Gauging Interest: Model S Front Caliper Upgrade Kit

[dfwatt]

I concur that the RB replacement rotor for the stock PUP brakes is a great upgrade, but again, it comes with a cost and is not available to those without the PUP brakes.

I will weigh the S calipers and the PUP 3 calipers this weekend and post my results, but I don't think there is much or any weight difference between the two.

Ultimately, what I am offering is targeted to those without the PUP brakes and those with PUP brakes that are looking to track the car and are budget-conscious.

Actually that last part is not true they do make a convergent vane design replacement two-piece rotor for folks who are trying to upgrade their standard brakes. I think if you look in my original post you'll find a link to both front and rear convergent vane rotors for both standard and Brembo brakes on the model 3 along with convergent vane rotors for Model S calipers as well at least by my recollection. In any case we agree that it's good to have options. Yours still might be the cheapest way to get greater thermal capacity, at a cost of weight, RB might be the best way to get greater thermal capacity with a weight reduction. I guess it's all trade offs

 

[MasterC17]

Actually that last part is not true they do make a convergent vane design replacement two-piece rotor for folks who are trying to upgrade their standard brakes. I think if you look in my original post you'll find a link to both front and rear convergent vane rotors for both standard and Brembo brakes on the model 3 along with convergent vane rotors for Model S calipers as well at least by my recollection.

I should have clarified, there are two-piece rotors available from RB for the non PUP brakes but they retain the stock size rotor and the stock calipers which quite frankly are not up to the task of track duty on a ~4,000lb car.

Let me be clear - I am not trying to compete with RB. They are catering to a different customer-base.

Ideally, I would like to keep this on-topic which is me offering a budget-friendly solution that fits all (those with and without PUP brakes).

 

[Orwell]

I like that your solution allows for 18" wheel fitment which is cheaper, lighter, and has much better selection.

 

[MasterC17]

I like that your solution allows for 18" wheel fitment which is cheaper, lighter, and has much better selection.

Agreed! Additionally, my solution has much better brake pad selection (at this time anyway).

 

[MasterC17]

I was assuming that the stock caliper was significantly lighter than the S one (and admittedly didn't crunch the numbers properly). You're suggesting it's not - but how's that possible? Aren't they both made from the same material? In any case, if you do RB convergent vane rotors, those are 15 lbs, which is 13 lbs less than the 28 lbs rotor that the S caliper mandates. That's still a boatload of unsprung weight - perhaps not as bad as tire tread weight in terms of impact on braking and acceleration, but it's still a lot. It's an open empirical question how much additional thermal dissipation their design promotes over simply a larger surface area.

Would be nice to get some input on that from RB as I suspect they must have testing data. It's all about air flow over a heated surface area, and contrary to widespread assumptions, the extra mass doesn't hold a lot of heat, as metals have a very poor specific heat (roughly one tenth of the SH compared to water, which is the gold standard). The bigger brake rotor does provide more total internal and external area to dissipate that heat, although again the internal vane structure of the RB disks may make that closer, and then there is the air flow question, which is not simply outside the disk area, but inside flow as well. Bottom line, hard to know how much a smaller but better designed disk compares with a standard straight vane larger disk in heat dissipation ability. In any case, all of this is beyond both our pay grades, and would be a question for RB and their design team.

FWIW the S Caliper is lighter. I suspect it has to do with the design of how the pads are held into "place".

S Caliper (w/ Pads): 11.2lbs
PUP 3 Caliper (w/ Pads): 11.6lbs

 

[dfwatt]

FWIW the S Caliper is lighter. I suspect it has to do with the design of how the pads are held into "place".

S Caliper (w/ Pads): 11.2lbs
PUP 3 Caliper (w/ Pads): 11.6lbs

Most interesting thanks. Both are a bit lighter than I thought

 

[Lucky13]

One thing that has not been discussed in this thread and really might not be a big deal. Is that the model 3 calipers were designed to make sure there is no dragging of the pad when the brakes are not applied. Not sure the same technology has been applied to The model s calipers. Does any one have any knowledge on this, to inform the group.

 

[dfwatt]

One thing that has not been discussed in this thread and really might not be a big deal. Is that the model 3 calipers were designed to make sure there is no dragging of the pad when the brakes are not applied. Not sure the same technology has been applied to The model s calipers. Does any one have any knowledge on this, to inform the group.

Great question. I don't know the answer

 

[MasterC17]

One thing that has not been discussed in this thread and really might not be a big deal. Is that the model 3 calipers were designed to make sure there is no dragging of the pad when the brakes are not applied. Not sure the same technology has been applied to The model s calipers. Does any one have any knowledge on this, to inform the group.

That is a good question and I do not know the answer. Subjectively, I haven't noticed an increase in my consumption, but there is so many factors it is hard to draw a conclusion without actual data.

That being said, I would be surprised if the same technology was not implemented in the S/X

 

[dfwatt]

That is a good question and I do not know the answer. Subjectively, I haven't noticed an increase in my consumption, but there is so many factors it is hard to draw a conclusion without actual data.

That being said, I would be surprised if the same technology was not implemented in the S/X

I'm not positive but I believe it is. I believe this technology was first applied to the Model S. The consumption differences in terms of watt hours per mile between the S and the 3 are mostly due to the weight and the fact that the S has a slightly less efficient induction type motor at the rear compared to the permanent magnet switched reluctance motor in the model 3.

