Model 3 mods

[gearchruncher]

Yeah light wheels being a performance advantage due to inertia and unsprung weight is one of those true things that is often vastly overstated

Quick math:

4,000 lb car @ 70 MPH: 888,000 joules
1 lb @ 70 MPH, 17" diameter: 182 joules

Yeah, so each pound you take off is 730 joules at 70 MPH, out of 888,000. 0.09%.

GRM added 12 POUNDS per corner to a MIATA and changed lap times by 0.31 seconds. No magic expensive forged wheel is going to save you 12 lbs vs any other reasonable wheel.

 

[tm1v2]

I absolutely felt a difference and benefit from replacing the uber-heavy 20" Uberturbines with much lighter 18" forged wheels. Very very obvious. The power steering just felt better overall, the car felt more nimble in quick back-and-forth turns. This was with 100% stock suspension still (no longer the case). I honestly wasn't expecting that much improvement, I was downsizing just for protection from bad roads / potholes.

Now would I have felt most of that same benefit from decent flow-formed cast 18" wheels? Yeah I think so. I went forged for the extra strength, not because I was counting exact pounds. $1k for decent cast 18s is certainly better value than the $2k I spent on forged, no question. But FOR SURE much lighter wheels - whether cast or forged - can be felt through the steering wheel and improve how the car feels in the twisties. That's in large part because those Uberturbines are just ridiculously heavy, there's no other way to put it.

(No I couldn't feel any acceleration difference. Any possible acceleration improvement was too small for me to feel or care about. I don't really do max acceleration runs anyways.)

 

[jackmott]

I absolutely felt a difference and benefit from replacing the uber-heavy 20" Uberturbines with much lighter 18" forged wheels. Very very obvious. The power steering just felt better overall, the car felt more nimble in quick back-and-forth turns. This was with 100% stock suspension still (no longer the case). I honestly wasn't expecting that much improvement, I was downsizing just for protection from bad roads / potholes.

Now would I have felt most of that same benefit from decent flow-formed cast 18" wheels? Yeah I think so. I went forged for the extra strength, not because I was counting exact pounds. $1k for decent cast 18s is certainly better value than the $2k I spent on forged, no question. But FOR SURE much lighter wheels - whether cast or forged - can be felt through the steering wheel and improve how the car feels in the twisties. That's in large part because those Uberturbines are just ridiculously heavy, there's no other way to put it.

(No I couldn't feel any acceleration difference. Any possible acceleration improvement was too small for me to feel or care about. I don't really do max acceleration runs anyways.)

A confounding factor is you also changed tires when you changed wheels, tires have a massive impact on how a car feels. As well human perception is just terrible at these things, no matter how smart/expert we are. I did this same 20" uberturbine to 18" swap and didn't notice anything. But I am so skeptical of my own perceptions, so who knows maybe I just got too cynical =)

 

[tm1v2]

A confounding factor is you also changed tires when you changed wheels, tires have a massive impact on how a car feels. As well human perception is just terrible at these things, no matter how smart/expert we are. I did this same 20" uberturbine to 18" swap and didn't notice anything. But I am so skeptical of my own perceptions, so who knows maybe I just got too cynical =)

Yeah, to be fair even just changing inflation pressure can be felt and have similar effects. And I did play around with inflation levels on the new tires a bit. The tire shop started me off around 44-45psi cold which felt too high, I ended up back around 42psi cold, currently 42.5psi cold, set during mild daytime temps (so they do drop lower on actual cold nights and such).

I'm not claiming what I felt would actually translate to consistently faster lap times on a racetrack, or anywhere else. Just it felt nicer for tight twisties which is the majority of my fun driving these days. I could feel the difference in casual driving too but I wouldn't say it mattered at all in casual driving.

 

[finaufan]

I have a Model 3 Performance on order. It will be daily driven, no track use. I want to feel connected to the road, in the same way you feel when driving a 911 - sharp handling and feeling like the car does exactly what it’s instructed to do (I understand I can’t mimic that due to the laws of physics, but want to get as close to that as I can).

Once the car is setup correctly, I don’t think I’ll need the ability to adjust. I’d like to run one set of wheels rather than having to switch. My climate has winter temps ranging between 3C and 11C.

In order of priority:
Handling/road feel/responsiveness
Comfort/quiet ride
Looks
Efficiency

I’ve read and re-read the countless threads on here, there is so much info to get my head around I don’t know where to start. There are some incredibly knowledgable folk in here who I’m hoping can point me generally in the right direction and save me from making (expensive) mistakes.

Rims/Tyres
I’m thinking either 19x10 +35 with 275/35 rubber like MPP run on their car, or 18x9.5 +22 with 265/40 rubber per below images. Rims will be Advan RG3 or GT.
Tyres I’m thinking will either be Pilot Sport 4S, or A052, or RE71R.
Flush fitment preferred for looks if possible, but performance more important.

Suspension
I’m thinking of going the MPP sports coilovers to get the ride height and damping where I want it.

