74_5.0L_Z

I'm in.

So far, I love the Odyssey battery. I moved it to the shelf behind the passenger seat. By changing to this battery, I was able to remove 30+ pounds from the car. Also in doing so, I have reduced the polar moment and lowered the CG (just a tiny bit).

The number that I used in my Quarter2.xls program should not be taken as gospel. It is a number that I arrived at by analyzing the coast down graph published in the 1970 review of the 240Z by Car and Driver. What I did was pick two point on the coast down graph (80 mph and 20 mph) and estimated the slope of the curve at those two points. The slope of the coast down curve at any point corresponds to dV/dt. Using the instantaneous accelerations at those two points, I solved the following : m*dV/dt=CdA/2*Rho*V^2 + Cr*V + C In this equation dV/dt was estimated from the graph at two points. V is the velocity at the two points chosen. Rho is the density of air C is a constant value that I used to account for the force needed to start the car moving from rest on a flat surface. The variables CdA and Cr are the drag coefficient times frontal area and the static rolling resistance. The units of CdA are ft^2 and the units of Cr are lbf/mph. One factor that I neglected in my original analysis was the inertia of the wheels and tires. To account for this the inertia of an original equipment tire, wheel and brake assembly would have to be measured and the equations would need need an additional term. m*dV/dt + I* dw/dt = CdA/2*Rho*V^2 + Cr*V + C where the term I x dw/dt is the mass moment of inertia of the rotating parts times the change in rotational velocity. Although I was trying to be as accurate as possible, it should be remembered that I made the Quarter2.xls program for fun. Even neglecting the inertia of the rotating assemblies, I believe the number to be accurate within +/- 15%. As stated on the downloads page, I welcome input to increase the program's usefulness and accuracy. Dan

My roll bar is angled back at a 10 degree angle, and is hard against the wheel well. This angle puts the roll bar parallel to the trailing edge of the front part of the quarter window.

I am in the process of replacing the stock seats with aluminum racing seats with the side bolsters. This in combination with padding should go a long way towards protecting my ribs. Oh yeah, I do have 5-point harnesses in the car.

I had similar design requirements. I have more several images in my album. http://album.hybridz.org/showgallery.php?cat=500&ppuser=7833

Fits fine if the engine is installed in the same position as mine.

Be careful with that last statement. Don't be too cheap. Stay away from the KYB gas struts. They are cheap, but are way too stiff in bump and too loose in rebound. I am using the Koni 8610-1149 with 250 lb/in rear/ 200 lb/in front. I don't find the ride very harsh, although I don't drive it on the street very much. If your going cheap then get the cheap konis or illuminas.

Be careful with that last statement. Don't be too cheap. Stay away from the KYB gas struts. They are cheap, but are way too stiff in bump and too loose in rebound. I am using the Koni 8610-1149 with 250 lb/in rear/ 200 lb/in front. I don't find the ride very harsh, although I don't drive it on the street very much. If your going cheap then get the cheap konis or illuminas.

I can't quite put my finger on it.....

I have made one other set for someone else, and I have a fixture for making more. I am a little shy of making them for others to to the possible legal ramifications (I am not an LLC). The other issue is price. It costs me ~$400.00 to make these ($300.00 in materials and $100.00 to have them welded). In this thread, I discussed the control arms at length: http://forums.hybridz.org/showthread.php?t=91888&highlight=control+arms

Try these guys: http://www.velocity-of-sound.com/commerce/search/index.php3?merchant_id=2107&keywords=&search_type=ANY&custom_store_category=8&by_category=+++GO%21++ They look interesting, especially if I were making my own.

I knew that was true for the thin 4130. I just wasn't sure about the 4140 due to the higher carbon content.

I used 4130 for my control arms. 4140 has more carbon content and is therefore less weldable and more prone to crack if not subjected to PWHT. Johnc is much more knowledgable than I on this subject, and I hope that he will correct me if I'm wrong.

Reverse the master cylinders. The smaller master cylinder applies more force than the larger one.

My pedal is fairly light, and the clutch disengages about halfway through the pedal throw. I have a Wildwood 7/8" clutch master cylinder and a Tilton hydraulic throw out bearing. The details of my clutch set-up are in some of my older posts like this one: http://forums.hybridz.org/showthread.php?t=87797&highlight=clutch

My combination is set-up for autocross, so I don't use drag slicks. My car weighs 2700 full of fuel with me in it, and has ~320 hp at the rear wheels. I am using the king Cobra clutch disk and pressure plate. I have had no troubles with clutch slippage since I installed it. I don't know how this clutch would perform under hard launches with drag slicks, but for me it works well.

I am using option D (Outlaw stage II) on the front, and my own version of a stage II on the rear. For the rear, I am using the outlaw 2800 calipers with 1.625" pistons, 1985 maxima front rotors, and custom adapters.

Well, after everyone's input, I have ordered the PC680MJT. It should be here in a few days. After it arrives, I will relocate my battery from the area behind the passenger side rear wheel well to the little shelf behind the passenger seat. This is about the easiest 30 lbs, I have left to remove from the car. In addition, relocating the battery will have the added benefits of a slightly lower CG and PMOI for the car.

Thanks for the reply. The Odyssey PC680 is a definite possibility. Is the car that you use it in a daily driver? Is it race only? How long have you had the Odyssey PC680 battery?

I was browsing the web for lightweight batteries, and I came across the brailleauto web-site. They have a couple of batteries that are extremely small and light (11.5 lbs for their race version and 15 lbs for their street version). http://www.brailleauto.com/ Has anyone had experience with these? Will it be compatable with my PowerMaster 100 amp 1 wire alternator? They seem like an extremely good way to shed 30+ pounds.