OK, I know enough about suspension to be dangerous.... So, I will leave it to experts.

Curent setup:

IX MR
Swift MR springs
Factory bilsteins
whiteline roll center adjustment kit
whiteline rear bumpsteer kit
whiteline steering precision kit
Whiteline heavy duty front bar
whiteline adjustable bar set to medium.

Alignment is numbers matching 0 toe front and rear. Front camber is -1, rear is -.8 I did the alignment myself, so it's as close to exact figures as the machine was capable of.


Now, my problem is that I do a TON of highway driving (more than 20-25K per year). As such, my front tires are getting eaten up on the inside edges.

My first thought was to reduce camber in the front using Camber bolts... However I am not a fan of those because I used to have the damn things slip during autocrosses, and I don't want to have to deal with that when I am the middle of Bum Frack, nowhereville at 2am and need to be in Texas by 6pm...

So I started to think about camber plates... But if I reduce my static camber alone, that will reduce my contact patch in cornering, and I don't want any more understeer than I have when I want it.... Also, I have run cusco camber plates in the past (15 years ago), and remember the coil binding and slip/grip issues I had between the spring perch and the camber plate....

SO......

I was looking into these:

If I add more caster, it will improve wheel tracking... and will induce dynamic camber making a more enjoyable experience for a daily driver.

https://www.evolutionm.net/forums/ev...er-plates.html

HOWEVER.... It does not address the coil binding problems.


My questions to you suspension experts out there...

1: Am I on the right path? Does my logic sound... well SOUND? Is there something I am missing or overlooking that would solve my tire wear delima?

2: Is there enough "space" (for lack of a better word) with the stock bilsteins threading/collar to add a torrington bearing (and races) between the stock spring perch, and.... well that makes me wonder too... What spaces the upper spring perch to the caster/camber plate? Does the upper perch just butt up against the bottom of the camber plate's spherical bearing??? If someone has the parts blown apart here so I can visualize it. I would appreciate it.

3: Is there any manufacturer who makes a sealed torrington bearing? Something that would fit in this location that needs no/minimal maintanance for those of us who don't blow my car apart on a regular basis.

Thank you in advance for your help.

 

As for the binding issues: I would e-mail Rick directly. For what it's worth, I have no coil binding issues with the Ciro plates and stock suspension with Swift Spec-R springs.

However, your tire wear sounds a bit abnormal, given only -1 degree of front camber and 0 toe. Yes, you are correct that increasing caster will add dynamic camber, but you still need some static camber for proper handling. I'll have to pull up my calculation spreadsheet when I get home, but I believe the added dynamic camber from the Ciro plates at full caster was around 1.5 degrees, but don't quote me on that.

Are you rotating your tires regularly? As in, every 5-8K miles for freeway driving? If not, start there. Also, have your toe-in verified somewhere to make sure it hasn't slipped. Finally, consider having a tire shop flip your tires from side to side as they approach the half-way wear point.

 

No, I am not rotating my tires that often. It's really not practical with the amount of driving that I do. That's like a rotation every 2 months. As I am very rarely in the same place every two months, Its just not something I can do without big headaches.

I did have my toe re-verified between the past alignment and when I last had my tires rotated. The shop that rotated my tires swore that my toe must be off, and that's what's causing my wear (they were trying to sell me an alignment). So I said "make you a deal. If you toss it on the rack, and it's out of the green, I'll pay for the alignment, but if it's in the green you rotate my tires for free"

So, I went out with them, helped them mount the heads, and the alignment came back spot on...

I would appreciate the calculation on the dynamic camber... It's nice to have the numbers. Also, do you have to regularly tighten the top strut nut? I seem to remember with the cuscos that they would back off every so often.


As for the coil bind.... As Miss Emily Litella would say.... "Nevermind" I was thinking of a problem in my mind that doesn't actually exsist.

 

The Evo is tough on tires and you're already at the minimum camber up front. I'm not even sure if you can go less than -1 degree of camber with the Ciro plates, by the way. Even if you could do 0 camber and full caster, you will still have more understeer. The additional ~1-2 degrees of dynamic camber you get from the added caster is a peak value, and it only applies at extreme steering angles.

Rotating your tires every 2 months is a small price to pay. It's certainly less work / cheaper than buying new tires when they wear out prematurely. And if you're really driving that much, you're already going to be doing other scheduled maintenance (oil changes, etc.) just as regularly. It really doesn't make any sense to have an Evo with a long list of suspension mods, but refuse to do regular tire rotations. And it certainly doesn't make sense to have a long list of suspension mods only to handicap your setup with 0 camber to avoid tire rotations.

