Domobomb

1985.

I am looking at a corvette without the Z51 package. How much does this car give up handling wise vs the z51?

I would be ditching the stock wheels, so, just comparing the springs rates, shocks, sway bars, steering ratio. stock vs z51 '85

And how does the Z51 compare to aftermarket parts today? For example, Z51 shocks, vs Koni.

Thanks

vetteoz

If you understand suspensions you can compare the spring / swaybar rates here
http://www.vettenet.org/susp_chart.html

Early C4's were very stiff ( to the point of customer complaints ) and generally stick like the proverbial

Z51 had Bilstein shocks unique to that package
Z51 also got you the better 3.07 rear on autos

PLRX

I don't think a 28 year old suspension would make a difference at this point, unless a full suspension restoration has been done.

The aftermarket sells all components to make any Corvette better than a Z51.

dizwiz24

Z51 bilstein shocks on soft base model springs are the best suspension combo, combined with 32 mm swaybar and the small (24 or 22?) Rear swaybar.

Good weight transfer for drag race, and still acceptable track performance.

Many a c4 racer has put stiff springs in only to find it slowed them down on the track

Domobomb

Thanks for the info.

I was basically asking if not having the z51 suspension makes a c4 handle like a donkey on roller skates.

I think I'll really just be missing the quick ratio steering.

I didn't know some people actually preferred softer springs at the track?

856SPEED

Well,

I have a Z51 equipped 85; owned it since 2001. The only thing I have not restored/replaced/upgraded are the suspension and most of the interior.

The suspension is still pretty crisp, the Bilstein (originals) shocks still work very good and the car is stiff but not overly stiff; handles extremely well on the twisties. They lowered the spring rates in 85 from 84 so the car is not bad at all when driving in traffic either; I make the analogy that it feels like a go-cart on steroids.

gerardvg

There are just minor differences in lap times that i have noticed between Z51 and base suspensions, i am a member of a corvette car club here in Australia and the wide variety of C4's are very similar in lap times. I am sure a driver that doesn't care if he hits a wall may find a slight edge with a Z51, however as said by previous replies modern suspension upgrades are way better.

kimmer

I changed over and it made a huge diff for autoxing. Biggest change is the body roll is almost nonexistant & the handling is far superior pre z51.

GREGGPENN

Interesting....

Several months ago, I queried one of the forum's Bilstein employees. I specifically asked if there was a benefit to "upgrading" to Z51 shocks. He recommended against it, though I can't remember why. I don't have that PM in my inbox anymore.

Because I have low-hanging side-pipes and custom front air-dam, I have extra interest in avoiding bottom-out situations. It seemed logical to assume a stiffer shock would help. Thought it might also help if stock spring rates have "relaxed". If I keep the car long enough, I might consider coil-overs....though I don't get THAT wild very often.

This is for a street car where I'm less-than-thrilled with common highways and city-streets. Camber brace and cross-brace are also in the works for this year.

GREGGPENN

Off-topic: I just went over and looked at Bilstein options on Lingenfelter's website.

And...

I saw the new kits to convert a new Camaro to look like a Trans-Am/Firebird. I think I finally found the car that will follow my ownership of a C4!

If you guys haven't seen it, take a look!

Alan777

My 120k mile 88' base with a rebuilt suspension + banski parts felt a lot better than my 54k mile Z07 does. It seemed to handle bumps/rough roads a lot better.

Age makes a bigger difference than the package. Also, the banski parts made a world of difference.

93Rubie

I think you guys are missing the point of the question.

Stock FE1 versus Z51, which handles better. Easy question, HUGE difference between FE1 of ANY year and Z51/Z07 package cars.

As far as shocks go, the Koni's would hands down whoop the crap out of the Z51 Bilsteins.

I went from a FE1/FX3 setup to Z07 springs and bars. NO comparison. Car handles WAY better.

How the car handles bumps, etc...is NOT handling. That is ride. From a pure handling perspective Z51/Z07 is what you want.

QCVette

On my Z51 I really like the quick ratio steering, the flat cornering, and even the stiffer ride. But on non Z51 cars it is not like a donkey on roller skates, it is a Corvette and they all handle pretty well.

ch@0s

"Package price $45,000 plus base Camaro SS"

GREGGPENN

Yeah...I saw that after my prior post. Re-f'in-diculous! Guess I'll be driving my C4 much longer than I thought! LOL

On another note, prior threads have pointed out Lingenfelter was a good price for Bilsteins. I found out there website isn't up-to-date and they think HD/Z51 stocks are discontinued. They wouldn't investigate. So, I called Bilstein.

Both are still manufactured and available. I found [even] slightly better pricing at ALLSHOCKS.com. Plus, at least they know what's still made/available.

I also asked a rep about installing Z51 (sport) shocks on my base suspension car. Here is his reply....So, I ended up ordering HD shocks.

84wuzmy1st

Yep, the HD's in other model cars are the same way. HD's for base suspension and spring rates, Sports for modified/lowered/special suspension.

JimGnitecki

Earlier in this thread, someone pointed out that a stiffer suspension is a detriment in drag racing.

1. Is this strictly because it impairs weight transfer from the front wheels to the rear, and thus limits the rear wheel traction, or are there other reasons as well?

2. Does this mean that a C4 with the Z51 suspension is more likely to lose traction in a hard acceleration start on the street as well?

Jim G

tntwolt

sometimes i wish i had a "softer" suspension when going around turns on crappy roads. scares the daylights outa wifey. otherwise i have no prob with my Z51.

Lucky86

I have a z51 and all i can say is it handles awesome, im pretty sure back in 86 z51 corvettes pulled 1.0 G lateral.

Domobomb

Yeah, I ended up buying the car sans z51.

I think it will still handle much better than my c3. And later on I'll think about upgrading if I think it needs it.

Also, I think it was the '84 z51 that was claimed to pull 1G using sticky street tires and an alignment tune.