Tony D

Grainger sells Magnahelic gauges for a quick readout, all one needs to do is construct a static pressure probe so you are not reading air velocity and getting a false pressure reading. I had a bank of Magnahelics, as well as some RTD's and Omega supplied sensors all over an S30 back in the early 90's trying to figure things out---having free access to analytical instruments at work makes for idle minds doing experiments...

Pedals will bend the wrong way when swapped to the other side of the car. It is FAR cheaper to simply buy a Fairlady Z and restore it than do a hacked-conversion. There was a stripped 80ZX Fairlady shell in fico's area that sold private party within the past month for $300. There is a 77 S30 2/2 in PA right now for sale as well, overpriced to be sure, but they are out there. Cheaper than the shipping and labor for a conversion of an LHD vehicle!

If anecdontes are O.K. then I can add we picked up 3mph at ElMirage swapping from the stock steel wheels and driveshaft to Convo-Pros and Aluminum Driveshaft. The Convo Pros made for more of a noticable difference in acceleration "feel". I have a 15# japanese lightened flywheel that accelerates much harder than my 13# Centerforce Aluminum unit, almost as hard as the Tilton 11# unit I have in another vehicle. Where the weight is removed is almost as important as how much. This gives more credence to why the Convo Pros felt like more of an improvement than the driveshaft alone--weight further away from the rotational centerline.

AMEN to that! It's taken me years to locate the proper parts for a period correct blow-through system using HKS EFI ITB's! I FINALLY located an HKS Type 2 Surge Tank, and that was basically the final part. Had two Type-1 HKS Surge tanks, and an SK Unit added along the way for possible "trading fodder" when the correct part eventually showed up. As it is, I will have to reconstruct the inlet casting for the Type 2 Tank myself, as the guy I bought it from didn't have it, though he sent me photos with proper scaling objects (rulers) laying on his other Type 2 (on a Box Skyline, matter of fact) so I can cast my own part. Period Correct is a BEYOTCH!

Have you seen some of the new tubular manifolds on Toyotas? Look like Aluminim Headers with very little plenum, and a throttle body hooked on a "collector" on one end. But to the original question: The difference between vacuum flow and pressure flow characteristics is a good reason.

If the manifold is off the engine, no need to crack the carb off the setup and waste the gasket, shine a light down the straight runner, and look for the numbers on the throttle plate. 40mm units will have "165" and 44mm units will have "175" stamped on each throttle plate. Seen 40's go from $250 to 600, seen 44's go from 350 to 1500+. complete sets. Sangyo manifold will almost surely be bored for the smaller L20A head ports, and be for 40's.

There is a variable drive assembly that uses a CVT and ball bearings to transmit the torque. Can't remember where I saw the writeup, it was in an English Magazine about a year ago, best I can do. Something about sepcial fluid couplings, and speed increasing sheaves with the ball bearings moving outward to slow the compressor at higher speeds, and they went towards the center speeding it up at lower speeds. It made the centrifugal supercharger that acted like more conventional superchargers, giving a more linear response in HP and flat torque, instead of the non-linear response typical to the centrifugal impeller wheel. BTW, "might as well use a belt" and poo-poohing hydrostatics may be a bit short sighted. True, you will have to use a dedicated pump, but the transmission of the power is seamless and easily accomplished around corners, and even transmitted elsewhere in the vehicle! Placing a hydrostatically driven roots with the rotor centerline perpindicular to the crankshaft, and standing it up at the rear of the engine bay is a packaging idea not seen with a conventional belt drive! Hydrostatic drive is far easier to accomplish at a 5hp level than even electricity in current automobiles. But with packaging similarities to the electrical option!

good luck man! severe cold and air density problems are one of the reasons I made the "EFI Switch"!

