my build thread. Dont think i've posted a good photo of brakes installed yet but hopefully there will a good photographer at club itr meet this week

[VTI-RRR]

ive seen a build thread from the states a em1 with 5 stud using s2000 brakes and 300mm rotor on em1 wheels cant remember if he used a spacer or not.

[crobaa]

My wheels are almost worst case scenario at +45 offset and convex shape. I'm surprised they bolt on without a spacer, even if it is barely