Vendor Redwood Motorsports Presents: AP Racing Radi-Cal II Road&Track Crossover Big Brake Kits!!!

[mcbarnet007]

Yeah, lot’s of answers, but no proof from testing. And that is the crux of it.

Ventilation drag is what causes most of the range loss due to the wheel design, aero cover off or on etc.

Ventilation drag is due to the high pressure air moving from inside the wheel/wheel arch, through the wheel spokes to the outside low pressure area.

The diameter and width of the disc brake, and the change in the internal ventilation design from pillar (standard) to curved vane, increases pumping losses a lot (thus why the curved vane type is so much better at disc cooling), and aero drag is increased with pumping losses. Also, the change in turbulence and the amount of turbulence in this area changes the amount of ventilation drag through the wheel. These are the facts.

Unless you have carried out testing to KNOW if there are negligible losses or not, saying so is disingenuous at best, arrogant at worst.

Fighting for justice? More like fighting for facts as a potential customer.

They are just selling a BBK from AP racing. Since they are not the manufacture, I doubt it's worth their time to perform scientific tests that's up to your standard. Track junkies or show car guys will buy them regardless if they have impact to the overall car efficiency.

 

[Dangerous Fish]

Fighting for justice? More like fighting for facts as a potential customer.

If you're asking these sorts of questions, I don't think you should be considering a BBK.
Using any road car on track is a compromise. One of the compromises may be range loss in this case. How much range loss is not something I would expect anyone to even attempt to measure, in the same way I don't expect anyone to tell me how my 265 wide tyres affect range.

 

[RedwoodMotors]

Yeah, lot’s of answers, but no proof from testing. And that is the crux of it.

Ventilation drag is what causes most of the range loss due to the wheel design, aero cover off or on etc.

Ventilation drag is due to the high pressure air moving from inside the wheel/wheel arch, through the wheel spokes to the outside low pressure area.

The diameter and width of the disc brake, and the change in the internal ventilation design from pillar (standard) to curved vane, increases pumping losses a lot (thus why the curved vane type is so much better at disc cooling), and aero drag is increased with pumping losses. Also, the change in turbulence and the amount of turbulence in this area changes the amount of ventilation drag through the wheel. These are the facts.

Unless you have carried out testing to KNOW if there are negligible losses or not, saying so is disingenuous at best, arrogant at worst.

Fighting for justice? More like fighting for facts as a potential customer.

I hear what you are saying. The issue is it is not as easy to quantify losses as you are imagining, and to be upfront like I mentioned previously, we have not specifically tried to "measure" the pumping losses of the rotors themselves. In the real world however, with a test car with wider and sticker tires than stock (may be washing out some of the smaller losses like pumping effects - or not - we don't know), we did not personally notice any significant or unusual decreases in range during every day driving. It's also worth noting that "range" is hard to measure consistently/scientifically as even using the cabin heater (at full tilt) can consume up to 30mph of charge alone. So even weather conditions need to be factored in, as well as traffic, and many other factors etc. to be accurate.

The best testing that can be done by the Tesla community as a whole, consolidating multiple data points. If ultimate range is a concern I would suggest waiting to see what the general consensus from the community is, and making your decision after reviews. No matter what we say or don't say, we're potentially biased, where general community members are not. The most effective range solution most likely is your stock brakes, but for track use it sounds like you want to upgrade them as they are not up to the task... as with everything there are tradeoffs, but if the magnitude of losses are small, and magnitude of the gains are large, it may be a tradeoff worth considering.

 

[Clivew]

Thanks for your input guys, but I think that is an old school approach. Just as Tesla has great forward thinking, designing and building these cars, I personally think Vendors need to up their game and design products that work and also don’t compromise efficiency (I’m not saying this one does BTW). Part of that process is testing, and informing the consumer.

As more and more people buy and track these cars, there will be an increasing number who will want that data before they buy.

