CSG and RCE tag-team suspension Q&A thread! Ask us anything!

[Turdinator]

Can someone recommend alignment specs for stock suspension with the stock oz spec 16" wheels and tires? I have ordered the whitline camber bolts for the front because I am wearing out my tires on the outside edge. The rear looks ok but if there is some grip to be had I am prepared to order the whitline rear camber bushes also.

[7thgear]

Originally Posted by Turdinator

Can someone recommend alignment specs for stock suspension with the stock oz spec 16" wheels and tires? I have ordered the whitline camber bolts for the front because I am wearing out my tires on the outside edge. The rear looks ok but if there is some grip to be had I am prepared to order the whitline rear camber bushes also.

find a proper alignment place that services the race community and set it to factory sepcs.

[CSG Mike]

Originally Posted by Turdinator

Can someone recommend alignment specs for stock suspension with the stock oz spec 16" wheels and tires? I have ordered the whitline camber bolts for the front because I am wearing out my tires on the outside edge. The rear looks ok but if there is some grip to be had I am prepared to order the whitline rear camber bushes also.

Sounds like you're doing some hard driving. Were you on stock alignment before?

Put in the camber bolts, and add the maximum amount of negative camber that you can get with the bolts.

[Calum]

Just an FYI, Whiteline has a set of bushings to add camber via the rear lower control arm now. I'm not endorsing the product as I haven't even seen it in person, but plus or minus 1.5 deg from a relatively cheap part that shouldn't require a keg and a large net to catch the wrenches you throw out of frustration, seems like a great idea to me.

[ayau]

Originally Posted by Calum

Just an FYI, Whiteline has a set of bushings to add camber via the rear lower control arm now. I'm not endorsing the product as I haven't even seen it in person, but plus or minus 1.5 deg from a relatively cheap part that shouldn't require a keg and a large net to catch the wrenches you throw out of frustration, seems like a great idea to me.

Got a link?

[mike156]

Originally Posted by ZDan

No center of gravity is "moving", period. And nothing is happening instantaneously when that corner comes off the ground. And cornering harder isn't putting additional load onto the *inside* rear, but rather to the outside rear.

For the purposes of this discussion, you have to consider five different centers of gravity. One for each unsprung mass and one for the sprung mass. When you change unsprung mass into sprung mass, you change the sprung masses center of gravity. True, the overall COG remains the same for the system, but it does "move" the sprung mass COG.

I did not intend to say it happens instantly when the wheel goes in the air. I'm saying more along the lines that when that tire goes into the air, you know you have turned every last bit of that unsprung mass into sprung mass.

Maybe wording was poor, but I’m not saying it adds additional weight to the inside rear with additional cornering load. It maintains a higher percentage of load on the inside for longer, the tire continues to loose load with additional cornering loads though.

I’ll admit here, this mentality is out of my norm. I’m a very analytical person and I’m not arguing anything you are saying with the assumptions you’ve made to your napkin math. I’m drawing off experience of guys a lot faster than I. I’m trying to rationalize why what shouldn’t work on paper does. Physics and dynamics are rock solid and I’m not arguing them. I’m just trying to figure out what works well in the real world and “reverse engineer” it back to vehicle dynamics.

[7thgear]

My laymen understanding of wheel lift is the result of limited chassis design and too much grip.
RWD will lift front tire when the front of the car has a significant grip advantage over the rear. It has SO MUCH grip at the front, that it can hold the line with only a single tire. If you try to add speed with throttle, you’ll just have the back end step out.
FWD will lift the back tire (something I know a lot about from my VW days) because the back of the car has much more grip than the front, the rear outer tire is getting so much grip that it can support the entire rear’s lateral weight transfer. If you try to add more speed by throttle application, you will simply understeer out.
If you have a balanced car where the weight transfer is distributed evenly and at similar rates.. then you’re maximized.. but at times you can’t achieve that balance due to constructional limitations.
A VW is 70/30 weight distribution stripped down… hard to design around that and keep a flat car.
But I think if as a tuner what to take home from this is that you would do well to find ways to add grip to the area that’s not lifting.

