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RSA manual steering rack

 
Old 04-27-2014, 02:08 PM
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repguyMN
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Default RSA manual steering rack

Hello,
I have a 92 C2 with a new RSA rack installed by PO
On the street steering is difficult when just starting out as expected. I have had it on the track twice and turn in is very difficult. I have had other experienced 964 drivers drive it and they felt it was much more difficult then theirs and one had a RS America so it was good feedback.
I recently had lowering springs installed and had an alignment/corner balance done. The shop said alignment was "aggressive street".
Questions:
1.Is the rack suspect?
2.what specs are other using RSA racks?
3.Do you feel the caster setting could be the problem? Mine is 4.34 R and 4.22 L
Most feel the steering should be much easier at moving speeds.
TIA
P.S. I could post a copy of my alignment sheet but have not yet figured out how to post pics?
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Old 04-27-2014, 03:16 PM
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Steve Weiner-Rennsport Systems
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Hi,

Need some additional details about your tires & tire pressures.
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Old 04-27-2014, 07:19 PM
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Hi Steve,
thanks for your response. I am running 17" Cup II with BFGoodrich Rivals. 225/45. I had 33psi cold tire pressure. Only did a couple of laps so I doubt they got too warm. Temp in MN was a brisk 45.
Kris
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Old 04-28-2014, 12:28 PM
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UncleRemus
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I would say that my RSA is only difficult to park. If you want to make steering lighter, reduce caster within the bounds of camber. I'm not sure of the ranges on 964s tho, because I haven't tried to set mine up for track work.
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Old 04-28-2014, 01:25 PM
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KaiB
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P.S. I could post a copy of my alignment sheet but have not yet figured out how to post pics?

Easy as 1,2,3.

Go to tinypic.com, browse your PC for the pic you want, upload to tinypic, size to msg board size, copy the link they give you (for forums and msg boards) and then come here and paste that to your msg.

As an aside, I don't trust alignment sheets unless I KNOW the shop and the quality of their work. Numbers mean nothing until they're proven.
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Old 04-28-2014, 02:55 PM
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repguyMN
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Thanks KaiB for the posting instructions! here is a pic of the specs. I understand they may not be of great value but just checking to see if anyone sees a glaring issue that could be the culprit.
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Old 04-28-2014, 04:55 PM
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You don't have any camber!
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Old 04-28-2014, 07:04 PM
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repguyMN
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That was my first thought as well UncleRemus but others at the track with more experience than on friendly track alignment felt caster would have more influence.
I do occasional DE driving. Nothing serious. My shop I think did not take this into consideration and put a street alignment on it. Do you have any copies of your alignment on your RSA?
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Old 04-28-2014, 10:40 PM
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I don't think I have a copy, but even my street cars get 1-2 degrees negative in the front.*

* Non-daily driven street cars.
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Old 04-28-2014, 10:41 PM
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And btw, camber does not affect steering effort. I was simply commenting that you don't have any camber. You want more.
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Old 04-29-2014, 03:13 AM
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Steve Weiner-Rennsport Systems
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Originally Posted by repguyMN View Post
That was my first thought as well UncleRemus but others at the track with more experience than on friendly track alignment felt caster would have more influence.
I do occasional DE driving. Nothing serious. My shop I think did not take this into consideration and put a street alignment on it. Do you have any copies of your alignment on your RSA?
A few thoughts,......

1. Your caster can be reduced to lighten the steering effort. Naturally, the amount of steering self-correction is lessened as well but I'd be shooting for something around 3.75-3.85 deg to make it easier to steer at low speeds.

2. Your camber settings are optimal for best tire wear, however you are giving up some grip in the corners with camber setting approaching zero. Like many things, camber is a compromise between grip and tire longevity so you must make some choices here. For street cars, I like .5 deg negative to help reduce understeer. Your call on this one.

Hope this helps a little.
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Old 04-29-2014, 11:10 AM
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Hi Steve,
Very helpful! Thank you!!
I will take my car in and have the adjustments made. I prefer additional grip over tire. I was noticing under steer so I believe you are right on.
Kris
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Old 05-01-2014, 09:35 PM
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This weekend I am going to put the car on jacks and see if I get any resistance in the steering. Should there be resistance is there anything that can be rebuilt, adjusted or lubricated in a RSA steering rack?
There has been excellent response here as usual and I thank everyone! My confusion is that some in my local club don't believe caster and camber have anything to do with the difficult steering? If it doesn't why the difficulty?
Just looking for other ideas to investigate beyond alignment?
TIA
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Old 05-01-2014, 09:54 PM
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I run 245 in the front.
It's crazy heavy even at the track.

I know went to a non assisted c2 rack and will feel it at the track next week.
Will report.
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Old 05-01-2014, 10:00 PM
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repguyMN
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Thanks Peter. I would like to know your alignment specs if you have them?
Good luck at the track!
kris
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