Spring Codes - ZR-1 Net Registry Forums

Ccmano · 04-19-2019

This should be a sticky.... courtesy of Hib Halverson, found this researching for a friend. Thank you Hib!

It seems I have an FHA on my 90’.

H

C4 Spring Code Chart

compiled by Hib Halverson
©2007 Shark Communications

Preface Notes:

1) GM had two RPO subsystems during the C4 era. There were engineering RPOs and marketing RPOs. What consumers knew as Z51 or Z07 was actually a combination of the FE3 (96) or FE7 (84-95) HD suspensions with other performance-related options. Some GM parts data refers to FE3 or FE7. When those RPOs are listed, it refers to cars optioned with either Z51 (84-91, 96) or Z07 (92-95).

2) In MY89-91, Selective Ride Control (SRC), which many refer to by its RPO, FX3, could be ordered in combination with Z51, however, a little-recognized production change which always occured in those MYs when those two RPOs were ordered together was a downgrade to base level (FE1) springs, front lower control arms and stabilizer bars. In those MYs the only conditions under which FE7 was present were; 1) if the car was ordered with Z51 and without FX3 or 2) it was an 90 or 91 Corvette Challenge car.

3) For MY92-95, FX3 and FE7 was added. A new RPO, Z07, was released for this combination. For MY92-95, FX3 was, also, available as a stand-alone option.

Coupe, front*

HMZ 84 w. Z51
BMB 84 base, 85-87 with w. Z51
HKX, HMP 85-87 base
FHA 88-91 base, 89-91 w. FX3&Z51, ZR1*
FHB 88-91 w. Z51
AA 90-91 w. ZR1*
FSS 92-95 base, 92-93 w. FX3
FSK 92-95 w. Z07
FSM 92-95 w. ZR1*
HA 94-95 w. FX3
22173028 96 base
17999032 96 w. Z51
Per Mark Haibeck all ZR1’s he has seen came with FHA.

Convertible, front

HMN 86-87
FHC 88-91 base, 89-91 w. FX3
FSR 92-95 base
JA 94-95 w. FX3
22173029 95 w. FX3
17999031 96

Coupe, rear

BMF 84 base
BMH 84 w. Z51
NYR 85 base(?) 86-93 base, 89-90 w. FX3&Z51, 90-91 w. ZR1
NYU 85-91 w. Z51, 92-95 w. Z07
RHY 92-95 w. ZR1, 96 w. Z51
RHZ 94-96 base

Convertible, rear

RCA 86-96
22112254 94-95 w. FX3

HAWAIIZR-1 · 04-19-2019

Thanks for posting Hans! I started trying to read this in bed waking up at 5:30 am Saturday. Hell with this and need to wake up and have coffee first.....too many codes for my brain LOL!!

Sent from my iPhone using ZR-1 Net Registry

DRM500RUBYZR-1 · 04-20-2019

Great post and information, and all seems 100% accurate.

However, try finding a 100% correct new replacement spring.

They generally only offer 1 or 2 for the entire C-4 lineup, and the mounts / blocks are not already permanently fastened to the spring.

Because of this we often try to find undamaged used springs, with the correct code, rather than getting the new replacements which often result in poor ride height, a change in ride quality, and "movable" mounts.

Try explaining to the suppliers that you are searching for an FSM code new spring.

p.s.

If your ZR-1 is towed, DO NOT let them strap the car down by the frame rails, but rather have them only use tire/wheels straps!!!

When they tighten up the straps on the frame, pulling the car down it makes the spring flex in an unorthodox way, often causing it to begin splitting leading to failure.

Marty

Marc Haibeck · 04-24-2019

Hi Hans,

All ZR-1's have a FHA front spring. I have never seen AA or FSM springs.

Ccmano · 04-24-2019

Quote:

Originally Posted by Marc Haibeck

Hi Hans,

All ZR-1's have a FHA front spring. I have never seen AA or FSM springs.

Thanks for the update Mark. Since posting this I’ve run into 3 Z’s with FHA front springs, including my own. To my knowledge Hib is usually pretty good with this type of information. I will add a note to the OP.
H

Joelbbvette · 05-23-2019

Quote:

Originally Posted by Marc Haibeck

Hi Hans,

All ZR-1's have a FHA front spring. I have never seen AA or FSM springs.

I have a photo of a 90 ZR-1 that was purchased with 600 miles and an AA Spring. Definitely original, system will not let me load a photo.

Joel

Corvette95 · 01-19-2021

Quote:

Originally Posted by Joelbbvette

I have a photo of a 90 ZR-1 that was purchased with 600 miles and an AA Spring. Definitely original, system will not let me load a photo.

Joel

Doing some research on ride heights brought me to this thread, I am attaching the build sheet to my 90 with an "AA" front spring. My car is early and also has steel half shafts. If anyone else has the AA spring (Joelbbvette) could you measure the front ride height?

Erik · 01-19-2021

Quote:

Originally Posted by Corvette95

Doing some research on ride heights brought me to this thread, I am attaching the build sheet to my 90 with an "AA" front spring. My car is early and also has steel half shafts. If anyone else has the AA spring (Joelbbvette) could you measure the front ride height?

Mine should be home by the end of the week. 1990 #996. I can measure it then.

Corvette95 · 01-19-2021

Quote:

Originally Posted by Erik

Mine should be home by the end of the week. 1990 #996. I can measure it then.