The best case scenario for a non-aero car is to have so much grip it would tilt on its side during a corner… then you know you’ve a monster handling car

Also, since we’re all dealing with production cars, the rollcenter and CG will always be away from each other, so the tendency to pendulum overitself will always be there… I think if you built a car very close roll/gravitycenters then there would be almost no “lifting” and transfers would happen atthe horizontal… but from my other limited understanding that’s still not alwaysbest because you’ve not eliminated bumps or springs or even the tiresthemselves

[Turbowned]

Sorry if this has been asked already (in which case please kindly point me to the right page - tl:dr), but I am doing some research on suspension arms and there are quite a few offerings.

Let's pretend cost is no issue. Let's pretend both products offer the same adjustability. Now I need to decide between a material: aluminum vs. chromoly. Now I know there are numerous different types of alloys between aluminum and steel, and that sometimes in order to make a certain kind of aluminum as "strong" as a certain kind of steel, the weight savings may be negated. I'm also under the impression that chromoly is on the lighter side of the steel spectrum? Looking at the suspension arms on this car, are there benefits (weight savings for example) to be had by going with aluminum suspension arms vs opting for chromoly (added strength for example)?

[solidONE]

Originally Posted by Turbowned

Sorry if this has been asked already (in which case please kindly point me to the right page - tl:dr), but I am doing some research on suspension arms and there are quite a few offerings.

Let's pretend cost is no issue. Let's pretend both products offer the same adjustability. Now I need to decide between a material: aluminum vs. chromoly. Now I know there are numerous different types of alloys between aluminum and steel, and that sometimes in order to make a certain kind of aluminum as "strong" as a certain kind of steel, the weight savings may be negated. I'm also under the impression that chromoly is on the lighter side of the steel spectrum? Looking at the suspension arms on this car, are there benefits (weight savings for example) to be had by going with aluminum suspension arms vs opting for chromoly (added strength for example)?

It depends on the part you are trying to make. Chromoly is stronger than steel but it is definitely any not lighter. Aluminum is lighter than both 4130 and mild steel or even stainless but it's much softer and weaker, therefore will require much more material to have the same kind of strength. You need to u der stand the differences between yield and tensile strengths of the materials and what is required of the part you are making. There are many other considerations as well, such as cost of material and cost of construction/fabrication. Are you going to weld it? Do you have TIG capabilities or only MIG? Will the part be cast or just riveted together?

For control arms I would go with 4130 tubing TIG welded. But if I had all the money in the world, I'd have the part cast out of titanium then forged and shot peened. But that ain't gonna happen. Chromoly tubing welded is the more practical choice for a custom part like this if you have tig welding capabilities. If you only have a MIG machine, 1020 mild steel is a good compromise.

[Dimman]

Originally Posted by Turbowned

Sorry if this has been asked already (in which case please kindly point me to the right page - tl:dr), but I am doing some research on suspension arms and there are quite a few offerings.

Let's pretend cost is no issue. Let's pretend both products offer the same adjustability. Now I need to decide between a material: aluminum vs. chromoly. Now I know there are numerous different types of alloys between aluminum and steel, and that sometimes in order to make a certain kind of aluminum as "strong" as a certain kind of steel, the weight savings may be negated. I'm also under the impression that chromoly is on the lighter side of the steel spectrum? Looking at the suspension arms on this car, are there benefits (weight savings for example) to be had by going with aluminum suspension arms vs opting for chromoly (added strength for example)?

There is also a stiffness difference. And fatigue.

And if you're going to be welding both chrome-moly and aluminium need after welding heat treatment for maximum strength and reliability.

If you or the shop won't/can't use 'normal' mild steel, but DOM (drawn over mandrel) seamless.

[Turbowned]

Originally Posted by Dimman

There is also a stiffness difference. And fatigue.

Right, I was trying to say that in only so many words.

Originally Posted by Dimman

And if you're going to be welding both chrome-moly and aluminium need after welding heat treatment for maximum strength and reliability.

If you or the shop won't/can't use 'normal' mild steel, but DOM (drawn over mandrel) seamless.

These would be purchased "off the shelf", not fabricated from scratch. There are available offerings in both aluminum (again, unsure of the alloy) and chromoly from a number of different brands.

[7thgear]

unless you're at the point where the g-forces you're dealing with generate enough deflection in the arm to mess up your morning coffee, I wouldn't worry about it.

[Calum]

Originally Posted by ayau

Got a link?

http://www.whiteline.com.au/product_..._number=KCA436

[7thgear]

^
it's just an offset bushing

nothing fancy.. until it mis-aligns itself O.o