 

[Clivew]

I hear what you are saying. The issue is it is not as easy to quantify losses as you are imagining, and to be upfront like I mentioned previously, we have not specifically tried to "measure" the pumping losses of the rotors themselves. In the real world however, with a test car with wider and sticker tires than stock (may be washing out some of the smaller losses like pumping effects - or not - we don't know), we did not personally notice any significant or unusual decreases in range during every day driving. It's also worth noting that "range" is hard to measure consistently/scientifically as even using the cabin heater (at full tilt) can consume up to 30mph of charge alone. So even weather conditions need to be factored in, as well as traffic, and many other factors etc. to be accurate.

The best testing that can be done by the Tesla community as a whole, consolidating multiple data points. If ultimate range is a concern I would suggest waiting to see what the general consensus from the community is, and making your decision after reviews. No matter what we say or don't say, we're potentially biased, where general community members are not. The most effective range solution most likely is your stock brakes, but for track use it sounds like you want to upgrade them as they are not up to the task... as with everything there are tradeoffs, but if the magnitude of losses are small, and magnitude of the gains are large, it may be a tradeoff worth considering.

Thanks for your reply, I appreciate it, and thanks for clarifying your points.

Yes, I definitely will need better brakes, but I just don’t want to take a big hit with efficiency, and would really like the data before I buy.

With wheels, tyres and geo, I can easily swap and adjust, before and after trackwork. With a brake kit, it’s not possible.

 

[Mash]

All curved vane designs are barely improve any flow at all. Just tiny. Not even remotely as big as amount of air that freely flows out. If you need bigger brakes - you must pass more air through them. Otherwise it's pointless and you need to chase for higher temperature of rotor. Get higher temp pads and fluid and keep stock calipers if you don't want to risk 0.01% of range. Or use this kit since it has larger rotors and you can be certain that there is less flow possible between the rotor and the wheel.

And, again, you fighting with a wrong crowd and claiming that you didn't get answers, while it's not true.

Yeah, lot’s of answers, but no proof from testing. And that is the crux of it.

Ventilation drag is what causes most of the range loss due to the wheel design, aero cover off or on etc.

Ventilation drag is due to the high pressure air moving from inside the wheel/wheel arch, through the wheel spokes to the outside low pressure area.

The diameter and width of the disc brake, and the change in the internal ventilation design from pillar (standard) to curved vane, increases pumping losses a lot (thus why the curved vane type is so much better at disc cooling), and aero drag is increased with pumping losses. Also, the change in turbulence and the amount of turbulence in this area changes the amount of ventilation drag through the wheel. These are the facts.

Unless you have carried out testing to KNOW if there are negligible losses or not, saying so is disingenuous at best, arrogant at worst.

Fighting for justice? More like fighting for facts as a potential customer.

 

[Clivew]

All curved vane designs are barely improve any flow at all. Just tiny.

Incorrect. The mass flow of air through a disc with tapered radial vanes (TRV) is approx 180% higher than a disc with circular pillars (CP), and that is comparing like to like, diameter and thickness. Even a disc with straight vanes (SRV) has a 100% increase in flow compared to the standard Tesla disc design.

Hmm, barely increase flow, and a tiny improvement? Ok.

If you need bigger brakes - you must pass more air through them. Otherwise it's pointless and you need to chase for higher temperature of rotor.

It’s not all about higher airflow. You need a disc with better heat transfer so that it uses the air flowing through it more efficiently, and more importantly, a uniform temp distribution, so as not to cause high stresses throughout the disc. The higher the surface area of the disc, the better, so bigger diameter, thicker and more vanes give higher heat transfer and a lower operating temperature. The downside is higher un-sprung weight, so a balanced design is best.

Get higher temp pads and fluid and keep stock calipers if you don't want to risk 0.01% of range.

0.01% range difference? Nice scientific approach, pulling an arbitrary figure out of the air, when it’s plainly obvious you have very limited understanding about brake disc aero.