 

[MasterC17]

I'm not positive but I believe it is. I believe this technology was first applied to the Model S. The consumption differences in terms of watt hours per mile between the S and the 3 are mostly due to the weight and the fact that the S has a slightly less efficient induction type motor at the rear compared to the permanent magnet switched reluctance motor in the model 3.

Precisely, that, and the Model 3 has a better drag coefficient (.23 compared to S at .24).

 

[Lucky13]

That is a good question and I do not know the answer. Subjectively, I haven't noticed an increase in my consumption, but there is so many factors it is hard to draw a conclusion without actual data.

That being said, I would be surprised if the same technology was not implemented in the S/X

I am with you just something popped in my head.

 

[Orwell]

FWIW the S Caliper is lighter. I suspect it has to do with the design of how the pads are held into "place".

S Caliper (w/ Pads): 11.2lbs
PUP 3 Caliper (w/ Pads): 11.6lbs

Thank you for obtaining this information.

If you get a chance, can you measure the piston diameters as well.

 

[remlemasi]

This brake upgrade + MPP Party Box + sticky tires on 18” Aero on my LR RWD would be a blast to take to the track and have excellent bang-for-buck.

$1000 for tires, $1000 for brake upgrade, $400 MPP Party Box (a guess) and you have a super fun track machine for and extra $2400.

Arguably more fun than a P3D if you love how RWD rotates

 

[juanmedina]

What you run at VIR? Any videos?

 

[caskater47]

I purchased my P3D+ with the intent of tracking it at HPDE's. It became pretty clear that the stock PUP brakes were not up to the task of track driving; at the very least new pads and brake fluid would be needed. However, pad selection was poor and the stock rotors are pretty thin at 25mm. So I began investigating ways to retrofit the Model S Calipers without it costing an arm and a leg.

I sourced Centric (StopTech) Rotors and had them custom machined and drilled to accommodate the Model S Calipers with some supporting hardware. Paired with Hawk DTC-70's and Motul RBF-600 they performed flawlessly at VIR.

I wanted to share my retrofit with the community and see if others would be interested in purchasing my kit. This kit will also work on non-performance Model 3's and those without the PUP. I am not ready to release them yet (still making some tweaks), but I also don't want to invest a bunch of time and money if no one is interested. I am guessing the kit will be in the $500-$600 range (rotors and supporting hardware, I can help source Calipers if needed, you can source pads of your choice).

Pro's:

• Rotors are 32mm thick compared to the stock 25mm, a 28% increase in thermal capacity!
• Fit's under the Stock 18" Wheel, PUP Caliper requires Stock 19" Wheels
• Pads can be changed without removing the caliper, unlike the Model 3 Calipers (PUP or not)
• Pad selection is much better
• Cost is reasonable, you don't have to spend an arm and a leg to get a factory-feel/look BBK

Con's:

• They are hefty at 28lbs each (compares to 21lb stock rotors), though I doubt you would notice any difference in most scenarios.

Without further ado, here are some photo's!

I already have the BBK but am interested in using the calipers. How difficult is it to adapt the bigger Model S calipers to BBK upgraded Model 3?

 

[juanmedina]

I already have the BBK but am interested in using the calipers. How difficult is it to adapt the bigger Model S calipers to BBK upgraded Model 3?

Sell the MPP BBK and buy Model calipers and the OP's rotors or RB'rotors. Your rotors are not compatible with the model S calipers.

 

[caskater47]

Sell the MPP BBK and buy Model calipers and the OP's rotors or RB'rotors. Your rotors are not compatible with the model S calipers.

That's not particularly ideal. I am trying to shave weight off the car, not add more. At 28lbs per rotor that is a rather significant increase.

 

[juanmedina]

That's not particularly ideal. I am trying to shave weight off the car, not add more. At 28lbs per rotor that is a rather significant increase.

It depends on what you are looking for. He is offering 355mm rotors that are 7mm thicker than the stock ones with 28% more thermal capacity than the performance brakes. He is sourcing cost effective rotors instead of 2-piece rotors which he could do and would weight around 21lbs the same as the non performance 320mm stock rotors. This kit also let you run lighter and cheaper 18" wheels and tires than the required 19" from the MPP BBK. The brake pad selection is much greater as well.

Is just two different way of improving braking. Both are great solutions.

 

[MasterC17]

It depends on what you are looking for. He is offering 355mm rotors that are 7mm thicker than the stock ones with 28% more thermal capacity than the performance brakes. He is sourcing cost effective rotors instead of 2-piece rotors which he could do and would weight around 21lbs the same as the non performance 320mm stock rotors. This kit also let you run lighter and cheaper 18" wheels and tires than the required 19" from the MPP BBK. The brake pad selection is much greater as well.

Is just two different way of improving braking. Both are great solutions.

Great way of looking at it, and thank you for the support!

That being said, based on the demand for a two-piece lightweight rotor, I have begun investing resources into developing a solution for that as well.

I am looking to provide a cost-effective (roughly $1,000) kit with a lightweight two-piece rotor. Looking to be around 19lbs each. Ultimately, I want to provide both options depending on the consumers budget.

I will continue to provide updates as progress to both kits is made. Thanks everyone for the feedback!