tube80z

It's early and I haven't had any coffee just yet. But isn't the torque created by the traction proportional to the lever arm from the outside to the inside at the front and rear pivot? I don't see where we changed that distance. If you were talking about lateral force I could see where that went up due to a change in leg angle but it wouldn't be a factor of two. And what we're talking about here is just shortenning this by only a couple of inches at most. Cary

I'm looking very forward to being able to write about the first drive in anger. Hopefully nothing breaks ... but it will be shared good or bad. Cary

Cool pic Steve. Heims will have lower friction when mounted this way versus trying to rotate the ball in the race. Just need to make sure that the range is appropriate, which it should be but one more thing to check. Terry, I'm not quite following your question. Do you mean the stress goes up because we've reduce the lower suspenion arm mounting distance (closer together)? Or is it something else. This would look real trick integrated into that AZ billet stuff in another post. Cary

In stock form I agree. But if you create a subframe as in Steve's pics of JT's setup then you can make a bracket that bolts up that can be shifted up or down. And if you make the bracket wide enough you can use spacers to adjust within that range and if you need more you use the alternative holes for the bracket. I guess at some point you may need to be able to move both. That would be a seriously low car. This is fairly typical on a lot of formular cars these days. Especially ones that are designed to use a couple different diameter of tires. I'm always happy to steal ideas from where ever I can Cary

Why wouldn't you make the inside adjustable? Then you could raise/lower the RC and play with antisquat/lift. Using something like Steve has in the pic above this looks like it would be a little easier to pull off. For the amount of work in that spacer it would almost be easier to cut off the bottom on and weld on an entirely new piece. I'm making this double shear on my car by welding a tab from the strut tube down to where the spindle pin goes through and using a bolt instead of the pin. The front of the strut will be done in a similar fashion. Cary

I don't there's any real reason to take pics. You could do a simple measurement of how much shock shaft you have and compare that to when a 8 inch coil stacks or you can put on some zip ties and go for a drive. The symptons you describe are the classic "flat ride" problem. That is where you pick spring frequency to give a flat ride as you hit bumps at a set speed. Given the car is riding rough -- often a pitching issue and you sitffen the rear to compensate. That leads me to speculate something has suddenly gotten very stiff in the front. It's time to put down the keyboard and do some real work Cary

A few ideas. Put zip ties on the shock shafts and a few of the coils and go for a drive. If you come back any of the zip ties are missing from the coils then you are probably binding the coils. Look for the zip tie on the shock shaft and if it is missing or burried in the bump rubber then you are probably bottoming. You might also check to make sure you have adequate shock travel and aren't bottoming the insert. That will probably require taking things apart and doing some measurement without the spring in place. Cary

I use a holesaw or step drill to make the base hole. Then I use these to flange the edge. I'm not sure that helps. The flangers inside ID is the hole size. So if your punches make that size hole then it sounds like you only need what's on top. Cary

Not that I want to get into a pissing match about this but the article doesn't have any real info other than they fixed bumpsteer. If you go to the site mentioned you won't find any tech info about the suspension. This does look to be nicer than the piece I looked at closely. I don't put much faith into anything written in magazines anymore as most articles aren't much more than an advetorial. I know I sound negative on this but what I'm trying to stress is that there's more to picking a suspension than just bolting on a few parts -- no matter how they are made. Could you fab one of these up to a Z and make it work. I'm pretty sure the answer to that would be a definite yes. But would it make the car any faster than an optimized strut setup -- that I'm not so sure of. Cary

I got a set from http://www.mittlerbros.com/Punches.htm. Now everything looks like it needs a flanged hole. Cary

Every time you post pics of this car I start drooling. Beautiful work. Cary

Are those a carbon based pad or a ceramic compound? I'm looking for something that works well but doesn't have as much dust as the PFC pads I've been running. Cary

It will effect steering, dive, RC, etc. How much I'm not really sure. I'm going to run a number of these scenarios on a generic Z car front end model to so we can have some actual numbers. Then we can put this to rest. If you have things you want to see now would be a good time to make suggestions. Cary

I've been resisiting the urge to write that it's a great conversion if you'd like your car to handle like a Pinto Cary

Carbs work by creating a pressure drop from airflow, not by manifold vacuum. Put a vacuum guage on a set of tripples and you will see zilch when you open them up. That's what the accel shot is for, to cover that condition until enough airflow makes up for the suddenly lean condition. Webers have so many combos because they were OEM carbs for a number of autos and needed to pass emissions. You won't find the depth of parts for Mikunis. The setup mentioned above sounds like it was originally setup for a pretty hot street motor or autoxer. We used tripples on the street with a 240 and it ran very well. The chokes were 32s and we had a little more cam. This was on a 2.4. When the car was no longer driven to events we went with 38s and a larger cam. It would only pull from hard from the 3500/4000 range to around 8K. It would do the same thing you mention when flooring it in lower gears. Besides checking the air/fuel ratio I'd suggest getting a decent Weber book. I have a factory manual that seems to be out of print but it has the basics to get these setup and working. I seem to recall seeing some good posts on this list if you use search that had much of the same info. Contrary to many opinions once you have these working well the seem to stay that way. Most of the issues I've seen come from carbs that are in poor shape and/or really crappy linkage. Bend a throttle shaft in one of these and it will really make tuning a nightmare. Cary "ah the good ol' days"

The rockers in these cars are weak by modern standards. In my friends 240Z that he put an LS-1 he put square tube in the rocker that the cage ties into. The tube that goes from the front of the rocker to the TC ties into this. The side bars for the car tie into this. I talked him into doing this after see a crash at a hillclimb where the driver was seriously injured because the rocker and floor folded in a crash. The car is very stiff, has an interior, and tipped the scales at 2500 pounds when we weighed it. I'd agree that in a car with a cage sub-frame braces are probably not as good as a few well placed tubes. Cary

I do think a relatively easy upgrade would be to create a new crossmember that allows you to run longer lower control arms. I would think something like a K-member the Ford mustang guys use would fit the bill. This would have the pickups for the TC rods and a new mount for the rack, which would need to be shortenned. Just a thought, Cary

You're right but it's almost impossible to do any real suspension work without them. You can do simple things like log the suspension travel and then look at it as you go through a corner. Then see where the all those points are that you worked so hard to design and understand what to change. Even as a lowly autoxer I don't run the car without collecting some data anymore. I'm hoping to add a number of channels this year and share the data. I'm saving to eventually be able to reach my holy grail, real time tire temps. The pic is Steve Epperly's 200SX GT4/5 car. Steve is a long time NASPORT racer and did run a B210 in the 80s. It was built very similar so that's why the pic may look familiar. Cary

A good rule of thumb is to run about twice the castor angle of the KPI. For roll centers try to keep it below 3 inches. Cary

A momentary traction loss. As in sudden and no warning. Cary

Sounds like you have a good start to me. Try and keep caster trail less than three quarters of an inch and scrub less 1.5 inches. A lot of the other numbers will fall into place. When looking at RC/ICs remember to look at their velocity rather than where they end up. The rate of change is what we call feel and are sensitive to. All manner of variations can be made to work and are dependent on tire/driver/use characteristics. Don't let RCs go through a tire or the ground or a tire under normal operating parameters. Bad things happen then. Cary

It was changed very little with offset at the top and the bottom. This car features custome built steering arms that move the lower mounting point towards the center of the car. The wheels in this case were something bolted on so the car could move. The race wheels are snug up to this upright. If I recall correctly they have about a half inch of scrub and less than ten degrees of KPI, but my memory isn't the best these days. Cary