Too much negative camber?

[Drew J]

Naturally, my car sits at -.4 and -.7 degrees of camber in the rear, and I've recently put camber plates on that take it to -2.2 and -2.0 degrees of camber.

My question is what is the maximum amount of negative camber you can run before you start getting uneven tire wear? I'm about to put my summer Toyo Proxes R1R 200tw tires on, and I'm assuming they're already going to wear relatively quickly just from being 200tw.

 

[CSM]

Naturally, my car sits at -.4 and -.7 degrees of camber in the rear, and I've recently put camber plates on that take it to -2.2 and -2.0 degrees of camber.

My question is what is the maximum amount of negative camber you can run before you start getting uneven tire wear? I'm about to put my summer Toyo Proxes R1R 200tw tires on, and I'm assuming they're already going to wear relatively quickly just from being 200tw.

it depends a bit on your driving habits and roads you drive on. If you drive a lot of long straight roads You might accelerate wear from camber faster.

FWIW, I ran -3F -2.7R all last season on my Scion on the RT660s and they have even wear. That was probably 8k total miles, including a bunch of autocross events and a road trip to SC and back

 

[Dpro]

Basically Camber plates are for corning its why you buy them and install them. Of course some people do it for looks on our cars its not unusual to see a lot of the Autocross,Canyon and track guys running at least 2 degrees up front sometimes even more. Does it help on turn in and corner? A lot does it keep the rear more planted going into a corner with 1.8-2.0 or more possibly. I know a Track guy out here who is on the forum who is close to 3 degrees in the rear and has some pretty fast times to show for it.

Yes if you love cornering then you will love negative camber. Alignments like to match negative camber front to rear. So do not be overly worried and seeing as you have camber bolts up front you have already started to travel down that road.

 

[jeffreylyon]

Any amount of negative camber will cause uneven wear on the inside of the tires if you only drive in straight lines. 0 camber will result in uneven wear on the outside if you aggressively corner a lot. I run -2.5º on the front, stock on the rear, and only street my car to events and have even wear on all 4 corners and fairly even temps across the tire after an A/C run. I could stand for a little more induce-able oversteer but I like that I don't need to mess around with the setup when I track the car.

MOUR camber isn't better and the balance shouldn't be between camber and wear but, rather, how the car is balanced. I increased rear anti-roll stiffness with a torsion bar so adding camber to try to find more rear grip (esp. since the torsion bar decreased roll) wouldn't make sense in my setup. However, I stripped out the rear seats over the winter so I may be looking for more rear grip this season and if temps tell me that my rear camber should be increased then I'll give these plates a shot.

 

[Dpro]

Of course not and it also depends on the chassis how much is needed. I should add the person I mentioned is TemecFiST. Now I know guys with torsion bars and camber plates. it all depends on the level of driving you are at as well. I will also say adding rear anti roll stiffness in the rear is not quite the same as adding camber. Adding rear anti roll stiffness can take grip away in some instances not add. Camber does add grip,. It also raises the breakaway point so one can use more speed in the corner before the rear starts to slide.
First hand experience with that.
I can also say it all varies depending on the setup of car for different types of driving.
I have always found camber to benefit for cornering though be it FWD or RWD. YMMV

I will also say you have a fair amount upfront . To a lot of people anything above a degree of camber is MOAR to use your terminology .

 

[Mikey456]

I think there is always a compromise when you get out of the factory spec. When just lowering the car you create negative camber -1. The car handles better and it’s worth it to me. I increase the rear trac of the car by running a 5 mm spacer. Sounds small but I notice more stability at higher speeds, more understeer at lower speeds and less 3 wheeling. I could always use more negative camber in the front to reduce understeer but I will increase tire wear especially when I’m on 200 tread wear tires. If u want to track the car it’s a good idea to have an extra set of wheels and tires. And rotate your tires often [emoji6]


2017 Ford Fiesta ST, Shadow Black, Recaro seats, Mountune RMM, Swift springs, 5mm rear spacers, Falken 615+ tires

 

