Leon

Ah, that sucks. I was planning on asking them about that, if I ever needed a new one. Looks stock to me, all stock downpipes I've seen have the piping sticking out from the flange. Now whether it's stock for a 240Z manifold, or 260Z, or 280Z, etc. I'm not sure.

IMO, the biggest reasons for the discrepancies on what "fits" and what doesn't is that it depends on what front valence is used and what exact tire you're using. The Xenon air dam allows for more tire up front compared to the stock valence. Also, there is a fairly considerable variation in size when comparing what seems to be the same tire between multiple manufacturers. Some will be wider, some will be taller, and some will be the opposite or a combo of those. Having said that, I thought I saw a thread before detailing exactly what works and what doesn't with the 16X8 Rotas. FWIW, I had 225/60-14 on a zero-offset 14X6 wheel and now have 225/50-16 on a 16X7 wheel with zero offset (maybe a tiny positive offset, not 100% sure). I've had no rubbing issues on either one, fenders are not rolled.

You could find a used one in the classifieds or the small Z-parts businesses (Z-barn, zparts, Z-Specialties, etc.). A quick search says you can get a brand new, billet spray bar from Larry Hassler at 626-358-2885. From: http://forums.hybridz.org/index.php/topic/102501-spray-bar-mia/

You NEED a new spray bar if you want that engine to run ok much longer! Do not try to repair the one you have if that's what you're thinking.

True, but only if the car is running VERY rich all the time. If you only get soggy at a certain condition, your plugs, exhaust, etc. will appear perfectly fine. My point is, you could be lean or rich, don't assume one way or another without hard evidence. Check all possibilities. My triples are jetted too rich right now. There is no black smoke and plugs look great, but I cruise at about 11-11.5 AFR. Sometimes I even drop below 11 AFR but I wouldn't know it without a wideband. WOT mixture is a bit leaner, maybe 12 AFR and there are no issues with bogging at that AFR.

I'm not sure on how you determined that it is "definitely going lean". Do you have a wideband? If not, then my first thought is that you're flooding the engine with fuel. The SM needles and 5 psi of fuel pressure are the likely causes. The fuel shooting out of the float bowl is a clear sign of this. Make sure your floats are set correctly as well, some SUs had different float heights front-rear depending on year.

There is no "best". Take a look at the exhaust sticky if you want detailed information, but if you want more low end torque then use longer primaries (collect further down) and vice versa for efficiency at higher rpm. I'm doubt there is a huge difference between the factory manifolds, but I don't have enough experience with those to verify. You can play with the 2-1 merge for minor gains at lower or higher rpm, depending on where you put the merge. Exhaust Design Sticky

I believe MSA sells new downpipes with some of their exhausts. I would call and ask, and you have the luck of being local and being able to save on shipping.

$50? I'd give him $20 and hang it on my wall.

No problem, glad to hear that. Nice job!

You're probably not getting enough voltage to the starter solenoid from your wiring. Measure voltage at the spade on the solenoid with a multimeter and have someone turn the key. I don't remember the exact excitation voltage needed at the solenoid, but over 10V should get it going. The solutions are to either clean all connections for the starter circuit or install a "starter relay" (search this). The flywheel has nothing to do with idle quality. Torque = Inertia X angular acceleration If the engine isn't changing speeds (accelerating), e.g. at idle, then it doesn't care how much the flywheel weighs. Everything else points to a vacuum leak. Do the spray test before anything else.

Care to post the answer, to archive for the search engine?

Yep. Dynojets are plain, inertial-drum dynos, which measure how quickly your wheels can spin up a drum of known weight. Power is calculated as Torque X Speed. Torque is calculated using T=Ia, I being rotational inertia of the drum and a being acceleration of the drum. This is a less accurate way of measuring actual power, since you're inferring power from how quickly you accelerate the drum. This also means that changing things like flywheels, brake rotors, tires, driveshafts, etc. will show a change in hp on a Dynojet, even though your engine isn't making any more power. Conversely, something like a Mustang dyno is a "brake" dynamometer, which uses a fluid or electromagnetism to put a force on the roller and against the wheels. These types of dynos measure (not calculate) actual torque delivered to the drum by way of a lever arm connected to the brake and a load cell that measures force at the end of the lever arm. This force is used to calculate torque, which is then used to calculate power, using Power = Torque X RPM. Therefore, a brake dyno (e.g. Mustang) provides a much more accurate depiction of actual power than a purely inertial dyno (e.g. Dynojet). My apologies for the tangent!

