C5 Corvette Suspension Geometry

[Lowend]

Don't get me wrong - I'm not saying that the C5/6 stuff is bad; but if I'm starting from scratch there is certainly better stuff for a racecar.
I've raced C5's they are unbelievable for out of the box cars. BUT they are out of the box cars; designed to live for 200K miles and keep grandpa happy with their noise isolation ect. If I'm building an open track car, I'm not looking for those compromises.

[Bjkadron]

I agree that the corvette has some compromises... But does anyone know of a fairly cheap computer program to analyze geometry? because it might be easier on the budget to copy a good suspension than spend a bunch on a program and then build that design. But from scratch is fine with me if anyone knows of a cheap program.

[BBShark]

Don't get me wrong - I'm not saying that the C5/6 stuff is bad; but if I'm starting from scratch there is certainly better stuff for a racecar.
I've raced C5's they are unbelievable for out of the box cars. BUT they are out of the box cars; designed to live for 200K miles and keep grandpa happy with their noise isolation ect. If I'm building an open track car, I'm not looking for those compromises.

Again, I am not building a racecar. I am building a car for track days where there is no passing, only a group out on the track trying to get their best out of the car. I'm not even sure if there is a vintage racing class that will allow the use of C5/6 suspension (if there is, it's out of my league financially). I also don't have a ton a money to put into a car that might be used 2 or 3 days a year. So, with this in mind, the C5/6 stuff suits my needs perfectly.

My original post was a request to find the pick up points for a C5/6 as a baseline. I was able to find that in the Suspension Analyzer 2.0 software (2001 Corvette) for others looking for this information.

[Steve1968LS2]

I'm with Matt. Those parts have impressive amounts of engineering and failure mode analysis behind them.

The only drawback I see is the inability to service the upper balljoint. If the ball joint fails, you have to buy a new upper control arm/upper bj/upright assembly.

The other weak point is the wheel bearing inserts, but the aftermarket has stepped to make durable long lasting bearings. See Steve Rupp's Defender edition thread for more information on that.

jp

That's no longer the case. Pfadt now offers an imporved lower ball joint and soon they will have an upper. Just need to be pressed in an out.

There are also new wheel bearing options (from same place) that employ a ZR1 type bearing not subject to the same side-loading problems as the C5/C6 versions.

So, C5/C6 control arms have been one our cars for years now. Anyone every heard of a control arm failing?

[Steve1968LS2]

Don't get me wrong - I'm not saying that the C5/6 stuff is bad; but if I'm starting from scratch there is certainly better stuff for a racecar.
I've raced C5's they are unbelievable for out of the box cars. BUT they are out of the box cars; designed to live for 200K miles and keep grandpa happy with their noise isolation ect. If I'm building an open track car, I'm not looking for those compromises.

Those compromises can be addressed. The bushing issue can be fixed with poly or spherical bearings. Camber can be increased, etc.

But even that's not necessary for the 95% of the people that are never going to drive thier cars at 10/10ths.

Is it the best stuff possible? Heck no, but for "off the shelf" stuff it has a lot going for it.

[Steve1968LS2]

So your debunking the myth that the spindles are not rebuildable?

--JMarsa

The uprights have always been rebuildable. The problem was that GM didn't sell the ball joints seperatly. Also, they take a bit more work since they are pressed in.

But now aftermarket parts are available. As a bonus the parts are better than what GM supplied. I thought I heard someone was selling stock replacements as well.

http://www.pfadtracing.com/catalog/p...roducts_id/129

[parsonsj]

Yeah, I asked Jordan if there was any plans for C4 bearings (since my uprights use C4 bearings). Nope.

I guess I'll just plan on replacing them annually.

jp

[JMarsa]

Thanks for the info guys!

--JMarsa

[Bjkadron]

[quote=I was able to find that in the Suspension Analyzer 2.0 software (2001 Corvette) for others looking for this information.[/quote]

How much does that program cost? And where can I get it?

[JMarsa]

It has a 30 day trial. Performance Trends is the company, just google the software name.

