tube80z

I ran a similar amount on my car using bias ply slicks (13" FA fronts). In the motec seminar it was pointed out that caster is very tire dependent. Claude's example of how to think of a tire was as a number of interconnected springs. If you coilbind any of them you slide the tire. Some tires need a lot more caster than others. Claude told us that one car they run uses 29 degrees of caster. The trick in testing this is to also realize that you'd need to change the caster trail as you increase the angle to test just caster. And the trail will change with tire diameter. It's the caster trail that leads to increased steering stiffness as you add more caster. Cary

I ran a similar amount on my car using bias ply slicks (13" FA fronts). In the motec seminar it was pointed out that caster is very tire dependent. Claude's example of how to think of a tire was as a number of interconnected springs. If you coilbind any of them you slide the tire. Some tires need a lot more caster than others. Claude told us that one car they run uses 29 degrees of caster. The trick in testing this is to also realize that you'd need to change the caster trail as you increase the angle to test just caster. And the trail will change with tire diameter. It's the caster trail that leads to increased steering stiffness as you add more caster. Cary

Some of us are also out in the shop putting mandatory vaction time to good use too I need to take some pics of the car and get back to you on this one. May be a day or two as I'm in the middle of a project too. Cary

If you're really serious about porting you might try and find Practical gas flow by John Dalton. I think it may be out of print. It details how to make molds of the head, build a basic flow bench, and various techniques. Get an old head and section to see how far you can cut before striking water. Then prepare to spend a year or so of spare time to develop a port shape that works well. Taking of sharp edges and blending mold moarks is not too hard. But trying to alter the shape of the port to flow more air across the entire lift range is not trivial. And no engine shop will port any head for $200. If they quote that for a price I wouldn't let them work on anything of mine. Cary

Another useful item to add is the little felt lubricator/cleaner before the liner on the inside of the machine. It will help to make things work/last a little longer. I've also found is that some liners are made much better than others. When I adjust tension I set it so that the drive wheels just slip if the wire is pushed directly into the concrete floor. That's saved me from dealing with bird nesting. I don't know how I could function without a welder. Cary

What about MIG brazing http://www.google.com/search?hl=en&q=MIG+brazing&btnG=Google+Search Cary

One area I'm going to work on this year is getting up to pressure much more quickly. That was one area pointed out in the motec seminar where amatuers and pros often diverge. In the first bit of brake application it is almost impossible to raise the pressure fast enough, although you can have too much and lock wheels. The trick is to hit hard and fast in a controlled manner. Cary

An interesting item that I learned recently in a class was that ducting air to the disk is not really a good way to cool brakes (pissing in the wind was the comment I recall). We were shown what is happenning at upper levels of the sport and they duct air in through the bridge in the calipers to the back side of the pistons. We saw some slides of brake heat of the various components as they were used. And the biggest reduction in temperature to the pistons/caliper/fluid was when air cooling as done this way. Air to the rotor did help but not a lot. Mind you, I haven't tried any of this but found it interesting and thought I'd pass it on. Cary

I tried one out a while back and found the wirespeed not very consistent and it made welding rather difficult. If you're looking for a good unit to do bird crap welds this would be a keeper. I'd stick with a known brand myself. I'm not sure what they use for liners, contact tips, etc. Cary

I've been using the centerforce II dual friction setup. I got it cheap and really didn't expect it to last based on how soft the pedal was. I have the engine out of the car and it looks pretty good given the abuse it took this last season. Cary

That's very interesting. I wonder why no one could give me rate versus pressure info then. I wouldn't put these on a car until someone can answer basic spring rate questions. Cary

No, I don't mind. But in all honesty I just hold a degree in advanced bench racing, which means believe half of what I say and even less of what I do. Cary "back to welding to make some heat ..."

