Daeron

just to make sure we are clear, don't come running up here to west palm and thrash me when something goes wrong (say, your mixture leans out unexpectedly and you put a hole in your piston) because this IS an awkward and "temporary" way to set something up. If I were trying to do something like this I would be : A-1: STUDYING EVERY PAGE OF THE EFI BIBLE UNTIL YOU KNOW IT BY PAGE NUMBER. A-2 Find a way to make sure the mixture is a bit rich B through E: Find four more ways to make sure the mixture always runs a bit rich; these old computers cannot react quickly, so when one pair of parameters for some reason makes the ECU want to lean the mix out, you NEED to be sure at least one other parameter is countering that. REALLY, the only way to do this sort of thing right is to know the progam algorithm behind the ECU. and then F: Get it to run right. This is a touchy job; be careful and don't get the idea that "the guys on the internet said they used to do it all the time." What I said was, WHEN EFI was retained and tweaked without departing from stock, this is how it was done. I never even messed around with any of this stuff, but when I first got my 280 in Y2K I did some searching and found a few of these tricks. By the time I was at a point where I might have tried to dinker with any of them, I had decided it would be unwise for me, in my situation with my tools.

Now I am thinking about using 240 tails, with amber bulbs in the backup light section, for the turn signal, one red for brake, one red for tail, and 280 backup lights.....

!!!! I used to live in North Wilkesboro, and my brother and his ex wife lived in Asheville for a few years while they were in school at UNCA!! My dad's 72 240 (My first memory; THE Z CAR in my mind, like, numero uno) was totalled by a ten point buck taking a leap out of the forest on one side of 115, (between Wilkesboro and Statesville) onto his hood, then into the woods on the other side of the road. Datsun went into the ditch, Buck went off in the brush A-OK. One time my Uncle was visiting in HIS tricked out 72, and blasted by my schoolbus.. all my classmates were instantly glued to the side of the bus asking if that was a porsche or what?!?! ahhh, good ol north wilkesboro. Used to know an awesome restaurant there on the Yadkin River.....

Have you considered the 240SX tranny swap? That transmission is essentially (other than gearing) the same transmission that was in the Nissan hardbody pickups; it is a fairly robust box, and all that you need to do to mount it on an L6 is take the bellhousing/front section of your L transmission, have one of the holes on the front machined out a little to accept a larger bearing or seal (I cannot recall which at the moment, search can help you more) and then put that front cover on the 240SX box. It is a firmer, more solid-shifting, more modern evolution of the gearbox that the Z came with. The transmissions that Nissan used from the 60s all the way through the 90s (at least, most likely further) were a family of evolving gearboxes from hitachi (90% they were the manufacturer, if not it was Fuji Heavy Industries, parent company of Subaru) that all grew one from the next. the autos and the stick shifts were kind of parallels.. My point is, the 240SX transmission is a fairly easy, fairly respectable upgrade. Sure, it won't be as bullet-proof as the 300ZX tranny, but THAT box is just on the other side of a technological divide.. the 240 box is just on THIS side of that divide. And I may be wrong about the ZX T5.... it wouldn't be the first time. I was trying to deflate your hopes a bit on that, but not quite dash them. Other than the one that was IN my dad's 83 turbo car, I have never seen one in the flesh; world class BW T5, I have seen but probably couldn't pick out of a lineup; ZX T5, I can't even picture TBH. I am simply remembering that it was written the gearbox was a red-headed stepchild of borg warner and Nissan, and not really that much akin to either... I wish I could find the thread but its long gone.

Welcome to HybridZ! Nice looking design, have you noticed this thread? http://forums.hybridz.org/showthread.php?t=143460 They are taking a very differeent approach, and it is for a DETT, but the basic thought is the same: pull an audi-style airbox off for your inlet manifold.

These are the things that you do to tweak the stock EFI system; this methodology was worked out from 1975 until about 1995-2000 when market technology became cheap enough for us mere mortals to start buying and installing aftermarket EMSs on our turbo cars, and the turbo Z world really spooled up... Its things like this (the fact that the only way to upgrade is through "bandaids") that people say "You can't really upgrade the stock system, just carb it" and that was the ONLY solution for a 280Z/X for many years. Seriously; until about 98-99, if you got a 280Z or ZX and it wasn't in super great mechanical shape, ditching the EFI and throwing some SUs on was step A-1. Regardless of whether or not its "the right" way to build it, it WILL work. Throw a potentiometer into the CTS circuit for an on-the-fly enrichment option! Advance the AFM flap a notch or two (or retard it, who cares?) Find a Cressida AFM and swap the Datsun AFM guts in while you are at it! This is modifying in hardware. It just takes grade 8 "lugnuts" (or, from a different point of view, the ability to cope when things break down)

The T5 that went into the 83 turbo 280ZX wasn't your everyday world-class BW T5.. I think the entire case was different, but I am not positive. I do NOT think that using the bellhousing on another T5 variant is a simple option, because I am fairly certain if it were, it would be much more well documented. I can't give you anything more positive (sorry, this is all "i thinks" and "probablys") because I am not very familiar with the BW gearboxes (more an old-skool Datsun purist than an American Iron guy TBH) Never underestimate what you can do in an early S30 with an L28, electronic ignition, well-built SUs with the right needles, the right cam, and a set of 3.90 rear gears. The 260 came with 3.36 rear end gears if its a 5 speed; upgrading to, say, a Subaru R180 3.90 LSD with custom CV axles would be a GREAT way to beef up the rear, give you better traction and control over your drive wheels, AND lower your gear ratio to something more typically "japanese compact" in one fell swoop.

