johnc

Air will always move from a high pressure area to a low pressure area. Low pressure areas are created where air is accelerated (relative to the surrounding air) or heated in an unconfined space. That movement from a high pressure to a low pressure area creates a force on a surface that impedes flow from high to low. Engine compartments are designed to draw air in through the front grill opening and exhaust that air down, under the vehicle. If the engine bay became a significant high pressure area then air couldn't come in through the grill opening, it would all stack up in front of the car (which it does to some extent anyway). Adding an undertray without allowing for an air exit from the engine compartment will create all kinds of problems.

For thicknesses up to .120 welding 4130 sheet or tubing is basically the same as welding mild steel. You don't need any pre-heat although the steel should be at room temperature and if you're in a really humid environment, pre-heating to 100F should get the moisture off the metal. For thicknesses over .120 you'll need to pre-heat to 300F-400F and stress relieve after welding at 1,100F for tubing. Its also important to keep interpass temperature over 300F-400F during the welding process. FYI... there isn't a part I can think of on a car where you would need 4130 anything thicker then .120. Use ER80S-D2 filler if the welds need to be as strong as the base metal. Use ER70S-2 or ER70S-6 if the elongation is more important. You can also use 310 or 312 stainless. As always, cleanliness is important and you must remove the green scale that most 4130 tubing comes with. No need to backpurge tubing and absolutely never quench 4130.

What's so surprising? Its Italy for God's sake!

Milling A new block? You'ld have to mill about a half-dozen. The first will be screwed up in the milling process itself. The second will uncover problems in the CNC program. The third will uncover problems in the materials. The fourth will uncover problems in dimensions. The fifth will blow up on the dyno. And the sixth will finally be installed in a car, only to be blown up due to plumbing problems (oil, fuel, or coolant).

The BMW link example above ignores the vertical loading on the strut (spring). Bill Savage has a pretty cool modeling system that can do some finite element analysis and he came up with the effects I mentioned above when modeling the strut tower braces installed on my 240Z. I think Keith Thomas (katman) has also done some modeling while developing Chet Whittle's ITS 240Z. I'm no engineer (well, a monkey see-monkey do engineer) so I"m just repeating what I've been told.

The strut towers tops move in towards each other under suspension load and they also twist - clockwise for the driver's side and counter-clockwise for the passenger side. Lateral strut tower braces stop the inward movement but do little for the twisting.

Bends in round tubing create flex points and weaken the structure. Keep the strut tower bars as straight as possible. Also, try to run large OD and thin wall tubing. The strut tower bars on my 240Z are 4130 1" OD .049 wall. Here's a picture of a strut tower brace I built for a STX class BMW 325is. It planted the front so well the owner had to reduce his rear spring rates by 50 lb. in. to get the car back to neutral. It was all built with 4130: .085" sheet, 3/4" OD .055" wall tubing, 1/2" OD .063 wall tubing, and 3" OD .063 wall tubing. The strut tower loads go into the large 3" OD tubing instead of through the strut bolts (like so many off the shelf braces).

Stop! Forget about the strut tower bars. If your radiator core support is rusted, fix that first. You're wasting your time building anything to strengthen the chassis if the chassis is not already in good condition. Also, there's no reason and no place anywhere on a 240Z where you would need to use 1/4" steel plate.

Importophobe.

Adaware helps keep the spyware off. Norton helps keep the viruses off. Zone Alarm helps keep everyone off. I have scheduled tasks that run periodically to update all the above.

Dimensions 8610-1149 Stroke: 151mm - 5.94" Max Length: 550mm - 21.7" Min Length: 451mm - 15.7" Tube Length: 330mm - 13" OD: 43.5mm - 1.71" There are 3 8611s and the one with the closest stroke to the 8610 is: 8611-1257 Stroke: 143mm - 5.63" Max Length: 500mm - 19.7" Min Length: 357mm - 14.0" Tube Length: 290mm - 11.4" OD: 45.0mm - 1.77" The OD of the 8611 makes it an almost impossible fit in the 240Z strut tubes unless you're willing to bore or power hone the ID of the strut tubes by .010 after welding. It will probably fit OK in 280Z strut tubes. 8611s are not supplied with gland packing nuts and they might require a different type then what's used with the 8610. The 8mm reduction in stroke means changes in what is the "normal" strut shortening length and lower spring perch height. The 8611 compression adjuster is on the bottom of the shock and requires a 1/2" hole in the bottom of the strut for access. That's fine for the rears but you're screwed on the fronts. Even for the rears you'll have to bore the spacer and come up with some kind of adjuster extension to get in there.

Nissan OEM NTN Timken or Japanese made SKF 'Dems de only wuns I buy.

FYI... these pumps do not like to pull fuel. Mount them as low as possible in relation to the tank and as close to the tank outlet as you can. Once you get a siphon going they are fine. Don't run them dry.

For $300 buy it and drive it until something breaks. Then enter it in a local demolition derby and have a blast!

Good tools are always worth the money.

On the engine dynos I've seen they just use a big tank (5 or 10 gallons) with attachments for rad hoses. The big tank has a city water input and a drain so its refilling at some rate less then what's circulating through the engine. I think just a big tank by itself would work fine for the low load, short time testing stuff you'll be doing on that stand.

