Faster steering rack- any other options?
 

I'd like to get a slightly faster steering rack in my 912, but I can't seem to find what I'm looking for. I'm looking for fewer turns lock to lock, largely for the autocross.

I understand the Quaife unit is both largely unavailable and not quite up to the standards of the original ZF unit.

I thought for a while that the 930 had a slightly quicker ratio, but this seems mis-information; it sounds like it's the same as the 911 rack other than mounting position.

Other than going custom I'm not aware of anything else that isn't unobtainium. I've head tell of some factory racing racks, but they are more than rare. That would be my ideal, though- a real ZF quick-rack.

I see from searching that I'm not the only one with this question, but I thought I'd ask the collective wisdom again to see if there might be any new information or developments out there. Any ideas?

-Pete

You can buy a rack/pinion that will turn lock to lock in 2.5 turns of the steeringwheel here: 911 Rennsport Lenkung - Albert - Motorsport

They also offer a complete steeringrack with this gearing.

Pete,

Are you building a dedicated autocross 912 or wanting to ‘improve’ your street car? What year? SWB is noticably different from '69.

To answer your specific question, the easiest (best?) way to have ‘faster’ steering is to shorten the steering arm. Many do this by bending the arm down (which effectively shortens it). This also re-positions the arm to reduce ‘bump-steer’ with a lowered front suspension. Naturally, care must be exercised to not damage the arm.

A 912 makes a great autocross car and can be very suitable for big-track events. It is lightweight and naturally better balanced than a 911. Just like 911s, it can be vastly improved from original. Most of the same techniques (and parts) apply.

Best,
Grady

chris_seven did research and found that the 911R used a 904 steering rack which was 2.07 turns lock-to-lock with the same total wheel angular displacement.

How about trying something simple to start with like a smaller diameter steering wheel?

He wants fewer turns. A smaller wheel will turn the same amount of times, just take less arm movement for small steering angles.

I understand he wanted fewer turns but I thought it may be because he wants "faster" response and a smaller wheel gets more response from a shorter distance. Hence, faster. It is not a best case but a whole lot easier and cheaper and he can easily go back to the stock wheel if he doesn't like it.

Thanks guys- good input.

Peter- good lead. I'll see if I can't learn anything about the quality of that unit. You wouldn't know any details, would you?

Grady- The car is already a dedicated autocross/ track car, and really 912 in name only. It's a 69, and it's got a slightly extended wheelbase. I did consider messing with the steering arm length (which also changes the Ackermann). So far I've tried to keep this set of JRZs stock and not change the metallurgy of that part, but...

Flieger- Nice, I'll chase that down. A 904 rack shouldn't be too expensive... ;)

Joe- I already have a small diameter wheel. It helps some, but not quite enough...

-Pete

Pete-
This 912 wouldn't happen to be the early car with the Gt3 cup motor in it, would it?

If so, forget the steering rack, just turn the wheel slightly and push real hard on the gas pedal when you want to turn.

;)

how about something like this?
QSP

oha - have seen that beast in the makings a while back when I visited the bay area. Unfortunately I wasn't allowed to snap pics at the time.....

Mmm. Yea, turning it with the rear alone is not quite as easy as I'd expected, mostly because the thing puts power down almost too well. It'll take full throttle in first gear and stick it. When the tires are warm, anyway- if they're cold it sees wheelspin through 3rd in a straight line.