Caliper Upgrade, Tube vs Passage

[JT68]

"I found a minimum thickness for the Jag is 8mm or .315.

From the 311s wiki.

New rotors are approximately .433" thick with a minimum thickness of.325"."



Pretty sure that is wrong?? Discard for a .5” rotor is going to be around .440-.460. Maybe that was a nominally thinner rotor? Normally you get around .050-.060" for turning//

Stock roadster rotors are new at about .425/.430 discard around .375/.380. .325 would be on the ragged edge! Not a good idea.

I already went through this with Wilwood, a .400(av) rotor is too thin for a .5 application. They said it requires a custom caliper as well. You don't want the pistons hyper extended-bad plan.

Regardless, it will be up to the caliper manufacturer, so if they say .375 is ok, you should be be ok. but I'll be surprised if they say .375 is OK for a .5" caliper.



You lost me on the bolt on aspect though? Michael's Z32, Wilwood and Volvo are all “bolt-on” not requiring cutting/welding/grinding. Caliper brackets and vented rotors are all bolt on, right? All require custom hydraulic lines. All are totally non-stock. Most Wilwoods do use an adapter- that just a good design and a non-issue for Wilwood and the 1000's of folks that run them everyday.

Regardless, you’ll probably have to discard the rear backing plate no matter which caliper you choose, that's no big deal, that’s a "bolt-off" - but you will have to remove the rotor&hub to do it.

I sure would go with an AL caliper if you have the choice, why replace 10lbs of unsprung Sumitomo iron with 10lbs of unsprung British iron for a non-vented rotor.

[Curtis]

These are designed to be direct replacements for the stock brakes, that means the stock rotor. The stock Jaguar caliper measures almost exactly the same as the datsun. Virtually no difference. This is why I first bought a used Jag caliper to compare to.

That would mean they are to fit from a new rotor to a minimum thickness rotor. Searching for Jag rotors I'm getting dimensions from 13mm to 11mm for new thickness. Minimum so far has been 8.6, 8.5, and 8mm. To me this means they are designed to take in consideration for minimum rotor, plus brake pad wear, plus rotor wear for piston travel.

If they decide to be conservative then I'll buy a set somewhere else and as I said keep my mouth shut this time. But, Zeus wants these to work on Datsuns. Unfortunately they are closing down for Christmas and New Year. So January.

[Curtis]

Wilwood kits require an adapter. Do they fit stock wheels? The bolt spacing is wider then roadster.

As to the other kits, they all need adapters too. These require no adapters and are the correct spacing. Backing plate might require minor trimming but I doubt it.

In any case I will get a set and try them on. If they don't work I'll sell them.

[JT68]

Ah, I see, you are wanting to run stock steel wheels. Wilwoods will fit under 14" Libre, but not the 14" steelies so far as I have seen. They just barely interfere. The 240z sumitomo is a great little caliper too-very economical, but does require a bracket-thats a nice mod and period correct as well.

[Curtis]

Ah, I see, you are wanting to run stock steel wheels. Wilwoods will fit under 14" Libre, but not the 14" steelies so far as I have seen. They just barely interfere. The 240z sumitomo is a great little caliper too-very economical, but does require a bracket-thats a nice mod and period correct as well.

Yes, that's the whole point of it for me. Take off stock calipers, bolt on upgrade directly with no adapters needed, make a pipe, put on stock wheels, bleed and test drive. Start slowly in the neighborhood then test them a little more at a time.

The whole selling point all these vendors make is it is a direct replacement upgrade with no changes. Use your wire wheels even.

[Curtis]

I have been corresponding with Zeus about the calipers. They want another market for their product. They went out and found two roadsters to try them on.

From Zeus:

"Good and Bad news:

Good news is that both the Aluminium caliper Z8005 and the Sg iron caliper Z8000 fit the upright on the vehicle very well and centered on the disc perfectly. there was no difficulty with the steering arm or other mechanical structures on the car.

Bad news: The caliper did however just compromise a good wheel fit on the vehicle. the 'race wheel' was not too bad but the standard alloy and the original steel wheel were a no go.

Good news: is that as the manufacturer we can do things about this and we should be able to solve it fairly quickly. We 3D scanned the wheels and upright so will work on the program next week and let you know

In the meantime could you tell us what size /type wheels you have on your vehicle?"

[mikeb]

I've been corresponding with them as well and got an identical email from them today. For there to be wheel interference with the stock wheel, their caliper body must have different outside dimensions, right?

Curtis, you mentioned that you purchased a used Jaguar caliper. Did you compare the stock Jaguar caliper body and the Nissan (Sumitomo) caliper body with respect to the outside dimensions?

I'm actually glad that they're taking the time to get everything right.

[Curtis]

Yes, i compared. No difference so I'm not sure why these do.

[mikeb]

So I checked and the Jaguar stock wheel is 15". I may be wrong, but I assume that would have given Zeus more room to work with when designing and engineering their replacement calipers. That would explain the wheel interference issue.

[Curtis]

So I checked and the Jaguar stock wheel is 15". I may be wrong, but I assume that would have given Zeus more room to work with when designing and engineering their replacement calipers. That would explain the wheel interference issue.

Maybe so but E type series 1 and 1.5 caliper fits exactly the same as the Datsun caliper with the stock 14" wheel. I bolted it on mine. Maybe the new ones are a little bigger because of the 15" wheel.

[Curtis]

Jaguar caliper.

IMG_2653.JPG

[Curtis]

Getting closer on the Zeus calipers. They ran off a couple test sets in aluminum after modifying their design to fit the roadster wheel.

[mikeb]

Good to hear, Curtis - thanks for the update.

[spl310]

Hmmm... Aluminum would be nice....

[Curtis]

Hmmm... Aluminum would be nice....

We'll probably get a choice.