Thanks, I may have it figured out by then ..BTW the Flowmaster I sold ended up costing only $86 to ship UPS.

Erik · 01-19-2021

Quote:

Originally Posted by Corvette95

Thanks, I may have it figured out by then ..BTW the Flowmaster I sold ended up costing only $86 to ship UPS.

Let me know if yiu still need it.

Damn. That was good. I still haven't gotten an answer, after many attempts, to find the shipping and handling charges on this side of the border. We pay a lot for the privilege of living in Canada.

04-19-2019	#1
Ccmano Join Date: Jun 2006 Location: Sparks, NV Posts: 2,852	Spring Codes This should be a sticky.... courtesy of Hib Halverson, found this researching for a friend. Thank you Hib! It seems I have an FHA on my 90’. H C4 Spring Code Chart compiled by Hib Halverson ©2007 Shark Communications Preface Notes: 1) GM had two RPO subsystems during the C4 era. There were engineering RPOs and marketing RPOs. What consumers knew as Z51 or Z07 was actually a combination of the FE3 (96) or FE7 (84-95) HD suspensions with other performance-related options. Some GM parts data refers to FE3 or FE7. When those RPOs are listed, it refers to cars optioned with either Z51 (84-91, 96) or Z07 (92-95). 2) In MY89-91, Selective Ride Control (SRC), which many refer to by its RPO, FX3, could be ordered in combination with Z51, however, a little-recognized production change which always occured in those MYs when those two RPOs were ordered together was a downgrade to base level (FE1) springs, front lower control arms and stabilizer bars. In those MYs the only conditions under which FE7 was present were; 1) if the car was ordered with Z51 and without FX3 or 2) it was an 90 or 91 Corvette Challenge car. 3) For MY92-95, FX3 and FE7 was added. A new RPO, Z07, was released for this combination. For MY92-95, FX3 was, also, available as a stand-alone option. Coupe, front* HMZ 84 w. Z51 BMB 84 base, 85-87 with w. Z51 HKX, HMP 85-87 base FHA 88-91 base, 89-91 w. FX3&Z51, ZR1* FHB 88-91 w. Z51 AA 90-91 w. ZR1* FSS 92-95 base, 92-93 w. FX3 FSK 92-95 w. Z07 FSM 92-95 w. ZR1* HA 94-95 w. FX3 22173028 96 base 17999032 96 w. Z51 Per Mark Haibeck all ZR1’s he has seen came with FHA. Convertible, front HMN 86-87 FHC 88-91 base, 89-91 w. FX3 FSR 92-95 base JA 94-95 w. FX3 22173029 95 w. FX3 17999031 96 Coupe, rear BMF 84 base BMH 84 w. Z51 NYR 85 base(?) 86-93 base, 89-90 w. FX3&Z51, 90-91 w. ZR1 NYU 85-91 w. Z51, 92-95 w. Z07 RHY 92-95 w. ZR1, 96 w. Z51 RHZ 94-96 base Convertible, rear RCA 86-96 22112254 94-95 w. FX3 __________________ 90'ZR-1 #1461 Red/Black Ported Intake, Degreed Cams, OBX Headers & Exhaust, Fidanza FW, Secondary Delete, Custom tune, C6 GS Wheels. Sold 08 C6 Z51 Crystal Red Metallic Sold Vararam Intake, Tune, Sold 05 C6 Z51 Red/Black Sold 90'ZR-1 #1723 Black/Gray Sold but not forgotten 91' Z51 L98 White Vert. My First, you always remember your first. Sold. Last edited by Ccmano; 04-24-2019 at 10:36 AM.

04-19-2019	#2
HAWAIIZR-1 Join Date: May 2010 Location: Japan Posts: 3,573	Re: Spring Codes Thanks for posting Hans! I started trying to read this in bed waking up at 5:30 am Saturday. Hell with this and need to wake up and have coffee first.....too many codes for my brain LOL!! Sent from my iPhone using ZR-1 Net Registry __________________ Craig "ZR-1 NO KA 'OI" "ZR-1 ICHIBAN" 1995 #228 Black/Black with Dunn Heads ZR-1 owner since September 2003 ZR-1 Net Registry Founding Member #0074 NCM Lifetime Member #2048

04-20-2019	#3
DRM500RUBYZR-1 Join Date: Sep 2008 Location: Mullica Hill, New Jersey Posts: 2,574	Re: Spring Codes Great post and information, and all seems 100% accurate. However, try finding a 100% correct new replacement spring. They generally only offer 1 or 2 for the entire C-4 lineup, and the mounts / blocks are not already permanently fastened to the spring. Because of this we often try to find undamaged used springs, with the correct code, rather than getting the new replacements which often result in poor ride height, a change in ride quality, and "movable" mounts. Try explaining to the suppliers that you are searching for an FSM code new spring. p.s. If your ZR-1 is towed, DO NOT let them strap the car down by the frame rails, but rather have them only use tire/wheels straps!!! When they tighten up the straps on the frame, pulling the car down it makes the spring flex in an unorthodox way, often causing it to begin splitting leading to failure. Marty

04-24-2019	#4
Marc Haibeck Join Date: May 2007 Location: Addison IL Posts: 241	Re: Spring Codes Hi Hans, All ZR-1's have a FHA front spring. I have never seen AA or FSM springs.