johnc

http://speedtv.com/commentary/10824/ http://www.nsxfiles.com/mumford.htm http://www.nasaproracing.com/news/mumford.html

Tokico Illuminas that are used in Z applications (Z, MR2, Rabbit) do not have enough rebound control for spring rates over 250 lb. in. When you go to springs that stiff, or higher, you need to start moving into modified Konis, AD, and Bilstiens. For 99% of the people on this board, 250 lb. in. springs are plenty. 200 front and 225 rear (or vice versa) are ideal with a set of Tokicos.

That's not true. EPA estimates are based on a very specific dynamometer test done at the National Vehicle and Fuel Emissions Laboratory in Ann Arbor. These tests are designed for comparing the fuel economy of one vehicle to another and are very accurate and repeatable when used in relative comparisons. http://www.fueleconomy.gov/feg/how_tested.shtml

For those that want some serious speed around a race track: http://sccaforums.com/forums/159737/ShowPost.aspx Some lap times: Willow Springs (big track): 1:30.xxx on 140 treadwear street tires. Willow Springs (big track): 1:23.xxx on Hoosier RS03s. Thunderhill: 1:58.xxx on 140 treadwear street tires. Thunderhill: 1:53.xxx on Hoosier R3S03s. On Hoosiers it can run with and beat Radical SR3s.

I'm getting close to closing this thread. You guys need to stop making such absolute statements about this engine vs. that engine without bringing tech to back up your assertions. And when I mean tech, you need links to third party stuff, not just your own opinion.

Ford HD has been around a long, long time and is the normal stuff Ford installs in their medium duty trucks. Its fine for light to moderate track use but it is very hydrophillic and is basically useless once it picks up water. As recommended above, it needs to be changed frequently and (IMHO) its price difference over Motul, AP, etc. doesn't justify the need to completely drain and refill the brake system periodically.

Doubles are $1,200 for 4.

You're not drag racing a live axle car (unless you've done a swap). If your IRS rear suspension is setup properly and you're running a LSD your Z should launch straight and square. You're not battling the lateral location problems caused by alive axle. With a straight and sqaure launch a front ARB has no effect on how the front suspension behaves. No, my logic didn't go that way, yours did. You asked our opinion and I offered mine.

So... you're going 100+ toward the lights and the driver in the next lane crosses into your lane, would you want the front anti-roll on or off the car at this point?

Fiberglass and CF hoods and hatches: http://www.betamotorsports.com

Rim diameter depends a lot of shock choice. The more sophisticated your shocks, the shorter sidewall you can run. With Tokicos or single adjustables you're probably limited to a 45 series sidewall at best. That would mean 15 or 16" rim diameters. For single rebound adjustable shocks your choices are very limited. Carrera probably offers something but I don't know any specifics. The Koni 8610-1149RACE can have the compression revalved fro about $100 per shock and, according to Keith Thomas, there's a Bilstien applicattion P30-0032 that needs to also be revalved to work correctly in a 240Z applicaiton.

Welding medium carbon steel (4130) requires heat management to keep the carbon from migrating together and creating a brittle part. But, there's a lot of misinformation because the processes are designed for thicker 4130 sections then what we normally deal with in the automotive world. So the pre-heat, interpass temp control, and post-heat numberas are irrelevant. Our basic problem is having the part cool too quickly after welding, not too much heat input. Not matter what you're doing you're heeating the weld and a good part of the HAZ to 2,800+ degrees. What's important is to control the cool down and that's why time is spent reheating and "normaling" the weld area.

The Koni 8610-1437RACE is the same dimensions as the 1149 but compression damping had been doubled. For most applications that's OK but in a 240Z its probably too much. If you race on smooth tracks they might work out. For SM2 you'll need at least 265 width tire to run at the national level. I'm currently working with a customer to build a to-the-limit SM2 240Z and we are trying to decide between 295 and 315s.

LLCs tend to be a problem when converting from them to a regular C corporation. LLCs can be a big problem if you're ever planning to go public. But, if you're planning on running the business as a partnership and want the personal liability protections of a corporation then a LLC is a great choice.

It can be for a person with the right personality and drive. I think you'll do fine, but keep an eye on the family. Your are probably going to start working harder then you ever have and its common to take your family for granted. Your wife and kids will support you but they most likely don't share the same zeal or excitement that you do. Keep that in mind as you spend your third week away from home and wonder why your wife is upset that the front sprinklers don't work.

