Good Morning,

Let me start by saying that I am using this information for drag racing and as such my questions may seem a little strange.

The reason I am asking this here is because in my experience if you want to get the best answers on something suspension related you go to the people who use their suspension actively (i/e road racers)

Now for the questions:

I have been reading as mush as I can find on this topic of corner balancing and I think I have a basic understanding of things but I need clarification on a few things. First of all I can see how on a car that is evenly weighted (lets say 600 lbs each front wheel and 450 lbs each rear wheel) that when you add spring preload to lest say the RF wheel it will increase the weight on that wheel as well as raise that wheel in terms of ride height. My question comes in where there is an excessive weight imbalance. Our drag car for example is about 300 lbs on the rear wheels and 650 to 680 on the fromt wheels. Before I get to my question i want to give as much information as possible about the cars suspension.

Front has skunk 2 pro series Coil Over shock with 600LB springs
Rear has skunk 2 pro series Coil Over shock with 1000LB springs
Both springs are 8" in length
There is very little preload on the rear (just enough so that topped out the spring doesnt move around)
The front has the preload cranked on both sides just to keep the clearance needed for the slicks.
The front sits about 1.5 inches lower than the rear.

Now my question is this. With so much weight on the front of the vehicle I am curious as to how I can even out the weight on the front so that the LF and RF wheel have an even amount of weight on them. By what I have read it would seems that I would want to add preload to the RF wheel to compensate for the fact that the driver and engine sit on the left side. As I understand it that would increase the weight on the RF wheel making it more even to the LF wheel. What I am having a hard time wrapping around my head is that I feel like that would lean the weight more towards the LF wheel and make it even heavier. I dont have scales to just roll the car on and play around to find my answer and the only reason I even have a broad Idea of the weights of the car is because we did put it on scales 2 years ago and I vaguely remember the numbers. I just want to get the car as even as I can up front so that it will hopefully track a little straighter.

Any and all help is appreciated. Thanks.

 

The only real part of this equation you are not understanding is that the weight is transferred across the car not from side to side. For example when you say you are worried about adding weight to the LF by raising the RF, this will only happen in small amounts as most of that weight is going to end up on the RR.

Drag race corner weighting is very simple, set the ride to height to maximized front weight. Then adjust the side (usually RF on the honda) unstill you get as close as you can to equal. I will admit it can sometimes be next to impossible to get a 50/50 split if you are too far off to start with. Just get as close as you can, and then work on moving weight around on the car to find that balance.

I usually only touch to lowest corner to distribute weight accordingly, and if you have to raise that corner too much to get where you want just lower to whole front some and start again.

Zack

 

Ok after reading what you wrote several times I believe what you are saying is that no matte what the inclination of the car (i/e my car where the back sits 1.5 inches taller) the weight is transferred diagonally across the car. I suppose my next question is this. I have a hard time understanding how if the front springs are the same rate on both sides and the left side sags more to me that would mean that there is more weight on that wheel, or maybe that is what your saying? You say you start with the lowest corner Im assuming that would be the lightest corner as well. If that were the case you would then add preload to lift that corner and add weight is that correct or do I have this backwards.

Sorry if Im not getting it it just seems counter intuitive to me at the moment but I get the cross weight thing kinda like lifting a table leg on a 4 legged table the leg diagonally will support the weight and the other two lift up.

 

You are getting close haha. The ride height won't move the weight much front to back. And yes I usually start at the corner with the lowest weight and you add preload to increase that wheel weight. Basically pushing it into the ground and making it support more of the cars weight. Likewise removing preload from the heaviest one will decrease its weight. Make sure only to do one corner and adjustment at a time untill you get a good feel for it. I have found that no more than about 2 turns of a collar at a time is best.

Even tho the weight does move primarily across the car changing one wheel is still going to affect the weight of ALL FOUR wheels, all be it a small amount on the opposing 2.

Note that rake is still important on a drag car as it slows weight transfer and is better for aero!

Hope that helps,
Zack

 

Ok heres a new question for you, If I were to have a car that was on stock suspension front and rear (lest say a 95 civic coupe) and with a B series engine in place the LF ride height (as measured from ground to fender through centerline of wheel) is lower than the RF and for arguments sake I now had coilovers on the car with the same ride heights as what I started with using stock suspension (LF still lower than RF) Then is it plausible to say that if I were to crank up the RF coil spring it would also raise the ride height of the LF wheel. because it would be removing weight from that wheel in theory. Or would it be more effective to raise the LR coil spring so that it doesn't transfer weight to the rear in my case. Or would it have the same effect either way.

As for the Rake thing Im not sure what you are referring to, as you may have gathered from my sig line I race motorcycles (road race) and to me rake is the angle that is crated when comparing the angle of the fork tubes to a perpendicular line to the ground. In this case am I correct in assuming that you are referring to the pitch of the car being raised in the rear vs even height.

Again, thank you, thank you, thank you. You have been extremely helpful. If you ever need any advise with setting up a track bike let me know I have a level of expertise in that area and would be glad to assist.

 

Well in this case the wheel weight on the left front must be much higher than the other or the ride height to be lower. The one missing part of the question is whether or not the car is at the height you want it to be. And also how many pounds it is actually off on the wheel weights. There is a limit to what you can fix by adding preload, and if the car is very unbalanced it is possible not to be able to reach the ideal 50% cross-weights.

How the weight is distributed is hard to predict, but I would say that raising the opposite side in this case probably wouldn't solve the problem. I would instead lower both sides untill you can crank up the preload on the light side to achieve the balance you are looking for. Hopefully that makes sense.

Also you can add quite a large amount of preload without increasing ride height, part of this is simply due to the fact that if your adding preload the pressure on that wheel is already lower therefore you can add more rate before lifting the car.

Zack