Goughary

I'd like fewer turns lock to lock. Has anyone changed their steering rack or modified theirs for a quicker steering ratio?

I do not want to change from power to manual. I have 91 C4, and simply dont want to move my hands as much in tight corners...

In a previous post, I found this:

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here are the correct turns lock to lock(this is all documented in factory lit.)
Both 964 and 993 have power assisted steering, however 964RSA and RS manual racks are available(more turns = slower
911 is ~3 turns lock to lock, non assisted
964 is ~2.81 turns lock to lock, assisted
993 & 993GT2EVO is ~2.47 turns lock to lock assisted
993RS 2.73 assisted
964 manual ~2.6

Actual steering ratios, again factory specs, higher# = slower
964 18.48 slowest
993RS 18.25
993 16.48 fastest

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Does anyone have any experience with this? Basically, I'm assuming that eventually I will need to rebuild my steering rack, so when I do that, I'd like to change the ratio if I can, or swap it for another power rack that would be a better ratio. Is any of this possible or worthwhile even? Forget the money issue, I know it's expensive, but so is everything else I have done...lol. All money I wiull never see again, but neither is last night's dinner...

f3nr15

Can you swap your 964 rack out for a 993 one?

Goughary

I could do anything if it's pssoble - but looking to find out what the options are before spending the money to find out I'm wrong...or that it made little to no real difference...

has anyone changed steering racks and wants to chime in? I thought for the 993 guys, the 964 rack was an upgrade?

darksilver

From what i know: If you do change the rack to a different one with a shorter ratio - then you will most likely have to change the pinion as well. As the pinion is an integral part to the rotating valve of the steering gear, it is very likely that this will not be possible.

On the other side: If mounting/positioning/length of the 993 steering gear are comparable to the 964 - maybe theres a way to change the whole gear. (as possible with many BMWs)

Seems to be open to someone who has experience with rebuilding those parts.

Cheers

tbennett017

IMHO, I'd only do a complete rack swap...also these cars are old enough that a rebuild will happen eventually. I replaced mine with new 2 years ago.

f3nr15

You probably need Bill Verberg to chime in - perhaps PM him?

Goughary

Bumping an old thread...funny thing is I went looking for this information, only to find out I was the one that started the thread I had been thinking about. I hope I don't get too old to drive my car before its done...

I still would like to replace my steering rack with a quicker 993 rack.

I need to know how much work goes into the change. If it's plug and play, etc...anyone have any experience with this?

Vandit

Looks like the answer is yes, the 993 rack fits the 964, but you might also have to swap out some of the hydraulic lines/fittings.

https://rennlist.com/forums/964-foru...964-993-a.html

I wouldn't mind doing this as a faster rack is always welcome and I feel like my rack is f'n sloppy.

Goughary

Thanks Vandit. I know I saw that sometime in the past...if I can aquire a cheep rack to rebuild, I'll do a write up and step by step on what it takes...

Goughary

That thread references the problem with the 993 ps rack into a 964 c4.

http://www.pcarworkshop.com/images/1...0294geolab.pdf

So here's the question, on the rack in that tsb, is the ratio still the same as the standard 993 rack?

koenig_roland

Nice mod!
I`am also thinking about it, but in the same task, i would swap to electrical power-steering pump. Faster ratio, faster response because of a lot shorter ps-fluid lines and getting rid of the ugly ps-pump assembly in the rear..

It is planned for the winter 16/17 (i`ve to source parts first) with a full upgrad to monoball bushings all around

ThomasC2

Ratios are strange, beacuse my steering feels quicker and more responsive with my manual rack than before. Or if drive one of my friends assisted cars. But the numbers say that the manual rack is the slowest.

Bill Verburg

w/ e boost for the steering you want to be sure to retain the variable boost feature.

kos11-12

Good move, the front boot electric steering pump is on my plan as well, a few here have done this mod successfully , I have the 993 inner tie rods and the ERP rose joint outer tie rods and it made the steering very sharp and precise . you guys have tried back to back the quicker steering rack, does it really makes good difference ?

tdiquattro

Can I add/ask a couple of questions.....
Is the lock to lock on the 964 including the 17" end stops?
If not then is this part of the difference (ie the 993 all have end stops)
The turn ratio quoted is for the complete suspension setup? if so then the 993 may well have shorter arms on the hubs?

What I am getting at is the racks are the same. Can anyone confirm having 2 on the bench and actually turning the input and measuring the output on the rack?

Also it seems not all 993 racks are equal, there are different versions? (but maybe all the same ratio?)

Ok lots of questions, but you see what I am getting at.

Hope someone can help, cheers.