Accord Dynamic Data

[domesticated]

Basically we put the vehicle on a huge machine and hard mount the chassis to the machine, then each tire to an arm and contort the suspension to get these measurements. It takes about 4-7 days to collect the data. Most OEs have their own machine and measure all ofoff of their competitive data.

[CyborgGT]

So... Chrysler has access to other manufacturers' engineering data?

[Karl]

Awesome info, and I can only imagine how long it would have taken to take all those measurements.

Thanks

[domesticated]

It's from lock to lock, so the steering wheel doesn't matter. The steering center is zeroed before the test. I would say the rack is very slightly not laterally centered in the vehicle. There is a lot of compliance in the system that could cause this.

[cp[mike]]

damn this is crazy awesome! i commend you on what must have been a ton of work getting all those pictures posted.

curious about this one,



would the slight difference between start/end points of the left-to-right graphs be indicative that your steering wheel is mounted slightly crooked out of line from the rack? or are the tierods barely not matched to each other?

[domesticated]

Great stuff man! do you by any chance have access to suspension point data? Time to crack open RCVD again!

No I don't sorry.

[dbsharp]

Great stuff man! do you by any chance have access to suspension point data? Time to crack open RCVD again!

[sonikaccord]

Bump, we can use this to design the perfect custom suspension

[CB7DX420]

I dont understand how to read a bit of those graphs or what the data means, but its very thourogh and is clearly some very important and hard to find data, totally sticky worthy!
one of these days i'll learn what it all means.

[Tishock]

I appreciate you adding this info. I've actually been looking for some of this data. But give us a little time to process the information . You posted 82 pages/graphs in here. Hell it took a while just to copy, title and organize the images on my computer. And it's going to take some time to make sure I actually understand it all.


.

[marcusv8thunder]

Ive seen this for race cars before, its important to know how the suspension behaves, so that you can then control and adjust it etc.

But ive never seen this for a road car, but thinking out loud now, i guess all cars that come out the factory in the engineering office will have this data, but wont be publicly available.

Really interesting to see these graphs, as ive driven the Accord in both stock and modified states.

Anyone on this forum can relate and understand the camber and toe graphs, we have this issue when lowering the CB, rears toe in and -cambers up, and the fronts toe out and - cambers up but at different rates.

[domesticated]

It depends. Kinematics won't change. Unless you physically change control arms and such. Lowering your car reduced the moment arm of from the roll center. Roll rates will be affected.

[sonikaccord]

That is alot of data...
So weight reduction, suspension changes, bushing upgrades, chassis bracing...how will these affect the graphs?

[domesticated]

The first sentence in your response is the reason no one has responded. Know one has a clue about suspension geometry. Most would much rather buy cheap ebay suspension and complain about it. It's just easier for most to do it that way then it is to actually do research and know a little bit about what it is they are modifying.

Good info.... Wish I had the same for the CD chassis....Not sure if there would be much of difference between the two or not...

I'll look this summer. They should have every production vehicle ever on record. I'm not going to stretch my bounds though. I'll talk to the guys when I get back.

[domesticated]

Any of the measurements as far as camber and weight is done without driver. All data on step steer, yaw, roll, or lateral anything is with driver. Those are all dynamic tests with driver. Driver is within the 95th percentile, gas tank is a 3/4 tank. Alignment won't change no matter what you do to the car, unless your crazy and you start changing the kinematics yourself with some custom stuff. You lower your car 2", you camber will go in that much according to the graph. If you lower your car the roll center will lower appropriately (small error). Most of this data will still be accurate. The things that will change the most is steering frequency and yaw rate. If you care enough to know exactly you will know the math and physics to make adjustments. Or you will have your own G meters to get an approximation. Very few OEMs even have the equipment to perform these kinds of test. It requires a lot of very expensive equipment.