Z51 steering rack
Racer
Joined: Oct 2006
Posts: 438
Likes: 14
From: Tucson/Santa Paula AZ/CA
2017 C4 of Year Finalist
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
If you are looking for some type of visual identifier, I can check mine in the morning for any labels.
Mick
Last edited by QZRBLU; Jul 27, 2013 at 10:53 AM.
Team Owner
Joined: Sep 2003
Posts: 25,393
Likes: 2,741
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.
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.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Racer
Joined: Oct 2006
Posts: 438
Likes: 14
From: Tucson/Santa Paula AZ/CA
2017 C4 of Year Finalist
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.
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.
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
Last edited by QZRBLU; Jul 27, 2013 at 11:18 PM.
Team Owner
Joined: Sep 2003
Posts: 25,393
Likes: 2,741
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.
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.
Racer
Joined: Oct 2006
Posts: 438
Likes: 14
From: Tucson/Santa Paula AZ/CA
2017 C4 of Year Finalist
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
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
Racer
Joined: Oct 2006
Posts: 438
Likes: 14
From: Tucson/Santa Paula AZ/CA
2017 C4 of Year Finalist
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
Mick