Brake bias is not a "set and forget" kind of deal, this is why cockpit-adjustable proportioning valves exist. As previously alluded to, weight transfer changes depending on the level of grip. Production car brakes will be set to best grip scenario, i.e. in the case where you have the highest amount of weight transfer to the front. Thus, the brakes are tuned to be heavily biased towards the front. Tuning the brakes to best-grip is safest, since the fronts will always lock first, no matter what surface you're on. If you tune to wet conditions, you will have too much rear bias for when it's dry. This causes an unstable condition since you'll be locking the rears before the fronts and going for a ride on the carousel. Therefore, you must tune the brakes with the same grip conditions as you plan to experience on the track. Ideally, you'd be tuning at the track, but as long as you're using the same tires and similar ambient conditions, you should be close. If you want to set your brakes for the wet, you'll have to go through the same procedure, increasing rear bias until the fronts lock just before the rears. This gives you two distinct rear bias settings, "dry" and "wet".

Exactly. Runner geometry should be based on having as little pressure drop as possible, while having them tuned to your specified rpm range, i.e. "resonance tuning". Tuned rpm depends on intake length, diameter, air temperature, and valve timing. Generally speaking, a longer and/or narrower intake tract will be tuned at lower rpm, and a shorter and/or wider runner will be tuned at high rpm. Holding runner geometry constant, increasing cam duration will shift your tuned rpm range higher and decreasing duration will shift your tuned rpm lower. Temperature plays a more minor role. Keep in mind that frictional losses increase with the square of velocity, which is inversely proportional to the square of the diameter! With that said, these properties would push me to use as wide of a runner as possible, while matching it up to the head port, and varying intake length to get my tuned rpm. Air horns or a taper cast into the intake at the proper location will widen your tuned rpm range and a radiused entrance will decrease entrance losses. That should give you a start!

You can always cancel the transaction before they ship!

I'm not discounting nor debating the merits of your project. Try to internalize what I've said (wrote), instead of picking one aspect and debating it. We're talking about building any sort of car. Who said "aero" or non-"aero"? Maybe my L28 Roadster is going to have a splitter, and a huge wing. That's not the point... I'll repeat: With an understanding of the dynamics involved, you can make almost anything "work" right.

Seconded. I bought a cheap ebay Champion radiator and it's been cooling great. It's been on the Z for about a year and a half.

Like NewZed said, the difference between a 3.54 and 3.9 is small. I doubt fuel mileage would change much, if at all, and your top speed is limited by aerodynamics, not gearing. You'll be fine with either, but I'd probably opt for a 3.54 if you have a torquey turbo. I'd save the 3.9 for something a bit more tightly wound. Here is a great site to compare gearing, numbers and a nice chart: http://webspace.webring.com/people/cz/z_design_studio/

I wouldn't mind at all. Hell, I'll help install the shocks right there in my driveway if that were the case!

Could you elaborate on whether the aforementioned required octane rating is RON, MON or API? An N42/N42 will run on 87 octane with ease. I run 89 in my L24/E88 and the E88 has machine shop scribes, so it's possibly slightly shaved (don't remember if it has cam tower shims, but comp is likely a bit over 9:1).

I don't drink, so you'll be sipping on a beer whilst I pop open a fresh, cool bottle of Martinelli's apple cider. There is something you need to understand, however. Like I said earlier, one thing like weight distribution (that LONGER engine under the hood) is not going to kill a design, nor is it going to make it a winner. Staying true to the point, just because you put in a V6 into the Roadster absolutely does not automatically dictate that you've improved any of those attributes you mentioned. The answer to this question is simple: Because I (or you, or he, or anyone) want to. There is no "optimized purpose" but rather there is a design intent and the car is modified in order to fit within your specifications. I'll repeat, 50-50 is not "perfect" weight distribution, because there is no such thing! You may still be skeptical, but Formula 1 cars and many other race-cars do not have 50-50 weight distribution. They are rear-biased, some more than others. Are you going to walk up to an F1 engineer and tell them that their weight distribution is not perfect? The chassis can be tuned to your liking, and there is a compromise to every decision. A well set-up 70/30 car can outhandle a poorly set 50-50 car. It's all in the chassis tuning. Rotational inertia and traction to the rear wheels are the extra pieces to this topic, the merits of which I brought up in a previous post. You want an autoX car to be able to dance around cones because of low inertia, but do you want a Bonneville LSR car getting squirrely or spinning at 200mph because of low rotational inertia? Like I said, it all depends on your design intent. What's perfect for one is crap to another!

I have a bingo!

I have a used set of KYB GR-2s that I pulled when I did a suspension rebuild. All are in good working order, and likely not a lot of miles on them (I removed them shortly after I got the car). They're boxed up and ready to be shipped, send a PM if you're interested!

FYI, the dyno numbers you're getting are likely "corrected" so temperature differences are already accounted for. Any overlaid dyno sheets from the Mustang dyno? Glad to see the hard work led to some gains.