johnc

What Paul said...

Aluminum allows in the material types typically used in wheels are the heat treatable alloys (2xxx, 6xxx, and 7xxx). The initial heat treatment for these alloys is evenly heating the material up to 1,000F, holding the temperature for a short time, and then quenching in water. This dissolves the alloying materials in solution and holds them there at normal temperatures. This gives the material a T4 temper and is stabilized by letting the material sit for a few weeks at room temp. Most aluminum allows are given an additional heat treatment to get the highest levels of strength. This involves evenly heating the material to 400F, holding it for a couple hours and then immediately removing it form the oven and air coolling back to room temperature. This process is called Artificial Aging and brings the material to a T6 temper. This second process is where an improper powder coating can add another level of artificial aging and reduce the strength of the material.

I've never seen a set with anodized rims. You can always call and ask.

Don't powdercoat aluminum wheels. I've seen a couple wheel failures from wheels that were powder coated. Two possible causes: 1. In a racing environment, wheels temps sometimes get high enough from brake and tire heat to cause the powder coating to soften. On multi-piece wheels if there is powder coating under the bolt heads or nuts holding the peices togther, they loose torque and the lateral load tear the wheels apart. Saw the results of that on a set of BBS wheels that were re-coated and raced on a Viper. 2. The heat from powder coating can add another aging process to the aluminum used to manufacture the wheels. It can take the material from a T6 up to a T7 or normalize it back down to T0. Either change reduces the strength of the underlying material.

Man! Sorry to hear about the wreck. I guess those full face bike helmets are looking better all the time.

Sources of information: http://www.euro-emc.co.uk/electromagnetic_pulse_protection.htm http://www.military-information-technology.com/article.cfm?DocID=1185

You'll get more "horsepower" by doing a valve adjustment, change and properly gap/index the plugs, change and properly gap the points, replace any bad plug wires, change the fuel filters, and properly tune and balance the SUs.

Are you expecting a need for an EMP hardened vehicle with extra fuel in the near future?

You're going to cause a wreck with that bright, loud, nasty machine.

Having built both cars for customers, I can say without a doubt that: 1. The car with the most time and money spent on preparation and development will be the faster car. 2. The car with the best driver will be the fastest one around the track. If you put $10,000 into either car, you'll have a fast track car. The BMW might be cheaper though because rust is really not an issue, at least from what I've see here in CA. With the BMW you can also race with BMWCCA which is about the best marque club racing series in the country. Don't expect to be happy with just doing track days for the next 10 years, you'll want to do some real racing sooner then you think. The 240Z will be worth more when done, especially to the Vintage crowd, so you can get more of your money out of it when it comes time to sell. Except for the M3, none of the E30s are increasing in value, especially when prepped as a race car.

Both of mine are white.

Initially the customer did the traditional modified E36 thing and adjusted the front to gain maximum static camber. That was when he was running 245 width tires. When he went with 285 width tires he didn't adjust anything. I had to talk with him for a few months and finally convinced him to reduce the static negative camber and only use what he could get through the camber plates. That freed up the offset rear LCA bushing so we could play with the roll centers and anti-dive. We took out all anti-dive and were able to run 700 lb. front springs and reduce the front ARB size. The car pitched forward more but would really bite on turn in and just fly around corners. Most recently, after the video, we added in a little anti-dive in the front (asymetrically in fact - based on the corner weights), brought the front roll center up, and adjusted the spring rate. Now he's got the best of both worlds and is faster. Sorry, forgot to mention that yes, we did raise the rear roll center, but not as much as the front. We probably have a little more work to do back there but the SP rules limit what can be done.

I forgot how much you had lowered the car. Getting the rear roll center back above ground is a good idea. A couple months ago I purchased Mark Ortiz's "Managing Your Anti" video. I and a couple of my customers watched it a number of times because the concepts are hard to grasp. In general he takes a force vector approach to determining roll centers, anti-roll, and anti-dive which is different then the more traditional geometric approach. We made some changes to the roll centers on a SCCA Solo2 DSP BMW 325i and noticed some subtle, but very nice attitude changes. Under hard braking the entire chassis squats down instead of pitching forward. Back to back to back testing at a practice last month showed a 3 tenth improvement in course times. At the nationals the car is currently 4th overall in DSP with the final runs today. The car is first overall in DSPL and won the overall L2 championship in ProSolo. I need to learn more about this force vector stuff. I feel like a miner in a cave without a flashlight.

Grammar... http://www.grammarbook.com/

That's a huge tire for the back of a 240Z. I doubt it will fit with just a roll of the fender lips.

Please use punctuation, spelling, and grammer.

Just curious, why are you raising the rear roll center?

There are lots of handling disadvantages to a live axle car in addition to what's already mentioned: 1. Anything that happens on one side has an affect on the other. 2. Wheel hop under braking. 3. Binding under compression. 4. Lateral location (panhard bar typically) is affected by sprung weight movement. 5. Wheelbase changes in roll. 6. Lack of compliance/suppleness due to unsprung wieght and the resulting shock valving needed to control that weight. 7. Asymentrical torque affects on the chassis under hard acceleration. 8. Engine torque loads affect suspension compliance. 9. Limited wheel travel due to the big punkin' banging on the floor of the car. These can all be reduced significantly with proper tuning. But they just add a lot of work that isn't need with a proper IRS.

Solid engine mounts are only for a race car, something that is never driven on the street and always driven wearing a helmet. The advantages are: 1. One less point of failure. 2. Handling improvements, car transitions better because the mass of the engine isn't moving opposite of the chassis. 3. Engiune can be moved back, down, and closer to other things because it will move much less. 4. Slight structural improvements. The disadvantages are: 1. Vibration. 2. Vastly increased vehicle inspection and maintenance because of the vibration - nuts and bolts all over the car loosen up, electrical parts break, parts fall off, hoses need to be protected from chafing, radiators need to be rubber mounted, exhaust system mounts need to changed. 3. Noise. 4. Transmission has to be solidly mounted also.

So, we headed down a political path with this thread?

I'm sorry to hear of his passing. My wife and I will say some prayers tonight for him and his family.

George, You should get a copy of the factory service manual or one of the Haynes manuals for your car. The mount I mentioned above is the mount that's under the front snout of the differential and bolted to the removable crossmember.

The driveshaft won't whine. IMHO... what's likely is that the front diff mount was damaged enough that you're getting some metal-to-metal contact in the mount. The whine you're hearing is probably normal diff whine, its just being amplified by the damaged mount.

I had to run out and get some parts so I stopped by the yard. Lots of 1/4" x 18" OD stainless pipe and a 3' length of 24" OD. They do have a stainless steel tank they are planning on cutting up and scrapping. Its about 40" OD, 18' long, and is probably 3/16 to 1/4" thick. There's about a 12' section in the middle with no openings so a 7' section could easily be cut out. It will be a week or two before they get around to working on the tank. If its something you're interested, give me a call at the shop. The phone number is on the web site.

What's the dimensions on the stainless drum? There's a metal scrap yard a mile from my shop and they have lots of large OD stainless piping.