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S12W on 73' Z MM adapter plate issues


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So, I'm moving to install the S12W calipers and 300ZX rotors on my 240Z. I contacted Joe at Modern Motorsports and got his adapter plates for this project. However, when I went to throw on the adapter plates they wouldn't even make it past the top of the hub on my 240Z. 

 

I thought it was because I had painted the hubs after having them dipped, so i went ahead and sanded all the paint off, but it still doesn't even want to go down. I have contact Joe at MM and have pointed this out to him.

 

Did some measurements and here is what I found . . 

 

post-2769-0-04374900-1428944406_thumb.jpgpost-2769-0-24297000-1428944418_thumb.jpgpost-2769-0-39858800-1428944428_thumb.jpgpost-2769-0-08460700-1428944439_thumb.jpgpost-2769-0-13102500-1428944449_thumb.jpgpost-2769-0-33504100-1428944458_thumb.jpg

 

As you can see, it looks like the ID is about 2mm less then what is needed to clear the hub down to the hub's lip. 

 

My question is, has anyone else put the S12W/300ZX/MM setup on a 1973 240z? I thought this had been done before and that there would be no issues, but now I'm running into this problem. Joe is looking into it on his end, and will be getting back to me soon. 

Edited by New-to-240z
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Just curious, but what is this "adapter plate" that you got from Chequered Flag.  His web site only shows parts for CV shafts, not rotors and brake parts.  All inboard stuff, brakes are outboard.  Except for the stub axles, which allow different wheel bolt patterns.  You could install all of the CFJ stuff without changing any of the brake parts, and vice versa, I believe.  

 

http://www.chequeredflagracing.net/Datsun.html

 

With that in mind, is your question about the brakes or about the CV shaft flange adapter?

 

And, by the way, that "thinness" you're measuring is called a "diameter".  You could go with "width" maybe, but "thin" is confusing.  

Edited by NewZed
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Joe is having someone re-make the piece. This piece will fit the 240Z dimensions I provided, and I will test fit everything on my end. 

 

I contacted Silverline Motorsports and they make a spacer too, but it is flat only. Joe spoke to the design of his spacer in that it has a 'seat' for the mounting surface of the 300ZX rotor face. I'll be working with Joe to make sure the new pieces fit the 240Z hubs.

 

Can someone with a 240Z and the old MM spacers do a simple thickness check? I would like to compare the two to make sure that the rotor will be seated in the same location after the spacer has been installed. As I've heard of people having to add 'hardened metal spacers' to make the alignment perfect between the caliper and rotor.

 

Will update this post with more info as it progresses.

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Is that a replica of an MM original part, or something Joe designed?  You can really create some confusion when you try to adopt someone else's name.

This is somewhat of a replica of another spacer Joe had. I will get more info next time I talk with him. He's a good guy and willing to help make things right. I would think he is correct in the benefit of having a 'seat' for the rotor face cutouts. 

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Just curious, but what is this "adapter plate" that you got from Chequered Flag.  His web site only shows parts for CV shafts, not rotors and brake parts.  All inboard stuff, brakes are outboard.  Except for the stub axles, which allow different wheel bolt patterns.  You could install all of the CFJ stuff without changing any of the brake parts, and vice versa, I believe.  

 

http://www.chequeredflagracing.net/Datsun.html

 

With that in mind, is your question about the brakes or about the CV shaft flange adapter?

 

And, by the way, that "thinness" you're measuring is called a "diameter".  You could go with "width" maybe, but "thin" is confusing.  

I have re-worded my descriptions for you. :-) (I thought the point was there, but your wording makes sense)

 

These adapters/spacers are for the front brake setup.

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You might double-check your hub measurement, if Joe is going to use your number.  It looks like your caliper body is contacting the hub before you've spanned the full diameter.  

I told Joe this as well when talking to him on the phone. I will be finding a way to take new measurements when I get home. (Any Ideas?)

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I told Joe this as well when talking to him on the phone. I will be finding a way to take new measurements when I get home. (Any Ideas?)

 

When my verniers won't fit to measure in an instance similar to this, I use calipers:

 

900045890_0_9999_v1_m56577569831146162.j

 

Set them so that they just slide past the widest part, and then measure them with the vernier's.

 

Alternatively you can get long reach verniers:

 

image_20873.jpg

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Didn't have either of those tools, but am doing the best I can (family issues last night. Had to take these this morning before work)

 

Pic of the actual spacer showing double lip..

(The bottom lip portrudes out the back of the spacer a little bit to allow a mounting/seating point for the grooves cut out on the 300zx rotor mounting face)

post-2769-0-84851300-1429023384_thumb.jpg

 

Thickness from back to front of spacer...

post-2769-0-94850600-1429023380_thumb.jpg

 

Hub measurements . . 

post-2769-0-65568500-1429023368_thumb.jpg

post-2769-0-03929200-1429023373_thumb.jpg

 

I know I know, the measurement still isn't perfect. I'll try something else out today after work to be 100% certain of the diameter of the hub. 