The starter system jet may be clogged. it is totally independent from the rest of the jetting systems in the carburettor. There is really no adjustment to it, but I have seen the jet for it clogged with witish corrosion if the gas had water in it an the owner let it sit, or if the carbs sat for a long time and the gas evaporated leaving water in there to corrode.... I have started the car at -35F and it fires right up. A weak ignition system may be the culprit, the starter system makes for a VERY rich mixture, and if the sparky system isn't up to par, it may have trouble igniting it. You have to leave it run on the starter for about a minute before it starts "loading up" and you ease it half off for another three minutes, and from there I usually could drive away. But if the air is -35, chances are good you WILL need different jetting to compensate for extremely dense air! As I recall I was a jet size or two richer.... What am I saying, "carbs are easy!" Efi with that stupid air temperature pulsewidth correction is "hard".... I digress! LOL

ms does not need a vacuum signal to work, Alpha-N mapping will work just fine for a race engine running a fuel delivery map using nothing more than engine speed versus throttle position. This is how they did it on the original Nissan Rally EFI setups, and how most EFI was programmed "in the beginning". As for fuel injector placement, take a look at every single F1 setup out there, and you will see injectors at the mouth of the velocity stacks. Hovering above the bell. Can't get much further upstream than that, given current aerodynamic requirements. There are lots of TB's out there that can be made to work, the Mazda 929 has an integral idle bypass screw, the Ford 460 unit Mack shows is big, and has the ability to change the pivot geometry with repositioning of the bellcrank to make tip-in on partial throttle driving more tractable. Just remember that big throttle bodies make for tip in response that is beyond insane in it's touchiness. Work your throttle actuation carefully, something not progressive and fairly deadbanded just off idle would reward you with drivability in coming off from a standing start without racing the engine to the stratosphere. Triple 45mm TWM ITB's and a Tilton Low Inertia flywheel will give our Bonneville car a 0-7500 "blip" in the wink of an eye. Atomization doesn't come into it, the injectors take care of that nicely----that big air gate makes for a lot of air that can get into the cylinder quickly with very little throttle application.

please be aware that both models on that site look to be 2+2's. not a problem for me, because that is what I have (THANK YOU THANK YOU THANK YOU!) so having this will make some nice, informed decisions about what I am going to do on the Bonneville car! BTW, 226mph has been done in a 280ZXT Coupe in a one-way run at Bonneville in the early 90's. I believe Jkurz will have more stimulating details about what happened on that run... So aerodynamically, the vehicle is pretty stable.

MS Forum has some stuff on writing code for sensor circuits... There may be another method...

Well, discussing it with JeffP and his EE Buddy at work, they both are of the opinion that the floating reset pin on the MS is a BIG mistake, and Jeff has long said I should tie the pin high or low to prevent nusiance resets. The EE Bud suggested a 4.5K resistor tied to ground on that reset pin. I really am not having reset problems that I can see, it is far more bizzare than that. Oh, to only have a reset problem to solve! In the begining with the Com issue, I took to pulling that pin out of the socket to prevent resets!!! I stuffed it back in after they replaced the motherboard, modem, com section of my Vaio Laptop.......

connect the starter system! The discs on the top of the carb, towards the manifold pivot, and they activate an enrichment system that will allow these carbs to start and warm up the car even in -40 temperatures. IT IS NOT A CHOKE! Once you open the throttle plate, the starter system ceases to have the vacuum required to function. It will fire the engine, and you can ease it off till the engine is up to temperature, then drive the car. You can drive with the car partially warmed if you can stand the popping, but it's ill advised as it's still lean. The discs operate opposite the stock starter system in the SU's, so you either need to hook up another cable to the stock choke lever and run it to the front carb, or try to do it with the stock choke cable---but they don't like the bend like that. Easiest thing to do is take a coat hangar or welding rod, and bend it so it fits in all three carbs starter disc holders, and then just clamp your actuating cable in the far end. There are setups that rotate the discs the other way _so I'm told_ but I have never seen one. They actuate by pushing them to the front of the car. You _might_ get by with hooking the stock choke cable up to the rear carb, and starting it with only one carbs starter system active, but the other two will run raggedy b utt lean till it warms up. Welcome to the wonderful "Carbs are Simple" world of myths and happy reminisces! LOL

Why would the throttle plate have to be mounted _on_ the supercharger? I would think a suitable pipe with a radius pointed wherever you had room would allow a throttle plate to be mounted pretty much everywhere, and give you a bit of "softness" on drop-throttle to prevent blower surge. Frank's compressor has provisions for a bypass under drop-throttle, and when he starts fabbing it up on a JCR Plenum intake, will find he really should have kept that RHD Z-Car he had, as the rearward facing TB setup will make it hard to clear the brake booster. But he will find that making the cowl air intake area into a large air filter box will solve a lot of problems in the T/B Mounting arena! LOL

