Canuck

Just wondering if anyone has installed the quick ratio steering system and what did you think of it. I know its a dangerous add-on but this car ( 91 convert ) is fully 'fixed' for serious autocross. I am contemplating this but not sure of how to achieve this or if there is a kit available. I know about the pre-rack multiplier ie: 2:1 ratio but would like to hear from some people that have tried this. How many degrees from lock to lock? I think it would be a great advantage to forego the hand over hand steering.

Any input would be appreciated.

Thanks guys
Terry

Barbara_S

I have 2 corvettes - a quick rack is in my 88 which I've autocrossed for 7 years now. When I bought a 91 the difference seemed very noticeable, It was sluggish in turn response when the 2 cars were compared side by side so I put in a quick rack that I bought at a yard and it helped the steering issue. There is less hand over hand with it at autocrossing. It should make a noticable difference to you.

Aardwolf

I had the 13:1 rack in my car and it needed a rebuild. I ended up buying an inexpensive barely used rebuild with the slower later year C4 ratio, 15:1. I don't think it will make a difference for me, in road course racing I never turn the wheel more than 90°. There are two ratios used for the C4 years, listed above. The Z51 and Z52 cars had them. FYI The fast ratio, 13.0:1, is 2 (1.96) turns lock to lock, and the slow ratio, 15.5:1, is 2 1/3 (2.36) turns, lock to lock.

Turn One rebuilds PS pumps and racks. When I talked to them they said they could make the rack whatever ratio you wanted. I made a thread about it in C4 tech. Run a search there for more rack and ratio info!

You could also try a small diameter steering wheel. This doesn't change the lock to lock but your hands move less.

mr.beachcomber

I have an '89 Z51 with the quick steering ratio rack that I use for auto-xing as well as daily driving. Compared to my '89 auto, the Z51 is much more precise in reacting to steering inputs.

I don't think that the quick ratio system is "dangerous"; however, just be aware that if you use a death grip on the steering wheel, you will be feeding minute, constant inputs to the rack unintentionally. (The slower, stock steering ratio tends to have more slop built into it IMHO.)

If your auto-x class allows the change, the smaller diameter steering wheel is a faster, cheaper fix than adding the quick ratio steering rack and its attendant power steering cooling system. Have fun!

trackboss

It's easier to install a smaller wheel and get similar results.

Canuck

Thanks to all who replied. I will consider them all.

Terry

Aardwolf

FWIW the C5 has 16:1 ratio for turn to turn, 2.66 turns!

yakisoba

Friend of mine has a 91 ZR1 that he tracks. He was getting low marks from his instructors for shuffling his hands on the wheel. I drove the car and discovered that the steering would simply not let you do what you needed to do in tight corners. Even fully crossed up, it needed a tighter ratio. Thus I think on the C4 this is a good thing.

ZR1 MK

Forget the separate multiplier boxes.
You have three choices. One is to go to a smaller diameter steering wheel (13-13.5"), two is to change to the 13.0 ratio rack or three do both.

One should never shuffle a wheel or need to do so under any circumstances.

Aardwolf

I measured the stock steering wheel in mine and it's 14.5" diameter. I'm not sure how much 1.5" difference makes. I would like to add a quick release hub sometime though and will try a smaller wheel then.

ZR1 MK

I sold my stock 1990 steering wheel and went to a 13" after only few months of ownership. I dont remember the stock size, but it was larger than 14.5". Some where on the low side 15". The difference was drastic and highly recomended.

frankgtb

who makes the quickest ratio racks for c5s?

mgarfias

That was one of the first things I noticed in my Z. My previous fast car was a messed with 3rd gen fbody (stolen) that had the quick ratio box, and the steering arms gronked to clear the wheels which effectively quickened the ratio. Was something like 1-3/4 turn lock to lock. Was crazy nuts and I loved it.