MASTER THREAD: Comprehensive Road-Course Modification Guide — Optimizing the 3 for the track

[Mash]

I'm switching to 19s to maintain 26.5" diameter and take out a bit of sidewall. It's a hunch so I can't really vouch for it yet, just make sure you stay close to that diameter to keep the drive motors in their peak efficiency range (and reduce heat).

Since I have both sizes, I don't feel that it's a good idea for the track setup. But your experience might be different.

 

[drew.cleaver]

Since I have both sizes, I don't feel that it's a good idea for the track setup. But your experience might be different.

I appreciate that and will note it in my memory bank but I think on a 100tw tire it could react quite different. Also, remember my options are limited in 100tw for anything close to 26.5" so it is a compromise always like most things seem to end up.

 

[ten10ths]

...And 10mm spacers would need hub ring repeater, because no hub left at this point and wheels won't be stable without it. Certainly you also need longer studs. Like the one from my signature.

Thanks for the tip on the Dorman wheel studs. There's a pricing glitch on Amazon right now for those for $7 for a set of ten.

Who did you source the spacers from? I'm having trouble finding 10mm for the 14mm studs.

 

[Mash]

Thanks for the tip on the Dorman wheel studs. There's a pricing glitch on Amazon right now for those for $7 for a set of ten.

Who did you source the spacers from? I'm having trouble finding 10mm for the 14mm studs.

I had to build custom on spot with lathe machine. You need, as I've said, not only spacers, but also that spacer needs a new hub. So I think it has to be custom made. Or you need different ET for front and rear.

 

[Davidss2]

Hubcentric is nice to have not necessary especially for a track wheel setup. I have zero hubcentric spacers on my track wheels and there is no vibration. The car works fine just lugcentric.

 

[Mash]

Hubcentric is nice to have not necessary especially for a track wheel setup. I have zero hubcentric spacers on my track wheels and there is no vibration. The car works fine just lugcentric.

Maybe your spacers are thin or your wheels are not wide enough, but wheels are not supposed to sit on studs at all - they won't be centered and studs would give up eventually.

 

[drew.cleaver]

Thanks for the tip on the Dorman wheel studs. There's a pricing glitch on Amazon right now for those for $7 for a set of ten.

Who did you source the spacers from? I'm having trouble finding 10mm for the 14mm studs.

I had some of these made specifically for a set of wheels with different center bores that NEEDED 15mm of backspacing due to incorrect offset (mustang wheels) Custom Wheel Adapters, Wheel Spacers, Hub Rings for your car! | Motorsport Tech

However, a mechanical engineer friend that designs and manufactures race car hubs insisted I not worry about centering rings as the wheels are lug-centric.

I think it's a nice reassurance to have, but not really necessary according to some smart people.

 

[Mash]

I had some of these made specifically for a set of wheels with different center bores that NEEDED 15mm of backspacing due to incorrect offset (mustang wheels) Custom Wheel Adapters, Wheel Spacers, Hub Rings for your car! | Motorsport Tech

However, a mechanical engineer friend that designs and manufactures race car hubs insisted I not worry about centering rings as the wheels are lug-centric.

I think it's a nice reassurance to have, but not really necessary according to some smart people.

Despite your friend experience, I have to tell you that studs are not designed to carry the weight of a car. In fact no screw threaded fastener designed for lateral force resistance. Cone seats and large tolerance of lug hole and stud is especially made to let some movement of the wheel on studs to let it properly seat on the hub.

Studs job is to make sure that the wheel is not shifting from the hub surface during turns. The job of hub itself therefore is to transfer weight of the car to the wheel. The reason why hub is rusting on most of cars is very high iron content to have high tensile strength and avoid deformation of the edge. This is true for all cars, racing or not.

There is no such thing as lug-centric wheel design. It's just some aftermarket wheel sellers lie about that to sell wheels with mismatched bore. Aftermarket wheels also not designed to be lug centric, because it's impossible to balance them in such case.

 

[Zextraterrestrial]

They are not out yet. Soon though!

So you’re the one testing these...u suck
What tires are you running? & 18” A7 hopefully?

 

[Zextraterrestrial]

So you’re the one testing these...u suck
What tires are you running? & 18” A7 hopefully?

& please, what exact spec wheels are you running, offsets

 

[Davidss2]

There is no such thing as lug-centric wheel design. It's just some aftermarket wheel sellers lie about that to sell wheels with mismatched bore. Aftermarket wheels also not designed to be lug centric, because it's impossible to balance them in such case.

Respectfully you have an interesting theory but it just isn't correct. Can you point to any one of the tens of thousands of street and race cars who are running lugcentric and had a failure because of it? Regardless of whether you personally feel like it isn't "proper" it is safe and considered normal safe and prudent in the real world.

