katman

Try Jere Stahl. http://www.stahlheaders.com

Another thing to consider is the additional stress placed on the stub axles from dragging the rear tires around all the time. In ITS race cars I've seen and heard about several stub axle failures and all but one occurred on cars with welded diffs- including two that I was *intimately* familiar with (one of which totalled the car). Since going the LSD route 7+ years ago we haven't had any of that, nor have my cohorts. The failures could have been due to the cornering stresses of racing, but my personal, albeit unsubstantiated, opinion is a welded diff is asking for eventual trouble.

Streetable 300 hp is possible with an L28 base, how much money you got? Realistic budget is the first thing to nail down.

Well now we're starting to deviate from the statement that got me started- that is that a tube frame is lighter than a unibody, to which I disagreed. If you're talking about penetrations due to crashes from racing, or additional suspension and engine loads beyond the original unibody design, well then yeah, you gotta add something. But I stand by my generalization that a shell or unibody will weigh less than a truss or tube frame for most road going apps. Also correct as pointed out that practically all "monocoque's" are really semi monocoque in that they have reinforcing stringers and frames to keep the shear panels from buckling. So do unibody cars with their stamped in beads and welded in stiffeners here and there. My apologies for using the term monocoque when I should have said semi-monocoque, very good point. Replace the shear panels with diagonal tubes however and you'll probably weigh more. Regardless, if a tube frame car for normal road apps was lighter, everybody would be doing it. Some sort of exoskeleton or unibody will always be lighter. Even for road racing, the reason you see cages inside of unibody cars is because the rules mandate the use of the tub to begin with (SCCA production type racing, BTCC, etc.) or tube frame construction (NASCAR). In full on race classes the cage goes away in favor of a tub of some sort, LeMans GTP for example. Tubes are easier to analyze than shells so the cost to design is less. Say, I dabble in airplane design occasionally too, and I can't remember the last time we designed one with a tube frame (World War I?). So to summarize, can we agree that if we don't have a GTP budget we need to add some reinforcing to a stock unibody for some of our hybrid apps, but replacing the entire unibody with a tube frame right off the bat isn't necessarily the lightest way to go? I believe Michael's summary to be correct- in the end a little tube work inside an existing unibody is the way to go.

You're missing the concept of a "monocoque" structure. The panels carry shear loads which are in effect the diagonals of your tube frame truss. A monocoque, or unibody, will usually be lighter than a tube frame, which is why airplanes and real race cars aren't , like, tubular man. This is especially true when the loads are not simple.

Exactly. HybridZ is devolving. I think the moderators need to be more selective in what's allowed and where its posted. I'd route that to the Forum entitled "I'm broke so I bought an old clapped out Z, don't have the patience to read a Factory Service Manual but don't mind getting on a computer to ask somebody else to do it, and by the way how do I get 500 hp for $25?" But of course I'm an a$$hole so it's a good thing I'm not a moderator.... Uh, no offense meant to the original poster of the question, my apologies in advance.

Hey Danno: Email me a new dyno chart. You still got that hole at 4300? Glad to see you back on the road.

Yeah, and a filter to delete posts without any punctuation, capital letters, or one misspelled word per sentence.

Me thinks not. All real race cars are "unibody" (F1, CART, etc), as are all real airplanes. Give me an axially stiffened shear panel over a truss any day.

Most of the time long pedal travel is rear shoes out of adjustment. On our ITS cars we retain the parking brake so that during the course of a race we can pull it up a notch to take up some of the wear and retain a high pedal. It's also possible to taper the front pads and rotors such that there's a lot of slack to take up there too. So basically keep everything trued, adjusted, and properly bled. Fade isn't a problem unless you have pads that aren't up to the job you're requesting. If you're racing with stock calipers and drums (like in ITS) then you need some cooling ducts too, but if you're fading on the street it's probably a cheap pad.

No, Sir. It's not required by NHRA. Don Should be. Without it it's just extra weight you can bang your helmet on. After seeing a bunch of these NHRA cages I wonder what it is they're really trying to protect you against. Good thing drag racers don't roll very often.

Is there a diagonal in that main hoop?

Check the coil bind height with an 8 inch spring, you might want to go to a 10 or 12. Probably okay, but with 220# rates (which I think is too high for a street car, but I'm old) you'll compress the springs 2-1/2 inches or so right off the bat, and you want another 2-1/2 for bump travel minimum. That's 5 inches of squash for an 8 inch spring. Hmmmm.

Awesome car. Beautiful work. Cage looks like the typical S&W or Chassisworks beginnings. For drag racing I suppose all you need is something to attach your belts to and meet the NHRA rules. For road racing it would need a real diagonal in the plane of the main hoop, an attachment to the rear strut towers with a "strut bar", a crossbar just above the tranny tunnel connecting the two forward downtubes, more generous plating between said downtubes and the floorboards, and at least two "NASCAR" style horizontal door bars on the drivers side before I put one of my drivers in it. So, it ain't what I'd consider safe for road racing, but it probably meets the criteria for which it was built.

What you should do is determine a realistic budget. Then we can go from there. Shortly after that you should start using punctuation. Us old guys need that...

Yeah, what JohnC said- camber. I also vote lower rear spring rate and you could add 1/32-1/16 total toe in in the rear (personally I like zero toe for zero drag but you might try it). In the driving technique dept. you can slow down more at corner entry, turn in sharper, take an even later apex. This allows you to unwind sooner as you add power and effectively makes the straightaway you're entering even longer. With a V8 Z you don't get to nail it immediately after turn in like we do in an ITS car, so not being able to get the power down might eventually end up being a case of too much power for the available tires. Something I pray for every day.....

If you aren't racing I wouldn't put on an oil cooler. Rarely does the oil get hot enough on the street (turbo maybe), and so you end up running cold oil, reduced flow, and a lot of wasted apparatus. If you are racing, then as previously mentioned you can unscrew the filter nipple from any other L series block. For racing we usually bored them (the nipple) out to reduce restriction, as well as smooth out the sharp edges in the boss area where the main galley enters it. We also "blueprinted" all the sharp edges in the timing cover and the aftermarket adapters and fittings for the oil system.

Our two time ARRC winning ITS 240Z used 400 lb/in front and 350 lb/in rear springs and about $4000 worth of remote reservior custom shocks to control them, but I wouldn't do that on the street with street tires. Normal or "performance" street shocks just aren't up to that kind of spring rate, nor do the tires particularly care for it. I wouldn't go over 200 lb/in on either end of a street car, shocks most definitely will still be a problem, and make dang sure you have at least 2-3/4 inches worth of bump travel and 2-1/4 or so worth of rebound.

Depending on your speed, it can raise high enough to block your vision. But then again, I'm short.

I can't think of anything closer to a "semi metered fuel leak" than a 4bbl downdraft carb on an L6 motor, unless the manifold bends straight up through the hood a foot or so.

The Vanilla Sky car is now owned by a guy in the Atlanta area. It is deep blue and it is a Z, with a small block chevy for an engine.

"neither one is what I would call cheap." Yee who gets an engine cheap usually gets a cheap engine.....