I would have to humbly disagree on that point. There is not enough surface area to do much of anything to the incoming air temperature due to the JT effect at partial throttle, and at WOT it doesn't stand a snowball's chance in hell of affecting temperatures. If it was that kind of setup, like on stationary engines, or F1 Honda engines, it would havea thermostatic velve tied to intake plenum temperature. The true reason was as above, to keep carbon from heavy PCV sloughing off and pliable while driving, and to let it move into the floor of the plenum where accumulation can be tolerated instead of at the throttle plate. Datalog with a standalone EMS system and you will see the effect on intake plenum temperatures are almost totally dependent on vehicle speed and underhood temperature. Disconnect or pinch off those lines and do the same test and you will see nil temperature changes. The wonderful world of Megasquirt opened my eyes on that 'warms the air" myth straightaway! It heats the metal, in both EFI and Carburetted Applications. In both cases it's to prevent a buildup of contaminants on the metal portion of the body to prevent throttle plate interference/binding/sticking.

How the flywheel is constructed is as important as what it's made of, or how much it weighs. I have a cut down stocker that weighs 15# that has a MUCH more radical throttle response characteristic than the current 13# aluminim flywheels from Midway/Centerforce. It feels more like an 11# tilton. As important as the weight and construction is the engine you put it on, a light flywheel will make a more dramatic felt difference in a car with more torque. An L28 will be as twitchy with a 14# flywheel as an L24 with a 10# unit. My wife absolutely hates driving my L28 Blowthrough Turbo 73 with the 15# Flywheel, she refers to the throttle pedal acting as "the on off switch" with a 3.7 OR the original 3.36 gearset out back. Put her in the L28 EFI N/A Fairlady 2+2, and the 13.5 Centerforce is nothing she finds objectinable, even with the 3.9 gears and a Big Throat T/B making tip-in touchy on top of it! Put the same 13.5 flywheel behind her L26 with 3.7 gearing and "it's perfect, leave it alone, don't change anything!" Available torque impacts the felt response, absence of an inertia ring as John C discussed reduces the MOI, and makes a heavier flywheel act like one much lighter with an intact inertia ring. I don't own ANYTHING without a lightened or aftermarket flywheel that is lightweight. If you have a decent throttle linkage that is set up correctly for progressive tip-in then it becomes eminently drivable. The lighter weight and big throttle plate area makes for a car that ACTS like one with MUCH more horsepower tha it really has. For a wonderful example go drive a Mustang with a V6, and then one with a V8. The V6 will shoot across and intersection on tip-in response, and then fall on it's face due to lack of torque and horsepower, while the V-8 model while lazy out of the hole in comparison to the V6 (stock vs stock here) will quickly walk away because of the torque and hp it has... The naysayers of the lightened or lightweight flywheel are mostly parrots squwaking things they have heard from another parrot. Welcome to the internet!

Wow those plugs make hooking up the kenescope easy! On large industrial engines, there are kenetic taps on the head for reading actual BMEP Trace on the scope, and we had specialty plugs to hook up the the smaller (er, that is a relative term) engine without the taps for the peizo pressure sensors used on the larger units. That plug would be very very interesting, taking a screen shot would make calculating BMEP and watching for detonation a piece of pie. You could read detonation clear as day with a sensor on that plug---for dyno tuning or realtime correction of mixture and spark advance it would RULE! omigod! I've been pulled into the project intellectually. You bastard!

