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BMR Front K-brace, 4 point

SVO MkII

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2018 EB PP coupe. I'm running -2.5 deg camber in front with a 19x11 305 square set up. I'm still getting a lot more wear on the outside edges of the fronts (fortunately, I can rotate all four around). I still use the car as a daily driver (smaller wheels/tires), so I don't want any more negative camber up front. I'm wondering if installing something like the BMR front 4 point k-brace would reduce front deflection enough to materially improve the outside tire wear. Anyone have any experience with installing one of these? (I installed one on my GT vert, but that was just to tighten up the front, no track use)
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strengthrehab

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What is your full alignment setting, specifically toe measurement?
 
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Norm Peterson

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Essentially 0 deg (-0.04 L, 0.0 R)
So you've got just a hair of toe-out.

A K-brace will not reduce roll, which is what's driving your front tires over onto their outer tread blocks. The only other thing I can think of that could reduce this wear would be to add more roll stiffness - mainly with firmer sta-bars though firmer springs would also help a little.

So might better dampers (shocks, struts) in that they would better control any "overshoot" in roll if you're throwing the car into the corners with too-rapid steering inputs. On track, sometimes riding the inside curbing can put the outboard tires into positive camber relative to the track pavement if it's significantly higher than the pavement. Stay off of those even if they're gentle.


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SVO MkII

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So you've got just a hair of toe-out.

A K-brace will not reduce roll, which is what's driving your front tires over onto their outer tread blocks. The only other thing I can think of that could reduce this wear would be to add more roll stiffness - mainly with firmer sta-bars though firmer springs would also help a little.

So might better dampers (shocks, struts) in that they would better control any "overshoot" in roll if you're throwing the car into the corners with too-rapid steering inputs. On track, sometimes riding the inside curbing can put the outboard tires into positive camber relative to the track pavement if it's significantly higher than the pavement. Stay off of those even if they're gentle.


Norm
I have the Ford Performance Track Pack suspension with camber bolts (resulting in the -2.5 deg camber). It's pretty stiff. Any firmer and it ceases to be practical as a daily driver. I realize lots of serious track setups are running -3.5 deg with camber plates, but again, not ideal for street driving. Having installed one of the BMR K-braces on my GT vert, I can see how it could theoretically reduce caber change under load. The loaded lower control arm is pushing back against the front sub-frame rail. Any flex of that mount/sub-frame will have a positive impact on camber (reducing negative camber). The K-brace triangulates the lower control arm mounting point with the sub-frame, and ties the two from sub frames together. Again, just wondering if anyone installed one of these and noticed any changes (improvement) in tire wear.
 

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Here's something to think about.

Camber and toe are tied together. Full minimum to full maximum on a camber plate (J&M in my case) gives a swing of about 1.8 degrees of camber (~0.9* each way from center). Min to Max also gives about 3mm of toe-out at the rim per side (calculate the angle if you want, it's just a reference). So, if you set the camber plates to their minimum camber setting (it would be about -1.6* for you w/ the bolts) & 1mm of toe-in, then you can loosen the plates & pull them in to Max at the track. Your front camber will go to ~-3.4* and you'll have ~2mm of toe-out on each side. Both settings go in the correct direction and about the appropriate amount. At the end of the day, you jack the car up, return to your minimum camber setting & drive home. It's 10 minutes work & completely repeatable.

You're wearing the outside front, but it's likely not solely an issue of camber. It's also going to be related to understeer which is making you turn the wheel more & creating larger slip angles on the front end. If you reduce the understeer, you'll see good gains in tire life.
 
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SVO MkII

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At the end of the day, you jack the car up, return to your minimum camber setting & drive home. It's 10 minutes work & completely repeatable.
I thought about this, but I wasn't sure how "repeatable" this would be. Let's say you do a half dozen track events a year. You can tighten, untighten each time, for years, with no adverse effects? Do you need to at least replace the nylock nuts after a while? Just curious.
 