Questions:

1. Pros and cons of each wheel size?
2. Pros and cons of each of the three listed tyres?
3. MPP have a heap of other suspension arms and items available, all listed below. Which are recommended, and which are absolutely must have?
4. Is there anything else I should consider, or have missed?

Front upper control arm
Rear spring arm with sport springs
Sway bars
Compression rod bearing (caster adjustable)
Rear camber arm
Solid front lower control arm bearing
Rear toe arm
Rear trailing arm
Rear traction arm

Thanks

DId you get your car and make these upgrades? I'm planning similar upgrades (MPP sport coilovers, FLCA bearing, and compression rod inserts) on my new M3P and would like to hear your experience.

 

[Bennny]

DId you get your car and make these upgrades? I'm planning similar upgrades (MPP sport coilovers, FLCA bearing, and compression rod inserts) on my new M3P and would like to hear your experience.

Latest delivery update says August-October.

I have ordered:

Advan GT 19x9.5+29
Rays TE37 19x9.5+28 (couldn't decide, so got both)
Michelin PS4S 265/35/19
MPP Sports coilovers
MPP FUCA
MPP Control arm bearing
MPP Rear camber arms
MPP Rear toe arms
MPP Compression rod inserts

 

[Bennny]

Just a little heads up to those ordering these parts from Australia - you get hit with the following on import:

Border Charges/Fees applicable:
Duty $ 400.08
GST $ 891.96
Customs Electronic Entry fee $ 88
Quarantine fee $ 0
TOTAL $ 1380.04

 

[mpgxsvcd]

There is a noticeable difference with 18's and 19's. The 19's will feel more sharp in turn in with the shorter sidewalls, and this seems to be a goal of yours. This doesn't mean they actually grip better, just they are a bit more immediate as you turn the wheel. You're already going down from a 20 to a 19. 19's are a bit heavier generally. 18's have to be carefully chosen on a P3D in order to fit over the brakes, not all 18" wheels will. 18's are cheaper with more choices in tires, but that doesn't seem to be a primary concern.

I just switched to 18" T Sportline wheels and 235/45/18 PS4S tires. While acceleration is significantly better I feel that handling is worse. I can really feel the tall sidewall with the PS4S tires. I don't do any aggressive driving on turns so that doesn't matter to me. I just cared about drag racing. However, I would definitely recommend a 19" wheel instead of the 18" wheel if you are going to be driving hard in the twisties.

 

[gearchruncher]

However, I would definitely recommend a 19" wheel instead of the 18" wheel if you are going to be driving hard in the twisties.

Most really fast road and AutoX racers run 18's. It's not that simple.

 

[tm1v2]

I just switched to 18" T Sportline wheels and 235/45/18 PS4S tires. While acceleration is significantly better I feel that handling is worse. I can really feel the tall sidewall with the PS4S tires. I don't do any aggressive driving on turns so that doesn't matter to me. I just cared about drag racing. However, I would definitely recommend a 19" wheel instead of the 18" wheel if you are going to be driving hard in the twisties.

@mpgxsvcd What suspension and bushing mods do you have?

I haven't used the PS4S yet, but historically Michelin summer performance tires like the PS2 were known for somewhat squishy sidewalls, relative to their category. Good for ride quality, but not the best for sharp steering response with taller sidewalls. It's a tradeoff...

(And it doesn't cause any problems for outright grip. It's just something you feel and sometimes have to work with slightly delayed responses.)

I care more about sharp steering response so maybe it's good I didn't end up getting 18" PS4S. I was going to try them but 245/45R18 was on months long backorder when my wheels came in.

 

[mpgxsvcd]

Most really fast road and AutoX racers run 18's. It's not that simple.

You are right. It isn’t a simple decision. I am sure there are ways to remedy the tall sidewall issue but those will be compromises too.

I was just remarking on my experience specifically with 18” PS4S tires on the Model 3 Performance. The handling felt noticeably late to react and then more abrupt when it did react.

Maybe a 40 series tire or different tire is better on an 18” wheel? However, I did want to share my experience specifically with 18” PS4S tires. I can’t recommend that tire without any other changes for curves.

 

[mpgxsvcd]

@mpgxsvcd What suspension and bushing mods do you have?

I haven't used the PS4S yet, but historically Michelin summer performance tires like the PS2 were known for somewhat squishy sidewalls, relative to their category. Good for ride quality, but not the best for sharp steering response with taller sidewalls. It's a tradeoff...

(And it doesn't cause any problems for outright grip. It's just something you feel and sometimes have to work with slightly delayed responses.)

I care more about sharp steering response so maybe it's good I didn't end up getting 18" PS4S. I was going to try them but 245/45R18 was on months long backorder when my wheels came in.

I have no other changes except for the wheels and tires. Everything else is stock in that respect. I didn’t care about handling and I still have the 20” UberHeavy wheels and tires so I can switch back to those anytime I want.

 

[Mash]

CUP2 tires have much stiffer sidewall, but they can't keep traction if there is any moisture, especially if it's not hot.

 

[Bennny]

MPP goodies started arriving today. Just need the car to arrive so I can start fitting them…..