MA61 brakes on RA40 strut - bracket

[RobertoX]

Hi,
I'm planning on putting the brakes from an MA61 on a RA40 strut and need to sort out the calliper mounting bracket.

Is there anything available for this from another car that will bolt up or do I have to make one?
Getting one made shouldn't be too difficult but it would be easier and cheaper to use an already available one.

[thechuckster]

totally different holes and attachment setup.

If you want to keep the RA40 struts, look in Joel's (TurboRA28) member's ride thread as in there somewhere is/was pick of attaching Mazda 4-pot calipers to an RA28/40 strut and brake bracket.

[rob]

this is the closest you'll get to putting ma61 brakes onto your RA40

http://www.toymods.net/forums/showthread.php?t=25965

ignore the ke35 stuff, the XT130 strut will go straight into your ra40 then put on the mx62 calipers onto the ra60 discs and you are done

[RobertoX]

Hi rob, thanks for that, I was playing with something similar at the wreckers on the weekend.
xt130 struts with some ra60 calipers and hub/disc (same as ma61 I think)
Obviously they didn't fit up because the caliper bolt spacing was wrong. also the hub offset was wrong.

The other thing that I noticed is that on the xt130 strut the flange to bolt the calliper to is machined on the inside (inboard) wheras on your conversion you bolt the calliper to the outside (outboard). Does it sit flat? When I had a look at it the surface didn't seem flat and I wasn't too keen on bolting the calliper to the wrong side.

Another thing, I noticed the discs you used are vented, I thought the standard RA40 ones are solid or am I wrong? (I only have the strut).

Anyway, it looks like a nice simple conversion you've put together there!

[rob]

dude it sounds like you didnt even read my tech article, please re-read my article properly then ill be happy to answer your questions.

[RobertoX]

Yeah I read it, but for some reason I read 'RA40 discs' ?? nevermind...

How about the calliper bracket mounting surface? I read further down in the thread someone had this machined flat. I can't see mention of this in your article (I read it again just in case ), obviously you haven't had any problems with callipers falling off and the like, cos you probably wouldn't be posting now.

[rob]

Yeah I read it, but for some reason I read 'RA40 discs' ?? nevermind...

How about the calliper bracket mounting surface? I read further down in the thread someone had this machined flat. I can't see mention of this in your article (I read it again just in case ), obviously you haven't had any problems with callipers falling off and the like, cos you probably wouldn't be posting now.

2nd post 2nd line

"I used washers as the amount you space the bottom bolt is slightly larger than the amount u space the top bolt, using different thickness washers will solve this. Also you can use the MX62 caliper bolts BUT they dont screw in all the way, better to get bolts that are approx 4-5mm longer"



or yeah as Chuck says grind it flat and space it out with a flat steel plate or equal sized washers.

[RobertoX]

Ah ok, I see what you've done, I skimmed over that bit because I thought that the washers were only to position the calliper correctly.
My problem with it is that it's not like you have 2 parallel flat surfaces ( stepped) that you can take up with the thickness of a washer. The surface has a slight curve to it.
It's probably ok but not ideal. If I go this option I'd get it machined flat (just because it's brakes).


The other thing is that I have a set of MA61 brakes sitting here and some RA40 struts and all they really need to come together is a suitable bracket. Looks like one will have to be made, so I'm still undecided.

Cheers guys

[Hen]

With the method Rob's suggesting, yes you need to machine the "other" side flat so your calipers mount to it properly.

I looked around a bit at all this gear a while ago. AE86, RA40, RA60 and XT130 struts, various calipers and so on. In the end I went with what Rob wrote up. Seemed easiest and best for me.

From memory it was going to a stepped adaptor (time consuming or expensive to machine) for anything else. Also with the RA40 struts, because the brake mounting flange is fairly big, caused some headaches fitting the adaptor within the disc hat.

Hen

[Norbie]

I put MA61 brakes on RA23 struts years ago, there's quite a few photos of the brackets I made up here:

http://www.norbie.net/BrakeMods.htm

I'm pretty sure the process would be the same for RA40 struts.

[Hen]

I'd forgotten about that... in fact, I was planning on following your lead Norbie until I saw the XT130 - MX62 setup.

Hen

[RobertoX]

Hi Norbie,
Good stuff with the article, that is exactly what I am talking about.

The process should be the same I think, I've measured it all up and it should be able to fit bar the spacer that is welded to the MA61 Caliper bracket.

Did you remove this spacer? (I can't quite tell from your pics). You show one part of the process that mentions a spacer however it looks like this bolts to the back of the new bracket, is this just to account for the extra length of the MA61 bolts?
- looks like it is removed in this pic: http://www.norbie.net/Celica/BrakeMod04.jpg
If you did remove it, did you grind it off?
(it looks like there are 2 spot/projection welds that hold it on, it might be possible to drill these out, not sure).



Also, what type and thickness of steel did you use?

Cheers
Rob

[Norbie]

Yes I did grind it off, and it was a hell of a struggle from what I recall. Sorry I don't remember what thickness of steel I used, this was done 8-9 years ago.

[RobertoX]

Great, thanks for that.
It looks like the original way I was thinking of doing it is exactly the way you went about it, so that is good

I also like the one using xt130/mx63/ra60 as it uses all factory parts but as I have all the parts to use the ma61 stuff I think I'll go that way. I might even do an FEA on the bracket I knock up just for fun...