Like I said at the beginning, "TRWebb, I feel your pain!" That line is the COMPLETE history of my MS install in the 260ZT 2+2!!! ALLLLLLL MS power, fed through the relay box is coming from a 20A filter. It cleaned up the power pretty nicely according to the scope, and of course when the "runaway" happens the scope is never at hand, and I'm not letting it go on until I can grab it because it realllllly puts the petrol to the engine (injector firing at the same time, did I mention that?) Believe me, I would LOVE to not have problems like this. I mean challenging is one thing, but it is coming to the rapid conclusion that "some cars you just can't reach" to paraphrase an old movie, and apparently this Red 260Z is one of them, had I more time on the ground at home to get to the car and go through it from stem to stern in a methodical troubleshooting of it once again it might be solved, but at this point after literally years of having a day to do this or that I'm rapidly reaching the point where I will toss it all in and go with something else. Last time I said that vultures hovered... don't this time please! I will use the freaking box on something else, but I just don't think it will work on this car. Maybe try it on my 73 just to prove it out... Oh, and the battery, (take your pick, new red top ultima, new diehard, or any number of used and new batteries that have cycled through that "batery box storage point") makes absolutely no difference---it does it now and again, no rhyme nor reason to it. Shut the key off, try again, and it may do it again....or not for another hour....

Oh, I see it now. Along with 67 others... Yes, I read my PM's....er, now Congrats on Wendy and the "offspring" LOL Nino is in football, band, and we fitted the 510 with the SSS induction system (using the Fairlady Z 2 Litre Jets and Needles) but still have to figure out how to adapt the exhaust system before trying to drive it around the yard!

D'OH, Total Brain Fart, you are correct JM! "OA" is the common block! It's the counterintuitiveness of it all consarn it! Yes, the OB blocks came in the 50's, but were also availabe in very early 40 and 44phh's (we are talking 60-65, maybe as late as 67 or 68) By 1970, all the 40 and 44PHH's were produced using the "OA" block.

What I will add is there is no real reason to actually measure the bore if you have them off! 40's will have "165" stamped on the throttle plates, 44's will have "175" stamped there. A little brain scratching and you will come to the obvious conclusion what the numbers stand for... But the point about measuring at the back IS VERY IMPORTANT if you are junkyarding and find a set. Early Toyota Carburettors used a unified casting that shared external dimensions with the 40 and 44 carbs. In these carbs (early 70's) the 40mm versions had a 44mm bore on the air cleaner side of the carburettor, and used 44mm Booster and main venturis, while having a 40mm throttle plate and bore behind the main venturi. This was great from an interchangability of parts for racing vehicles because you could use 44mm trumpets, for maximum unrestricted airflow to the main venturi. To make them "legal" 40mm carbs there was an insert sleeve that went in the front portion of the throat of the carbs to neck it down to what later 40mm Phh carbs had cast into them. On a 44PHH you will see a vestigial casting bump left over from the days when there was only one casting for 40 and 44 carbs. That bump can't be seen in the photos above, but it's there, and it would have been machined for a setscrew and jam nut to secure the front necking down sleeve for a 40PHH application (same nut and screw type that is in there for securing the booster venturi). As far as that oddbal OEM Toyota carb, there is no way to mix up a 40 from a 44. In the production run the 40PHH eventually went to another type of casting that had a squarish float bowl cover, and that is the kind you find mostly out there. The older 40's with the same float cover as the 44 are few and far between nowadays. Try to find at least one with the vacuum advance tube on it, they are there on Mikuini Kits on the #1 Carb that feeds #1 & 2 Cylinders, and on the front carb in OEM Toyota applications as well. The other major difference is the "OA" and "OB" jet block difference, and I have personally never found one old enough to have the "OA", every one I have seen in 40 or 44 has had the later "OB". People don't realize the Mikuini people got the License from Solex in France around 1960! They made those carbs for almost 10 years before the Z was around. Those early carbs with "Solex" on the tops are the ones to check for "OA" blocks, but then only if it's in the first few years of production, but 66 or 67, most everything had "OB" and those are the majority of carbs that are out there, unless you are snooping around an confirmed old-school Japanese Racer active since the late 50's...in Japan! LOL Anyways, as for "Type" the Solex/Mikuinis are NOT like Webers where there were a million types of machining variations due to different internal passages. They were an OEM application Carburettor, and the production tooling was kept is VERY tight tolerance compared to what they ran at Weber. Believe it or not Weber bodies have much more variation in the internal passages than you would think compared to a 'cheap jap carb'! Basically if you get ANY body from a 44PHH, you can get the bits to standardize it to the other two. Check Main Venturi Size (usually 32 or 34mm) and Booster Venturi Diameter (usually 10 or 12mm). Those are the main body components that can really screw your mixture up from carb to carb if not identical. Jets, pump squirters, and small bits are obvious things that you know might be different, but the booster venturi sometimes gets overlooked, because people didn't realize there was more than one available! If buying used, if at all possible LOOK IN THE FLOAT BOWL! Literally take the cover off. If you see corrosion, look closely and be aware that brass jets like to seize irremovably (is that a word?) into the body, so if you have a seized accel pump jet because of corrosion.... It also is an indicator of car in handling the carbs received over their lifetime. Carbs taken off a running engine are best, those that have sat around for years (without the gas being drained, water sitting in them....) can be a crapshoot. But yes, you can construct a set, the components are available. Cheaper to buy as a set, but it can be done individually. I just found a set in Eastern PA and and am in the process of "discussin" stuff with the current owner.... LOL