 

The spacer looks to be about 0.20 mm thicker, but that is negligible I would think.

Edited by New-to-240z
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A cheaper option would be making some spacers to fit between the calipers and the ears... the only downside would be the caliper sticking out towards the wheel more.

 

Is this fancy machined thing so necessary ?

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The caliper ears fit behind the hub's caliper mounting points, so I don't think that is possible. The idea of the spacer is to push the rotor back,which means that it would sit farther forward without the spacer and the calipers would need to be moved from behind the hub mounting points to in-front of them(and possible have spacers to move them even further forward if needed). I don't know if this would work...

 

Then again, I'm not looking at anything right now. Just kinda typing while thinking.

 

On a side note, does anyone know where I can get new bolts to use? I'm guessing the stock bolts won't be long enough anymore with the spacer. 

 

@Miles : Did you reuse your stock bolts for mounting the rotor to the hub with the spacer?

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As a safety concern, before you go any further, you need to completely understand the vented Toyota caliper installation which is documented in detail in several HybridZ threads.

 

Recommend:

 

  • Return the spacer as it is obviously the wrong part.
  • Understand that when you modify brakes you will create a domino effect such that other components of the brake system will become mismatched resulting in less performance and may become  unsafe.
  • You will find that the stock 7/8 in. master cylinder is not matched to the Toyota brakes  (research it).
  • Yes longer bolts are required and they should be at least grade 8. 
  • Maintained stock brakes with quality  stock pads are fine for most applications.  Many many threads confirm this.
  • If you haven't read all of the FAQs on brake "upgrades" do so now.
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As a safety concern, before you go any further, you need to completely understand the vented Toyota caliper installation which is documented in detail in several HybridZ threads.

 

Recommend:

 

  • Return the spacer as it is obviously the wrong part.
  • Understand that when you modify brakes you will create a domino effect such that other components of the brake system will become mismatched resulting in less performance and may become  unsafe.
  • You will find that the stock 7/8 in. master cylinder is not matched to the Toyota brakes  (research it).
  • Yes longer bolts are required and they should be at least grade 8. 
  • Maintained stock brakes with quality  stock pads are fine for most applications.  Many many threads confirm this.
  • If you haven't read all of the FAQs on brake "upgrades" do so now.

 

@Miles : Thank you for all the info and concern (that is why I post here and trust people's opinions.)

 

I have already . . 

 

- switched to S13 240sx Rear brakes

- Upgraded to 1" Wilwood brake MC (Removed internal residual pressure valves in MC since all brakes are disc now)

- Installed Wilwood proportioning valve for rear brakes

- Upgraded front and rear pads respectively

 

Thank you for the Grade 8 recommendation for the bolts. I'll take one of the bolts to my local parts place and have them match the pitch and so forth to the stock bolts. 

 

As for the spacer, I am waiting to receive the new spacer from Joe. If this does not work, then both will be returned and I will just purchase the spacer from Silverline Motors (as it is a simple spacer itself without the 'steps' that MM's spacer has).

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A cheaper option would be making some spacers to fit between the calipers and the ears... the only downside would be the caliper sticking out towards the wheel more.

 

Is this fancy machined thing so necessary ?

 

 

The caliper ears fit behind the hub's caliper mounting points, so I don't think that is possible. The idea of the spacer is to push the rotor back,which means that it would sit farther forward without the spacer and the calipers would need to be moved from behind the hub mounting points to in-front of them(and possible have spacers to move them even further forward if needed). I don't know if this would work...

 

Then again, I'm not looking at anything right now. Just kinda typing while thinking.

 

On a side note, does anyone know where I can get new bolts to use? I'm guessing the stock bolts won't be long enough anymore with the spacer. 

 

@Miles : Did you reuse your stock bolts for mounting the rotor to the hub with the spacer?

Just in reply to the ideas above...

 

Yes, there's more than one way to skin a cat... or upgrade brakes.

 

When most people go to 5 lug using the Z31 hubs, they add a spacer very similar to what is being discussed here, and use the Toyota Caliper. Which works, because with the spacer it's all a bolt on affair.

 

When I did my swap, I went a different way. I didn't really care for the rotor spacer. There's just something about moving the rotor farther away from the hub and applying a shearing force to the bolts holding it all together I don't care for, with the added leverage of the spacer and longer bolts. Don't get me wrong, I know lots of people have used the spacer set-up with zero issue, I just don't feel good about it. So Instead I used the Z31 caliper as well, and made an adapter plate to get everything to work together.

 

Initial bracket, it got some additional machining after this:

post-3537-0-64281000-1429039863_thumb.jpg

 

post-3537-0-47659300-1429039967_thumb.jpg

 

post-3537-0-81666500-1429040008_thumb.jpg

 

Just another way that something similar can be done. However, it would likely cost more because of the custom machine work for the caliper bracket than going the typical route. The benefits of going this way are debatable. I've been running this for about 3 years now I believe and not an issue with it.

 

Something similar could be done with the 4 lug set-up, but a caliper that has no piston on theh front side would likely need to be used.

Edited by Six_Shooter
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