Steering Ratio Help

[lastdime]

My MK4 has a power steering rack that is 2.5 turns lock to lock. It is extremely responsive and I want something that when I turn it an inch, I'm not off the road. I've gotten used to it, but still want to make a change. What do you have and how do you like it?

[CraigS]

a 3.0 turns lock to lock is what I run. Loved the 2.5 for autocrosses so ran it for an entire summer. Never did like it on the street so it came out in the fall and never went back in. From Autozone
#6406; 3.0 turns lock to lock
#6439; 2.5 turns lock to lock
#64163 2.25 turns lock to lock

Double check the #s since this is something I saved a few years back. Also take a small pair of vise grips w/ you to check the rack before you leave the store. The rebuilders don't care much about getting the correct rack in the box.

[lastdime]

Thanks, that really helps. I was wondering it the 3.0 would be enough of a change and at least for you, it has been.

[davekp]

I have a 3 turn and I'd like it a bit slower, but none seems to be available.

[Big Blocker]

Seems as if the powered racks are a bit limited in ratios . . .

FWIW, my manual Flaming River rack is 4 turns lock-to-lock, pretty much feels like power steering with low pressure, but better than full manual, if you get my meaning - running 275 x 17's up front.

There are gear reduction boxes available, not sure I've ever heard of one being used in a Roadster.

Doc

[CraigS]

If the 3.0 is still a little twitchy check these; 1- tire pressure. not sure what tires you have but I run 275-17s as low as 18-20#. 2- caster should be as much as you can get w/ a max of 8-9 degrees. 3- have you cut the spring in your pump to lower PS pressure?

[mike223]

There are gear reduction boxes available, not sure I've ever heard of one being used in a Roadster.

Complete story - I ran 15:1 manual steering for several years - I was reasonably happy with it, but decided it wasn't something I was going to want to wrestle with in a parking lot in 15 years.

It was about 3 turns lock to lock.

Added EPAS between the firewall + the dash - very pleased, documented here: https://thefactoryfiveforum.com/show...ll-A-Part-EPAS


I found that if I got "boxed into" a tight 90 degree turn on an autocross course - it was a full turn to get in and a full turn to get back out before I could get back on the throttle hard - lots of fast "hand over hand" - too much.

Worked a 2:1 steering quickener into the footbox - works pretty good on the autocross course, but the EPAS does not pull it well in "parking" situations - additionally I found it to be "a bit much" for "out on the big road".

It is literally 360 degrees lock to lock.


Replaced with a 1.5:1 steering quickener - much better out on the big road - but a little slow for a tight autocross course.

It's about 2 turns lock to lock, and works muck better with the EPAS in parking situations.


These are the steering quickeners I'm using:

They could be installed backwards for increasing your turns lock to lock if anyone is interested in that option - they also fit the same footprint and use the same splines in + out.


I would not put one between the steering wheel and an EPAS - the EPAS has a torque sensor on the input side and would read resistance from a gearbox as driver input (and try to assist - resulting in no self centering, regardless how much caster you add).


https://www.speedwaymotors.com/Speed...kaApdWEALw_wcB

https://www.jegs.com/i/Mr.+Heater/50...caAhSqEALw_wcB

[lastdime]

Thanks guys for all your suggestions and information. Now I'm really confused!