tube80z

Maybe winGEO changed how they handle the roll axis but that was one of the many things that got optimumK started. I remember Claude Rouelle talking about how winGEO calculates roll and how it was incorrect so they decided to build their own software. Both would be hard to justify for casual use when susprog3D gets you very close results for about $120. I just hope Rowley does the extra volumes he talks about in his first book. I really like the real world examples in his work compared to the more academic approach in RCVD. Neither are an easy read in my opinion.

It's a BS term that I made up. But what I mean is where the suspension loads are put into the chassis. That distance from front to rear is part of the torsion spring we call the chassis. The closer together these get the shorter the spring and potentially the higher the rate. Longer cars (wheelbase) are often less stiff than a shorter model. Hope that helps, Cary

I think you can argue unsprung weight is reduced from the classical definition. But if you look at the suspensions interia it is often greater and you really need to look at the dynamic rather than static case. You also have to look at suspension friction being increased too and ff the rocker and push/pull rod are all not in the same plane you'll introduce some bending that can cause additional friction effects. On a closed car (GT) the aero advantages are often not really there. But you do get increased motion ratios and the ability to change them and if done right you can reduce spring-to-spring chassis length (meaning the car will be torsionally stiffer). And you cannot discount the bling factor. Think of the chicks you could pick up showing them your cool rocker arm suspension Cary

I've used peelz away floor stripper. It's organic and doesn't have much of an odor and it works just as well. You put it on and let it sit for about a day and then peel off the undercoating. It's a good option if you need to keep the fumes down. Cary

A friends NA KA powered car is 1850. So no reason you can't hit your goals.

13 inch wheel and tires are anywhere from 20 to 40 pounds lighter than the 15 inch equivalent. The yokos are the heaviest, then GY, then Hoosier. That was the main motivation for going small on the new car.

The V8 car ran the 15 inch radials (GY, hoosier, and yoko) 10 inch front and 14 inch rear wheels on all. The 4-cylinder car is running my wheels and tires, 10 inch front and 12 inch rear on the bias ply hoosier. We may try radials later in the season.

My rear tires are 23.0 x 12.0-13 C3000, which are recommend on 12 to 15 inch rims. These are bias ply tires. Cary

The GYs will work fine on a 12 inch rim, just a little slower. Hoosier lists recommend rims on their site but the 12 works for me. Cary

Are you pluging the exciter directly to the battery? It's only deisgned to see 5 volts and you must run a resister on the line for the alternator to live. Cary

That sounds more like a cantilever, not an FA tire. My experience with them was they require a different setup from the FA tires. And for the edges wearing in the radials you need to control roll better or you will see that. That's one of the main reasons a bunch of us now run droop limited. Cary

So how do you rate the performance versus the cost, that was the winner for me. For autox we usually set these around 22 PSI, higher for track work. From back to back driving of a car with kumho radials to the atlantics I needed to change my driving style. What I found worked much better was to increase my steering input velocity, meaning I aggressively turned the wheel. If you used to watch Fernando Alonso a few years back on Michelens you'll get the idea. The other area where I found a large difference was braking, and you had to be a lot more careful you didn't lock a tire because the rotating weight is a lot less (I was using 13s). At the temps you running we typically spray them down with water between runs. The 35s may be a better choice with the heat you have. Now we just need to convince you to put on the rears Cary

I did this to a race car we used years ago. It's a good option but you need to know two things. If you ever plan to weld on the car in the foamed areas you pretty much can't. And you better make damned sure you don't have any hidden rust, as repairs are very hard once foamed. In the end rust was in my car and this more or less sealed its fate. But before that became and issue the foam did make a noticeable difference. Cary

Hi Ron, A swaybar will definitely add a radial load to the bearing. But it's common to see lots of cars running bearings with shock/rocker loads going into them with no problems. The only ones I know about that change the orientaton of the bearing are cars that make tons of downforce (as in 3000 lbs+) and then you limit the max amount of steering lock you can run. I've been looking closely at either using a captured spherical or the low friction CT balljoints. Given the cost of the latter I'm leaning that way with simple Afco control arms. It almost doesn't pay to make this stuff anymore as cheap as you can buy it from them. Cary

Here's something similar using a strut turned into a double a-arm. I'd personally use a captured spherical bearing for this application but a good quality 3/4 rod end should suffice (that's what was used in the attached pics).

Not to pick on you but the RC position does matter in these cars. I'm sure it's related to other factors but this was an area of experimentation last last year with a friends LS-2 powered car running FA rear tires setup for autox/hillclimbs. If we raised the RC to get the car to turn in better it lost bit coming out of corners and was much quicker to overheat the rear tires and cause the handling balance to shift towards oversteer. If we lowered the rear RC the car put down power much better and didn't overheat the rear tires but wouldn't turn in that well. We played with spring changes and moving the front RC to try and solve this but there appeared to be a sweet spot for this car with the rear RC. We ran out of time before trying to add a rear ARB to see if that would help to get the car to turn better. Unfortunately we didn't have a complete model of this car to understand what else we were changing. Cary

Look again, looks to be about the same as stock to me.

Like the attached?

That's very similar to an idea a few of us have been talking about. The difference being the clevice was a single piece mounted under the strut and could be spaced down with spacers to control the rear RC. Now, who'll be the first to build one? CAry

Thanks, I may have misread you're previous post but what I got from your analysis was that all the force in accelerating or braking was going through the front heim. That's what I was having trouble understanding. With the top of the strut being fixed it's also going to pick up a good deal of the load. In playing with stock arms bolted to my bench I was amazed at how little resistance they offered when twisted. With the wheel being offset from the strut axis there's also a force trying to turn the wheel into the car (when accelerating) and this puts the toe-link into tension. And vice versa for braking. I've had a number of cars with rod ends in bending. I'm not saying it's ideal but I know when the end is starting to get overloaded the jam nut has a habit of loosening up. And the next phase is usually some small bending you can feel. So far these parts have been beat on very hard and this hasn't been an issue. Not exactly an engineering analysis but I'm comfortable enough with them. If they can survive wheel hop that broke my back (and why I'm not racing this year) I think they should be okay. That said they are inspected before each race. Cary

I'm curious how you came up with this. I don't understand how there's a single rod end in bending outside of attached ARB loads. Cary

Here's another option This is John Thomas' rear suspension. It bolts into place of the stock crossmember.

More grip. That's what I'm told. It depends on the surface you run on. Lost of bumps digressive will probably be better but a smoother surface should favor linear valving. Cary

It was farther up in the post, http://www.jakelatham.com/radical/info/brake_calculators.shtml I used this one to sort the brakes on my old car and when loaded with good data helped me sort some balance bar issues I was having.

And if you have all that you can use the link above to do the work yourself. And better yet you can see what different sizes will do.