katman

I came up with that hoop placement before SCCA allowed us to have NASCAR style door bars protruding into the door cavity. I still believe that to be the best place for the main hoop, and your interpretation looks perfect. After you get it gusseted in at the bottom it will be perfecto. After SCCA allowed us protruding door bars I built a second car with the main hoop in...drum roll...EXACTLY the same place, because I still believe it to be best/strongest like you have it. Our trashcar style door bars had an "S" bend in them to clear the door sill. PM me and I'll send you some pictures. I would think that if you fit the door bars into the post and welded the post sheet metal to the bars you'd be just as strong for all intents and purposes, but its a lot of work. Our rules didn't allow us to do that.

Truesports, Pegasus Racing, Coleman Engineering, Koni, Bilstein, lots of real racy car parts places carry them

On our ITS car we were allowed one "engine stayrod" to react engine torque. I did this: On the mount that sees the tension, i.e. the driver's side, I drilled a hole through the entire mount along the stud centerline, which also removed the stud. Then instead of the stud I used a long bolt, and on the side of the mount closest to the engine put a thick rubber washer, a stout metal washer, and a locknut. Viola! Poor man's captured engine mount, and SCCA engine stayrod.

That's the brake warning circuit, and gutting it will result in pumping all the fluid from the front brakes into the rear of the brake master cylinder. You will end up with no brake and a big mess. What year is your car? The stock proportioning valve is in a different place depending, but your Tee idea is on the right path.

There's also a good chance the clutch disc is fused to the flywheel, so when you crank it over the first time make sure its out of gear, not just clutch in. First start up on an engine that's been sitting I usually pour some oil over the cam, take all the plugs out, spray some WD-40 in each cylinder, unplug the coil, and turn the engine over with the starter for about 20 seconds to get some oil in the bearings. And yeah, you're looking at some nasty gas tank issues.

What sanctioning body?

"Also, I have no idea why tying two diaganal bars into the transmission tunnel would help for any reason. The trans tunnel is pretty thin sheet metal and would provide no rigidity if stress was placed on those points" Werd. I always thought the two diagonals to the tranny tunnel were a waste of tubing. Structurally a diagonal in the plane of the main hoop from driver's head to passenger side bottom of main hoop would add much to the integrity of the rollover structure, but if the sanctioning body doesn't require then you decide whether it's needed or not. In road racing it would be.

1973 MGB with a Rover V8 and the Fast Cars suspension. 1972 240Z with an M70 BMW V12. 2004 Ferrari 360, stock, with Jessica Alba in the passenger seat ('cause, well the engine is already cool).

We don't bore combustion chambers. Cylinders yes. Heads, no.

Hard to beat the stock tank for location and weight, and maintainintg the stock rear deck integrity for tank separation and safety. I've agonized over this for our ITS race cars, and built two cars with cells, and I've decided I absolutely wouldn't want anything other than stock for a street car. That's my opinion.

Dude, that's the end of your cam spray bar. Time for a new one. Do not run motor until you replace it.

To clear the combustion chamber. Because of the valve size and placement the combuston chamber on L heads is often outside the dimensions of the bore in the fore/aft sense. For example, a stock factory L24 gasket measures about 3.515 inch in the fore/aft direction but only 3.335 inch perpendicular. These dimensions can vary by +/- .050 thou or so depending on the gasket and brand. For example, our ITS engines used a custom solid copper gasket with an odd shaped hole to minimize the volume. SCCA tech inspectors routinely measure the long and short dimensions of the oval and then average the dimensions to calculate a circular area that they multiply by the gasket thickness to get the gasket volume as one of the inputs to their compression ratio calculation. In our case I we couldn't get repeatability close enough from stock gaskets to keep my blood pressure down during ARRC teardowns, so I designed one that minimized the clearance around the bore and/or combustion chamber. The dimension minimized by our +.040 L24 bore was 3.329 (included +.020 for tolerance), and the dimension minimized by the combustion chamber of an E88 (early rare E31 combustion chambered E88 mind you) was 3.509.

"The fire ring is actually a little egg shaped." Actually most head gaskets have oval holes.....

Teo Fabi was a downhill skier before he took up car racing because "cars were faster".

Buy a Honda Civic for daily driving, and use the gas money you save to hop up a Z! But if I had to pick between the two it'd be the ZX. No question.

Road racing with what sanctioning body?

"I dont think solid bushings are allowed anymore, the rules state: "Suspension bushings may be replaced with bushings of any materials (except metal) as long as they fit in the original location."" I remember that stupid rule!. Instead of the typical Kontrolle style delrin/aluminum rear inner camber/toe bushings I had to make some completely out of Carsan or something like that. Ditto the T/C rods and outer rear. We might have used poly for the front control arms. What a PITA. @%#$ SCCA...

In the mid/late 1990's I set up Atlanta Region BSP champ Chet Wittel's 280Z (later 4 time ARRC Champ Chet Wittel). I'm sure the rules have evolved, but from what I recall to be competitive you almost have to trailer it. Here's what we did. Everything revolves around Hoosier Autocross tires. Get it low. You can do that by dropping the suspension, which causes all sorts of geometry and shock travel problems, or by running shorter diameter tires. We had all solid or spherical bushings everywhere. Springs were not that stiff really, in the 200 in/lb range for two reasons- one, parking lots are bumpy, and two, soft rear for early hard throttle application has always been one of our mainstays. Car at minimum weight. Maximum allowable engine mods. Limited slip 4.11 diff. Adjustable Koni shocks, because autocrossing is 60 seconds of transitional handling. Shocks are key, which is why you see a lot of remote reservior double adjustables in that sport now. But the most important cog in the machine is the driver. Jon is correct in his assessment; sounds like a fun car to drive, but competitive BSP will require something a little more extreme.

Yeah, I believe worrying about the lift of a crank throw would be polishing turds to a very high lustre.

The front struts have a bearing between the upper spring seat and the insulator. The rears have a rubber block. If you put everything back together right, and didn't mix front to back the front strut/spring/upper spring seat should all rotate under the insulator easily as an assembly when you turn the steering wheel.

A straight bar with heim joints at both ends would be LESS prone to bending than one welded to the towers, because by definition there are no induced moments. It would be what we call a "two force member". Jon is right, for a straight bar.

"Race header"...snicker snicker. Looks like an old Monza POS to me. And the one in the first post is a 6-1 MSA. Also good for more noise and a pony or two at best.

Of course Mr. Coffey's crank wasn't prepped by a "mostly Chevy V8" shop either, but instead by one that understood the nuances of heavy metal balancing L6 cranks.

Nissan assembly lube when building Nissan engines.

I wouldn't trust a "mostly Chevy" shop to knife edge and heavy metal balance a Nissan L6 crank. Fuggetaboutit. Spend the money on dyno tuning instead. The payoff will be greater.