Then what kind of Analysis are you talking? Stress analysis or suspension analysis? The stress analysis can be done through Solidworks. The suspension analysis we have been working with some engineers and just some smart guys I know. I have had some Hot Rod front suspension spec from some guys alot smarter then me and we have been running with those numbers. But we are now working to improve things even further then that.

Here is an email from some things we are looking into on the C5 suspension.

So I just got done running a few simulations with the C5 Corvette Hardpoints that you emailed to me. The only other thing that would be nice is if I had more accurate Anti Roll Bar hardpoints. Something I found over the past year is that in keeping those motion ratios linear, you can drastically improve the handling of the vehicle.


Some quick notes I have on the C5 chassis:


For Longitudinal Case (3 degrees pitch braking, 3" travel, then 3 degrees acceleration, 2" travel)


Camber looks very good in this situation, appears to be the main focus of this car.
Toe needs serious help - 1.3 degrees toe out in front under breaking (should toe in), rear stays within .7 degrees which isn't bad.
Track change isn't bad, the track increases on the side that's being loaded- good for stability.
Wheel/Shock Motion ratios look not too bad, but something that can be improved with rockers- also, can make them with a rising spring rate to help the car become stiffer as its loaded - all dependent on the springs though.
Roll Center height looks okay except for full breaking, it does go below ground. Having a Higher RCH would help this and can be done a number of ways, I'd be curious to see what happens in a C5 with you mash on the brakes all the way then cut the wheel...
Pitch center looks really good- migrates less than 13", less than 15% the wheelbase, it is pretty high though- probably to make the car more responsive under braking and accel without sacrificing ride characteristics...


Now for the Lateral Case - Go into a ~ 1.5 G turn (4 degree roll) and simultaneously turning the steering wheel 60 degrees.


Camber looks okay in the front - due to the similar amount of KPI and Castor, not much camber gain on the outside (.3 deg) so the can be improved a lot, just by adding a little bit of castor, but it all depends on what the tire wants, It may not be that camber sensitive in that case we shouldn't even look at camber.
Rear camber looks bad, depending on what the tire wants - outside wheel goes way positive (3 degrees) and inside goes way negative (-4 degrees) This is probably why I see a lot of people setting these cars up with so much negative camber in the rear. This can definitely be improved and make a huge difference on track.
Toe change is fairly mild- rear moves to create oversteering moment, front is pro ackerman with about 2 degrees difference - seems pretty good. Starts at about 103% and moves to 133% which makes sense if this car is running on radials.
Track change in rear is near nothing and okay in the front- could stand to go a bit wider under compression.
Roll center heights stay damn near the same in roll, and migration is 2 inches inside on the front and 2.4" inside in the rear (less than 4% the track width). This seems to be the large focus of the suspension design as this is what looks the best.


Overall I can see where these cars get their good handling characteristics, but there is a ton of things that can be done to improve it, from a kinematics perspective. I'm curious to see how this differs from the C6 setup and if they made any geometry changes for the ZR-1.


Let me know what you think.



Bobby Alley
Chief Engineer
Sooner Racing Team


So like I said, I may not be that smart but I know some guys who are. Someday we will be able to track test some of these projects and show beyond the drawing board the functionality that they work better then we can probably drive.

At the end of the day the best mod you can do to your suspension is put slicks on. All this time looking for the unicorn of suspension geometry perfection changes with every car. Plus is anybody on this site going to beat on their car enough to justify all the effort we put into geometry. Probably not, but it sure is fun.

Rodger

"Stress analysis or suspension analysis? The stress analysis can be done through Solidworks."
Your building Chassis man you should be doing every possible analysis that should be done. I know you CAN do things in Solidworks, but are you? And not just Frame rails...
You can only do with what you know.maybe when you finish Johns car you could do some proper testing which will give you real feedback on Street tyres
Im trying to figure out the product you offer and its benefits

I try to figure out the product we offer every day, and how to make it better then then the product we offered the day before. I would say by the amount of work we have in the shop, we must be doing something right. Because it certainly is not my good looks, that is for sure. :yes: :yes:

We are bunch of young guys trying everyday to build the baddest most functional stuff we can. The problem is it takes 1000's of hours to build a car to the level of some of these projects in our shop. I'm going to go out on a lib and guess that the clients we build cars for trust us and respect our knowledge and abilities. Are we the master of solidworks? Nope Do I know some guys who are? YEAH. Ever heard of MARS or an F-16? Did I ever claim to know it all? Nope. Could we improve on every trade done in my shop? I hope so or I have no reason to show up tommorrow.

Yes, we plan to test and tune Johns nova someday. But at the end of the day what will that prove? There are a ton of legendary cars built that have never proven or done anything to live up to the hipe or mythical legend the magazines created them to be. And tons have fallen on their face in front of God and everyone.


