Hib Halverson

Oh, crap...I had to dig out of the archives the C4 suspension tuning chart Scott Allman (the Corvette RH engineer from the 90s) and I worked-up.

The rates are in newtons/millimeters. Dimensions are in millimeters except for wheel dia. and width which are in inches.

The column headings ft. spring rate | rear spring rate | front wheel rate | rear wheel rate | front bar dia. | rear bar dia. | front wheel size | rear wheel size | front tire | rear tire | codes

S-Solid antiroll bar
T-Tubular antiroll bar
1-Delco shock
2-Delco shock, convertible specific
3-Delco/Bilstein gas shock
4-Delco/Bilstein gas shock, Z51 specific
5-Ride-adaptive Delco/Bilstein gas shock
6-Delco/Bilstein gas shock, convertible specific
7-Delphi bi-state ride adaptive gas shock
8-Delphi bi-state ride adaptive gas shock, convertible-specific
9-Delco/Bilstein gas shock with valving revised for improved ride
10-Delco/Bilstein gas shock with valving revised for improved ride, Z51- specific
N-Normal, front, lower control arm bushings (ft. 11k n/mm, rr 2.3k n/mm)
HD-Heavy-duty, front, lower control arm bushings (ft 13.5k n/mm, rr 3.5k n/mm)
E-EMT tire available


So...C4 ZR1s had low spring and wheel rates compared to C4s with RPO Z51 or Z07, and that was especially true at the rear because the rear spring rate is what you feel in your butt. Soft asses of the gold chains types who bought most of the ZR1s drove the customer input that had GM put very soft rear prings in C4 ZR1s.

That said...folks interested in better handling would fit C4 ZR1s with higher rates springs, higher rate stabilizers appropriate for autoX or tracking along with other suspension mods, however, even with mods, C4 ZR1s could not violate the laws of physics. The heavy LT5 engine was a hindrance if the competition was a C4 Z51 with a Small Block V8 juiced-up with some aftermarket pieces or maybe a transplanted '96 LT4 fitted with the GM "Hot Cam" and headers.

mfain

Hib,

Is your knowledge of the C4 ZR1's history what makes you speculate that the C8 ZR1 will not be as track focused? With the big wing (option) the rear spring rates will need to be significantly higher to handle the downforce at high speed. In your opinion, is it likely that there will be a "performance option" that gives better spring/shock rates and suspension calibration for track use at the expense of a soft ride? Thanks

jvp

I won't speak for Halverson, because Lord knows he can speak for himself (help us, please!) Generally, the ZR1 (or ZR-1) was primarily the baller car even though the R in ZR1 is Racer. The C7 ZR1 was the anomaly of the bunch and, truth be told, wasn't originally envisioned for the C7 generation from the get-go. The C4 ZR-1 and C6 ZR1 were baller cars that just happened to also do fairly well on the track. They'll likely have two versions of the ZR1: one with better street manners and one with a big-*** spoiler in the rear with the associated suspension to go with it. The gold bracelet club will be encouraged to select the former, not the latter. ;-)

robob

Not a joke. Mine is harsh. Since you haven't driven mine, you wouldn't know:-)

PRE-Z06

Harsh is a relative term, have you driven another C4 for comparison?

range96

The answer lies in Hib's post.

The '90 ZR-1 was pretty harsh, my '95 ZR-1 was way too soft (floaty) in tour mode.

PRE-Z06

Gotcha, I didn’t become a Corvette fan till the C5 and didn’t realize they changed the suspension on the C4 ZR1 in ‘92. Also didn’t realize they made a Z07 option on the C4, which it in ‘91 and the Z51 option in ‘90 were both even stiffer than the original ZR1.

Bald Guy

For the privileged.

Good luck and enjoy safely.

Racer X

Looking at that picture, does anyone have any thoughts on what that bump is at the front of the targa panel?


A telemetry module, maybe?

robob

No, but that doesn't matter. I'm comparing it to my other cars and cars I have driven. And I have drive many:-)

PRE-Z06

So have I, some prefer aftermarket suspension some like a Cadillac so was trying to understand where you’re coming from.

okaythen

This summer that's great news, so will it be available at the dealers later this year? or next year?

GTS Bruce

Children. Please go somewhere else to whine at one another.

IdahoZ

I’m thinking a base of $185k, with $100k+ markups

BooSSted

Interesting all those who find a TT option as unthinkable... GM already had the blackwing, which I remember wild speculation it would be introduced to Camaros and Corvettes. Pacing the competition and given GMs shift with the C8 the ZR1 will undoubtedly be turbo'd ... The question is if they have some hidden tricks with batteries, AWD , active aero among other things found with Porsche, McLaren etc ...

JMB

No batteries, no AWD...just a good Ole fashioned RWD TT LT7! Active aero is likely with the ZTK Track Pack option!

JockItch

From the Bash... engineer saying the LT7 will not be FPC.

PuffC8

It also has AFM lol

JockItch

Oof. But considering the fuel efficiency of the Z06, almost to be expected... especially with them going CPC. Still very excited to see the details, but also happy that this leaves the Z06 and LT6 unique in the C8 lineup.

RapidC84B

Very interesting... CPC w/ AFM followers. Any word on the LT6 getting AFM then?