Leon

That's awesome, love the three different takes.

I saw all three of them in his shop a little over a year ago, you guys don't even want to know what else was in there... Every time I stop by it's pure automotive nirvana, it just doesn't get any better.

You know, we can play the bench racing game, quote magazine and internet numbers all we want but it won't get you anywhere. You need a defined set of parameters which will constrain your design. Once the needs are nailed down, it becomes very easy to accomplish your goals. You state, and I infer, that your needs are almost purely subjective; the car must feel and sound fast, but must be smooth at idle and around town. Hell, slap on some triples and twice pipes, and you're good to go! There is no need for most of the stuff you list in your first post. I have a ton of fun with my triple carb'd, twice pipe, stock cam L24 that put down 121 hp/136 lb-ft (before the new exhaust and advanced timing, need to go back to dyno). It's smooth, torquey and makes all the right sounds. Just consider this, before delving further into this internet automotive gobbledegook.

195 degree thermostat? It's not winter, use a 180 degree, unless you're in a very hot climate in which case use the 160. I run an ebay 2 row radiator with no fan shroud and a 180 degree thermostat. Cools great.

Who knows, maybe someone thought they were progressive, and not synchronous carbs... Seems like whoever set them up had absolutely no idea what they were doing. You need to start over with these carbs, and a wideband O2 sensor goes a long way in telling you what's really going on. I run Webers so I can't give you numbers, but 130-140 mains will definitely work better than mismatched 95/105 mains. As far as tank pressure, I just don't see how it can be pressurized with the car running unless you somehow have more fuel coming back than leaving (if that is the case, tell me your secret). It's likely to drop in pressure without proper tank venting. I would put a string over the lip of the filler as I remove the cap to see which way the air is going. I bet it's drawing air in, sound can be deceiving.

Do you have mismatched main jets in each carb? How did you determine that your tank pressure is above atmospheric?

FWIW, there is no "grade 8" in metric fasteners. Metric class 10.9 would have similar strength to standard grade 8. Getting metric class 8.8 hardware would be like using standard grade 5. http://www.k-tbolt.com/bolt_chart.html

In my past FSAE engine project, we did engine dyno testing of 3 different plenum volumes (something like 1x, 2x, 4x displacement, need to look it up) and had the largest plenum tested give us the best results. Of course, the testing was done on a restricted 450cc single-cylinder engine, and may not mean anything to you. Honestly, the only way to really know is to make your plenum modular and go to the dyno. Good luck!

I used a flat-head screwdriver and a hammer, no dremel required!

The threads are BSPT (or BSPP?). BSPT would be tapered and BSPP is parallel threads, you should be able to tell by looking at or measuring the holes. NPT will fit but not seal as well due to different thread design, not sure how dramatic the difference would be with exhaust fumes though. You can use McMasterCarr to get the plugs as well.

Great input, I really appreciate it! Thanks for the heads-up HowlerMonkey, I wouldn't have thought to try different model clutches. I would definitely like to avoid any interference, but I don't do much high speed driving, just autoX for now. Hopefully, that problem will not manifest itself. Again, thanks for the great feedback!

(1) Cooling: the stock fan cools better, or least good enough for my application. Temps never rise, even in 100+ degree weather. (2) Simplicity: no need for putting in a new electrical circuit with the stock fan. (3) Electrical Load: would need to upgrade the already-weak stock alternator if using e-fan. (4) Cheaper Cool, sounds like it works but I would need a ZX fan clutch as well. I may be willing to take that spacer and studs off your hands if I don't use a ZX fan or am too lazy to make my own. Great idea on using PC or thin rings! I have an ebay 2-row Champion radiator that I believe is dimensionally equal to the stock unit. I measured current fan-to-radiator clearance at a bit over an inch using a '72 fan. Sounds like both options are viable, and it comes down to what is easier/costs less. A CNC-machined Titanium fan would be sweet but is not within the budget of this project! Thanks for your input, all!

This is exactly what is happening in my Z (triple Webers and headers) when it's hot out. It can get bad enough for me to have to pull over for a little bit. I don't have a heat shield though and am planning to make one next week. I'm hoping that it will solve my problems, but I guess we'll see. I'm also using a stock fuel rail and was thinking of insulating it at the mounting points to limit conductive heat transfer.

But in all seriousness, what is the point of this thread (and all threads like it)? I know this sounds blunt, but why not just run on the track and see what you get? Otherwise, this is just pointless bench-racing, d*ck swinging. My 2 cents...

Could be, but first thing I'd do is pop the valve cover off, especially since it's a fresh engine. Check valve clearances and that everything is tight.

That would be an intercooler and aftercooler! The word intercooler is improperly used most of the time. Technically, most "intercoolers" people talk about are actually aftercoolers. And that's my fun fact of the day!

I'm planning to install EDIS in my Z using Derek's trigger wheel and sensor mount. I plan to use Megajolt to control spark while keeping my triples, along with the rest of my engine the way it is. This means that I'm keeping the stock clutch fan and do not plan to use an e-fan. The problem is that apparently there is interference between the stock fan and VR sensor mount. The first solution I thought of was to make a spacer. The spacer would be very simple, but it would require custom machining and new fasteners for the fan. I decided to search to see if others have faced this problem and how they solved it. Somewhat accidentally, I discovered that the 280ZX cooling fan extends further towards the radiator than the S30 unit in order to accomodate a three-row damper. If you think of the cooling fan as analogous to an automotive wheel, imagine that the cooling fan's "offset" went from positive (S30) to negative (S130), thereby extending the fan towards the radiator. What I need is for someone to measure a 280ZX fan width and distance from the front-most part of the fan to the hub. A ZX fan is identified by the mounting hub being at the back of the fan. Or, maybe someone has experience running a 280ZX fan in an S30? I'm using a 2-row Champion e-bay radiator, and there is currently a little over and inch of radiator-to-fan clearance. 240Z Fan 280ZX Fan

The previous exhaust was just a pipe off the stock manifold to a straight-through muffler at the end. It was loud and had terrible resonance. Currently, each pipe has a glasspack in the tunnel and a smaller one at the end. There is very little resonance, and it's not too loud on the freeway anymore, which is great! I can have a conversation and somewhat hear the radio as well. It's just really loud at WOT, especially past 3500rpm, and while it sounds good I think it might attract some unwanted attention. The one thing I don't like about the install is that one of the pipes passes under the differential, effectively blocking the rear jacking point. I suppose I can jack it up by the curved transverse link bar (the one that hold the back bushings of the LCAs), but I feel iffy about placing a bending load on that bar since it locates the LCAs.

Got a better video, sorry about girlfriend yelling to someone we know at the start! Not sure what I think about the exhaust, I love the twice pipes I feel a little obnoxious when I get on it. I also need to schedule another dyno run to see the effect of the twice pipes.

Sure. My experience tells me that this post is going to the tool shed for breaking forum rules...

I got 2 grade 8 bolts from the local hardware store for my endlinks, the ES ones were too short. I have the size and length written down somewhere...

Thanks for the extra info, I'm not from the area so my info comes from word-of-mouth (key?).

I don't know what's funnier, the first post or the second!

I'm interested when you do another run as well. Derek (or anyone using the setup), do you know if there will be any interference if I'm using a stock clutch cooling fan instead of an e-fan?

Holy crap! :shock: