zwede

I've driven many different cars hard (on tracks) including 2nd and 4th gen f-bodies and BMW's. First of all, the BMW's with stock tires sucked. They understeered like pigs and were just pathetic. This was 2000 325 and 328. Also drove a 323 with 17" rims and good tires. This car hanled way better, so it was mostly a problem with the factory tires.

The F-bpdies stock are OK but understeer too much. With a perf alignment, 17" rims and bigger swaybars they handle well. Still plow some, but the weight distribution is off (around 54/46, I think).

C3's with stock tire size are OK, not great. They pulled about 0.77G vs 0.87 for a stock 4th gen f-body. However with modern 17" tires, some bigger swaybars and a good alignment they handle real well. The C3 takes more driving skill than a new car, but can be driven very fast. I had my '71 on a roadcourse a while back against modified 4th gen f-bodies and was passing several of them. I could take turns noticeably faster than they could.

So in my opinion suspension technology has improved, but not nearly as much as tires. Is a Z06 faster than my C3? Certainly in the hands of a pro. But how many of us a pro race car drivers? With real-world drivers I think they are close, with the Z06 being somewhat faster but not that much.

Turbo-Jet

Yeah, the C5 is the first Corvette for which suspension designers did not have to desifn the parameters to account for frame flex.

My personal experience is not a good example. I drive my '72 454 with old 235 15" tires and the original worn suspension (bushings too!). I autocross a '94 Z28 with Eibach springs, 255 16" Firehawks, and a few other suspension upgrades. The Camaro will run circles around my Vette. At a local autocross, I ran 1:49s with the Vette, 1:32s with the Z.

Also my Camaro is one of the quickest cars in my club, which goes to say that good rubber, good alignment and mild upgrades can go along way when used on 'dated' solid axle suspension.

MassVette

Change the wheel size and tires, and it's a different car! My 79 has 17" rims, and the 67 has 15 " rims. The difference is like night and day.
:yesnod: :chevy :chevy :yesnod:

MotorHead

I don't know about a Grand Prix GT but it must be one heck of a car compared to the Grand Am GT because my Corvette would run circles around that poor excuse for a sports car. Basically the Grand Am GT is a family sedan with a spoiler and fake dual exhaust

I think we underestimate just how good handling our Vettes are simply because they are older, with a few inexpensive upgrades ( tires, shocks etc. ) it will outperform 99 % of the cars on the road 30 years later :D





[Modified by MotorHead, 8:44 AM 11/1/2002]

67HEAVEN

Bingo. No comparison. To drive one is to believe. Same as the GTP with slightly less power. Anyone needing a fun ride with four doors.....look no further. :yesnod:

mrvette

Chuck, can't agree with you on that rack/pinion thing....sorry, but my '72 was in great shape all around all new and tight everything that moved, and I felt it allways following/jumping the grooves in the road here in Florida with our lovely sand base.....thing got so bad on some roads it would even try changine lanes.....Yeh, I thought there was a problem too, but NO.....course my problem was accentuated by 275/17 rubber all around....
well going to my own install of RackPiinion solved the problem overnight. with NO other changes....

so this is direct experience with a GOOD C3 in great/new shape and then afterwards.....with no other changes.....
other than tires/wheels....that Rack/Pinion is the biggest single change to that car I ever made, even more highly thought of than the DPFI over the old carb.....even more of an improvement than the O/drive tranny for highway cruising.....

GENE

stngry63

I don't see how a rack 'n pinion will make a C2/C3 faster. Tires determine the cornering limits. Improved feeling in the steering wheel does not. I'm only running 215/70VR-15 tires so I don't have a problem with my car following the ruts in the road. The road feel through the steering wheel is great. I don't have power steering. Some of the complaints about lack of road feel are probably not because of the recirculating ball steering box, but are because of the stock power steering with fat gushy tires. I always scratch my head when I see sports cars, with a lot of money sunk into them, sitting on low dollar tires. VR tires, a good alignment, and practice makes an old Vette handle well.

Chuck Harmon

Gene,

Rack & Pinion and the original setup only determine the direction the tires point. How would changing this eliminate the tendency of following the grooves in the road if the original system had no slop? It would seem to me that something else was changed, perhaps the castor angle. I would agree that changing the gearing in the sytem could make a much better driving experience, but this really wouldn't affect handling unless the driver didn't have muscle to turn the wheel.

I would love to hear from Mr. Shea on this point of R&P vs worm and ball (recirculating ball).

Chuck

sammyb

Guys,
It's not a question of if modern sports cars handle better than C3s, but modern family sedans do, as well. In looking back into the old Road and Tracks, a stock '69 427/435 Vette pulled only about .75Gs, or just a tad under my wife's '98 Oldsmobile Intrigue at .77Gs. In terms of slalom performance, there's no comparison between old and new shock technology and suspension geometry.

Now, sure, we can talk tires all day, and the stock OEM tires were ghastly, but a lot of the modern cars run on pretty limiting tires, including the rock-hard Goodyears on the Intrigue and the Run-flats (lovingly called run-craps by the forum members) on my C5.

The other things to keep in mind are:
-Steering feel: Even without power steering, the C3 has numb steering.
-Braking: Integral in road course racing is braking, and Corvettes didn't get decent brakes until 1984.

Keep in mind that small block cars handle better than big blocks, and also, modifications go a long way in improving handling, but we're talking stock to stock.

But that's not to say that the C3 isn't a really fun car. I love mine. I actually like catchable sports cars that have rather abysmal handling, like Triumphs and Corvettes. What's the fun of having a car if you never get that hanging-it-all-out feeling?

joe73vette

A friend of mine drove my 73 around the same fun roads he drives his Audi A4 Sport. The vette was very stable and easy to get comfortable in, but ultimate grip was way less than the Audi. Tires undoubtably make the biggest difference.
Joe
PS, All of you who kept up with a BMW or such, did the other driver know he was racing?

mrvette

Chuck, I do hope Jim weighs in on this, he was immense help to me a year ago when installing this conversion....
I think it's the way the old system works....that valve in the drag link, even if tight as hound's tooth, that whole idea of moving the controll ball slightly to cause flow/power assist is fine IF the tires are not fighting the road, but when they do, the wheels tend to flip/actuate the steering controll assist and toss the car around......NOW, mind you I did NOT feel this effect so much up north in Maryland, with clay based soils and rocks and differant road specs'......but down here in Florida I think the rutting is because of the sandbar we live on...and I noticed it immediately the further south I came....I 95 travel route....
but it's my surmise the controll valve idea is not such a good design with wide tires on a sports car.....it was most likely FINE years ago before we had lo profile wide tires, but these days....well, either try the rack/pinion or give up the wide tires, car was a bitch to drive much, just tired of fighting the wheel....
NOW that could be construed to be 'too much ROAD FEEL'....which is a funny way to look at it.....but true none the less....now for some reason, I don't think the car has enough road feel......BTW the ratio is much closer to 12-1 on my rack, being 2.75 or so lock to lock.....instead on 3.8 or so....

at any rate to get my road feel back, I'm tempted to limit the pump pressure by changing controll/bypass valving....someday...

GENE

MotorHead

A big block with pie cutter tires pulls the same g's as a new Intrigue 30 years later, hmmm I don't see much improvement here

Chuck Harmon

mrvette,

One item that is rarely mentioned with servicing the front steering is the ball stud on the tie rod that connects to the pitman arm. On my car it was very worn when I fully disassembled the full front suspension and steering components. The steeroids or other R&P setups would have replaced this link reducing a great deal of slop. Once this ball stud was replaced and properly adjusted, my car tracked very nicely. I actually have greater road feel with my '69 w/ manual steering than with my ZO6's R&P setup. I set the 69 to less than 1 degree of caster to make it easier to steer at low speeds. In my opinion, the Z has too much caster which is great for straight line stability, but makes things a little more resistant to direction changes on tight twisty roads.

I am replacing my factory steering with a power recirculating ball box to allow a quicker steering ratio AND make the car easier to drive in city traffic. Unfortunately my arms and shoulders are not what they used to be :(

Chuck


[Modified by Chuck Harmon, 10:35 AM 11/1/2002]

VegasJen

all i have to say is tires, tires and tires. and wheels to fit those tires while we're at it.
i'd like to see that same stingray/intrigue comparo with modern tire technology. as argued in some of the above posts, there haven't been that much of technological leaps in suspension design in the last forty years like computers. the only part of that equasion that is even close is the leap in tire technology. seems there were no substantial breakthroughs in tire technology for 20-30 years and then right about the time the '84 came out and the gatorback tires, tire tech has exploded. just imagine going back to 1972 and talking to a goodyear or goodrich engineer and telling them that in 30 years there would be 285/30-18 tires. the response would likely be something like, "yeah, right" or "and monkeys might fly outta my butt".
tires are still the first and largest factor in handling capabilities, steering input and (unfortunately) ride quality.

oh yeah, i'm going purple today! :D

Jim Shea

I really don't have much to add with respect to the handling characteristics of a C2/3 compared to a C5. Chassis stiffness, weight distribution, tires, shocks, computerized active handling, traction control, the power available from the the C5s lighter, computerized, fuel injected engine makes the comparison to the C2/3 almost a joke. The technologies are just way to improved with the 30+ years of vehicle evolution.

You aren't going to get any definitive answers out of me with respect to rack & pinion steering vs recirculating ball and linkage for the following reasons:

When Gene says that changing over to R&P in his C3 was the greatest single improvement that he has made to his car, he is the one that drove the vehicle before and after. He is the one that is satisfied. I won't dispute that he is very much happier with his new R&P installation.

I do know that Saginaw tried to convince Chevrolet engineering to convert the old linkage booster system to the more modern rotary valve, integral power recirculating ball steering gear. (The original relay rod and tie rod geometry was retained.) Chevrolet engineering always said that the rotary valve gear did provide as much road feel and feed back as the linkage booster system. (The very thing that Gene says that he found too much of - down in Florida!) If I was to guess, it is very probable that economics was as much of a factor as performance in making the decision at Chevrolet to stay with the linkage booster until rack and pinion was designed into the C4.

If you just change the steering gear from a linkage system to a long tie rod (center takeoff) rack and pinion, you modify the toe change characteristics of the suspension/steering system. You don't affect the caster or camber. It is very possible that the long tie rods that Gene (and Steeroid) use with their R&P installations could very well improve the roll steer (bump steer) characteristic inherent in the C2/3 chassis design. However, I don't have any engineering data to support my supposition.

I am also sure that the much faster steering ratio with the R&P could also provide a significant degree of improved responsiveness and feel. There are fast ratio (12:1) Corvette steering gears being advertised by Flaming River Industries. This would result in considerably quicker steering than was provided by the 16:1 ratio of the production gear. It would be interesting to see how the faster ratio recirculating ball gear would compare to the R&P setup.

This is an interesting debate.

stngry63

You hit the nail on the head for the fun of driving an older car. The C4/C5 are too fast for back road driving. The view up ahead isn't far enough for 100+ mph. Drifting an old car or catching the rear coming out on skinny tires is :D

mrvette

CH, Yeh, I join with you in the comment about mr. armstrong's shoulders there, I have the displeasure to drive a buddies' 4 cyl S10 manual steering...once in a while....HATE that damn truck....

GENE

mrvette

Jim, glad you joined in here, I do think it's an interesting debate also....very much so...

Another angle on the topic here, in another thread there is a subject brought up about possibly extending the top of the steering spindle, by raising the upper controll arm BJ stud...so as to effectively 'shorten'?? the control arm geometry to make the top of the tire pull in more in a tight corner.....
I had assumed Zora pretty well settled this sort of issue well beyond my understanding....is there anything to be gained by doing this mod???

looking for a general answer, or do you know something Vette specific that negates any NASCAR device 'improvement' we could install???

GENE

sharkthehunter77

jesus, how much handling do u need. Most of the C3 vettes that are in good conditionor better will do just about anytying their owners will ask them to on the your average twisty backroad, highway on ramp, emergency lane change. My car corners flat and will take most non switch back type back country roads will as much gusto as i would try IN ANY CAR. these yuppies have repewat there "it'll take you in the twisties" mantra for there asorted beemers, audi's, Hondas, porsches,...etc But how fast are u really willing to go on that back country road not knowing what the hell lays ahead just beyond sight. I can see a Honda S2000 outpacing a big block on a tight course but thts not daily driving. A well set up late model shark with a talented driver should represent vettes just fine

ddecart

Wow. There's some good discussion going on here. I'll trrow in my 2 cents worth, or maybe more. I'll try to keep it under $5 worth though :D

I'll start out by saying that the ride and handling of my C3 sucks. It's fun to drive, but compared to modern cars, it sucks. I actually have a "non-car" vehicle at work that will kick my Vette's butt in handling. 0.86g max lat, well balanced and great on an autocross course. The vette would win on the drag strip, but it's much harder to drive fast. The steerign on my car is vague at best with lots of compliance that you won't find in many modern cars. Compliant, NOT sloppy.

Let's look at the C3 bit by bit. The first major difference between the C3 and C5 is the chassis stiffness. I don't know how stiff the C3 is, but in comparison, it's a wet noodle. So what? Well, if you assume you have an infinitely stiff chassis, you can focus on each suspension corner as an independent unit. What happens at that wheel only happens to those suspension components. With the wet noodle chassis, an input at one corner affects that suspension, and the frame and the other corners. That's one reason that over the past 15 years or so cars have been handling better without sacrificing ride. In the old days to get the handling leve you wanted, the suspension had to be REALLY stiff to make up for the flex in the body. Not so anymore.

Now for the front suspension. C3's are pretty generic SLAs. C5's are pretty generic SLAs. Spring configuration is different, but that really makes no difference at all. I'll have to look specifically, buti don't think 5 and C3 camber and steer rates are very different from each other. What will be different are compliances. Bushing rates essentially. Without looking, I can't make a call to say which car has the stiffer bushings or where.

Before we look at the rear suspension, let's hit tires. These are the single most significant improvement over the past 30 years. Remember when the 16" tires on the C4 were a big deal? Now SUVs are running around with 17s from the factory, if not bigger! Tire technology has grown by leaps and bounds. Tires can be stiffer laterally (handling) without being too stiff radially (ride). Keep in mind that I don't have to have the suspension as stiff anymore, so it can be softer and the tires a little stiffer without sacrificing ride quality or handling. Tires...BIG item!!

Now for the rear suspension. This has seen the biggest improbvement over the years. The C3's suspension design really leavs a lot to be desired. Using the halfshaft as a suspension link isn't all that great of a design. Kinematics are compromised and there's a limit to what can be done to control steer & toe. The C4 suspension was an incremental improvement over the C3. From what I've been able to decipher, the C4 rear was originally intended for the late C3's but never made it into production. The trailing arm was replaced with a pair of links. These can provide a longer effective arm length in the same amount of space. I can't quite picture the rest of the C4 suspension to talk in depth about other changes. But they were incremental anyhow and in the right direction. With the C5, the sheet was blank. They were able to design in the toe and camber curves they wanted. Ride and handlign were able to be balanced better than they were previously. Unfortunately, I don't have any C3 suspension data, but I'll see if I can find some early C4 data for comparison.

The composite spring in the back was a BIG help to get a better ride. Reducing the inner-leaf friction did a lot to reduce the harshness. Sure, we get bounce when we do it for a C3, but we also don't have the benefit of being able to tune the shocks on a variety of roads.

Now for steering. I mentioned much earlier that my car isn't that great. Road feel, precision, feeling like there's a natural connection between you, the steering wheel and what the car is doing are all rather poor. Who's to blame for all this? My suspension parts are new, my steering gear is accurately setup for preloads, I don't have any old & crusty parts in the system, so what's wrong?

Well, in general a recirculating ball gear has more internal friction and is less precise overall than a rack & pinion setup. That's not to say that a good recirc ball isn't as good as a r&p setup, but in general as a group they're worse. They tend to be more vague as far as feel goes. The friction part means that more of yoru steering work is going into making heat in the gear and not into steering the car.

The slave-cylinder setup is rather odd as well. I'm not going to claim I know a lot about it, but I'm not confident that it's not a contribtor to poor steering feel. The tuning of the valve and torsion bar are big factors in the steering feel as well (using integral assist terms here). How much boost do you get for a given torque at the steerign wheel? That determines whether the steering is heavy or light and changes your perception a great deal.

That said, is the steering going to make the car handle better? Probably not. One thing I should mention, and I'm not sure who put the faster ratio gear in, but THAT ALONE will make a huge difference. Comparing apples and kiwi-fruit in a sense. The lower (faster) ratio is going to give you a more responsive system that you may be attributing to the R&P setup and not to the steer ratio.

So, with all that I hope I helped the discussion. You might wonder what I'd do to my own car if I could. Well, if I weanted to improve handling, I'd go with a bigger front sta-bar and a rear bar (balanced of course), stiffer springs front and rear (gotta be stiff with all that chassis flex) and bigger tires. (I didn't even hit on brakes here. Bigger wheels allow the packaging of MUCH bigger brakes. That's a big bonus). For the steering I'd probably go with a power recirc-ball gear, or possibly a r&p. Either way, I'd like a numerically lower ratio to bring up the steerign sensitivity (# of g's for a given steering wheel angle).

It's hard to say exactly what I'd do without beign able to predict the effects of the changes ahead of time through compyuter modeling. I'm very data-driven at work and change things for specific reasons with specific targets in mind. Going off of 'feel' isn't quite my forte.

Well, there you have about $4.95 worth. Did I help?