Leon

Looking good. Do you have the part number for the merge collector? I plan to go single eventually as well, I may have to take some elements of your design if you don't mind!

My Z's don't have EGR, so I don't know. However, you will automatically fail smog for no EGR on your ZX.

I'm not sure about the 280Z, but most modern EFI systems have a "flood clear" mode, i.e. if the TPS detects WOT at cranking the ECU will turn off the injectors.

Clive! You're not allowed to post porn on hybridZ!!!

As for the carb-manifold interference, how about some thicker soft mounts between the two? Like seen here: http://forums.hybridz.org/index.php/topic/109179-triple-40mm-mikunis-and-n42-head/page__pid__1021537#entry1021537 I know Dave (cygnusx1) made a bellcrank to use the cold start units with minimal hassle.

Yes, enjoy it! I try to work on the Z only when I'm satiated with driving it around and/or some issue is really bugging me.

"Finish" it up and drive it for a while. After logging a few thousand miles, you'll have a good list of stuff to do, believe me!

Bingo.

That's great! I'll be doing this eventually when I get back to work on my 240Z shell (whenever that will be ). Good write-up!

Nicely done! A bit less cumbersome than the 1st iteration. It will be nice to have cruise in the Z for those long highway trips.

Looking good! I'm digging the Clifford Research header. Let me know if you have any questions regarding Megajolt.

Sounds like a damper issue to me. You are having to soften the Tokicos, which have very stiff compression damping, a lot in order to be comfortable. However, given the "bounciness", this says that the spring rate/damper combo is now very underdamped, meaning that the damper has less control of the spring/mass. A damper with relatively stiff low-speed damping but softer high-speed damping should still perform well, while riding better. I'm hoping to find a damper that can accomplish this and accomodate a Z coilover install as well, as my Z has Eibachs/HPs now which ride rough and have very little bump travel before the ES poly bumpstop (which I haven't cut, yet). The nicer bump stops should help too, if you hit them often. Just take a look at a bumpstop some time and it will be pretty obvious whether you're been riding them or not. A lower unsprung/sprung weight ratio will improve ride and generally decreasing unsprung weight (wheels, tires, brakes, some suspension parts, etc.) will have a positive effect on ride, handling, acceleration, braking and traction.

You're right on the former bit, but not the latter. Higher velocity generates more "backpressure" (pumping losses).

I always have a pair in the car, can't go more than 30min without them.

I swear to god, I'm gonna pistol whip the next person that says "back pressure"! Read the exhaust sticky. FWIW, I like the first video after he added the resonator. Nice, crisp sound. My next exhaust is going to be a 3" single, have 2" duals now (L24).

Right, although that's without taking d into account.

You did the math wrong, again.

Donate $20 to the site and list it in the classifieds here. A good body shouldn't be too hard to sell, probably fetch $400-500 or so depending on condition.

Just a little bit of algebra... You're using: f=nv/2(L+.3d) You have a known frequency (f), speed of sound (v), pipe diameter (d), and the harmonic you're shooting for (n). You want a length of pipe that accomplishes this. This means solve for L: Multiply both sides by (L+.3d): f(L+.3d)=nv/2 Divide both sides by f: L+.3d=nv/2f Subtract .3d from both sides, and voila: L=(nv/2f) - .3d Then as they say, "plug and chug". n=1 is 1st harmonic n=2 is 2nd harmonic n=3 is 3rd harmonic ... [edited typo]

FWIW... Flow=571.3CFM @ 7000RPM As I thought, you were using the percent value for VE instead of actual VE (decimal).

The higher the rpm, the higher the CFM, the LOUDER the sound. There is no formula relating CFM to frequency, as we've said, that doesn't make sense. The amount of air flowing through the pipe will change its volume (or "amplitude" as zero already mentioned), not frequency. You make it sound easier than it really is. There are a bunch of waves interacting with each other, especially in a multi-cylinder engine. How are you going to deduct a given frequency from before the X-pipe to after? In other words, how are you going to relate what the engine is doing to what's coming out of the end of the pipe? As zero already mentioned, differing lengths of primaries will cause the waves to reach each other at different times thus resulting in a different (average) frequency. I covered this in my first reply. N represents the harmonic that you're calculating, e.g. N=2 to calculate the 2nd harmonic. I don't really get what you're doing here. Aren't you trying to solve for frequency (f=261Hz)? In that case, to get the middle-C frequency of 261Hz, the length of pipe needed in your example would be 25.5 inches (.65m). Secondly, I think you made an error in the calc you did. With speed=343m/s, L=1m, and d=0.0254m, f=170Hz. Since N=1, this is all based on the first harmonic.

Nice, I was just about to post that. Fifty-seven thousand CFM would be a pretty good flowing engine... I bet vega used VE% instead of actual VE in decimals since the calculated number is two orders of magnitude too big, i.e. VE=90 instead of VE=0.90. Vega, I'm not sure if you're approaching this problem from the correct angle. CFM and pipe composition are not directly tied into the natural frequency of the air passing through the pipe, meaning that changing the CFM through the pipe is going to change the volume of the sound but not the frequency at which it resonates. As zero mentioned, the composition of the pipe is tied into the natural frequency of the pipe itself, e.g. a tuning fork. What matters more, in terms of exhaust design at least, is pipe length, valve timing, RPM, and exhaust temperature. This is the same thing as discussed in the sticky: exhaust resonance. It looks like you're looking for a specific sound instead of a performance gain. The concepts are the same, except now you're going from known specs to a required frequency rather than the other way around. [EDIT: Damn! Took too long to post, zero covered some of this already.]

Oh man, that is freakin' fantastic!!!

As an aside, I'd recommend Megajolt for spark control since you're wanting to run Webers. MS only makes sense if you plan to go EFI later.

There are tons of old L-series in the Sacramento area, and Bay Area as well. It will be easier and cheaper in the long run to just swap an L in. A cheap, wonky, hastily-done V8 conversion probably won't fetch much from what I've seen.