MyE28.com

This thread is a fantastic read! I would imagine, chris, that this knowledge is what your buddy is looking for.

So they can spend their spare time replacing oil pans.

Ken H. wrote:So they can spend their spare time replacing oil pans.

No doubt. As the Chief Inspector, I will now be collecting a minor fee for all pans replaced. It's a mere 10% of the cost of parts plus a $15.00 for the official inspection certificate. I have the collection forms, you may have them defer to me for a copy.


Henry
Chief Inspector

[quote="wkohler"]I'm done. Forget I asked. I thought it was an interesting idea to discuss but obviously no one else does. Instead, they'd rather lecture me like I'm some sort of moron and that I'm not "understanding" something that I've understood for years.[/quote


I thought it was a good question and subject. Sorry if I came across as condescending or lecturing.

What Randy, Paul, Tammer and Shawn (the second time) offered is pretty much the type of discussion I was looking for, and their comments pretty much parallel my thoughts on this idea. If I were to put stiff springs, etc on a Ford E350, I still couldn't autocross it because it would tip over. Obviously an exaggeration of the argument, but it is valid nonetheless.

I know a lot about suspensions and what is needed to make them work, but I found the idea intriguing of making all of the adjustments higher, keeping the ride height higher.

Thanks.

Shawn D. wrote: As the vector moves sideways, the outside tires take on more vertical force and the inside tires thus take on less. Thus, the outside tires are taking more of the sideways thrust, while the inside tires are taking on less. This is not linear, though, because the increase in grip on the outside tires is less than the decrease in grip on the inside tires, especially as the trip limit is reached. Reducing the CG height reduces the change in distribution of vertical force, thus allowing all four tires to have more even distribution.

I agree and If theoretically you could move the CG below the tire contact patch like a weight slung down under the road surface (think of a hanging roller coaster) the whole dynamic would shift from outward lean to inward lean. So theoretically the proper position of the CG would cause nothing to happen, no weight shift inside vs outside, and the suspension could remain flat as designed in static state. I think this requires the CG to be in plane with the contact patch which is difficult to imagine but it clearly indicates that the optimum for equal distribution of load and minimizing all the corrections based on dynamics would drive you there.

Lowering should approach the theoretical ideal and every % of lowering should result in a similar % reduction in weight bias on cornering just as you said above. Distributing the forces more evenly should result in uniform tire deflection and wear on all corners and maximum grip. But since tires are now mostly designed with an outside and inside it might not work out that way under all conditions. I don't know?

And maybe I really don't get the original question and why some have taken offense and others poke fun. I will keep my car up off the ground to save the oil pan and air dam and keep my tires from rubbing stuff though. We just changed the pan gasket on our e30 project and it is a pain in the butt to get one out.

wkohler wrote:I know a lot about suspensions and what is needed to make them work, but I found the idea intriguing of making all of the adjustments higher, keeping the ride height higher.

Thanks.

Making the spacers to do this would be relatively easy if you really wanted to mess with it. I have plans* for my wagon and may do something like this. I want to keep the stock ride height, or maybe go even higher. I want to add stiffer springs, but I want to still have the car handle as well as possible at that height. Dropping the front and rear subframes down something like 1" would do help maintain the desired geometry, and give me more room for the silly mess I plan to make of the car.

*thread coming soon

Look how low the old 6 series racecars were.

Why does it matter?
Some people do it for looks, others do it for less under drag coefficient and handling.
I personally think a vehicle with tucked tires and wheels that come flush with the wheel wells is neat "if done correctly". Its more of an art than for any other purpose.

Takedownrcm wrote:Why does it matter?
Some people do it for looks, others do it for less under drag coefficient and handling.
I personally think a vehicle with tucked tires and wheels that come flush with the wheel wells is neat "if done correctly". Its more of an art than for any other purpose.

Thank you for NOT reading the question that was actually asked.

-tammer

Tammer in Philly wrote:

Takedownrcm wrote:Why does it matter?
Some people do it for looks, others do it for less under drag coefficient and handling.
I personally think a vehicle with tucked tires and wheels that come flush with the wheel wells is neat "if done correctly". Its more of an art than for any other purpose.

Thank you for NOT reading the question that was actually asked.

-tammer

Just giving my $.02. If you dont like my answer then ignore it. Problem solved...

Takedownrcm wrote: Just giving my $.02. If you dont like my answer then ignore it. Problem solved...

Not sure why you felt qualified to answer a post you didn't read.

WOB.
-tammer

tn535i wrote:I agree and If theoretically you could move the CG below the tire contact patch like a weight slung down under the road surface (think of a hanging roller coaster) the whole dynamic would shift from outward lean to inward lean.

That`s an interesting thought, but would it even have to be below the road surface? The way I imagine it, it would be the same having most of the weight below the control arm pivot point or something like that. Could be wrong.

As a side note, I for one am very much in favor of stiffer suspension on a daily driver without massive lowering. Both of my cars now have spring rates that are roughly double stock, and ride heights within 1" of stock. All the benefits of ground clearance and normal tire wear, quicker response, and no falling-out-of-your-seat rowboat-like body motions that come from wimpy stock springs and worn out old shocks. (good for towing trailers too)

I think the force is still applied at the contact patch and the CG is still above it, so there is no way to trick physics. But you could probably manipulate suspension movement in many ways since there is a lot of transfer of load through various components. So for example even the moment or angle of the suspension contributes to force getting transfered through to the spring. You are pushing on a double hinged arm that will try to move in the direction it happens to be off neutral axis. This might become significant the further off axis it gets and either try to raise the car and CG with inward force (I think of the Corvair) or vice versa. I think we are near neutral on ours so lowered or not it may be small fractions of the rest of the system. But I don't know.

best benefit of lowering my m3 is that the rake changed giving me a bit more visibility out the rear, its was harder to see over the rear spoiler and lowering the car gave me a better view. ex i can see the curb behind the car when parallel parking an couldn't before



other then that id say spring rate was nice, less body roll and better feel from the road.

12valves wrote:

tn535i wrote:I agree and If theoretically you could move the CG below the tire contact patch like a weight slung down under the road surface (think of a hanging roller coaster) the whole dynamic would shift from outward lean to inward lean.

That`s an interesting thought, but would it even have to be below the road surface? The way I imagine it, it would be the same having most of the weight below the control arm pivot point or something like that. Could be wrong.

Note my point above about the CG vector. If it's above the road, it can be vectored past the side of the contact patch and make the vehicle flip.

wkohler wrote:I'm done. Forget I asked. I thought it was an interesting idea to discuss but obviously no one else does. Instead, they'd rather lecture me like I'm some sort of moron and that I'm not "understanding" something that I've understood for years.

I don't think people realized that all you were asking was other people's perception on the subject.

I stepped into a conversation I wasn't qualified to....won't do that again. I answered at the depth I could. I didn't realize the depth of the question. Live and learn.