Leon

Like most discussions on the internet, I'm sure this would've went much better if it were done in person. I'm passionate about taking a data-driven approach to problem solving and it's frustrating when people don't read and process what's been written. Especially when we're having a technical discussion which involves carefully chosen wording and little riff-raff.

You took what you said and what I corroborated and then completely contradicted it in your response to me, seemingly just to start an argument. That's the only way that statement could be taken, no matter what your intentions were. Point taken on the struts but the conclusion to your post was that statement above which certainly seemed like trolling for a pissing match. Anyway... If you're going to graft a double-wishbone suspension onto your Z, more power to you! I enjoy seeing cool fabrication projects. But when the premise involves just tossing something in because it might theoretically be "better", that doesn't fly around here and is the reason HBZ used to be great. This would've been thrown in the Shed long ago...

The irony is tantalizing... People, especially "internet experts", love to fixate on one attribute that they may or may not understand very well and always miss the big picture. I'm sure you can dig up endless amounts of convincing information on the great importance of Ackermann, or camber gain, or front toe settings, or rod/stroke ratio, or backpressure, ad nauseam. What's lacking is looking at the system as a whole. What is the use-case for the car? In this thread, we seem to be talking about a track car. What's your maximum steering input on a road course? Maybe 120 degrees? Even with 100% Ackermann, you're going to see negligible differences between L/R slip angles. To quote an excerpt from page 545 in "The Multibody Systems Approach to Vehicle Dynamics" by Blundell and Harty (my emphasis in bold): It's the same story with caster angle, it's effects are also dependent on steer. Steer angles on the track are low and thus caster effects are minimized. It's a slightly different story at an autocross, depending on how tight the course is, but lack of caster can be mitigated with adjustments to static camber, camber compliance, and roll stiffness. The solution to lack of camber gain is, you guessed it, static camber. The various suspensions that have been put into cars were all invented for a reason. There is no best. I hope I've done my part in resuscitating said dead engineers.

I can see where this is going and I'm not interested in getting sucked into another tedious, head-banging, never-ending straw man argument. In fact, I'll bet the OP never returns or follows through so this is likely to turn into another pissing contest... Sure, there are some modern strut suspensions that use split-lower arms but not all of them do, the E30/E36/E46 M3 for example. I used Ben's statement as a jumping-off point as he decried struts as the sole reason the Z isn't competitive anymore which I don't agree with. It could be (is) a myriad of factors that all add up. It's not a malicious jab but a friendly argument, and he redeemed himself afterwards saying that in spite of the apparently non-competitive struts, his car handles fine, wizard-like even. And this is coming from someone that is actively competing. You're getting things twisted, Jon. I like how you threw in "better geometry" into the argument when what I really said was, "thinking you can just graft a double-wishbone setup into a car and have it be better is a bit silly". Obtaining better geometry is not at all a trivial task, which is precisely what I had meant if you look back at the previous sentence, and most people don't have the knowledge and/or skills to pull it off. Maybe you can agree, considering the last paragraph in your first reply essentially argues the same exact point which you've then gone and contradicted in your reply: I run 225mm rubber on my Z and it's fine. Camber plates give me about -2.5° of camber. I'm not competing with anyone but it's not a bad handling car by any means. Ackerman doesn't matter as much as you think it does and caster/camber gain don't matter much either if you dial in enough static camber.

Camber gain, shmamber gain. Just dial in your static and send it. It'll be fine. I would not place the entire blame of a car being non-competitive on the fact that it has a strut suspension. Are M3s non-competitive? How about Porsche 911s and Caymans? Yeah, they have other crap in the rear but you get the point. OP, what limitations of the strut are you planning on eliminating with your double-wishbone setup? Have you driven the car on track and gone through the process of dialing in the chassis? I'm not saying that the S30 has the most optimal geometry but to think you can just graft a double-wishbone setup into a car and have it be better is a bit silly. Why not just spend the time and money on dialing in what you have? Unless the real reason for the question is that you just want to play around and make something different, in which case as you were...

Excellent! Curious how they fit.

If you plan to make your own, here is a quote from Keith: Use polycarbonate, as acrylic will lose its transparency after enough contact with gasoline.

