Leon

Fairly loud. I have two glasspacks per pipe, and it's almost too loud on the freeway and kind of obnoxious when I get on it. I do like the sound, but I also really like the deeper sound of those twice pipes that you posted. Actually, I can try to stop by tomorrow after work, if I take the Z to work like I plan to. I'll shoot you a PM.

Actually, NOx emissions peak around 16.5:1. At 19:1, NOx levels likely drop down to where they were at ~14:1, or lower, as combustion temps keep dropping. If you can actually run your engine at a consistent 19:1, your NOx emmissions are fine. However, if you're having intermittent incomplete combustion (likely, especially with an older engine at 19:1AFR), then HC will skyrocket from these misfires. This is yet another common fallacy, so bear with me on this one. Burned gas (combustion) temperatures are dropping as the mixture leans out, not increasing. Higher cylinder temperature means higher cylinder pressure, higher cylinder pressure means more torque. Otherwise, if temps were increasing as you went leaner, you'd get best power from an engine by running it lean. This is not the case. The maximum combustion temperature point is slightly below stoichiometric (e.g. rich, about 13:1). This is because the dissociation of certain chemical compounds in the cylinder presents a little bit of extra oxygen, which can be taken advantage of by putting in a bit more fuel. Formation of NOx depends on temperature and the amount of O2 present in the exhaust gasses. The reason NOx is a maximum when the engine is lean (~16:1) is because as the mixture is leaned out, rising O2 concentrations initially offset dropping combustion temps. This is akin to the torque and power relationship. The torque curve has a peak (dictated by the engine's design) at a certain rpm. Power is an equation dependent on torque and rpm (generally speaking: Power = Torque X Speed). Look at engine ratings, the rpm where max power occurs is always higher than peak torque rpm. Why? Because the increase in rpm initially makes up for the loss of torque. Same thing with NOx! Except now you can look at combustion temps as the "torque curve" (maximum dictated by AFR, at ~13:1) and O2 concentration as the "engine rpm" (keeps increasing). NOx is your "power curve". As combustion chamber temperature begins dropping, O2 concentration increases. The initial increase of O2 offsets the decrease in temperature and therefore increases NOx to a maximum when slightly lean. After that, NOx drops back down. Reference: "Internal Combustion Engine Fundamentals" by Heywood

The thought did briefly pop into my head! However, it's a lot of work, for which I have absolutely no time and I'd have to go through a bit of a process to make a swap like that legal in CA. It's a cool car, but I'm essentially looking for a "plug-and-play" (turnthekey-and-play? ) kind of thing.

Anyone up for a Ferrari into S30 swap?

Apparently, the holes in the flywheel for the pressure plate are not tapped deep enough for the stock bolts. If this happens, you must use shorter bolts in order to make sure that the pressure plate is clamped down properly. http://forums.hybridz.org/index.php/topic/57299-ordered-a-105lb-fidanza-flywheel/ http://forums.hybridz.org/index.php/topic/100321-fidanza-flywheel-act-clutch-install-and-pedal-mods/

Bobby, thanks! That's the kind of post I love to see! You are completely right about autoX or track driving not dictating the purchase. I realize that it's probably less than 1% of the driving I do and choosing a car for that 1% would be a bit silly. This car definitely has to be one I can live with day-to-day. After all, I have the Z if I want a harsh ride, virtually no sound insulation, loud exhaust, no heater, no defrost, and no power steering! I really appreciate the mpg numbers, I thought the M Coupe would get better than 26mpg but I'm not surprised. This is the draw of the S2000 and Z06, both are seemingly capable of 30mpg without much trouble. On the topic of the sunroof, I now realize that (in the M Coupe's case) it actually adds a bit of headroom, so that eases the search. Maintenance is the other big thing. The typical ~$15k M Coupe will need a few things, whereas the S2000 should be good to go. The Honda's reliability always pulls me back to the S2k. Plus, I do think the S2000 is very good looking, although it doesn't have the presence of an M Coupe. I will be doing my due diligence to figure out what I really want. More test drives to come, hopefully I'll hop into a Z06 soon!

