22% Steering Rack

[Pokey]

I'm looking at two steering racks.  The first was manufactured in the early 2000's and is stamped as shown in the picture.  The second was recently purchased and has a different character string stamped in the same place as the other rack, plus another character string stamped on the opposite side of the circular hole.  That other character string matches the Caterham part number for an 8% rack.  I'm told that the older rack is a 22% ratio, but lock-to-lock they are identical at just shy of two full rotations.

 

Right now the new 8% is installed but I'd like to replace with a 22%.  I'm thinking that I was told wrong, that the older rack is also an 8% ratio but am wondering if anyone can identify why lock-to-lock isn't the best way to tell.  Maybe I need to pull the rack on the car and bench them together to see if the tie rods move the same distance?  That wouldn't seem likely as that would mean one rack can turn the tires more than the other, but?

[MV8]

I think you mean 8:1 and 22:1 ratio racks. The higher the ratio, the lower the steering effort to turn the car but the degrees of rotation increase. Turns lock to lock is something else and independent of the ratio.

 

If your racks move the rack the same distance for one 360 degree turn of the pinion/steering wheel, they are the same ratio.

I'm guessing these use the triumph spitfire/herald rack but I'm not sure. If you want less effort, a standard replacement spitfire rack (versus a high performance rack) would be what you want with a numerically higher ratio for easier steering.

 

A link to the listing might help.

Edited July 2, 2023 by MV8

[MV8]

Ok, I see 8% quicker for the 8% so it would seem the 22% quicker would be a numerically lower ratio than 8% quicker.

The 8% would be lower ratio than a standard rack.

 

https://caterhamparts.co.uk/racks/3011-steering-rack-8-ratio-wide-track-s3-rhd-cars.html