johnc

Probably not directly. Some folks have a lot of trouble distinguishing satire from reality.

Amazing paragraph! Where do I begin?

Pretty nasty work getting everything ready for welding. People sometimes wonder why I charge what I charge to build a roll bar. The welding is only a small part of the work involved. Its like painting a house, getting the paint on is the easy part.

I think the Bishop thing would work out, although we would have to really keep an eye on Tim around the alter boys...

1. Remove the spindle pin and separate the control arm from the strut. 2. Burn the rubber bushing out using a torch. 3. Find a throw-away deep well socket that just fits the metal bushing sleeve that's left in the control arm. 4. Find another throw-away deep-well socket that just fits the outer tube of the control arm that holds the bushing. 5. Press the sleeve out of the control arm using a 20 ton press.

I don't have any evidence. All I have is the advice given to me by the owner of Sunbelt on a "no budget limit" NA engine. He could have chosen any Nissan block and head combination. For my application and for the reasons Jim stated above, he went with the N42 block. Sunbelt builds all of the Mazda, all of the Nissan, and most of the BMW engines under contract by the OEMs for SPEEDTV's World Challenge Touring cars. I'm not an engine guy so I relied on their judgement. It worked out pretty well at least for me.

More is better. If I were doing one the .080 plate would have a 90 degree bend at the bottom, start on the floor, and basically cover the front face of the strut tower. 100 square inches can do a lot to help that strut tower.

To expand on my statement above... When working with Jim Thompson at Sunbelt to build my monster NA engine we talked a while about heads and blocks. For an engine that is being built with no limits, head selection (between the N42 and P90) is less critical because custom pistons can be made to give whatever combustion chamber swirl is deemed necessary and the ports are going to be welded and machined to give the desired shape, flow, and velocity. Block selection is more important and the most important power production item to focus on is how circular the bores remain under the clamping load of the cylinder head, heat, and load. Bores that go out of round lose ring sealing and lose power. That power loss is also uneven because some bores go out of round more then others. The early N42 block has cylinder bores that stay "rounder" then the F54 block. That's a direct result of the siamesed cylinders of the F54. They expand unevenly and cause distortion even when bored and honed in a heated machine with a torque plate attached. Its not that big a difference but its enough that when I spent $20K on an engine, we went with the N42 block over a F54.

I posted a link to your head on the west coast Z racer list. There are probably a few guys that might be interested in it.

Wow! It looks like the world is coming aorund to what the Z engine builders have been saying for a while.

SCCA says .080 minimum thickness, no more then 100 square inches, no longer then 12" on one side, and no shorter then 2" on one side. If you're going to the top, cover the whole top of the tower. If you're going to the front side, something 4" x 8" should be fine. If you wrap the plate around the tower it will help witht he strut tower brace.

You're building a box right? Why do you need two walls on one side of the box? Think of the floor as a shear panel (which it is). Cutting the panel across its width and putting a tube in there turns it into two shear panels with the tube as one side of both panels. You're creating a place where loads are concentrated to a 1" square .063" wall tube. It would be better to augment the shear panel with a tube attached to it then to cut the shear panel. That's my thinking at least. Without any specific load numbers on the floor its really just a gut feeling with no tech to back it up. Just a monkey see engineering design based on what Nissan did with the factory seat mounts.

Don't cut the floor. What you're building is a box with the floor as one side. Look at how the factory seat mount is built and you'll see that they went to great effort to keep from cutting the floor. What would be even better would be to build a U-shaped channel with flanges that have holes punched in them for spot welding to the floor. The edge of the flange can be stich welded and the flange holes can be filled as spot welds.

I suggest you remove the adjustable tracks and set the seat up for yourself. But, most folks don't want to do that... Take your 1" square tubing and cut one side off so its a U-channel. Contour the open end so it fits tight down on the floorpan and connects to the rocker and the tunnel while keeping the top surface sqaure and level side-to-side. Stich weld the U-channel to the floor pan, rocker, and tunnel. Drill holes in the top big enough to get a 3/8" nut through the opening. Weld a 3/8" nut to a 1/2" washer, insert the assembly nut down into the hole, and weld the washer to the top of the 1" tubing. Tip: Order 3/8" four corner weld nuts from McMaster-Carr and 1/2" uncoated metal washers.

A forklift works well too.

NHRA doesn't care about FIA, they only look at SFI certifications. And no, there doesn't appear to be an exception for SFI certified seats in the NHRA rule book but if the SFI specification says "No back brace" then NHRA will accept that.

In NHRA the safety requirements really depend on what specific class you intend to run. In their General Requirments section 6.2 is has the following: "The driver's seat must be supported on the bottom and back by the frame or crossmember. Except as noted in SFI specifications, seats must be bolted with four bolts (and nuts and washers) on the bottom and one bolt in the rear into the crossbar; all bolts must go into frame or crossbraces."

Although that's true, its misleading in this example. If you were citing two linear rate coil springs stacked on top of each other I wouldn't argue at all, but in this instance we are talking about 1" tall rubber bushings that in my press take 500 psi of hydraulic pressure to compress 1/4" and 2,200 psi of pressure to compress 1/2" (just checked it). They act as extremely short progressive springs. Lateral load transfer is based on weight, CG, and track width. Chassis roll resistance is provided by the width of the spring base (the distance between the springs on each axle), spring rate, and by the ARBs which transfer load laterally. The chassis doesn't care if the roll resistance is from bushings, the ARB, spring rate, or spring base - it just feels a rate. Softer bushings just slow the initial rate the ARB adds to roll resistance and may allow an additional fraction of a degree of roll in the chassis but the bushings themselves are a very small contributor to roll resistance. On the track you'll feel softer ARB bushings as a little delay in the front end taking a set. If you've had turn in understeer problems then it will delay the onset of understeer enough that the front tires may be able to finish turning the car before the full ARB load is applied. This might keep the front tires from overloading and make the understeer appear to go away. Its not, its just been put off a bit.

FYI... this will only affect the initial response of the anti-roll bar and will really only affect understeer at turn-in or in the very first part of the corner. Once the end link bushings are compressed the anti-roll bar rate is based on its OD and the combined length of the lever arms.

Nissan never developed any of the "R" differential units. They were developed by Hitachi and were (are) available to various OEMs in many different ring gear sizes from 120 to 380... anyone looking for a H380?

That sucks! At least you have a good attitude about it and it looks like things will get fixed as they should.

I think we deleted or closed most of then. Search.

Don't personally confront the carrier. He can easily claim you threatened him and now you're dealing with the postal cops. If you're lucky the only thing that will happen after the mail cops do their investigation is that the post office will not deliver mail to your home anymore. Write letters and go through the chain of command.

The high end spring rates for those progressive springs are at the max that the Illuminas can control with rebound. In fact, your rears are about 40% beyond the rebound capacity. Progressives are fine on the street and can work on a race track. The complaint about then from racers is that they are very difficult to tune. EDIT: And those GR2s will be screaming for mercy...

You're joking right? Perceived weight distribution (not actual weight distribution) is the cause of understeer and adding weight to the rear of the car to correct the "perceived weight distribution" fixes it?