So let me ask what do you use for grammer check?
Thanks

:D

To make it better each time around you would have to do several duplicate chassis builds of the same function and car(C5 suspension, 4 link, watts, etc.) Is it in a camaro, truck, nova, cuda, etc. If you look at the projects Rodger has going on each one is designed differently for its purpose.
AS far as the 69, C6 IRS set up, we are talking new territory, most builds to date have been C5 based including the trans setup. When you take the C6 rear/trans combo all pick up points are different than C5 including track width, tranny mounting points, a arms, etc.

Rodger --

I don't care if this stuff ever gets tested! It's the baddest, koolest looking stuff going!

I have lots of tools - I sure wish I had the talent to use 'em like you guys do!

Best,
Greg Weld

:thumbsup: X2 What Greg said. Except I doubt I have as many tools......

The projects that come rolling out of your shop are inspiring to many. I don't know how hard any of these will ever be pushed or tested, but it really does not matter. If you are giving the customer what they want, that is the product you offer and the benefits are many. Keep it up!

That is a great thought process for the frame and floors Rodger. What are you going to do for a hood, etc with the engine placement that high? The valve covers appear to be about even with the hood hinges! I can't wait to see this one transpire, like all the other projects in your shop. :yes:

regarding stress calcs, current production cars have huge torsional rigidity, I wonder what these custome frame body combos work out at

found some figures online

Aston Martin DB9 Coupe 27,000 Nm/deg
Aston Martin DB9 Convertible 15,500 Nm/deg
Audi TT Coupe 19,000 Nm/deg
BMW E36 Touring 10,900 Nm/deg
BMW E36 Z3 5,600 Nm/deg
BMW E46 Sedan (w/o folding seats) 18,000 Nm/deg
BMW E46 Sedan (w/folding seats) 13,000 Nm/deg
BMW E46 Wagon (w/folding seats) 14,000 Nm/deg
BMW E46 Coupe (w/folding seats) 12,500 Nm/deg
BMW E46 Convertible 10,500 Nm/deg
Chrysler Crossfire 20,140 Nm/deg
Chrysler Durango 6,800 Nm/deg
Dodge Viper Coupe 7,600 Nm/deg
Ferrari 360 Spider 8,500 Nm/deg
Ford GT40 MkI 17,000 Nm/deg
Ford Mustang 2003 16,000 Nm/deg
Ford Mustang 2005 21,000 Nm/deg
Ford Mustang Convertible (2003) 4,800 Nm/deg
Ford Mustang Convertible (2005) 9,500 Nm/deg
Jaguar X-Type Sedan 22,000 Nm/deg
Jaguar X-Type Estate 16,319 Nm/deg
Lambo Murcielago 20,000 Nm/deg
Lotus Elan 7,900 Nm/deg
Lotus Elan GRP body 8,900 Nm/deg
Lotus Elise 10,000 Nm/deg
Lotus Elise 111s 11,000 Nm/deg
Lotus Esprit SE Turbo 5,850 Nm/deg
McLaren F1 13,500 Nm/deg
Mini (2003) 24,500 Nm/deg
Pagani Zonda C12 S 26,300 Nm/deg
Porsche 911 Turbo (2000) 13,500 Nm/deg
Porsche 959 12,900 Nm/deg
Volvo S60 20,000 Nm/deg

Rolls Royce Phantom: 40,000 Nm/deg
BMW E90: Supposedly 25% higher than E46, look above
Audi A2: 11900 Nm/deg
Audi A8: 25,000 Nm/deg
Audi TT: 10,000 Nm/deg (22Hz)
Golf V GTI: 25,000 Nm/deg
Ferrari 360: 1,474 kgm/degree (bending: 1,032 kg/mm)
Ferrari 355: 1,024 kgm/degree (bending: 727 kg/mm)
Ferrari 430: supposedly 20% higher than 360
Renault Sport Spider: 10,000 Nm/degree
Volvo S80: 18,600 Nm/deg
Koenigsegg CC-8: 28,100 Nm/deg
Porsche 911 Turbo 996: 27,000 Nm/deg
Porsche 911 Turbo 996 Convertible: 11,600 Nm/deg
Lotus Elise S2 Exige (2004): 10,500 Nm/deg
Volkswagen Fox: 17,941 Nm/deg
BMW Z4: 14,500 Nm/deg
Ferrari F50: 34,600 Nm/deg
Lambo Gallardo: 23000 Nm/deg
Ford GT: 27,100 Nm/deg
Mazda Rx-8: 30,000 Nm/deg :eyepop: (hard to believe)
Mazda Rx-7: ~15,000 Nm/deg

be fun to rig up some tests

the really high end stuff is all over 20,000Nm/deg

The engine seems high when you take a 1" wedge out of the body and set the rocker to 5" of ground clearance. The transalxe is actually rotated to 1 degree dowm hill to lower the front center of gravity. With a rear spindle center of a 20" rim of course the transaxle will be higher then normal.

We have some pretty slick ideas on the hood, If it is not obvious this car will be pretty custom. Reshaped fenders, reshaped tailpanel, Reshaped roof skin, Shortened nose. I have quite a few tricks up my sleeve on this car.

See ya in Columbus.

Thanks Greg, You have some pretty slick stuff yourself buddy.

Rodger