Or use this kit since it has larger rotors and you can be certain that there is less flow possible between the rotor and the wheel.

A bigger diameter disc and a design which gives up to 180% more flow than the standard disc = less flow because the distance between the disc OD and wheel ID is smaller? With at least an inch gap, there will be no restriction of flow. Again, this shows you have a very poor understanding of aerodynamics.

Sorry to Redwood, but this does show your brake kit gives a big improvement in heat management!

 

[Dangerous Fish]

@Clivew Where do you intend to track your Model 3? How many laps do you think you'd do each session/day?

Depending on the answers to these questions, you may not even need a BBK, just uprated pads and maybe larger rotors.

I feel you might be over-thinking this.

 

[Clivew]

@Clivew Where do you intend to track your Model 3? How many laps do you think you'd do each session/day?

Depending on the answers to these questions, you may not even need a BBK, just uprated pads and maybe larger rotors.

I feel you might be over-thinking this.

Bedford Autodrome, mainly the GT circuit which is approx 4 miles a lap. I’ve been tracking there in various road and race cars since it opened 20 years ago.

I’m not over thinking, I’m weighing up the options on the market so I don’t buy the wrong kit. It would be much easier if it was a dedicated trackcar, but it’s primarily a road car that will be used very hard on track. But, yes, just bigger discs is an option. Decent pads and fluid is a given, plus extra brake cooling if necessary, after monitoring disc and caliper temps.

 

[Dangerous Fish]

Bedford Autodrome, mainly the GT circuit which is approx 4 miles a lap. I’ve been tracking there in various road and race cars since it opened 20 years ago.

I’m not over thinking, I’m weighing up the options on the market so I don’t buy the wrong kit. It would be much easier if it was a dedicated trackcar, but it’s primarily a road car that will be used very hard on track. But, yes, just bigger discs is an option. Decent pads and fluid is a given, plus extra brake cooling if necessary, after monitoring disc and caliper temps.

My advice is not to jump in straight away with a BBK, especially if you're concerned about modifications affecting efficiency.
In any case, you're going to be worrying far more about a charging plan for trackdays at Bedford, especially on the GT circuit.

Take your car there and do a few laps with uprated fluid and pads first. You may be surprised.

 

[Mash]

Do you realize how small is this figure of 2g/second of airflow? Compare to amount of air going between the brake rotor and wheel - its nothing. I have no idea why you can't read even your own stuff.

Incorrect. The mass flow of air through a disc with tapered radial vanes (TRV) is approx 180% higher than a disc with circular pillars (CP), and that is comparing like to like, diameter and thickness. Even a disc with straight vanes (SRV) has a 100% increase in flow compared to the standard Tesla disc design.

Hmm, barely increase flow, and a tiny improvement? Ok.

It’s not all about higher airflow. You need a disc with better heat transfer so that it uses the air flowing through it more efficiently, and more importantly, a uniform temp distribution, so as not to cause high stresses throughout the disc. The higher the surface area of the disc, the better, so bigger diameter, thicker and more vanes give higher heat transfer and a lower operating temperature. The downside is higher un-sprung weight, so a balanced design is best.

0.01% range difference? Nice scientific approach, pulling an arbitrary figure out of the air, when it’s plainly obvious you have very limited understanding about brake disc aero.

A bigger diameter disc and a design which gives up to 180% more flow than the standard disc = less flow because the distance between the disc OD and wheel ID is smaller? With at least an inch gap, there will be no restriction of flow. Again, this shows you have a very poor understanding of aerodynamics.

Sorry to Redwood, but this does show your brake kit gives a big improvement in heat management!

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[Clivew]

Do you realize how small is this figure of 2g/second of airflow? Compare to amount of air going between the brake rotor and wheel - its nothing. I have no idea why you can't read even your own stuff.

You really are clutching at straws.

