Identifying Z51?
Thread Starter
Intermediate
Joined: Aug 2004
Posts: 37
Likes: 0
From: California
Identifying Z51?
Hello,
I'm trying to determine whether my '90 is equipped with the Z51 option. The RPO sticker in the center console is partially torn off. I was able to identify several RPO codes that were still intact on the sticker. It has FX3 adj. suspension, KC4 which is the oil cooler, GT7 which I believe is the 3.33:1 rear axle, and then FE7 and J55 which someone told me is performance suspension and brakes. Would this indicate a Z51 optioned car? Is there some mechanical piece on the car that would indicate if it is? Thanks for the help.
I'm trying to determine whether my '90 is equipped with the Z51 option. The RPO sticker in the center console is partially torn off. I was able to identify several RPO codes that were still intact on the sticker. It has FX3 adj. suspension, KC4 which is the oil cooler, GT7 which I believe is the 3.33:1 rear axle, and then FE7 and J55 which someone told me is performance suspension and brakes. Would this indicate a Z51 optioned car? Is there some mechanical piece on the car that would indicate if it is? Thanks for the help.
Burning Brakes
Joined: Dec 2003
Posts: 1,183
Likes: 1
From: MidOhio
According to "Cor-Vette Specs": the '90 Z51 had HD brakes as so:
FRONT: 12.9" outer working diameter x 1.1" thick. (11.9"x.78" was base)
REAR: Same as base, 11.9"x.78"
SWAYBAR: FRONT 1.2" diameter vs .9" base. REAR .94" dia vs .75" base
I'm assuming yours is a manual, coupe 'cause it says that's the only way you could get the Z51.
Sometime during the '89 build they dropped the 13.0:1 "fast" steering ratio that gives you slightly less than 2 turns (1.96) lock-to-lock. They installed 15.64:1 "slow" steer on both base and Z51's. It gives about 2-3/8 turns lock-to-lock. From my experience, the slow steer is plenty fast unless your racing.
FE7 is the HD suspension and I don't know how you would get that without the full Z51 package.
J55 is the HD brakes. From the labels I've seen (non HD suspension mostly) they don't code the brakes. I guess they do if they were the HD version, makes sense.
Keep the shiny side up!
FRONT: 12.9" outer working diameter x 1.1" thick. (11.9"x.78" was base)
REAR: Same as base, 11.9"x.78"
SWAYBAR: FRONT 1.2" diameter vs .9" base. REAR .94" dia vs .75" base
I'm assuming yours is a manual, coupe 'cause it says that's the only way you could get the Z51.
Sometime during the '89 build they dropped the 13.0:1 "fast" steering ratio that gives you slightly less than 2 turns (1.96) lock-to-lock. They installed 15.64:1 "slow" steer on both base and Z51's. It gives about 2-3/8 turns lock-to-lock. From my experience, the slow steer is plenty fast unless your racing.
FE7 is the HD suspension and I don't know how you would get that without the full Z51 package.
J55 is the HD brakes. From the labels I've seen (non HD suspension mostly) they don't code the brakes. I guess they do if they were the HD version, makes sense.
Keep the shiny side up!
Last edited by tonymax2; Jan 9, 2005 at 12:44 AM. Reason: reword J55 comment
