Optimal Ride Height

[Domesticated]

I've recently done these mods to my car:

Function Form Type 1's
All new ball joints and control arms
Complete poly bushing kit
Adjustable camber

I have 215/40/17 Kumho Ecstas right now, but I'm switching to 215/45/17 Michelin PS3s.

My car drives phenomenally and has ubber awesome steering response especially after the new rack and pinion and power steering pump with 2 degrees of camber in the front. But at high G loads my front tire will rub the frame rail. My car looks sick how it sits, but I prefer dynamics over looks.

Anybody know the optimal ride height to be as low as possible without the tires touching the car at all during limit handling? Plan on taking the car to GingerMan next week to tune my alignment and corner balance the car and I would like to not worry about setting the height.

[stretch JDM]

Check out (Slow)'s set up in his MRT . He does road course racing and seems to have it down to a art. Wish I could help ya more friend . Also look in our AutoX thread for more ideas and set ups.http://www.cb7tuner.com/vbb/showthread.php?t=126498

[Domesticated]

Is there a page here dedicated to technical suspension data? I happened to run across a book that has close to 60 pages of dynamic information our cars and as soon as I get permission to copy it I will upload it.

[mndude07]

The CB7 suspension needs to be modeled. No one has done it. I plan on doing it in the near future.

[Domesticated]

Not a bad idea. I might have to do that. Wouldn't take too long either I think. Maybe a weekend.

[mndude07]

Not a bad idea. I might have to do that. Wouldn't take too long either I think. Maybe a weekend.

I don't mean in solidworks. Buying the kinematics software is the hard part. At that point, taking measurements should only take a few hours.

[Domesticated]

What are you trying to find out from using the software?

[mndude07]

What are you trying to find out from using the software?

With a decent suspension kinematics software, you can choose an optimal ride height, spring rates, and ultimately shock valving based on desired camber curves, toe settings, desired roll center characteristics, etc. I don't have my CB7 anymore, but once I go through the process with my prelude, I was going to find someone with a CB7 to be a guinea pig.

[Domesticated]

Oh, well I can tell you that the software is a novel idea, but in reality there isn't much use in modeling. There are so many things that you can't model as in bushing friction, drive train mounts, chassis stiffness, and even tires. When I do shock tuning my tire pressure can't be more than 2psi off or a back to back comparison is irrelevant.

[HappyGilmore]

With a decent suspension kinematics software, you can choose an optimal ride height, spring rates, and ultimately shock valving based on desired camber curves, toe settings, desired roll center characteristics, etc. I don't have my CB7 anymore, but once I go through the process with my prelude, I was going to find someone with a CB7 to be a guinea pig.

I can leave you one of mine I don't mind driving to STL and I know about your last CB and you had good info to share last time we met. Just let me know I am down to help out!

[johnnyblaze2g]

I am super fruity.

[mndude07]

Oh, well I can tell you that the software is a novel idea, but in reality there isn't much use in modeling. There are so many things that you can't model as in bushing friction, drive train mounts, chassis stiffness, and even tires. When I do shock tuning my tire pressure can't be more than 2psi off or a back to back comparison is irrelevant.

Tire pressure is important to keep as constant as possible. However you can get a very good approximation by making some assumptions such as negating bushing friction(delrin bushings, or sphericals have very low mu), assume perfect rigidity in the chassis and mounts. You can achieve very good balance with a software that helps you analyze the suspension geometry and what happens at various roll angles, and how the suspension acts in ride and single wheel bump.

Of course no model is perfect...but to say that it is pointless just because you can't accurately predict the chassis properties is ridiculous. It will get you most of the way there, and will do so much faster and more closely than tuning the chassis "by feel". For a many production cars, you would have to be running a pretty aggressive ride frequency upwards of 2 Hz before chassis flex is going to have a significant effect. Do you have a better way to figure it out?

[Domesticated]

It works perfect for a car that hasn't been made yet. It helps cost saving in optimizing general geometry. We did the shock tuning for the 13 Viper on an 08 chassis. When we put the same shocks on the new chassis which is geometrically the same but has more support and is more rigid, the car handled dangerously. We had to do a shock re tune when switching from PS2s to Corsas and having a trans mount not torqued properly also threw the car all over the place. The guys in lab do good work and it's those simulations that design the major geometry, but when the car hits the track we have to spend months re tuning at least once or twice a week. Dynamically a chassis is very sensitive. It sucks for us that re tune a pre built car and our only option is off the shelf parts, or expensive track time and expensive tuning and re tuning because you never get it right the first time.

[speedfr3ak]

if its a dd just slam that cb to tha ground dog now being realistic u set ur suspension for what ur cb is used for if its a dd, track car or a weekend warrior yaaaaa got me? Mines a weekend warrior/dd im running exedy c.overs koni yellows so i can adjust alll type of ways utilize other members setups and find one that best suits u

[Domesticated]

Thanks, that was very useful technical data I was looking for...