--JMarsa

[LSfan70s]

My original post was a request to find the pick up points for a C5/6 as a baseline. I was able to find that in the Suspension Analyzer 2.0 software (2001 Corvette) for others looking for this information.

Awesome! Thanks!

[Bjkadron]

Thanks for the info!

[LSfan70s]

Thanks for the info!

Were you able to find the trial? I can not find it.

[LSfan70s]

Were you able to find the trial? I can not find it.

Nevermind. I got it.

[outlaw 03]

Any word on the pick up points? I'm in the process of gathering info/knowledge on to put C5 stuff under my A body.

[Bjkadron]

click on the "it" in the previous post.. It is the link to the software download with the info on it.

[outlaw 03]

click on the "it" in the previous post.. It is the link to the software download with the info on it.

Thanks.. Above it was mentioned that anti-dive would be needed to make this system work in a heavy car. How do I "analyze" it? My original plan was to use the entire C5 cradle but that puts the motor way too far back. So now I plan on building a "clip" to replace from the firewall forward using C5 arms, spindles & Rack (I got a real good deal on it). I have a lot of Fab experience and but not in properly setting up a suspension from scratch any advise would be much appreciated.

[79PonchoUK]

It's funny how this thread is bad-mouthing C5/C6 parts. Here's what I think:

1. C6 parts are strong...very strong. I dare anybody here to try and break them. The weight of these pieces go great lengths in helping our cars perform better...and ride nicer.
2. Upper cross shaft movement is extremely minimal in everything except all-out racing applications. NOBODY here will be able to stress these to their limits. NOBODY.
3. The geometry can be easily modified for more anti-dive (not a whole lot is needed), radical camber gain, and still have a fraction of the roll center migration of any modified F-body suspension.

Those who are in the "know" of suspension design understand the C5/C6 design is hard to beat. Right up there with the most exotic Euro cars.

Do you consider the transverse leaf a better idea than the traditional coil setups found in most 'exotic' cars?

Considering the advantage of not needing mounting points higher up in the chassis...there must be a notable CofG advantage?? Is the spring lighter than the steel coil equivalent too?

I remember an article over here where a lotus suspension engineer looked at a corvette suspension as part of the article and I believe the remarks were "neat, great design....only problem is that it's expensive". lol

[LSfan70s]

Thanks.. Above it was mentioned that anti-dive would be needed to make this system work in a heavy car. How do I "analyze" it? My original plan was to use the entire C5 cradle but that puts the motor way too far back. So now I plan on building a "clip" to replace from the firewall forward using C5 arms, spindles & Rack (I got a real good deal on it). I have a lot of Fab experience and but not in properly setting up a suspension from scratch any advise would be much appreciated.

This should help clear things up

Instant Centers are where ever two suspension lines cross. Its late so you get a screen shot of the Z6 Z06 chassis unmodified edited in paint after a 16 hour day, no bitching.

#1 is the anti dive (the one I've been really playing with) you can follow the two green lines back to the A frames and see how their pointing. That angle is like the bars on a live axle only they don't move as much as the car squats, remember those 4 points are fixed to the frame they don't travel with the suspension like a solid rear end does

#2 is the anti dive almost the exact opposite of #1 but for the front suspension to keep your front end out of the dirt when you get on the brakes but without needing super huge springs.



-R^3

That quote gives a good explanation on what we (you, me, all building this kind of thing) are looking for.

I also bought this book that has helped clear things up: Suspension Engineering

Good book

[silver69camaro]

Do you consider the transverse leaf a better idea than the traditional coil setups found in most 'exotic' cars?

Considering the advantage of not needing mounting points higher up in the chassis...there must be a notable CofG advantage?? Is the spring lighter than the steel coil equivalent too?

I remember an article over here where a lotus suspension engineer looked at a corvette suspension as part of the article and I believe the remarks were "neat, great design....only problem is that it's expensive". lol

I don't really consider it to be a better design, just something different that works within the packaging requirements. The leaf is pretty light, I'd imagine it's probably the same weight as a steel spring, although much less of that weight is unsprung. I think racers swap the leaf for coilovers to make changing spring rates easier.