SC not working above "X" rpm? Who said that? Better tell the NHRA Guys!!! I would also run less compression. I would NOT use the MSA header! (I know you have one...er yeah, one...) That setup will need a larger primary tube than a regular L-Engine due to the volume increase by the SC. Either Doug Thorley or Burn Stainless can assist in supplying a header or components to build one. For that setup I would make the header myself as "off the shelf" headers will not give you the correct tue length nor diameter. It's not as hard as everybody makes it sound, and if you go through Burns Stainless, the engineering fees are refundable through a credit towards a purchase of one of their merged collectors. We passed both places while you were here with Xander! Passed Burns on the way to Porterfield Brakes, and Doug's place when going by Aircraft Spruce to my house!

The L20A crank in the L28 does NOT yield 2.6l, but slightly less than 2.5L. This was the combination used in Bob Sharp's "240" to run in the GTU (Grand Touring Under 2.5 Litres) The engine indeed does have the possibility of having long rods. As for the pan, I would NOT machine the block, simply alter the L28 pickup with a longer tube facing in the correct direction, and install the L20A Pan onto it, using the proper alteration for turbo oil return of course. This is the course I took when swapping an LPG powered L26 into a Box Skyline, and it worked just fine. You start boring holes and it gets expensive. Screw up on the welding, and you just find another pickup and start over! BTW, with the weld/modify option you are able to alter how high the pickup sits off the bottom of the pan, so you can get it lower to suck oil at the high end of the load spectrum (high revs for long duration) so oil drainback is not that much of an issue. Like running another 1/2 quart in your pan without the windage drawback! I rally didn't have a soft spot for the Kenmary for a long while, thinking them to look a bit too much like the Plymouth Sattelite my mom drove me to elementary school...but now I am coming around and wouldn't turn one down if it came my way. A Box Skyline, on the other hand, would be no hesitation on accepting it into the livery! LOL Good Luck with the pan, it shouldn't be much of a problem. Ours worked fine, and it only took maybe half an hour to make up the tube. Nowadays I'd do a tube from SS (since I have the benders) and go all custom on the pickup, but that's over kill and there is no real reason to go that far!

Yeah, in an EFI car with heavy PVC possibilities the hot area will slough off carbon and reduce throttle sticking. On a carburetted vehicle it was solely due to the JT-Effect whereby air rapidly expanding at high velocity (cracked throttle plate to high vacuum) tends to chill to freezing temperatures. Thanks to some gasoline added to the mix, and it's vaporizing somewhat, it gets even colder. Any moisture in the airstream can condense at that point (at best), and in some cases stick to the intake or carburettor body where it had been supercooled byt the air and flash-freeze to make an ice buildup. This icebuildup can hold the plate open, with disasterous effects! My VW Bus with a Zenith 32NDIX could make a HUGE ice-ball under the carb on humid days back in Michigan. I'm talking ice built up like at a cryogenic valve, sometimes over 1/4 thick. On the inside, who knows? But externaly it built up like crazy and caused drivability problems (another reason on CARBBED cars). But on EFI vehicles it depends on where the PCV is admitted and managed. I'll lay money BMW's schematic for the PCV system doesn't allow a lot of contaminants into the intake system upstream of the throttle body like the Datsun did. Trace out a few cars, and you will find that is usually the case, PCV ducting will determine if the EFI T/B is heated or not. Unlike claims to the contrary, engines are engines, and engineering is similar no matter who builds it!