Keith sells all of his stuff here: https://www.webstore.com/user,pgr,82598,owner_id,other_items However, I don't think he makes the optical tool anymore. You can make one yourself using polycarbonate rod stock (I think 1/4" should work but measure your e-tube well to be sure) and a plastic sleeve. Alternatively, I've also used the depth gauge of a caliper.

Interesting, I'm not familiar with that naming convention. If we assume that the 50 is the fuel orifice and 100 is air, I'm surprised at how soggy your cruise is. How many progressive holes do these carbs have? Do you have pin gauges or some way of measuring small orifices? Drill bits could be a good substitute, double-check with a caliper. See if you can measure the hole diameter in the idle jet (part with 50/100 engraved in it) as well as your progression holes. Also measure your float level using Keith's method and let us know what you get.

What's your idle AFR and what's the F# of your idle jet? Both the idle and main circuit affect cruise mixture strength. I've attached Keith Franck's white paper on tuning Webers (SK is essentially the same), it should explain some things about sidedrafts that none of the tuning books nor manuals talk about. Weber_DCOE_Tuning_White_Paper.pdf

Yeah, it's in my build thread:

You should've absolutely done a valve adjustment by now but that is of course separate from any fuel leakage issues. Which barrels are leaking?

Put me down for using the bigger lift cam. Max lift isn't one of many aspects of cam design. Holding duration constant, you will have a more aggressive ramp with the .540" cam, meaning you will achieve higher lift per crank angle. More area under the curve equals more flow due to a decreased flow restriction. Porting also decreases flow restriction and has an additive effect. Not sure what you mean by the flow "saturates". I run the Isky L6 grind (270 duration/.540" lift). I use flat-top pistons, without valve reliefs, and stock retainers along with Isky springs and whatever Chevy valve stem seals Rebello uses.

Using the pictures as a guide, looks like either the Centric or AMS are your best bets.

Cool find! Is the bolt pattern the same? Rockauto has them for $15...

Sweet! Glad to see one's of Derek's heads make an appearance in a build thread. That clutch master cylinder is ready to self-clearance the air cleaner as soon as the motor fires up. It may need a little clearance dent, as painful as that may be to do. Looking forward to see this come together!

Ah, you never mentioned it was coming from the pump nozzles! Have you verified the state of the check ball and weight, underneath the inspection screws located beneath the float cover?

If the needle and seats don't leak, what makes you think it's a fuel pressure issue? Sounds like you ruled that out. Sometimes the needle/seat can get jammed and needs a love tap with the back of a screwdriver. Have you tried to run it since messing with the float covers?

I'll say it again, find a shop with a Dynapack. No fussing with ignition pickups and they are very consistent. Always be ready for it all to go wrong!

Well it sounded great in that video! Sorry to hear but glad you caught the issues before tossing driveline bits all over the road (or track). I highly recommend finding a shop with a Dynapack in your area, you can thank me later.

It's critical that rubber bushings are torqued with the car at ride height. Rubber bushings rely on the rubber between the inner and outer metals to stretch as the suspension moves through its travel. The bushings will see added wear and not work as designed, if you leave them pre-loaded and "let them settle".

Larger chokes will tip in the mains later so your mixture is showing lean due to that. Try tipping in at a higher RPM. You shouldn't have to make an abnormally larger step-up in mains for a 2mm increase in choke size. E-tubes affect both tip-in and the AFR curve when on the mains. The interaction between float level and emulsion tube is critical to both. Run what you got tomorrow and do your best to keep the tests controlled, otherwise it will be impossible to tell the difference between runs. Sounds like you did a pretty good job of preparing. Looking forward to hearing about what you find.

Dynapack is king of chassis dynos as far as I'm concerned. A much more precise machine than any roller.

For a quick and dirty measurement, use an IR gun on your oil pan, radiator, cylinder head, and intake. Otherwise, you're looking at plumbing in oil temp and IAT sensors (assuming you already have a decent water temp gauge). You can also get creative and mount some thermocouples to the important bits but you'd want a datalogger to read them.

The obvious is often missed. 🙂 Glad I can be of some help! If I were closer, I'd attempt to involve myself more. I've done some exploratory dyno sessions like this and always either run out of time, something goes wrong, and/or I question my data because I didn't log engine temps. Doing my best to pass on my experience.