 

[Mash]

Respectfully you have an interesting theory but it just isn't correct. Can you point to any one of the tens of thousands of street and race cars who are running lugcentric and had a failure because of it? Regardless of whether you personally feel like it isn't "proper" it is safe and considered normal safe and prudent in the real world.

Your lack of safety data in conjunction with engineering denial doesn't make my "theory" incorrect. There are no lugcentric wheels on the market, only wheels with wrong bore size which easily vibrate at speed and overstress lugs. Just because you and your friends didn't push your cars enough to destroy a wheel, bearing or studs doesn't mean that you should make bad advices to others. At the end of the day maybe you did, but can't connect dots.

 

[dfwatt]

Respectfully you have an interesting theory but it just isn't correct. Can you point to any one of the tens of thousands of street and race cars who are running lugcentric and had a failure because of it? Regardless of whether you personally feel like it isn't "proper" it is safe and considered normal safe and prudent in the real world.

The fact that you can often times get away with a lug Centric instead of a hub Centric Mount does not make what Mash is saying wrong. As you up the g-force on the suspension and load the wheel heavily where you start approaching maximum structural loads, it just is not safe to not have a hub Centric mount. If you look for example at the Porsche GT2 RS you will not find anybody running it with just lug Centric Wheels. If hub-centric mounting was just some kind of over cautious fashion you would not have every manufacturer following that principle.

 

[fastp3d]

& please, what exact spec wheels are you running, offsets

18x10.5 I do not have the exact offset as unplugged made it a custom set. If I were to guess I would say ET30

 

[ahhlun]

To me, the first concern to address is the brakes. While not needed for a leisurely day out at the track, or your first event, they quickly become a weak-point if you are pushing it. That being said, I personally would not recommend BBK’s, as they are generally expensive and overkill. Regenerative braking in my experience does help with heat dissipation and brake component life significantly. A nice set of rotors, and (in particular) pads in combination with high performance brake fluid is more than suffice for most people. For Performance Model 3’s the stock rotors are enough if you don’t want to spend money on the upgraded rotors, and they are cheap to replace.

For the above comment about BBK is overkill, does this apply to both P3D and P3D-? I think P3D- has a bit worst brake right.

Also about regenerative braking, I have seen Youtube videos recommending keeping it at 0 or 20% due to overheat issue, do you do this?

 

[MasterC17]

For the above comment about BBK is overkill, does this apply to both P3D and P3D-? I think P3D- has a bit worst brake right.

Also about regenerative braking, I have seen Youtube videos recommending keeping it at 0 or 20% due to overheat issue, do you do this?

I was speaking in regards to the P3D+. The rotors on the P3D- are quite small, as well as the pad sweep area. At the end of the day, the true deciding factor is your personal braking habits. How experienced are you? How hard are you on brakes?

I didn't personally find that turning down the regenerative braking had much of an impact on overheating - but again whether that will even be any issue at all comes down to how hard you are pushing the car and the supporting modifications. If this is your first track day it's not going to be an issue.

I think most people have found that P3D+ Calipers + Rotors with aftermarket track pads and high temp brake fluid has served them well enough. I ended up buying two BBK's - one from AP Racing and the other from MPP. They are both great options and if you have the $ to spend and you would benefit from them I would recommend them.

 

[Zextraterrestrial]

For the above comment about BBK is overkill, does this apply to both P3D and P3D-? I think P3D- has a bit worst brake right.

Also about regenerative braking, I have seen Youtube videos recommending keeping it at 0 or 20% due to overheat issue, do you do this?

P3D- front and rear rotors are the same size
I did a hillcimb and melted my centering rings to my hubs w/ 255 A7 getting to what the car reports as 80% brake temp...a 5 lap autocross enduro on RE71R and just hit 94% brake temp on stock P3- rotors...somewhere around here is when it tells you braking may be reduced (probably 90%?)
I just changed to MPP rotors on front but not to the big ones. stock rotors just mix the air in between the plates, don't pull air directionally I imagine the directional fins should be enough for hillclimbs and enduros(hopefully w/ bigger A7 too?)..probably will only see thunder hill and Laguna Seca ever.
recommend SS lines, rotors and a brace make a big difference in brake feeling - to anyone even if you don' Auto X or race
& if you auto X you probably don't want a BBK unless it is super light & you can fit 18" too

 

[Mash]

For the above comment about BBK is overkill, does this apply to both P3D and P3D-? I think P3D- has a bit worst brake right.

Also about regenerative braking, I have seen Youtube videos recommending keeping it at 0 or 20% due to overheat issue, do you do this?

Don't turn off regen without seriously upgraded brakes.

 

[MasterC17]

I've quite lost my mind. Tested a few things this weekend - will parse the data and share some results!

 

[MountainPass]

If that's what losing your mind looks like I want to lose my mind as well!