Leon

Did you try your old jetting with the repaired ignition system? That would be telling whether the F7s helped or not. In any case, does that hiccup occur if you went WOT at 2k and as you pass 3k, or does it only occur if you go from cruising to WOT while at 3k RPM? This is an important distinction.

Wow, that Harada manifold is a really quality piece. Looks like an evolution of the Nissan Comp manifold. Looks like it's worth every penny to me. What is it about the Mikuni manifold that makes it worth it?

You guys need to understand, we're working with a system where one change affects many other things. There are plenty of guys out there running DCOEs that are "satisfied" with the way their car runs. The beauty is in the tuning, not simply swapping parts. If setting up carbs was that easy, there would be not debate! The F7 is a much better suited tube for DCOEs because it allows you to run leaner idle jets and accel pumps. If you have a tip-in stumble (different than off-idle stumble), a proper e-tube combined with correct jetting will solve that as well. If nothing else, throttle response will be crisper and you'll get better gas mileage. There is no magic bullet here, you have to work with the system, not individual parts.

Will do. I have a busy weekend ahead of me but I will take a look at exactly what I have and then give you a price.

Hey Dom, I have an L24 block with a new set of pistons waiting for a new home. I got it with one of my Zs and the previous owner said it was supposed to be used as a race motor. It looks like it got cleaned up, machined, painted, and never assembled. I have brand new pistons and rings for it as well. Crank is out of the block but included. Just needs to have clearances checked and assembled! I'm sure I'll never get to it, it's hard to let go of that hoarder mentality... Not sure about pricing yet but send PM if interested!

Looking snazzy!

Wow... Excellent work!

Mike, I'd be curious about what those are if you're willing to share. I started tracking last November and have done 10 track days since. Back in August at Laguna, I "instructed" for the first time, hopping in our shop BRZ with another shop guy, who was a first-timer. It was definitely unsettling to say the least (early turn-in into the Corkscrew is not fun). Now, I am by no means qualified enough to really instruct but I wanted to help the guy out since he'd been involved in motorsports for a long time but never actually had a chance to drive on track. Ever since then, I've been doing some reading and thinking. Ross Bentley's "HPDE Instructor Manifesto" is great, I think it was recommended on this site, possibly. I figure that even if I don't instruct in the next year, or three, or ever, I will at least have a better perspective from all of this. Anyway, if you decide to post your thoughts, plans, and experiences, I'd be very interested and grateful!

Try Vintage Connections, under the "Prices" tab.

Hang in there and congratulations!

Nice! I like the surprise at the end too.

With the caveat that the above only pertains to transmissions originally from a Z/ZX. You can easily have a one-ear tranny with wide ratios, e.g. if it came from a truck, 200SX, etc. With that said, the question here is why do you need to know which transmission you have in order to replace your clutch? As long as it's a B-type trans, which I assume is what you have, any clutch will fit. The only variable here is the throwout bearing collar height. This is all in the archives. Here's a useful link regarding early Nissan transmissions: http://www.gracieland.org/cars/techtalk/gearing2.html

Do tire pressures influence cross weight? Yes. Is adjusting corner weights via tire pressures a good idea? Definitely not. With that said, many variables affect corner weights so it's a good idea to know what they are. Knowing that tire pressures affect corner weights should lead you to make sure to set tire pressures to spec (whatever that may be). Even wheel alignment can affect corner weights through weight jacking caused by camber changes.

Exactly. Tirerack is a good source to compare different tires of the same size. They publish actual section and tread widths.

Just remember that off-idle stumbles are different than tip-in stumbles. You can test for an off-idle stumble by very slowly and steadily bringing the revs up in neutral from idle to about 2500RPM. If it stumbles doing so, you either have the incorrect idle jet and/or you need to drill a new progression hole. With the F7, you should be able to run leaner idle jets and smaller air jets.

Why not? All VTEC does is switch cam profiles. No big deal, put a big cam in there and you're good. We've got a K20 Civic at the shop that makes 211whp with big cams and no VTEC. That 211 is at 8400RPM and the power curve still climbing as the motor was designed to spin to 9000RPM. This is on a dyno where stock STIs baseline at 225hp. The customer is more interested in it staying together than going for max power, and the sequential box is only rated to 230hp... Anyway, you're doing your due diligence Derek, keep up the hard work!

The F7 seems to be the best solution as far as Weber e-tubes go. It'll be a bit fat at cruise because of its smaller impedance but low-end and midrange throttle response should be way better than any other tube. Just remember to set your float levels to 25mm using the top-down method (unscrew a jet stack and measure from the top down to the fuel - should be 25mm). I never said F11 tubes are "the worst", nor any tube for that matter. Some are just better than others, and while there definitely is a "worst" one, I haven't bothered to find it. Also, it's important to note that the e-tube is not the only part of the carb's metering controls. We're talking about just one piece of the puzzle here, but in order to have a properly tuned engine one has to take a more complete approach. What are your float levels? What ignition system are you using? Are your valves adjusted properly? And it goes on. Keep in mind that using racers for comparison to primarily street-driven cars is invalid. They don't really care about the e-tube very much. If the motor spends most of its time in the main circuit, the e-tube isn't doing anything in terms of tip-in. All it has the ability to do at that point is control how much the mixture leans out at high rpm. I don't think most people really understand this concept and just wing it on e-tube choice usually purely based on he-said, she-said type of information. Why do you think F11s "work" for so many people here? I bet it's because it's the tube that came with the carb. My carbs came with them too. They sucked. It depends on your definition of "work". If "work" means you have to pick a soggy idle jet and live with a flat spot, well then have at it! FWIW, I've never heard of using main jet orifice opening in the e-tube as a tuning tool. Sounds really silly to me. The main jet performs the metering of the main circuit. A typical main jet will have 25 times less cross-sectional area than that 7.5mm orifice you mention!

I actually had some time to work on the Z today! Got the fresh cam installed and timed. When initially putting the motor together, I had installed the distributor 180* out even though I had thought I did everything right. Rookie mistake. Since the cam was out, I decided to fix that by installing the new cam 180* from where it was to get everything all lined up again. Pulled the old ZX distributor out as well so I could put the reman unit in. I also pulled the intake off in preparation for swapping in the TWM. I plan to port-match it to the carbs before tossing it on so that's the next step there. Still need to install the new rockers, check wipe, and finish the fuel system before the engine comes back to life! It's been about a year since I last drove this thing...

Refer to the quote you found. Your issues are caused by a poor choice of e-tube and exactly reflect what I described in the post you quoted. The F2 is not a good choice for the DCOE. It's air bleed holes are too high up with none of them below the fuel level. This makes it an absolutely horrible tube when put in the DCOE. The file of interest here is called F2_e-tube_in_3_wells, it illustrates that the F2 was designed for the Weber IDF and has no business sitting in a DCOE: https://groups.yahoo.com/neo/groups/sidedraft_central/search/files?query=f2 I found some good lines from Keith on the matter as well:

Same here.

Cannon made lots of manifolds. Are you looking for one that's meant for triple carbs? I have one that has been port matched for 45mm DCOEs and custom-welded heim joint mounts so that the throttle linkage bar doesn't bind up. Send PM if interested.

And I rest my case...

Was your car on the same exact dyno they used in the show? If not, the comparison is completely invalid. There are some great posts in the archives about comparing dynos, if they're not stickied they should be. I've seen as much as 50-60hp swings with the same car running on different dynos.

Looking good Dan!