Use heat to break those flywheel bolts loose, the installer probably used loctite. BTW, from the looks of that flywheel, you bolt in new friction material instead of resurfacing.

And when you do get a spark, make sure you index the VR sensor to 6 teeth from the missing tooth at TDC. Six teeth is 60 degrees (for 6-cylinder), 5 teeth is 50 degrees (for 8-cylinder).

I'll measure things up to be sure everything is properly fastened, and then not worry about it.

Ah, thanks for reminding me! I completely forgot about that!

Well, I took a look at and drove this M Coupe today. These cars are definitely smaller than they look in pictures, similar to the S30 actually. I fit, but not much room for a helmet, save popping the sunroof. Overall, it's really just a smaller, lighter, quicker M3. It's sort of reminiscent of the E30 M3, except with more power (and weight). It has a ton of torque (compared to what I'm used to) and a nice kick at higher rpm. What I didn't like about this particular one is that upon inspection I found that it was hit in the front (new hood, left fender, bumper, headlights) and the front bumper did not align correctly. There were some slightly bent parts up front and some foreign-looking metal piping in front of the radiator. Shock mounts definitely need replacing and likely bushings, among other parts. There was no service history, and the guy was convinced that unmaintained E36 cooling systems are nothing to worry about. The salesman didn't seem like he really wanted to sell the car, even though it's been on the lot for 6 months or so. Apparently, he knows what these go for and everything else there is to know about cars... I'm casually on the lookout for a nice Z06 in the area, other M Coupes and the S2000 is still in very strong consideration. We'll see how much pain Christmas will bring to my wallet!

Finally!

Bigger tires in the back will increase understeer.

!!! Amazing find, that is just awesome!

5-speeds were offered as options (US) starting in 1977, and standard by 1979.

You do not want to direct air underneath the car, but rather the opposite. The radiator should vent to the hood. Simply put, you want air pressure to be higher above the car and lower below the car (aka: downforce).

It's always one or the other, with $ and time! If you have both, you are a lucky man. Lightweight flywheels are a fantastic upgrade, I may have to devote a weekend to get this done. I'll be ordering a new transmission mount (hopefully ridding myself of some high-speed drivetrain vibration), clutch and clutch master (just in case) tonight. I should also take a look at the shifter bushings while in there. If you want the 280Z 5-speed I can sell it to you cheap, I don't feel like storing it once I swap over to my ZX unit.

It should definitely be noticeable. I plan to put in a new clutch and transmission mount in the process. I will also be swapping out my 280Z 5-speed in favor of a 280ZX close-ratio unit I have sitting around. Time to find a chunk of time to do this, I think that is more difficult then actually doing the rest of the work!

Nice looking torque curve, that car must be very fun to drive!

This may just be the most awesome 280ZX I've seen, just because of the engine! Great work so far, can't wait to see this beast run!

I think a flex-pipe is more necessary on a transverse mounted engine, where the exhaust tilts up and down with engine torque. I don't worry about it as much on a longitudinally mounted engine, since soft exhaust mounts should be able to accommodate the slight bit of twist (unless your engine mounts are screwed). Nice job, seems like you're moving along nicely!

Good point JM, but the gearing difference between the cars will not be a "make it or break it" kind of thing. However, for the hell of it I compiled top speeds in second gear for the three finalists! M Coupe (S52) - 61.7 mph S2000 (AP1) - 66.3 mph S2000 (AP2) - 60 mph C5 Z06 - 71.5 mph

I drive like a grandpa on my commutes, meaning 65mph or slower and in the right lane. I get on it only when I need to pass or merge onto the freeway. It helps save gas (100mi round-trip commute), lets me relax and keep my sanity. Plus, I've never had a ticket (knock-knock-knock on wood ). Since I keep my speed down on the freeway, low gearing is not a problem and I actually prefer it. AutoX and spirited weekend drives are another thing altogether!

I believe THIS is what you're looking for.

I believe the Fidanza units are 10.8 pounds. This is compared to a stock flywheel which weighs in at something like 25lb!