johnc

That's one way or check with Tokico and see what they say. 6" of shock travel is good for a 240Z. Exactly! A well setup racecar is easier to drive at 10/10ths lap after lap. A poorly setup racecar in the hands of a great driver may be able to lay down a lap or two equal to the well setup racecar (I've seen some amazing qualifying runs in what I thought was complete junk) but over the duration of a race the poorly setup racecar will lose time and positions.

That's one way or check with Tokico and see what they say. 6" of shock travel is good for a 240Z. Exactly! A well setup racecar is easier to drive at 10/10ths lap after lap. A poorly setup racecar in the hands of a great driver may be able to lay down a lap or two equal to the well setup racecar (I've seen some amazing qualifying runs in what I thought was complete junk) but over the duration of a race the poorly setup racecar will lose time and positions.

I printed out the HTS and the Koni 8611 dyno graphs and had to do a bunch of coversions from Newtons to Pounds (I'm assuming the HTS dyno graph vertical axis is Pounds). Ignoring anthying beyond .3mps, which is a meaningless velocity (unless you're off road and just hit a 3' berm), I think the Tokico HTS compares very well with the Koni 8611 1259RACE. The scale on the Tokico dyno graph threw me because its so steep and logarithmic. The range of adjustment is greater on the Koni so its can be used on more applications but the HTS should work fine on a 240Z. I think the spring rates should be in the 250 to 400 lb. in. range. Now, back to previous concern, what is the total stroke length of the Tokico HTS? It can't be 2" as posted above. EDIT: Oh crap, I missed that the HTS is a single adjustable shock. I don't like it as much because the compressing damping gets too high for a light car like the 240Z when the rebound is getting good. Its the same problem with the Tokico Illumina. What's nice about the Koni 8610-1437RACE is that the compression damping stays the same while rebound is adjustable. With the 8611-1259RACE you can idependently adjust compresion and rebound.

I printed out the HTS and the Koni 8611 dyno graphs and had to do a bunch of coversions from Newtons to Pounds (I'm assuming the HTS dyno graph vertical axis is Pounds). Ignoring anthying beyond .3mps, which is a meaningless velocity (unless you're off road and just hit a 3' berm), I think the Tokico HTS compares very well with the Koni 8611 1259RACE. The scale on the Tokico dyno graph threw me because its so steep and logarithmic. The range of adjustment is greater on the Koni so its can be used on more applications but the HTS should work fine on a 240Z. I think the spring rates should be in the 250 to 400 lb. in. range. Now, back to previous concern, what is the total stroke length of the Tokico HTS? It can't be 2" as posted above. EDIT: Oh crap, I missed that the HTS is a single adjustable shock. I don't like it as much because the compressing damping gets too high for a light car like the 240Z when the rebound is getting good. Its the same problem with the Tokico Illumina. What's nice about the Koni 8610-1437RACE is that the compression damping stays the same while rebound is adjustable. With the 8611-1259RACE you can idependently adjust compresion and rebound.

It'll be hell for stout. An easy thing you can do is find the maximum droop of the TC rod as installed and then weld a small plate across the angle you cut in the tube, tying in the sides near the ends of the slot with the bottom of the bracket. This bracket will mostly see compression loads coming in from the TC rod and it looks plenty strong enough to handle the minor tension loads as the LCA moves up and down. Personally I would have gone with your idea of using the bracket tube (2 x 3) in a bigger size like 2 x 4 or 2 x 5 and contoured the bottom of it to match the frame rail at the angle you calculated, eliminating the 1 x 1 tubing. But that tube would be harder to work with given the tools you have. Either way, your doing the right thing. Hopefully with no springs, shocks, or ARBs installed you'll be able to easily move the front suspension up and down with one hand and it will move through a good arc (as good as it can get using the basic 240Z design).

Its a track car and won't be run on the street. The downpipe connects to the stock cat and exhaust for now but something different will be built later. I built the engine mounts, header, downpipe, wastegate plumbing, intercooler tanks, intercooler plumbing, throttle linkage, turbo oiling, fuel system plumbing, and a some other stuff. The car just went to the engine builder who's going to take it all a part and build the engine.

Just finished the fabrication work on putting a Cosmo 13B with a big turbo into a RX8.

Just when you thought it was going to be a dull shift: http://www.woai.com/news/local/story.aspx?content_id=EE418016-0667-4C62-9602-0C699962154F

After a memeber here posted e-mails from Koni, me looking at the shock dyno charts, and trading my own e-mails with Koni, my mind has been changed (actually, I got edumacted). It looks like the 1437RACE will be fine for a 240Z install. The compression damping is basically the same as the 8611-1259 abotu about 1 turn, which is about where the 8610-1149 was before.

From the CC Wiki:

From the CC Wiki:

I don't know enough about drifting to make a shock recommendation. Also, shocks don't explode, the shim stack usially fatigues and stops doing its job. Rebound damping goes away and the car just kind of wobbles down the track. Also, what Keith said - one of the rules we have on this site is proper punctuation, capitalization, etc.

I don't know enough about drifting to make a shock recommendation. Also, shocks don't explode, the shim stack usially fatigues and stops doing its job. Rebound damping goes away and the car just kind of wobbles down the track. Also, what Keith said - one of the rules we have on this site is proper punctuation, capitalization, etc.

Well, I do tend to be extreme in my zeal to save weight and lower the cg. And after watching Hans Stuck violently move the seat forward and jamb Boris Said's balls into the crotch strap of the M3GTR during a driver change pit stop, I prefer fixed seats.

