Leon

I'm so torn about exhaust options for my 260Z. I've been wanting to get the twice pipes but since the current exhaust is too loud for me, I'm not sure if I'll be able to handle them. I love the sound of the twice pipes though! Here's a clip of my 260Z that I got last month. Sorry about the loud noise at the start of the video. http://s518.photobucket.com/albums/u345/LeonVin/RLS30-004406/?action=view&current=P1010942-1.mp4

That is called a Bricklin. SV-1 to be exact, a very interesting car actually!

Great work, Stepan. Looks like you put some good, quality time into it!

I'd rather have the "mostly" 2.5 inch exhaust because that will give you less pumping losses than a true 2 inch, given it's not completely cobbled up. It's simple fluid dynamics. A 3 inch exhaust pipe won't hurt anything, a 5 inch won't hurt either (except for ground clearance). Once again, read the sticky I linked to earlier. BTW, higher exhaust velocity = higher frictional/pumping losses.

Read the sticky.

http://www.classictube.com/store/index.cfm http://www.classictube.com/store/index.cfm?fuseaction=product.display&product_ID=117593 Obviously, bending and flaring them yourself is a lot more cost-effective.

http://www.youtube.com/watch?v=13JK5kChbRw I couldn't resist!

The reason for my reply was that you sound as if you are complaining about your lack the knowledge on the subject. Instead, educate yourself (from the right sources). Here is my game plan: read, understand, test, analyze results. You can theorize all you want, but in the end, you're going to have to physically do something about it. When it comes down to making modifications you have to understand that failure is part of the game. I try to make my approach nondestructive when it comes to valuable parts for two reasons; (1) it costs $$$/time to replace and (2) those gains are likely to be minimal in the scheme of things. Sure, bore out a 45mm Weber to a 50mm but what will that really get you? Want to find out, then do it. Alternatively, use a 45mm carb and focus on something else, maybe it will be more worth your while. That's what it takes.

I keep telling you (and anyone else that's interested) to buy that engines book and read it. Invest in knowledge. Seems nobody ever takes up that offer. I guess that's the difference between someone that knows what they're doing and 1000 monkeys trying to write a novel...

Those wheels are definitely not the originals and did not come from the factory that way. I'm not sure on the claim that only 2 Z432s being in the US either, as I know the owner of one and have seen it with my own eyes. Maybe I'm just lucky... FYI, the original 432 wheels look like this:

Nope, that works for both. I'd imagine the addition of a spacer would simply mean a longer shank length.

Sure, velocity in an ITB system will promote mixture homogenization but so will the shape of the runners, combustion chamber and pistons. Thus, velocity is not as important in an injected engine versus a carburated one as I said in the original post. When you say "real high performance injection" I'm assuming that you're speaking of F1 and other race-only engines, where rpms are usually (very) high and there is plenty of velocity in the intake to keep the mixture atomized. I don't think they are very concerned about low speed operation and fuel condensation, at least compared to street applications. Plus, those runners are usually pretty darn straight. Port injection is just fine, and much better than carbs (as you've shown), for street and race engines as it has proven in countless applications. Notice I never said anything about needing larger runners, I think you've misconstrued my statement. Yes, it is correct that carbs do need bigger runners to flow as well as ITBs, but that's not what I said. Here is the last part of my post: As you make a runner bigger in a carburated engine, the velocity of the mixture decreases, therefore you have more fuel condensing in the tract. With a port injected ITB setup, fuel atomization is not dependent on manifold velocity, therefore you can utilize larger runners without detrimentally affecting performance or driveability. That's what I meant by that statement, nothing about matching performance.

Whether it's a Z or a Triumph or a bike engine, the same principles apply. As this thread discusses, the header and the collector pipe are the tunable aspects of the exhaust system. You're talking about tuning the secondary/collector length. This is what you would do with any engine's exhaust. Trust me, buy the Heywood book and read it. You will have many more revelations reading that book than browsing the internet or consulting engine builders...