I don't really have much to add to this thread. I got to talk with Trevor Harris once and asked this question. His answer at the time was they didn't have adequate tools to figure out the suspension and what to change for racing. We're pretty spoiled with the apps we have now and can run on a PC. Cary

That can be a tough one. I use a lathe to hold the tube and put tap in the tailstock to get the hole centered and square. I do this after welding though as I haven't yet figured out how to deal with warping from welding a threaded insert. In something like a pushrod (think formula car) this is highly loaded and if not square imparts a bending load on the rod end, which leads to failure. You gotta love all those pre-threaded tubes you can get from coleman. I know I've used a bunch on projects over the years. Cary

Greetings, I see some pretty impressive quarter times for some cars. I'm curious if anyone can give me 0 to 60 or 0 to 100 MPH times that correspond to the quarter mile times. I don't drag race and don't have any idea how to compare that to what I know. thanks in advance, Cary

I guess there are a couple of things that could be done. An assesment of the geometry between the two (RC, migrations, track changes, etc.) and perhaps what is the difference in weight. If you had a good guess for the CG you could come up with an idea if this would be better or worse and which way to tune. Total hersay but I'm told that the stock setup has a lot of anti-dive built in. So if you don't address that you may find that you know have more power steer effects than a stock Z suspension. Cary

A friend wanted to try these on his vehicle. A number of companies were called a few basic questions were asked. Like what is the spring rate of these bags. Long conversations about pressure were given to us but at the end of the day nothing about how pressure changes the rate or any ballpark figures. So I'm not really convinced these would be useful unless you're just wanting to set the car on the ground in a parking lot 'cause it looks cool. And as John mentions they seem to be backwards to what you'd need. Cary "self adjusting my ***"

Where I built my car they often build hotrods, etc. and what they use is Ford tie-rod ends on street cars. It just so happens a standard bridge reamer has the same taper as the Ford tie-rod end. I have some pics somewhere of all this. They prefer this mehod over rodends for street cars. The Ford end they use costs about 8 dollars wholesale. Cary

Ever seen a V8 car hold the brakes and apply some torque against the rears? When you can physically see movement it probably wouldn't hurt to make the installed stiffness of the pieces higher. For a race car using reduced travel I'd mounted the rod ends so that you don't try and move the joint around the ball (bolt is up/down). If you put these in a vice and move them you'll see it takes less force to move them in this direction. And if you're tricky with how you do the mounting on the inside you have the ability to change the rear RC. And if you go down this road I'd look at installing any sway bar directly to the strut so you don't put bending loads on the arms. Cary

I hear ya. We have a local venue that would be a lot of fun but the owners of the lot claim we'destroy it. So instead they have numerous RV sales where they put down the levelers and leave marks, etc. Locally we had an event at our fairgrounds that featured a slalom between concrete light poles, which didn't count for a penalty I did get to race a long time ago on an event hosted at a drag strip. It was actually a lot better than it sounded and we go 60 foot times. The ol' timers in the club tell me that we used to have a number of street autoxes around here. Entire downtown sections were closed off so a few nuts could have fun. What was this thread about again .... Cary

We rarely use cones at our events. But speeds can be high at times and I have hit a small tree, torn off two corners of the car on a concrete drain tile, started a small grass fire, and a few other things you don't normally see at autoxs. I guess I'm just a moving disaster, Cary

Must be nice to be a perfect *** model I slid around a bunch in my Kirkey so I made a few poured inserts to tighten up the fit. This is something fairly new to me too. Bead seats are made out of beaded foam just like a helmet liner. And they are much safer in impacts than the poured foam, which is the part I was interested in. There are some kits where you sit in a bean bag and hook it to a shop vac to get the shape you need and figure out how many beads are needed. Then you mix with resin and do it again. As I get old I seem to worry more about personal safety. And since the tube frame car is getting closer I'm trying to work on some of this. I spent a bunch of time talking to Pratt&Miller about the foam blocks on the side of the vettes they run in ALMS. You may laugh but I'll be running a HANS next year, mostly to get used to it for hillclimbing. Figure it can't hurt at an autox. Cary

Have you considered adding a bead liner or poured foam insert? I was going to use one of these for my tube car but I'm now leaning more towards a bead seat that fits into a basic alloy pan to get me lower in the car. cary

Has anyone hear used the flexible TIG torch? It looked interested and I was hoping for a review. Cary