Since when swapping to a 4th gen rear in thirdgens causes the wheels to stick out further, could handling be improved? I'm I missing something or would increasing the wheelbase in these cars improve handling?

hmmmmmmmmm.

No.

Handling boils down to one basic rule- Unsprung weight. You want as low of unsprung weight as possible in relation to sprung weight. the axle, wheels, brakes, and for the most part about 1/2 the weight of the movement suspension parts are all unsprung weight. The heavier this gets, the more it will unsettle the chassis of the car over bumps and will create a poorer ride quality also. Unsettling makes a car loose traction.


What does a wider 4th gen axle do? It is wider by about 4" (2" more on each end) Thats 2" more of polar weight when a solid axle moves upward and downward. Its like holing your arms outward and then moving your right arm down then up while your left goes up first then down. The longer your arms, the more momentum force is applied towards trying to stop that upward movement and reverse it downward(and vica versa).

What gains that are earned in track width will severely hamper you in transition agility. You may be more stable in a high speed sweeper (aka circle track car), but once you try and quickly turn left to right then right to left you are less agile and will have to trasition at a slower speed then a narrower car. You slip angle increases because of your track width in a slalom.

I can keep going, but I think you get enough info to already base a decission.

I completely disagree with that statement. If you wanted to define "handling" in a nutshell, I would say it has more to do with the amount of weight you have per square inch of tire on the road. So anything you do to get more rubber on the road is going to help I.E. Keep your existing tires flat to the road while cornering, or putting bigger tires on. Also having a wider track will increase maximum grip by helping to keep weight evenly distributed on both tires. Of course any weight you get off the car is less weight you need to make go around a corner.

You are correct that unsprung weight does help keep your tires on the ground when encountering bumps on course. You are also correct in that a wider track width will hurt you in a slalom. At the same time you don't see guys moving their wheels inboard to "increase" handling.

SuperGman, The added track width of the 4th gen rear isn't going to increase your handling an appreciable amount, and could possibly hurt your auto-x performance if it's a tight course. On top of that your car would look like *** with the tires sticking out 2" on both sides, and you would quickly mess up your fenders and cut down your tires. Spend your money on better tires and track time to tighten up the loose nut behind the wheel.

ok, So lets say we go with your answer the "in a nutshell, it has to do with the amount of weight per sq inch of tire on the road" Can you first of all give me a formula to back that equaltion? So we all know from your answer how much that amount is? You answer is lacking the helpful info you say exists in a nutshell.

Next question to your quote "per sq inch of tire on the road"- How do you think the tire stays on the road? Are roads perfectly flat at all times? Ans- not even at most times. So you still COMPLETELY disagree with my statement of unsprung weight?

Lets keep this to a friendly debate, OK?

Dean, I am keeping this friendly hence the "I don't agree" comment instead of a "you're an asshat" comment.

I agreed that keeping unsprung weight down helps to keep the tires on the road, hence increasing traction. I just completely disagree with saying that unsprung weight is the holy grail of making a car handle better.

No I don't have a clear cut formula that accounts for every single factor that influences vehicle dynamics. I just think it's better to visualize that the more rubber you keep on the ground, longer the better your car will handle. Track-width comes into play because it effects how weight is distributed lateraly. Keep all your tires loaded evenly and you'll increase your total traction. You agree? Like you said and I agreed that the added track width can hurt you in some situations like slalom's and tight auto-x courses because it forces you to drive an extra 4" each way to get around a cone, but not everyone is an auto-x nut like yourself.

So yes Dean, unsprung mass does effect traction, I just completely don't see how that related to the poster's question as why a wider track width would increase handling.

Thank you for understanding that my questioning is not an attack, its to promote thought. Most take my response as an assult, they are not intended that way.

Now- No I do not agree with the quote above. I fully understand what you are getting at and do agree with you intentions, but it doesn't quite work that beneficially.

Why?
That added track width puts further leverage upon the shock geometry and movement agility. It adds weight more outward from each shock mount- Moving the tires outward that little bit still does "fairly dramatically**" decrease the chassis control of the shocks when the axle leverage acts upon them. Now if the track werre perfectly smooth and the suspension did not have to differentiate on bumps between left side and right side variances then YES the track width will help keep both side ditributed evenly (hence why I first stated "circle track car"). Fact is, we are very rarely in a smooth steady state non transitioning corner such as an oval where you really never straight out. We also encounter very much worse bumps and dips on road courses, autox and especially daily street driving far more than a circle track car.

**Factory centerline of the tire to shock mount is 10". This would increase leverage to 12" or a 20% increase- that is substantial. Its not like the leverage goes from 22" to 24", 10 to 12 is fairly dramatic.


I do believe it is the "Holy Grail" . Ideally, I will predict suspension on cars 20-30 years from now are going to have a computer controled axis that will rotate camber & caster pitch and a gyro type single sided swingarm telescopic assembly of such that will resemble somewhat the front landing gear arm of a jetfighter tucked up inside each wheelwell. They will be the only unsprung parts and will vertically set the attitude of each whell pitch, chassis bank or pitch, and ride height.
I have the concept in my mind, but I do not have the mental capacity to design for what computer controls it would require

Side Note, I read an article somewhere where Mercedez Benz designed a car that does similar to what you're thinking, it can adjust all aspects of alignment on the fly depending on the turn and speed, etc, etc. Future cars are gonna be crazy man!

But anyway, back to the thread, I agree its not a mod that would greatly increase handling. These two guys both agree its not good, just for different reasons. My reason would be that you're adjusting the track width on the rear only which would throw off the balance of the car, track width does affect the understeer/oversteer characteristics of the car.

I guess we'll agree to agree on different levels....did that make sense?

My list of things to do to a car to make it "handle" is as follows:

More rubber
Less weight
Better control of weight transfer (springs and sway bars)
Camber control AKA: keeping your rubber square to the ground
Unsprung weight / shocks: To keep your rubber on the ground longer

I just don't believe that unsprung weight will help make a car handle better than any of the other 4 things I listed. I guess what got me with your post Dean is that the guy asked wheather or not a wider rear end would help handling, and you gave him a lecture on unsprung weight, when he needed a lecture on how the wider rear end would effect his motion ratios of his shocks and how the extra width would effect how weight transfered from side to side.

I just installed Bilsteins all around, an Eibach Pro Kit, and new tie rod ends, ball joints, and poly end links. My car with the 4th gen rear handles great...

It handled $1200 right out of my wallet with no traction loss at all!

Thats more like it for me lol