This is a comparison test, carried out by MIT, of flow and heat management of the small and thin discs (all the same size), rotating at a set rpm. This isn’t a Tesla specific test, using the standard CP Tesla discs against the curved vane Redwood kits. The test wasn’t to show ultimate airflow of a specific disc, but a comparison showing flow differences and efficiencies of the different internal designs.

Your last argument was that curved vane discs ‘barely IMPROVE flow’ compared to Pillar discs

With the size difference of the Redwood discs, flow will easily increase over 300% compared to the standard Tesla discs.

There is no way of knowing how that extra flow + the pumping losses will affect aero efficiency around/through the wheel, plus any pad drag, thus my initial questions to Redwood about testing for efficiency changes.

 

[Mash]

Most flow is going around the rotor, not through. They investigated the pumping action of the rotor through the vanes. And for this talk what is relevant, that the design of rotor vanes can't possibly influence drag significantly for reasons I said many times already. And nobody here is going to be proving that or otherwise. And demanding the reseller to do some stupid research project is ridiculous.

You really are clutching at straws.

This is a comparison test, carried out by MIT, of flow and heat management of the small and thin discs (all the same size), rotating at a set rpm. This isn’t a Tesla specific test, using the standard CP Tesla discs against the curved vane Redwood kits. The test wasn’t to show ultimate airflow of a specific disc, but a comparison showing flow differences and efficiencies of the different internal designs.

Your last argument was that curved vane discs ‘barely IMPROVE flow’ compared to Pillar discs

With the size difference of the Redwood discs, flow will easily increase over 300% compared to the standard Tesla discs.

There is no way of knowing how that extra flow + the pumping losses will affect aero efficiency around/through the wheel, plus any pad drag, thus my initial questions to Redwood about testing for efficiency changes.

 

[Clivew]

You make lots of definitive statements as though they are facts, when you have been proven wrong, time and time again, but still you continue.

You can’t even get simple things correct. I wasn’t demanding anything, I merely asked.

Do you have any data on differences in efficiency compared to the standard set-up?

 

[Mash]

I can't help you anymore to start actually reading before answering.
All of your questions were answered. If you want to prove that drag can be influenced measurably - do the test yourself, but move it out of the vendor page - this has nothing to do with this particular kit.

You make lots of definitive statements as though they are facts, when you have been proven wrong, time and time again, but still you continue.

You can’t even get simple things correct. I wasn’t demanding anything, I merely asked.

 

[RedwoodMotors]

I can't help you anymore to start actually reading before answering.
All of your questions were answered. If you want to prove that drag can be influenced measurably - do the test yourself, but move it out of the vendor page - this has nothing to do with this particular kit.

Agreed here, I think everyone has presented their points and knows where everyone stands. I'd like to get the thread back on topic for other issues, since I think we've discussed this particular topic as much as can be done in this thread.

Cliview I would encourage you to start a new thread to discuss the general principals of curved vane discs vs pillar vane discs in relation to range.

Happy to discuss other points or questions though with you guys, but I think we've covered this one as much as we can while being relavant to this thread.

Just a heads up, we still have the storewide 'EARLYADOPTER' coupon code going on the website for just another week (a heads up for anyone considering).

 

[Clivew]

Sorry guys, that went on far too long, we are now talking via PM. Please remove whatever posts you deem necessary to clean the thread.

 

[RedwoodMotors]

Hey everyone!

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BLACK FRIDAY Starts NOW. We are taking 10% OFF the entire website, use code ‘BLACKFRIDAY23’

PLUS we are auto-applying an ADDITIONAL 10% discount on ALL Redwood RW-S5 Cyclone Wheels for the Model3 and ModelY. These final sets of wheels in stock first-come, first-served!

You MUST apply the Black Friday coupon code to your order for 10% OFF, and then any additional discounts for the wheels will be auto-applied as they are added to your cart. Black Friday runs Nov 1st - Nov 30th, or while supplies last. Don’t miss it!

www.RedwoodMotorsports.com

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[RedwoodMotors]