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UC Steering Rack Ratio


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#1 antelopeslr5000

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Posted 11 September 2008 - 06:20 AM

Hi all,

I've search this forum and there seems to be conflicting information with regards to the steering ratio of the UC rack.

For part no. 9940277 (UC steering rack) 20.4:1 and 25:1 have been quoted.

Does anyone have a definitive answer?

Thanks!

#2 _hatcher_

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Posted 11 September 2008 - 07:10 AM

Hi all,

I've search this forum and there seems to be conflicting information with regards to the steering ratio of the UC rack.

For part no. 9940277 (UC steering rack) 20.4:1 and 25:1 have been quoted.

Does anyone have a definitive answer?

Thanks!


20.4:1 is the ratio

Dave

#3 _rorym_

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Posted 11 September 2008 - 06:00 PM

LH 16:1 UC and LX 20:1 A9X 25:1 off memory...someone will confirm.
R

#4 ls2lxhatch

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Posted 11 September 2008 - 09:18 PM

According to Toranamatt69 the front wheel moves 65 degrees from lock to lock, 34 degrees in and 31 degrees out.

My UC rack part #9940277 is 3.25 turns from lock to lock. Assuming that the wheel moved through 65 degrees the ratio works out at 3.25 * 360 / 65 = 18:1. This contradicts the information I have collected from the forum. It would be reasonable to expect the UC rack to have the most direct ratio as there was no V8 version.

9932244 18:1 65 * 18.0 / 360 = 3.25 turns lock to lock
9940277 18:1 65 * 18.0 / 360 = 3.25 turns lock to lock
9942632 20.4:1 65 * 20.4 / 360 = 3.68 turns lock to lock
xxxxxxx 25:1 65 * 25.0 / 360 = 4.51 turns lock to lock

#5 TerrA LX

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Posted 11 September 2008 - 10:31 PM

^ ah the lower the ratio would mean more sensitive so less turns lock to lock.

Edited by ALX76, 11 September 2008 - 10:43 PM.


#6 TerrA LX

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Posted 11 September 2008 - 11:11 PM

^ ah the lower the ratio would mean more sensitive so less turns lock to lock.



Sorry, higher ratio.

#7 ls2lxhatch

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Posted 11 September 2008 - 11:25 PM

18:1 means that you turn the steering wheel 18 degrees and the front wheel will move one degree. The 18:1 ratio will be harder to turn and quicker than the 25:1.

#8 76lxhatch

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Posted 12 September 2008 - 07:33 AM

I believe the UC rack has more turns because the extra caster from the RTS suspension puts more weight on the steering. Early LX (non-RTS) had approximately 18:1 ratio, I'm not sure whether LX RTS was the same as this or the same as UC (20:1).

#9 enderwigginau

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Posted 12 September 2008 - 12:36 PM

Just remember, the ratio of the rack itself may be different to the fitted steering ratio, due to various angles and offsets not related to the confines of the rack.

Grant..

#10 TerrA LX

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Posted 17 September 2008 - 12:25 AM

Sorry i just cant imagine an A9X having to turn the wheel further lock to lock as they had the fastest ratio fitted AFAIK.

#11 fuzzypumper

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Posted 17 September 2008 - 12:34 AM

Sorry i just cant imagine an A9X having to turn the wheel further lock to lock as they had the fastest ratio fitted AFAIK.


Yeh! but with a faster rack, no power steeering and the wide tyres they have, I CAN imagine how heavy the steering was :)

#12 TerrA LX

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Posted 17 September 2008 - 01:40 AM

^ the comp waznt held in a car park u kno lol.




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