What tires are you using anyway, and what tire pressure? Also, how are your bushings up front? If those are worn out, that could be part of the problem.

 

ahh yes, forgot tires and wheels... Those are always the starting point. Currently I am running some Cheap korean tire... Nexen N3000. Prior to that I was running Falken Azenis, and prior to that, Yokohama S Drive's. As you see, I have been going cheaper in tires each time I put them on. They are sized 235/40/18 on Volk RE30s

I am running about 40-42psi pressure (checked regularly)

My bushings are all perfect. I switched to the Roll Center adjustment kit, steering precision kit about 20K ago when I was doing the clutch. It's not a bushing problem, because I've had this problem since I purchased the car.

The reality of the situation is that I am not cornering enough to warrant this camber. If I was, my tires would be wearing evenly, and they obviously are not.

Also, rotating the tires side to side, then front to back, then side to side is not eliminating my problem of wearing the inside edges... It's just prolonging the time I need before I need to replace the tires. I am trying to reduce the wearing of the inside edge.

 

-1 and 0 toe should not be wearing your tires as you are describing unless something else is wrong. I have spent a lot of time at -3 or more with 0 toe and the only time I had an issue was with my E36 - staggered tires I couldn't rotate and a shop who did the alignment not using a rack because they don't believe in racks. After killing the insides of a set of old Kumho MX's, I got a regular shop to do the alignment with a regular rack and lo and behold the tire wear went away. This was with -2.5 in the front and about +7 caster. With regular rotation I ran my WRX at something like -3.5 in the front for 2-3 years, and even a little toe out, without any issues. Minus one in the front is really nothing.

I have to think either a) rotating front to back every 5k is going to help - obviously the front end of the car has a harder job than the rear, b) your toe isn't really zero, or c) there is something else worn out/wrong that is causing the wear.

"in the green" and "zero" are not the same thing.

 

you skipped a very important next part.

and from my first postThe suspension is tight... The alignment is SPOT ON (as measured with 2 different hunter alignment machines in two different states. the car tracks perfectly straight on flat roads nothing is worn... I just don't think you guys realize that there are significant periods of time when I hop in the car and spend 10 hours cruising at 70-80MPH in nearly perfect straight lines. Yes, I agree my wear is abnormal.... but I use this car in an abnormal way. This is my highway car. 95% of it's miles are spent on the highway.

Maybe I was not clear and it may sound like my wear is exaggerated..... I am typically getting about 40K miles out of a set of tires... so it's not like a bad alignment is chewing my tires up. It's just that the inside edges of the fronts are wearing faster than the middle/outside.

 

The Evo makes for a poor long-distance highway car, as you know. I think you need to re-evaluate your expectations here. Especially considering:

40K out of your tires is a lot of miles on an Evo. Are you really expecting to get much more out of them?

 

SPOT ON isn't "zero" either Sorry, if you had just said "the alignment rack said the toe was zero" I wouldn't have mentioned it.

Pretty much this.

When the tires die, you're saying there is still a ton of tread in the middle?

 

Yes. Tons!

 

It makes a fantastic highway car! Fast, light, comfortable, quiet, and gets great gas mileage for a car with this performance. With my entertainment system and cruise control, it just eats up the miles and asks for more. The only issue i have is that one single issue. And i am addressing it.

 

40K out of your tires is a lot of miles on an Evo. Are you really expecting to get much more out of them?[/QUOTE]

Bro, your getting 40k from a set of cheap tires, your words not mine, and you are not satisfied? Thats excellent wear...nothing "abnormal". The car is aligned with the wheels facing in a straight line, just like you are driving it on the highway-- in a straight line. Nothing abnormal about that. Thinking your expectations of tire mileage might need to be more realistic--getting 25-30k on any set of tires, on any car or truck I have owned in 30yrs exceeds my expecations and I would suggest most everyone elses on this forum. Count yourself lucky and move on.

 

sounds like an inflation/pressure issue then if both edges are wearing and the center is not...

 

I put my money on inflation pressure and possibly toe change. Rear trailing arm bushing and PSRS on front LCA may assist with that. You may not like the effect on road divider dots on the freeway.

Also front/rear tire wear will balance out with a more aggressive rear diff.

 

It might help to have pictures of how the car sits and the worn tires to try to help diagnose what is going on. I do agree that 40k out of a tire for an evo is pretty good, especially a cheap tire. If your doing 10+hr highway runs you definitely want to rotate your tires more often. How is the rear wearing? Tell us more about the worn tire. Is it sharp? Does it show scrubbing? Cupping? Pictures would greatly help. Are you running spacers? What kind of condition are your struts in? I would try setting toe to spec (idk what it is stock) rather than just 0 and see where that gets you.