Intake velocity is much more important in a carburated engine where the air-fuel mixture must travel from the throttle body all the way to the cylinder, through the manifold. This is because at higher velocities, pressure decreases and the fuel is better atomized. As velocity decreases, pressure increases and the fuel begins to pool in low spots and on manifold walls. The need of the fuel to vaporize is also another reason why manifolds are heated, at the detriment of performance. If you go with ITBs, manifold velocity will be less important when compared with carburated engines. That is another advantage of port fuel injection, you can have big runners that promote flow yet fuel delivery is not affected as it would be with a large-manifold, carburated engine.

Josh, you may want to re-read the thread, as I think you missed the point of the post you quoted. Here are the parts of post #13 that you didn't quote: Therefore, you want to correctly size the header and collector in order to tune the exhaust system. Again, you're very focused on velocity but that's not the only, nor the biggest thing that drives exhaust (or intake) tuning. System resonance is what really drives this phenomenon. I think I already mentioned it earlier but I'll reiterate. In the exhaust system, as the valve opens a compression wave is sent downstream to the header and collector. At a discontinuity, such as the collector, the compression wave reflects back upstream as an expansion wave. If this expansion wave reaches the valve right before it closes (after the peak in the valve's mass flow) it creates a secondary peak of mass flow-rate through the valve by essentially sucking out (technical term ) more gasses. Therefore, you size the length of the header and collector based on parameters such as valve duration, pipe diameter, exhaust temp, etc. This stuff is more complex than just "keeping the velocity up" as many think. Tony's car is a prime example of this, where the header/collector is tuned and varying the long pipe out back at best doesn't affect anything (but noise), and at worst starts robbing more and more power. I highly recommend getting this book and reading and understanding as much as possible. If you don't "get" something, then post!

Here's an idea, start it even earlier, Cossie style!

Same here. You should be able to take that misalignment out by playing with the slots.

Just use the slotted adjustment available at the bolts that mount the hood to the hinges. There are two on each side. Your hood is cocked to the right side, so adjust the left side down. You have to keep iterating until you get it just right. It takes patience and having another person to help, but I've done it by myself with good results.

A smelly exhaust can be caused by many things, a few already mentioned here. Your mixture may be too rich, you may have leaking hoses in the engine bay, an exhaust leak, expansion tank hose leak, etc... People have put catalysts on their carburetted cars and reported that the smell is much less severe. You just better have your mixture dialed in or you'll destroy the converter. Otherwise, switch to EFI as Jon put it. Like I initially said, the main problem comes from the aerodynamics and 40-year-old rubber seals of the Z-car.

Frankly, if you really read all the threads on cabin fumes, the answer would be given to you. It has to do with the aerodynamics (or lack thereof) of the Z. There is a large wake, a low pressure area, behind the car which traps the exhaust. Opening the windows drops cabin pressure, exacerbating the issue. Sometimes I run the fan, which helps but gets annoying when turned up.

PM'd

BJ, you're probably thinking of zhome. Scroll down to "Production and Sales History" and go to "Production Figures." According to my arithmetic skills, the number is 148,115 240Zs and approximately 426,447 S30s. I only counted the US figures, but you can add in the rest if you desire. EDIT: Now that I look at the chart below, I believe the total amount produced is 575,954.

Haha, touché! Great cars by the way, I would've never realized that white looks good on a Z.

The stock brakes are adequate. Friction material selection is critical to proper brake function. Organic materials will work better at lower temperatures and semi-metallic materials are more well suited for high temperature. There are options in between so you can essentially pick the right friction material for your situation. The pedal may get softer, but you should not lose brakes to a point of it being dangerous if you're using the right pads and shoes. Like has been said, switching to rear drums is better for consistency because of the tendency of drums to expand under heat and inherently not dissipate heat as well as disks. If you race and the rules allow it, I'm sure it's a worthwhile upgrade.

Metal actually weighs more after oxidation, since it picks up those pesky oxygen molecules! Sand it down to lose that weight!