My evo's steering feels really sensitive to bumps and things on the surface. I'm not talking about sensing them, but there's a really disproportionate amount of torque on the steering wheel when going over the smallest of imperfections. I tried driving over the same surface on my Sti and then on the Evo with my hands off the wheel and the evo's steering wheel wobbled significantly more. What this means is that I have to grip the evo's steering wheels harder and sometime driving over minor imperfections is quite disconcerting - you see a some small cracks on the road, drive over it and you steering is all over the place. The car keeps going straight most of the time though.

The main point is that I've only noticed this recently (after my episode with the tyres) and as i said, it doesn't happen on my sti (which is the closest thing I can find to an evo right now). I haven't done anything to alter my suspension geometry and so the re-alignment torque and so forth should be the same as stock. My wheels are offset +30 and 8.5" so that's not really a mile away from stock either. Alignment is good (all within tolerance) also.

According to the TSB on the evo8, there's an adjustment that can be made to your rack (steering) that will effectively stiffen your steering wheel - i.e. make it heavier. I _think_ this will help. So:

1)Has anyone made this adjustment?
2)Do I need to take the rack off the car?
3)Anyone had similar problems?

Many thanks for any info


p.s. Did a search under "power steering adjustment" and got nothing - which worries me.

 

And what TSB# would this be???????

 

2004 Mitsubishi Lancer Evolution Service Manual Volume 2,
It's in group 37, Steering
Page 37-46 >>K<< Total Pinion torque Adjustment

Why?

 

anyone else?

thinking of taking it into Mitsubishi tomorrow, but they're not all that familiar with evo's though...

 

I think I have the same thing going on.

Anyone else have imfo on this tsb?

Or having the same issues

 

I've had this "issue" from day 1 but I believe it is because the power steering is so powerful to be able to turn the wheels from straight to full lock in ~1.1 turns...coupled with tires that tramline like crazy...

If you really want to get rid of it, put your front wheels at about 0.004 toe-in (factory specs are 0 +/- 0.008) and/or put on some all-season tires. With my winter tires on, I didn't have any tramlining or feel the wheel trying to be pried from my hands. It all came back when I put my RT-615's on for summer though. I suppose you could somehow reduce the amount of boost your power steering is producing, but that wouldn't solve the underlying tramlining effect of high-performance tires and ultra-quick steering ratio. Also, Evo steering wheels are relatively small so the amount of leverage you have on the steering column itself is reduced.

Bottom line, if you have your Advans or similar performance tires on, keep both hands on the wheel at all times...which you should do anyway...

 

I agree this may relate more to tire choice and inflation levels - check your pressures.

 

I agree as well, I believe this might be caused because of the choice of tires, some tires tramline more than others, especially sticky ones. Your camber setting in the EVO can also cause this, the more -ve camber you have the more the tires tramline and the steering shakes. Also some have said the stock factory alignment can cause bump-steer when going over bumps, which would mean the arms don't swing along the same or parallel arcs.

On top of this add the quick ratio steering on the EVO and things get exaggerated quickly. I have experienced the same thing when going over bumps and instead of driving ham fisted I loosened up my arms and although the steering shakes I am able to keep the car pointed in the direction I want

 

You could also give the Whiteline bumpsteer correction kit a try, it should make a big difference in controlling the problem you seem to be experiencing.

-Dan

 

Steer ratio, tire compound, tire size, toe, camber and caster will alter the tramlining.

 

It's been a while since but I've actually chickened out of the adjustment 'cos it looks like major surgery - like take the whole rack off the car.

I've played around with the pressures quite extensively and yes, going a little softer does help but very slightly. I've accepted that it's just the way the evo steering is. I mean, if I drive it for several days consecutively, i get used to it. My Sti is stiffer but it is less responsive.

Tyre compound has a lot to do with it, as many pointed out. However, I had the stock advans on si it wasn't as if I had some strange tyres on it. Anyway, moving on to tyres that are less sharp (such as my current RE-01R's) clams it down a bit but it's still there. I'd rather not go to all weather since they're not really needed here.

The toe is interesting and I might try that. I don't really have the means to change caster and I'm on 'zero' camber and iirc, the 'other' toe setting would be -1 and that would worsen the situation surely?

 

Me thinks you might want to brush up on alignment terminology. Toe-in means your tires are closer together in front than in back. Toe-out means the opposite. Camber is how much the tires tilt (inward, or even outward). Toe-in has the effect of stabilizing the car in a straight line to the detriment of turn-in response. Toe-out has the opposite effect, making your car more twitchy and prone to tramlining, but with better turn-in response. Of course, this is only true to a certain extent but as long as you stay within the factory spec ranges you shouldn't have any adverse effects.

 

Sorry, i meant the 'other' camber setting.
The toe setting I agree, and will try out as mentioned...

 

I think if you have it set between 0.004 and 0.008 toe in, you'll notice a big difference in stability, although I don't think it will help for larger bumps or irregularities. Good luck.

 

check your toe