It depends on which 400 series stainless you have. There are two basic type: Ferritic and Martensic. I'm betting that the stainless you have is Ferritic because that is the most common 400 series used in industry. The most popular types are 405, 409, 430, 442, and 446. All these types contain 11.5 to 30% Cr, up to 20% C, and small amounts of Al, Cb, Ti, and Mo as stabilizers. When welding Ferritic stainless you need to use a filler that matches or exceeds the amount of Cr that's in the base metal. Ideally that's ER409 or ER430. For what you are doing ER309L is a good alternate. Don't preheat 400 series before welding and add a lot of the filler to the weld pool.

Look on page 3 of this thread. I posted dyno graphs for the recently revalved Koni 8610s and 8611s. Look at the knee points and you'll see they digress. Ideally you don't chose spring rates based on your shocks. Spring rate is chosen to establish a basic suspension "Platform" that achieves a neutral steady state cornering balance. To chose the ideal rate a lot of factors come into play: Gross vehicle weight Unsprung weight Balance Power to weight ratio Tire width and diameter Track characteristics Aerodynamic downforce or lift Driver preference Carroll Smith has a rule of thumb that is a good, basic place to start:

Look on page 3 of this thread. I posted dyno graphs for the recently revalved Koni 8610s and 8611s. Look at the knee points and you'll see they digress. Ideally you don't chose spring rates based on your shocks. Spring rate is chosen to establish a basic suspension "Platform" that achieves a neutral steady state cornering balance. To chose the ideal rate a lot of factors come into play: Gross vehicle weight Unsprung weight Balance Power to weight ratio Tire width and diameter Track characteristics Aerodynamic downforce or lift Driver preference Carroll Smith has a rule of thumb that is a good, basic place to start:

Actually, that's a common misconception about dual spring setups. Both springs are involved at all times so the spring rate you get with duals is not what either spring provides on its own. Here's a dual spring example: 1. Spring A: 250 lb. in. 2. Spring B: 500 lb. in. Let's apply a 250 load to the dual spring combination. Most people would gues that spring A would compress 1" and spring B would compress 0". Not true. Remember, spring B will compress 1/2" with a 250lb load so it is definately involved. What you actually have is a combined spring rate of 375 lb. in. (the average of 750 / 2) so the dual spring combination above will compress 2/3" and this spring rate is a constant UNTIL one of the springs in the dual setup bottoms.

I was thinking more llike this: http://www.speedwaymotors.com/xq/aspx/display_id.3392/qx/Product.htm You can't use these products because, as you said, there would be ground clearance issues. But I think the design can be incorporated in an adjustable height TC rod mount. And I meant Speedway Motors not Speedway Engineering. My mind was thinking one thing while my fingers were typing another.

I know this might sound a little crazy, but what about making a circle track adjustable panhard rod mount at the TC rod pivot? It basically a high strength vertical slot that has a post/clevis with the post riding in the slot and adjustable vertically via a jackscrew. The clevis captures the rod end on your TC rod. Speedway engineering has examples of what I'm talking about, part numbers 916-45000, 916-45585, 916-45493.

It all depends on the loads imparted to the welded structure. If you butt two tubes perpendicular to each other, fill the gaps with weld, and the tubes are only loaded in compression, then everything will work out fine in a wreck. But add shear loads to that joint and things will not be so fine. In a rollover at speed, there are shear and compression loads on the roll cage stricture. In a side impact there are tension, shear, and compression loads placed into the roll cage structure.

Is that the total stroke of the shock? And your shock graph shows a steep progessive curve which is different from the trend in the industry towards digressive shocks. In general, high shaft speeds require a much lower rate of increase in damping, with compression damping the main concern. Think of it this way: Your wheel hits a sharp bump at speed. The shaft is accelerated to about .5mps. The shock can do one of two things 1) transfer most of the load through the shock shaft into the chassis (progressive damping) or 2) let the spring take the load and not upset the chassis (digressive damping). Now let's say you're exiting the corner and applying throttle. Progressive rebound damping will tend to lift the inside rear wheel as weight transfers back to the out rear wheel. Digressive damping will let the inside wheel drop as the spring unloads and keep the inside tire on the ground helping accelerate the car. Maybe the shock requirements for drifting are different then for grip, but the dyno graph above shows a 1980s technology shock.

Is that the total stroke of the shock? And your shock graph shows a steep progessive curve which is different from the trend in the industry towards digressive shocks. In general, high shaft speeds require a much lower rate of increase in damping, with compression damping the main concern. Think of it this way: Your wheel hits a sharp bump at speed. The shaft is accelerated to about .5mps. The shock can do one of two things 1) transfer most of the load through the shock shaft into the chassis (progressive damping) or 2) let the spring take the load and not upset the chassis (digressive damping). Now let's say you're exiting the corner and applying throttle. Progressive rebound damping will tend to lift the inside rear wheel as weight transfers back to the out rear wheel. Digressive damping will let the inside wheel drop as the spring unloads and keep the inside tire on the ground helping accelerate the car. Maybe the shock requirements for drifting are different then for grip, but the dyno graph above shows a 1980s technology shock.

I'm pretty sure Pop is kidding us, but I'll play along. Proper fitup reduces the chance of Hydrogen cracking in welded mild steel structures.

No, I'm not saying that. My post above was conjecture. My only direct experience with CF has been in a L6 application. The V8 applications I've had experience with have all used OEM or OEM motorsports clutches and pressure plates. Don't know. Don't know. Use an OEM pressure plate and clutch or something from that OEM's motorsports division.