[jeffreylyon]

Of course not and it also depends on the chassis how much is needed. I should add the person I mentioned is TemecFiST. Now I know guys with torsion bars and camber plates. it all depends on the level of driving you are at as well. I will also say adding rear anti roll stiffness in the rear is not quite the same as adding camber. Adding rear anti roll stiffness can take grip away in some instances not add. Camber does add grip,. It also raises the breakaway point so one can use more speed in the corner before the rear starts to slide.
First hand experience with that.
I can also say it all varies depending on the setup of car for different types of driving.
I have always found camber to benefit for cornering though be it FWD or RWD. YMMV

I will also say you have a fair amount upfront . To a lot of people anything above a degree of camber is MOAR to use your terminology .

All of this is pretty well understood and explained. Adding rear roll stiffness reduces weight transfer over the rear "axle" and will *decrease* rear grip with respect to the front. Increasing rear roll stiffness will decrease roll and, thus, also decrease the amount of induced positive camber. Decreasing the amount of positive camber reduces the need for static negative camber. Camber does not add grip per se; setting more static negative camber may result in the outside tire sitting more square the the road when the car rolls into a turn. The "right" way to see if you need to run more static negative camber is by measuring the temperate over the face of the tire after a 10/10'ths run. If the inside of the tread if markedly hotter that the outside, esp. on the rear of a FWD car, then it's time for more negative static camber.

I wouldn't run -2.5º up front on a street FiST, regardless of how Hooligan I drove.

 

[Dpro]

All of this is pretty well understood and explained. Adding rear roll stiffness reduces weight transfer over the rear "axel" and will *decrease* rear grip with respect to the front. Increasing rear roll stiffness will decrease roll and, thus, also decrease the amount of induced positive camber. Decreasing the amount of positive camber reduces the need for static negative camber. Camber does not add grip per se; setting more static negative camber may result in the outside tire sitting more square the the road when the car rolls into a turn. The "right" way to see if you need to run more static negative camber is by measuring the temperate over the face of the tire after a 10/10'ths run. If the inside of the tread if markedly hotter that the outside, esp. on the rear of a FWD car, then it's time for more negative static camber.

I wouldn't run -2.5º up front on a street FiST, regardless of how Hooligan I drove.

You are pretty much re writing what I wrote in a more technical form . As far as positive camber goes I do not thing anyone wants to get into that situation.
As far as measuring the template over the surface of the tire even the engineering nerds I am friends with do not go that deep into. We are not a Formula One team lol.
Most just add negative camber for the positive results and adjust accordingly. I think your taking this way deeper than is needed for the average user here,
I know the reasons for camber and I do feel it adds grip IMO. I also would not run -2.5 on the street myself either .

 

[jeffreylyon]

You are pretty much re writing what I wrote in a more technical form . As far as positive camber goes I do not thing anyone wants to get into that situation.
As far as measuring the template over the surface of the tire even the engineering nerds I am friends with do not go that deep into. We are not a Formula One team lol.
Most just add negative camber for the positive results and adjust accordingly. I think your taking this way deeper than is needed for the average user here,
I know the reasons for camber and I do feel it adds grip IMO. I also would not run -2.5 on the street myself either .

I inferred that you were saying that adding rear stiffness may add rear grip. That may be intuitive but the opposite of what really happens. Positive camber happens anytime you roll the car past the static negative camber.

Every A/C event I've ever been to has had a bunch of guys measuring their tire temps. Many (most?) of the local TNIA guys outside of the novice group measure tire temps. Anyone competitive is measuring tire temps and/or it competing with someone who is measuring tire temps. And, yes, F1 teams measure tire temps constantly with I/R camera embedded in the chassis.

https://nasaspeed.news/tech/wheels-...cordingly-can-pay-dividends-on-the-racetrack/

So, to answer the OP's question, you're running too much rear camber as soon as the perceived improvement in car dynamics is not worth the increased tire wear *or* you care about track or A/C performance and your pyrometer tells you that you're running too much rear camber.