tube80z

You all should really listen to Jon. There are two types of padding I see on cages all the time. The first, often called pool noodles, really should stay near the water. The second is SFI approved and is a more rigid foam. It, HOWEVER, is intended to be hit by your helmet, not your skull. I know of no foam that is designed to deal with your head hitting a bar. Cary

I need to read the rules again. I didn't realize you could get away with such a big doubler plate. I wonder if you can flange holes in it to help make it stiffer? Cary

Reading this I see that I told you a lie. I don't do area. I've been doing 4 times the size. So for a 1.5 inch tube I've been doing a 6x6 pad. You wouldn't know I had a math degree I'll plug weld those too to make the stick better.

yep, that makes sense. I would close the gap across the lateral tubes to the floor rather than just use a couple of stands. That makes the floor a shear panel as Jjohn mentions. It would seem like it would be harder to rip out too. Figure in a wreck (worst case) that you might see some rather large forces on those mounts. And having more area will lower the load, or some my feeble thinking goes. Cary

I'm not completey sure I follow. Are you putting this tube across the car or lengthwise? If across I would use sheet metal to hook to the floor just like the stock piece, similar to what John mentions above. But I'm may not be following what you're doing here. For the tubes I try and do 4 times the area of the tube. Not sure why but somewhere along the line I picked that up. At least one of us is out in the shop working Cary "stuck at work"

What about FIA seats that don't require a backbrace?

John is right. The end links stack up and your spring analogy goes out the window, just like tender springs. This only changes the rate of change, not the rate. Cary

If you plot bumpsteer every 0.1 inches you'll get a curve. It depends on the curve whether you change the inner pivot point or the outer pivot point when trying to minimize bumpsteer. Cary

Oddly enough I've gotten it to work well. If I were to continue to run this car I would widen the front to be wider than the rear, if for no other reason having a fat but makes getting around cones a lot harder. The EMOD car is wider in front if that is any consolation. It's not normal but I thought I'd throw it out there. Cary

Hmm, I guess I won't tell you that my car looks like a 911 I would widen the front track but I've found that wider rears work for me. Cary

.5 to .7 times the corner weight figuring in motion ratio. I don't know about street ride but that would give you a starting baseline that should be decent for radials for a track car. I'd then do 20 percent variation from that to see which way to go for sure. Cary

Helped a friend with this just this past weekend. And I managed to dig out some 240 stuff I had to take a look at tonight. They won't work. At least what I have would require a different backing plate. And to change that won't be so easy. Cary

The car is an L-series with the motor set back per GT rules (#1 cylinder is inline with the front axle line). The PO did this and it was a botch job par none. I've cleaned up numerous bits but this is a parts car that turned into something more. The steering is stock but the rack has been moved back as far as I can. If I were to keep it I would be changing the front lower control arms to be much longer and adding more ackerman to the mix. The tube frame car is built around a Ford 5.0 but if I were to do it today I would use a LS-1 Chevy. A friend of mine put one in a Z and it is sweet (the red one at Shasta) Cary

Okay, so a few others have questioned this. I'm here to say BS. You aren't going to go a lot faster with some magic suspension under your Z compared to what you have. Will it be better, maybe, but it's a package deal. You need everything to work together. I have a 71 240Z that's not in very good shape I autox. The car was totalled 2 or 3 times before I got it. I use this a testbed for ideas to put onto my EMOD car. The car runs in SCCA prepared classes and so far this year has been TTOD at all but one event ( I got beat by a cart so technically I was still the fastest car) and won PAX at all but two. This 30 year old technology worked significantly better than man tunered STIs, EVOS, etc. It beat Vipers, ZO6s, ... This isn't meant to sound like bragging. But an old car with less than 10K in it is creaming cars that have as much as $50K in mods. How is this possible? It happens because I spent a lot of time fine tuning what is there to get the most out of it. You need to understand the limitations of the Z's suspension and work around them. The Z has a large advantage in weight and size over a lot newer cars. Don't screw that up. Cary

