Leon

I second that notion! GRM has made me drop my R&T subscription, which I have been disinterested in for a while now. It's always a good, informative read (and they love Z's!).

Were the wheels spinning in that test? Nope. Spinning wheels, especially at high angular velocities will create a lot of drag, so much so that it is very beneficial to block off the wheels as much as possible.

I'm 6'2" 185lb, and I am amazed at the roominess of the Z. There is plenty of legroom with the stock steering wheel and enough headroom for me to wear a helmet. I do also fit in an S2000 however, or maybe I keep telling myself that since I want one!

You took the words right out of my mouth (and the picture out of my brain)! Thanks for posting Ron, I was going to eventually if no one else thought of simply changing the geometry. How lazy I've become!

I know this is a bit old but I wanted to add my two cents... The answer is yes (kind of), and it's because of the engine's volumetric efficiency (VE). VE is the measurement of the engine's ability to completely fill the volume of each cylinder. Having 50% volumetric efficiency would mean that at an arbitrary operating point, the cylinder is being filled with air (and fuel) at half of its capacity. The volumetric efficiency curve will essentially resemble the torque curve that you see in dyno plots. What this comes down to is, around peak torque, your VE will be maximized meaning that the cylinders are being filled as much as they can be with air. Thus, at peak torque, you will likely tend to have your leanest AFR given that the engine is fueled linearly with respect to MAP (manifold air pressure). Of course, with standalone/tunable ECUs you can tune your AFR to whatever you like and if you want to run it rich to be on the safe side, you're probably not losing much power (although you are using more fuel and dumping more crap out the tailpipe). So I guess this only half-answers your question, as I'm not sure what would be the best AFR at each RPM point given the ability to tune the AFR at every point. It would be something to test on the dyno, by loading it up and playing with the ECU fueling curve to see what gives you best torque. So maybe I didn't really answer your question at all, but hopefully it will give some insight as to what is involved in getting an answer.

I also agree with oz's assertion that it's the cam. The 280Z's cam is already designed for low end torque, and by advancing it you are shooting those cylinder pressures even higher. I think retarding the cam a bit, or going with a longer duration cam should bleed off the pressure enough to prevent knock while holding the timing where it is.

Motorsport Auto, scroll down for info. It is in the Los Angeles area. It's a start...

Please follow the rules you agreed to, rule #5 to be clear. I really don't like reading stuff like this.

I was reading up on exhaust stuff, got bored, but felt like doing something semi-productive. This graph shows the relationship between pipe diameters and cross-sectional area, and the differences between a single and dual arrangement in terms of area. Choose a pipe diameter, find it on the graph, and follow the horizontal lines to find an equivalent diameter. The abscissa represents single pipe diameter (even for twice pipes) and the ordinate is total pipe area. For example, it can be seen that choosing 1.75" twice pipes (MSA) is equivalent in area to a roughly 2.5" single pipe. Enjoy...

13257-21000

Daeron is talking actual power, not differences from stock. And BTW, an L24 does not make near 200hp stock! It's closer to about 120-130whp (150bhp). You'd have to put in a considerable effort to get to 200whp. I agree that tackling the (likely poorly maintained) suspension first is the way to go. Do that and then drive it with a stock engine. You don't need 300hp to have fun! When my 240Z was on the road it ran pretty badly, partly because it was a $400 240Z. It very likely had under 100hp, and I had plenty of fun!

Nope, it's back on the presses! How to Hotrod and Race Your Datsun

I got my information from an F1 senior engineer. I guess that doesn't count...

Very good point Roger, and it reminds me of something along the same lines. Compare a Z to a 599 that was mentioned and the weight differences are relatively huge (~2300lb vs. ~3700lb)! The effective mass of the wheels will affect Z-car performance (i.e. time-to-speed) much more than a heavier car, meaning that the effective mass of the wheels is a higher percentage of total mass of the Z vs. Ferrari. Thus, the effect of larger wheels is much less noticed on heavier, more highly powered cars. Conversely, a reduction in weight of a Z's wheels will affect performance more than a reduction of the Ferrari's wheel weight.

http://zhome.com/ 07/1973 - "260Z Production Starts at RLS30 00001"

To the contrary, you want sidewall, just not soft sidewall. This "I have been told" talk is also not proof of anything. I have been told also, except by a former Formula One senior engineer and he doesn't agree with you.

Possibly, but I would not call those sidewalls "very little." Tire compliance is necessary, and you especially do not want a tiny sidewall for a race tire. As Jon mentioned earlier, you gotta put those big brakes somewhere.

Engine Drop No hoist? No problem. Two car garage? No problem. Use some jacks to drop the engine down. Once the engine was down I took it off the jacks and put it on a thick piece of cardboard. I had my brother grab the radiator support and lift the car while I slid the engine past the lower rad mount. It was my first time so it took some time, but I was definitely satisfied. Oh, and don't forget to (completely) drain the block of coolant...

That is not my conclusion, nor is it what I say. You seemed to have misinterpreted my post. Take another look at it...

I completely agree with Daeron. Tire compliance is a big issue when considering predictable handling. The shorter your sidewall, the less compliance you have. Let's take it to the extreme: Look at those tires! Do you see F1 cars running 20" wheels with no sidewall? Now I know that those tires are very different from what we run on the street, but if it was truly beneficial to run relatively big rims and small sidewalls then I think F1 would seek to do that. Besides, for myself at least, even 17" is pushing it on an S30. 14-16" seem to fit pretty darn well, IMO!

Ok, I suppose that my statement is not true in all cases, but given a heavier wheel and maintaining a constant diameter you will want less wheel and more tire. This is all very general and should be looked at on a case-by-case basis as JM points out.

Buy less tire? Do you mean go for larger diameter wheels, or just go to a lower profile tire? Rubber weighs less than metal, so having more metal in the wheel will increase unsprung weight even though the tires are of a lower profile.

I was at a winery this weekend and happened to see some spicy jam! Now, usually I'd grimace from the thought of such a mixture, but I remembered this thread and thought, "why not?" Opened my 10oz jar of Mango-Plum-Ginger jam today, and now it's almost gone (had help from others too)! Good stuff, I like the spicy sensation with some sweetness. This one has jalapenos and Thai peppers, but it isn't very spicy at least to me. I'll have to find a recipe... BTW, the jam came Oregon. You guys are pioneers!

I was surprised at the price, I definitely think there would be a market for these, although not a big one. I wonder how hard it would be to make it street legal, if you really wanted to...

Just came across this! I had no idea anyone was producing these. Looks pretty legitimate. I wonder if the GRP can withstand the stresses, how well its reinforced, and the design of the tube frame ...