We need to make a distinction between shock valving and adjustments. Ideally, the shocks is valved for the vehicle's sprung and unsprung weights, wheel rates, and driver preferences. The adjustments are just a fine tuning tool. You shouldn't (and most likely can't) use adjustments to compensate for incorrect valving. A quadruple adjustable Penske 8760 valved for a 3,200lb Corvette Z06 can never be made to work right on a 2,200lb 240Z even though there are 10,000+ different adjustment permutations on each shock.

That's not normal. Check the gland packing nut and make sure its tight. That's the most common cause of the banging sound you're hearing. You have to get a wrench on it to check and its difficult, but no impossible, with the springs in place. Second most common cause is the nut on top of the strut coming lose. Use a strap wrench on the shock shaft if you can't get an open end wrench on the flats and torque the top nut to about 20 ft. lbs. Don't go too tight. The thrid most common cause is failure of the teflon lining of the monoball in the top of the camber plate. Lots of times the teflon fails as a result of one and two above, but a few times its been the primary cause due to a manufacturing defect. If it looks like the monoball has failed you can send the plate back to Erik and he'll fix it. If the failure is from a bad monoball, the fix is free.

The Z06, at ~$50K is the best bang for buck performance deal out there.

True, but you do adjust suspesnion, shocks, etc. for specific tracks and for track conditions. You can tighten up compression and rebound on a glass smooth track but on a bumpy track you better back off compression or the car will be skipping. For asymetric tracks (like WSIR) you adjust shocks and camber to help the car turn (right for WSIR). ANd, if you're running in the rain you'll want to soften everything up as much as you can. Being able to adjust the car to the conditions and track gives you a little edge over the competitor who had non-adjustable stuff.

$31K plus trailer and it does it without a V8, turbo, etc. http://www.betamotorsports.com/products/rod4sale.html

From today's Washington Post: "A first review of the Sept. 11 commission's report indicates that the system failed, but that is wrong. While the U.S. air defense system did fail to halt the attacks, our improvised, high-tech citizen defense "system" was extraordinarily successful... Requiring less time than it took the White House to gather intelligence and issue an attack order (which was in fact not acted on), American citizens gathered information from national media and relayed that information to citizens aboard the flight, who organized themselves and effectively carried out a counterattack against the terrorists, foiling their plans. Armed with television and cell phones, quick-thinking, courageous citizens who were fed information by loved ones saved the White House or Congress from devastation." From: http://216.111.31.12/details.asp?PRID=32 At 8:48 a.m. Mohammed Atta took a jet headlong into the north tower of the World Trade Center. Eighteen minutes later and accomplice did the same to the south tower. When Jeremy Glick called his wife, his first question was an attempt to confirm something another passenger had heard on his spousal call: was the World Trade Center story true? Lizzy Glick paused, thought for a minute, swallowed hard, and told him the truth. Yes, they had. Moments later, still on the line with her husband, Lizzy Glick saw that another plane had run into the Pentagon. She passed that information on as well to her husband, who relayed it to the other passengers. Jeremy Glick then told her that the passengers were about to take a vote and decide if they should rush the hijackers and attempt to foul up whatever evil plans they had. He put down the phone and a commotion was heard by those on the other end of the line. Then nothing. A dead line. An aborted missile launch against the town where I live. That was 10:37 a.m. on Tuesday, September 11... just 109 minutes after Mohammed Atta rammed the first plane into the north tower of the World Trade Center. Just 109 minutes after a new form of terrorism -- the most deadly yet invented -- came into use, it was rendered, if not obsolete, at least decidedly less effective. Deconstructed, unengineered, thwarted, and put into the dust bin of history. By Americans. In 109 minutes. And in retrospect, they did it in the most American of ways. They used a credit card to rent a fancy cell phone to get information just minutes old, courtesy of the ubiquitous 24-hour news phenomenon. Then they took a vote. When the vote called for sacrifice to protect country and others, there apparently wasn't a shortage of volunteers. Their action was swift. It was decisive. And it was effective. United Flight 93 did not hit a building. It did not kill anyone on the ground. It did not terrorize a city, despite the best drawn plans of the world's most innovative madmen. Why? Because it had informed Americans on board who'd had 109 minutes to come up with a counteraction. And the next time a hijacker full of hate pulls the same stunt with a single knife, he'll get the same treatment and meet the same result as those on United Flight 93. Dead, yes. Murderous, yes. But successful? No. So I think the answer I come to is "yes, but at least not for long." They did whip us. And maybe those of us who've demanded to be let on airplanes at the last minute fed a culture of convenience that made it possible. But they only had us on the mat for 109 minutes.

Or you can buy my 240z and beat Z06's on any road race track.

There's a lot of on-going maintenance with a solidly mounted engine. The additional vibration through the chassis tends to loosen fasteners all over the car and things that don't like vibration will break (stereos, guages, etc.). If you're not willing to periodically check nuts and bolts throughout the car then I suggest you stick with rubber engine mounts.

Well said Mr. Washington.