tube80z

That's pretty much what I did. I used a tilton balance bar assembly and modified a stock pedal box to accept dual masters. Then I used the tilton prop valve to get the initial rear bite just right. The beauty of this setup is that I have enough variation to be able to handle wet or dry. In the new car I can display brake pressure on the dash from the datalogger so setting bias becomes very simple. Cary

Is that one of those double ball-joint versions? I played with that idea for a while but couldn't get everything to live in my tiny 13 inch wheels. Cary

Just curious, why is that? Cary

Thanks for the pics, those helped a ton. My only reservation on all this would be mounting this bolt in single shear and adding spacers to it. I think you could get away with it in single shear (similar to a balljoint on the bimmers) only if the spacer was really short. It would be much better all around to make the mount double shear. I'd also make sure to have as close to the amount of surface area for the bracket as the original. If you decide to go this way I'd use a tube to support the bolt rather than the clevis idea. The top could wrap over the top of the frame rail and the bottom the same. The tube would be welded to a plate that would cover the inside of the rail. Very similar to the clevis but with more surface area. I would stack spacers in this application. I'd make them one piece. I'd also suggest looking for a nord-lock washer system in this application to keep things tight (http://www.nord-lock.com/) In looking at this on my car it appears it could come off. I do think it adds to the strength of the rails but how much off it is used for taking the load the TC box would be a question. If you look at what 74_5.0Z's car you'll see that's pretty much what he did and I really like it. Bummer on the off, BTW. It was such a pretty car. I'd opt for this one myself. Either cut the rail for the square tube to go all the way through and use it as a double shear TC box. Or put a tube in it to hold your bolt. This would be the path I'd follow myself. Cary

So here's what I'm thinking. I spent a little time looking at this over the weekend and I didn't see an easy way given the frame rail is curved. If you look at 74_5.0L_Z's car he has flat frame rails and the TC box could be simpler. Don't laugh at my great power point CAD skills The idea would be to cut out around the round area to open it up for the TC rod to pass through (the red lines). The green lines would be a doubler plate on the frame rail that gussets from the original TC box would go to. Not shown would be the back side of this covered so that it forms a box. Hopefully that makes sense. For the adjustment I'd use two safety washers and aluminum rod as bushing material. This would give you good range of movement and an easy way to have bushings cut that would raise or lower this pivot. Now for the underbody brace I was looking at doing a triangle like this under the engine bay. The tubes from the rockers would be welded into the TC box. From the TC box to the crossmember I'd make these bolt-in using countersunk machine screws. I don't have a pic of this but you essentially slot the tube and weld it to a flat plate. The idea being that it is strong in tension and weak in compression. So if you ever had a major collision the engine could still eject out the bottom. Hopefully that helps. I couldn't figure out how the clevises would work that you described above. Wanna take a shot at a visual of your idea? 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

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