As you mentioned the stock rubber rotates the bushing in torsion and is a relatively low friction bushing. Poly bushing rotate on the metal tube that is rigidly clamped in place. Cary

What you're looking for are adapters. Earls and most others make them that thread into the caliper and allow you to hook a AN line to it. Or you can go the custom route and have hoses with the ends already installed. The adapters are expensive and most of the cost of this conversion. I've never damaged one of the hardlines on the caliper by taking them off. So I'm not sure why that is an issue. And how often do you do that on a street care anyway. On my race car, where these things are often taken apart, I use an adapter and a AN line. Cary

http://www.itwfoamseal.com/automotive.htm

And maybe not even then. This is really a mod I think aimed at someone who wants to increase stiffness, doesn't want a cage, and doesn't care if it make the car unrepairable. It's not going to make the car as stiff as a cage by any means either. We did it to make the car stiffer and hide this from our competition. When we found rust we were screwed. Or at least I couldn't figure out how to cut out and weld in new pieces. So if you decide to do this I'd research that very carefully and figure out of you think it is something you really want to do. I did the rockers, windshield frame, and the upper and lower front frame rails. And one more word of advice. Don't get it on you Cary

Most of this is polyurethane structural foam. It comes in various densities and does really work. We had an old race car that was done this way. But and a big but, is that if you have any trapped rust you will cause yourself a world of problems. And you can more or less forget about trying to fix anything that you've foamed. It isn't to weld around and is highly toxic when it burns. Cary

I don't have much to add to this thread but I thought of a few things I'd pass along. If you get race pads for track days beware of the dust if you have nice wheels. I use a very aggressive PF pad on my race car. The performance is great but the dust must be removed quickly or it is a real pain in the *** to get off. Almost all the new high tech pads require a transer layer to be built up on the rotor. And this layer is seldomly compatible with other manufactures pad materials. I can tell you for a fact the wilwood polymatrix and PF are not friends. I would suspect that to be the case with some of the others. I just helped a friend put some of the new ceramic based bobcat pads on his car. So far they appear to work work well and have little dust. This isn't a track day car but it looks like they make special versions. Heed the advice not to mix and match these. A lot of people swear by the porterfields. I guess I'm one of the few along with Jon that swear at them. I had a similar experience trying to use the R4S on the front of a Z and I'm just a lowly autoxer. Cary

Another option is the ground control AD (advanced design) dampers that I use. Probably not as good as Penske or Ohlins but my chassis isn't sophisticated enough to make use of them. I belive they are $399 per corner and have the two adjusters on top. I wasn't that big a fan at first but I had them revalved and really love them now. I run springs rates in the 400 to 600 range on car running on slicks. Unless you have done a lot of work to arrive at a balanced setup these dampers won't do you a lot of good. They don't magically make you faster. They are a fine tuning, icing on the cake, kind of deal. I found that when I got everything spot on that I could notice a small change in tire pressure (half pound). And once to this level the dampers can make noticeable changes in how the car works. I'm an autocrosser and part of the battle that I have is limited time to change the setup of the car between runs. Having adjustable shocks can be an advantage. Up to this point I've been using a fairly standard sway bar like John mentions. Ideally I'd love to make it driver adjustable for when I need to make a large change between runs. Half the battle in having adjustments is knowing what to adjust and the other half is being able to adjust it with minimal work in a timeframe that actually helps you. Cary

My engine and tranny are solidly mounted and I spend a lot of time retorquing bolts and using a lot of the green loctite. Safetywire would be a good idea too. Part of the prep for every event is my nut check. Every engine, suspension, brake, and steering bolt must be inspected and torqued to the correct value. But doing this has probably saved me from having some major issues. From time to time I have found parts that were about to fail. I don't think it can be stressed enough that is you race these cars hard you need to spend time on proper prep. A friend had all the bolts loose on the crossmember of his 510. We didn't notice it until we jacked the car up. Odlly enough it seemed to make little difference when we tightened them all back up. Still I wouldn't recommend trying this at home