neelas

What is the code for the quick ratio rack on a 90 Z51 vette. I'm trying to find one.

QZRBLU

This 'might' help: http://www.corvsport.com/Corvette/C4..._1990_VIN.html
If you are looking for some type of visual identifier, I can check mine in the morning for any labels.

Mick

Cliff Harris

The cap on the bottom of the steering gear has a code on it. It's "WT" for the fast ratio (at least it is on my '86).

QZRBLU

Cliff,
What does FH on the cap signify? I have all the handling options along with Z51 but no WT on the cap. June 1990 build.

Mick

neelas

I'll take alook at what says today

5abivt

Been a while since I put one in my 93. .. Will be doing one for the 94z too .. Any places carry these still?

cumbercr

My 85 Z51 has the code YP. It has the close ratio steering.

WVZR-1

I have a 2 - turn rack that is FX and I don't believe that there were 2 - turn racks after '89. Is that fact? I haven't been able to actually document a 2 - turn rack in a '90+ car.

You need to document the ratio/turns to determine just what rack that you have. There's no other documented way to accomplish that. You can't rely on the codes on the end cap.

QZRBLU

I'm going to lube my lift ramps next time I have the car out and check the lock-to-lock. Here are some more details I found for the Z51 RPO at http://www.buyavette.net/suspension%20packages.php :
1985-90 models: Heavy duty springs and bushings, Bilstein shocks, larger sway bars, fast ratio steering, and heavy duty cooling. Larger front brake rotors and calipers became standard in 1988, as well as 17 inch wheels. Both Z51 and base suspension spring rates were decreased in 1985 due to harsh ride complaints from the 1984 model.

And this from the original brochure page 29:

Z51 Performance Handling Package
This is an optional suspension package featuring components proven in SCCA sanctioned Showroom Stock Series racing. Equipment includes heavy-duty springs and stabilizer bars, heavy-duty brakes 3.33:1 rear axle ratio an 8 1/2" ring gear and power steering cooler.
The Z51 Performance Handling Package is available on Corvette Coupe with 6-speed manual transmission only. Recommended for specialized uses.
Z51 requires FX3 and my car supposedly has the 13.0:1 steering ratio which 'should be' the 'fast' ratio rack. I'll count the turns to be sure.

Mick

WVZR-1

If you actually wanted to confirm the actual ratio of the rack in the car you could put it on an alignment machine "caster pad" and with one turn of the wheel from center and the pads at 0 record the number of degrees the wheel actually moves. Many believe the ratio is determined from the gears/*****/teeth etc internal to the rack but that's nonsense. It controls it but isn't part of the calculations used. That's the reason you see sometimes the various statements regarding the C4 racks.

It takes a very precise "caster pad" to check it accurately.

I've never checked a 2 - turn rack personally but if it's the recorded 13:1 then it should be something near 28*

On your next alignment you could actually check it.

It might be interesting if some of the Z07 guys that feel they've got the 13:1 had theirs checked. I believe they'll find that they DO NOT.

QZRBLU

WV,
I have a lift but I do NOT have alignment plates. I DID work in an alignment shop way back after high school. My car has never been to an alignment shop but I have a jack plate and I can raise both front wheels with a pair of bottle jacks just enough to take the weight off of them and test. I'll just pretend I'm checking the ball joints.

Mick

QZRBLU

I performed my 'hack' test and I can turn the steering wheel one turn left and one turn right, from the center position and hit the stops. I'm guessing it's 2-turn lock-to-lock. Solid anti-roll bars front and rear too.

Mick

TJM

Rock Auto had them 1.96 lock to lock.

They also had a supply of 1.75 L to L

TJM

neelas

thanks alot for the info. will give them acall