Amir's car was 260Z to start with so it weighed about 220lbs. more then my early 1970. We did remove the side windows and window mechanism, removed the complete interior including the dash, replaced the bumpers with fiberglass, replaced the bumper mounts, driver's seat only, and put on a fiberglass hood. Amir's transmission was a lighter Nissan 5 speed and he was running a R200 diff. The SR20 install was as far back as possible without notching the firewall. Everything was behind the crossmmember and down as far as safe for a road race track. The IC was in front of the radiator and it was big Spearco and the radiator was the big Arizona Z-car one. On my 1970 I still had a full interior, both seats, windows and window mechanisms, steel bumpers, but I did have a CF hood and CF hatch with Lexan rear window. My 240Z had a lighter wheel and tire combination and lighter brake setup. The transmission in my 240Z was heavier and I was running a R180 diff. My radiator was a small C&R with a built in oil heat exchanger. Both cars run fuel cells of the same basic size mounted in exactly the same position. Both cars ran roll bars although Amir's Autopower bar probably weighed less then the Dave Kent welded in 8 point in my 240Z. Ultimately both cars were withing 10 lbs of each other and weight distribution was within 1%. The comparison as far as weight and weight distribution is about as close as anyone is ever going to get. Personally I don't think comparing a stock L6 install with a SR20DET install is fair. If the L6 is moved back and down then you'll find the wieght distribution numbers are remarkably similar once all the SR turbo stuff is installed. Now, a SR20DE install would end up with a more rearward weight bias.

Weight distribution is important but its not "..all that and a bag of chips..." There are a lot of Actura Integra Type Rs running very fast on road race tracks to prove that a 63F 37R weight distribution is not the disadvantage the Internet experts claim it is. Read up on the Chevy Cobalt/Skyline thread to get an idea. That FWD Chevy Cobalt was only 3 seconds per lap behind a 320hp, 2160lb. Datsun 240Z and it was down 50hp and was 150lbs heavier then the 240Z. http://forums.hybridz.org/showthread.php?t=105093 And yes, reducing yaw interia (polar moment) is a good thing because it makes a car more responsive. But, again, its not "...all that and a bag of chips..." and the Porsche 911 is a perfect example. It really all comes down to chassis tuning and driving. A 50/50 car with low yaw intertia theoretically might be faster then a 63/37 car with high yaw inertia, but it all comes down to the guy tuning the chassis and the guy behind the wheel. Either car can win on any given day.

The old "All things being equal..." arguement, which only comes slightly close to reality in a spec racing series. Otherwise, its a meaningless arguement. On that day, the Cobalt beat the Skyline by 8 seconds per lap. At lap 15 in a 20 lap race the Skyline would have been lapped by the Cobalt. Also, please remember, this whole event was part of a larger PR effort by General Motors. It was never intended as an objective test of anything. Real, objective tests are sanctioned race results posted after the fat lady sings, not anything printed in a car magazine.

According to the track guy at Buttonwillow it was 13CCW. A 1:58 is a quick time for that configuration. According to the specs the Cobalt SS made 265hp, 270ft. lbs., and weighed 2,300 lbs. It also had Ohlins multi-adjustable shocks and ran on 245/40-17 Hoosier R3S05s. But, by far its biggest advantage was Heinricy driving the car. Those other guys didn't stand a chance.

The power of HybridZ in action: I walked into Motorsports Auto's showroom the other day to buy some stuff for my 1971. One customer was standing around talking to a few of the other customers about his turbo'd 240Z. When he claims that his L6 is making 500hp and runs on regular gas it gets my interest. I walk up and ask the guy what turbo and what EMS he's running to get that power. He looks at me and looks at my HybridZ t-shirt and says, "Well, it really doesn't make that much power."

Same way a 190hp ITS 240Z beats a 450hp V8 240Z around a race track. Excellent handliing and outstanding driving. Horsepower is not the game in road racing, handling and driving is.

Alex, the "Skatitute."

Man, be grateful! I worked at a company who's boss was a cycling nut. Out of the blue one morning he called everyone into the office and said that today is a "team building" day and we were all going on a 15 mile bike ride around the Back Bay in Newport. He even arranged for a bicycle rental company to supply all of us with bikes and they were waiting for us out front. I just left and went home. The next day 2/3 of the company called in sick or injured and those that did show up had sore asses. No one mentioned my leaving and, in fact, no one talked about that day ever again.

Always remember that Chip got his start working with Boyd.

Well... assuming a stable environment then what they say is true. But in the real world oxidation continues. Exposure to any type of acidic gas or fluid (acid rain, air pollution) will strip aluminum oxide causing more to form. As aluminum oxides form the part actually loses aluminum. That's why bare aluminum wheels need polishing so often and why aliminum pits. That's also why its critical to shield aluminum with an inert gas while welding. Oxygen has such a strong affinity for aluminum that any oxygen present at the weld pool causes cracking because aluminum oxides are formed inside the weld.