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I thought about this, but I wasn't sure how "repeatable" this would be. Let's say you do a half dozen track events a year. You can tighten, untighten each time, for years, with no adverse effects? Do you need to at least replace the nylock nuts after a while? Just curious.
I'm a little OCD about rechecking (I can do it at home), but as long as that's all you're changing... That's all you're changing.
 

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I tried doing a street and track camber setting via camber plates as suggested above. I thought the toe change would be tolerable but the front wandered something fierce at high speeds on track and under braking.

Remember that a dual purpose vehicle is not great at anything. That’s inherent to compromise.

Also the car may feel stiff to you but it rolls more than you realize. Deflection of the subframe is certainly not what is causing this tire wear. McPherson struts systems need boat loads of camber on track.
 
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I tried doing a street and track camber setting via camber plates as suggested above. I thought the toe change would be tolerable but the front wandered something fierce at high speeds on track and under braking.

Remember that a dual purpose vehicle is not great at anything. That’s inherent to compromise.

Also the car may feel stiff to you but it rolls more than you realize. Deflection of the subframe is certainly not what is causing this tire wear. McPherson struts systems need boat loads of camber on track.
I got spoiled with my '72 911 track car (also struts). Very little weight in front, so very easy to control tire wear with only about -1.5 neg camber. I know, "apples and oranges". I guess with close to 2000 lbs on the front tires, they get a workout.
 

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Here's something to think about.

Camber and toe are tied together. Full minimum to full maximum on a camber plate (J&M in my case) gives a swing of about 1.8 degrees of camber (~0.9* each way from center). Min to Max also gives about 3mm of toe-out at the rim per side (calculate the angle if you want, it's just a reference). So, if you set the camber plates to their minimum camber setting (it would be about -1.6* for you w/ the bolts) & 1mm of toe-in, then you can loosen the plates & pull them in to Max at the track. Your front camber will go to ~-3.4* and you'll have ~2mm of toe-out on each side. Both settings go in the correct direction and about the appropriate amount. At the end of the day, you jack the car up, return to your minimum camber setting & drive home. It's 10 minutes work & completely repeatable.

You're wearing the outside front, but it's likely not solely an issue of camber. It's also going to be related to understeer which is making you turn the wheel more & creating larger slip angles on the front end. If you reduce the understeer, you'll see good gains in tire life.
I think this is the best approach short of putting more spring in front. You have lots of tire and you are causing excessive body roll. I seem to be alone in this belief, but you can't operate these cars on track with decent tires and have less than 300 lbs per inch of wheel rate. Look at what Vorshlag recommends with their coil-overs. You really need to be over 450 lb/in in front.
 

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I think this is the best approach short of putting more spring in front. You have lots of tire and you are causing excessive body roll. I seem to be alone in this belief, but you can't operate these cars on track with decent tires and have less than 300 lbs per inch of wheel rate. Look at what Vorshlag recommends with their coil-overs. You really need to be over 450 lb/in in front.
This we agree on. By adding a spring rubber, you can effectively cancel out a coil which raises the spring rate (and ride height) for competition and then remove them (2 minutes) when you're done. This has been my approach to the point where I run it all the time. Coil-overs with a 450 #/in front is my next step.
 

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I tried doing a street and track camber setting via camber plates as suggested above. I thought the toe change would be tolerable but the front wandered something fierce at high speeds on track and under braking.
That suggests a problem with the toe setting, but it's not necessarily a criticism of the means with which it was set.
 

strengthrehab

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Love my 450# MCS setup (also 750R--true coilover, though).

Previously I was at 560/1300 (divorced) setup. Still have 600 front springs if I want them.
 

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That suggests a problem with the toe setting, but it's not necessarily a criticism of the means with which it was set.
Toe was set at zero for street alignment at -2.8* camber. For the track I slammed the camber plates inboard to -3.5* knowing it would toe out but hoping it would still be stable enough. Unfortunately not the case so now it’s just -3.5* all the time.
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