Scoob

And the pompous ones will tell you it's the greatest thing since sliced bread.

Scoob

That right there, imho, is the package to have...true Z51 springs and bars with no FX3 crap, coupled with the 6-speed trans.

Edit: With the factory A4 you do not have Z51.

luvmy92

There is a big difference:

Z07 option also included the FX3 option whereas the Z51 option did not. In a nutshell the Z07 option included the following:

J55 brakes with 13" rotors in the front (these came standard in 95)
FX3 adjustable shocks
30mm front and 24mm rear sway bars - both solid (Z51 came with 26mm in the rear)
stiffer springs (Z51 was stiffer in the front and same stiffness in the rear)
stiffer bushings
275/40 tires all the way around

Mike

Scoob

My '90 with Z51 has FX3.

The bummer is that when have the Z51+FX3 setup you don't have true Z51 springs. You get softer springs.

I think J55 was standard with all Z51 packages from 1989 forward.

In 1989 Z51 could not be had with an automatic transmission.

luvmy92

Yes, but the FX3 was not part of the Z51 option. By that I mean you could have a Z51 car without the FX3. All Z07 cars came with FX3.


Didn't the 91 car come with the stiffer springs when mixing Z51 and FX3? If I'm not mistaken it was the only year to do that.


That is correct... I was just pointing out what came with the Z07 option


Not sure why they made the Z07 option with the auto either, but I know some guys are happy with it.

BTW, I take it pompous is a compliment?

Mike

Scoob

Not if I'm reading this correctly. http://vettenet.org/susp_chart.html

Uh, sure.

luvmy92

Actually, 91 was the first year for Z07 and they did combine Z51 with FX3. Notice the front spring rate is the same as the 90 Z51 car (115.5). In 92 they softened the spring rate to 90.1, which appears to be slightly softer than every spring used from 88 - 91.

Scoob

Indeed. I looked only at the FX3 line.

Z-07 freak

From Corvette Quarterly, Fall 1990 issue, page 46

The Z51 package for 1989 and 1990 required a manual transmission and was not available on convertibles. FX3 in 1989 required Z51 and was therefore also limited to manual transmission coupes.

"FX3 with Z51" (1989 & 1990) has been a source of some confusion to owners since it really gave you the softer suspension calibrations of the base car. The difference was that Z51 brought with it heavy duty brakes, engine oil cooler, finned power steering oil cooler, and larger front air dam.

In 1991, the Z51 designation has been dropped, both in adjustible and non-adjustible form. It was replaced with an adjustible system known as Z07. It provides all the heavy duty components of the old Z51 package with the FX3 system.

Yea, I'm pompous

Z-07 freak

Simply because of the change from "Gatorbacks" to Eagle GS-Cs.

teebee

You're right to say that most people don't even know what Z07 is, and I was no different. It was not until I checked my RPO codes that I found out my 94 A4 had it, and then I wasn't sure what it was until I posted here and did my research.

Is it worth more? Maybe to the right person, but the average joe probably won't want it as it is definitely a harsher ride, but the handling characteristics are fantanstic.

rstackjd

Ok, I'll muddy the water a littel more. I have an '88 'vert, A4, Z52. As I understand it the Z52 was simply the convertible version of the Z51 - true or no?

jwt1603

For model year 1988 the differences were as follows according to the Covette Black Book.

Z52 consisted of the radiator boost fan, Bilstein shocks, and the oil cooler.

Z51 came with those options and added the heavy duty radiator and heavy duty suspension. Only available on manual coupes.

They both came with 17 X 9.5 wheels and the faster steering rack.

From what I see in the book, Z52 was only available in '88. I thought it was available for a couple of years but apparently not.

Z51 specs changed depending on model year.

CentralCoaster

I guess my point was Z07 replaced Z51. They can't be compared since they were not available in the same year, unless I am mistaken. I bet GM killed the Z07 option because they didn't want it confused with the up and coming z06 option.

luvmy92

ahhh... get it now.

You are correct, they were not available in the same year. As was mentioned earlier, 91 was the only year where Z51 and FX3 were combined (and called Z07), as all later year Z07 cars came with a softer spring in the front and a smaller sway bar in the rear. Z07-Freak said this was because in 92 they switched from Gatorbacks to GSC's.

I think they killed the Z07 because there wasn't enough interest in it. They only sold 7 - 800 a year during the run. But what do I know.

Mike

Z-07 freak

Wacha talkin about Willis?

I meet Dave Hill once, and I asked him why the Z-07 was dropped. He simply said, if someone want an off road racer, it's easier for that person to make the changes to their Vette themselves, ratther than making it a factory option. I thought it was a weak answer. Or maybe because it was McLellans idea to begin with.

BigTexas

I have a 95 polo green Z07. It also has bose, dual roof panels, dual power seats, and sport seats.

B.

luvmy92

First year Z07 cars (91) had the the same Z51 springs and sway bars as past Z51 cars. They actually combined the Z51 suspension with the FX3 shocks.

From 92 and up they went with the softer front spring and slightly smaller rear sway bar (24 mm).

And I agree about the Dave McLellan statement. I doubt if those guys got along. McLellan was a genius compared to Hill (have met McLellan a number of times).

As good as the Z07 setup is it can still be improved upon. I had my shocks revalved and went the DRM controller prom and removable chips.

Mike

Z-07 freak

I know, I was just being pompous.

teebee1994 and I think alike.

Riks40th

also. Dave McLellan is the nicest guy in the world. He will stop what he's is doing if you want to talk to him. Hope the next Chief Engineer follows in Dave's footsteps when it comes to being around us "regular folks".

Rik

http://photobucket.com/albums/y126/Riks40th/