Miata Mailing List: June 1997, Message #71
sponsored by



     



From: 	doc@dickson.net (Doc Wynne)

Subject: Re: removing steering wheel...alignment

Date: 	Mon, 2 Jun 1997 12:56:22 -0500



On Fri, 30 May 1997 16:41:36 -0800, Bob Krueger

<voodoo@miata.net> wrote:



>Wow! 15 degrees would be a LOT to be off due to road crown, I would think.



 Well, we do get a bit more rain out our way. <g>



> Now it's straight

>again...essentially all the time, although like you say, road crown can

>affect the perceived straightness a bit as you steer slightly into the

>crown, but in my case nothing like 5-15 degrees. And I'm running -1.5

>degrees of negative camber in the front and -2 degrees in the back with

>zero toe all around, which are fairly aggressive alignment settings. I do,

>however, run the caster out as far as it will go equally on both sides at

>the -1.5 camber setting, which is 5.5 degrees on my car with the FM springs.



 You've actually got it easier with the springs than with those

who are on stock springs.



 When I was on all stock suspension, I originally did the "Miq"

alignment and while the car was quite a bit better, it didn't

turn in well enough to suit me for autox. I ended up with the

camber at -0.7 (all I could get) and 1/16" toe *out* on each

side, but the caster would only go to +2.3 The car then turned in

like it was wired, but it was very twitchy on the street. This is

when I noticed how much the wheel was "off" on some roads.



 Since getting the springs and shocks, I now have -1.8 in the

front along with +4.5 caster, and still keeping the 1/16" toe

out, and the car is *much* more behaved on the street, and I see

a lot less of the "off center" wheel while driving.



 To me, the biggest difference seemed to be the toe adjustment. I

had mine at 0 toe for a while, and the difference in that and

1/16" out is amazing...much more difference than from 1/16" toe

in to 0 toe.

 

>In my experience, the thing that has had the greatest effect on the car as

>regards road crown was insufficient sidewall stiffness. When I got my

>15-inch wheels and my first set of 195/50-15 D40 M2s, I ran the pressure at

>28, since that's where I had run the stock setup. Man, the car acted like a

>PIG on even slightly crowned roads, wanting to fall off toward the shoulder

>rather than go straight ahead without constant steering input. I upped the

>pressure to 31 all around and this went immediately away. Ever since, the

>car has behaved just fine on crowned roads. Others with D40s in our local

>group have also found that they seem to like a bit more pressure to keep

>the sidewalls adequately stiff. I run D60 A2s on the Honda, also at 31, and

>the same seems to be true for them.



 It was true of my SP8000s as well. I tried 26-28, and while it

rode fairly well, it was a pig as well. Going to 34 front, 32

rear made a BIG improvement. I'm now running 32 all the way

around with D60JLBs.



  Doc