Cool to see the model getting the street cred (I think) it deserves! Next episode.. a supercharged LT1 89 lamborghini?!?

Pull the valve cover and inspect all your cam lobes and rocker arms for any evidence of untoward wear. In recent years there have been instances of people chewing up cam lobes and/or rocker arms for no apparent reason; the popular theory for the cause is a lack of a Zinc compound in out motor oil (zdp) which is apparently incredibly helpful at maintaining the thin boundary layer of oil between lobe and rocker surface, and most supporters of this theory throw the term "poor metallurgy" out in the same breath, regarding the camshaft. There are a couple of threads that have gone on on this subject; I cannot recall who had the problems. Do you know the Screwdriver Stethoscope trick? One large screwdriver, butt the handle into your ear, and touch the tip to various points on the engine. It helps localize the type of noise you are talking about. When I do it, I sometimes go an extra hitch up and I VERY CAREFULLY push with the screwdriver handle until it sorta pinches down the ear canal, and I get a more solid transfer through into my eardrum... but obviously, on a running motor, you risk boxing the s#$% out of your ear. Good luck tracking down your problem! I would definitely try to pinpoint the noise a little better before changing the timing gear out.

I would say, save yourself some worry, and spend a *little* bit of the cost of having a machine shop doing everything on a few tools (engine stand hoist, etc harbor freight FTW) and tear this engine down, inspect as advised above, and re assemble it all yourself. If the compression calculation earlier (8.7:1?) is close to right, 18psi seems alot of boost to be running with 91 octane max. I tried to look over what you said the specs for the engine were.. 144 mm rods, 280 stroke, zero deck height add up to ~25mm pin height??? thats a TIGHT PACK unless something else is amiss, but the compression plus the boost on the octane might be a tad much.... The standard wisdom with a high quench design head like the P90 is to have the flat top of the piston coming i *believe* ~.0022 inch from the quench pad of the head (1 fast z/Brian is the person who I quote on that subject, I don't have the link handy) IF you need to dish the piston out a little to lower the compression a smidgin, then you would want to grind a peanut/trapezoidal type shaped dish into the face of a piston that will push close enough to the head in your bottom end when assembled. This little depression should mirror the combustion chamber in the head in all ways possible/practical. (It won't be nearly as large in volume or in outer "circumference") This will give you a nice even rounded-flatttish pancaked chamber for all that air/fuel to get squished into from the quench-pad area at the last moment, which should be the best shape you can get for your chamber. Obviously, pistons with sufficient meat are required to machine this depression into. The EXTREMELY close approach of the piston crown to the quench pad is critical; the number used should be researched and decided based on more than just my posting here. This is honestly just a tad beyond my ken, but I can kind of see where you need to go (I think) and dropping the compression, achieving proper clearance (WHICH your builders may well have already done) and giving those pistons that little scallop should be the magic bullet that dips your compression while increasing your engines tolerance for high compression, nipping your bud on both ends.

ohmygod I almost dropped my tool.....

have I given you the schpiel about twice pipes yet? Its all about pipe sizing (the MSA kit is equivalent to about a single 3" pipe IIRC, so adequate for moderate goals, it would probably hold you back from 400 but 300 oughta be doable.) As long as the exhaust pulses share a common collector (heh, turbo) there is no "inherent problem" with what we now call twice pipes for any motor. Unless I am *SADLY* mistaken, "twice pipes" back in the day specifically meant half the cylinders to each pipe, all the way back.. like side pipes, or whatever. Anymore, any setup marketed as "twice pipes" typically starts in one single pipe (collector) just like the MSA kit. So, thats the short version.. the short, SHORT version is, get a downpipe, attach it to the collector at the head of your twice pipes sytem, and don't worry about the exhaust again until A: it breaks or B: it is holding you back from 400 horsepower. I could give you the longer, more detailed version, with the math, and the pi, and the linear resistance to flow and whatnot, if you would like.. just ask and I will dig some of my previous posts up by search.

the motor in your car is not THAT high compression. Get her running. Get your megasquirt and associated bits, and when that is together and running on the car, then throw the turbo hardware on and retune. slowly disassemble and re build your turbo block and head while tuning and playing with intercoolers and stuff, and when the time is right (read: when the original motor blows) drop in your turbo block. Then, all you need is big injectors and a big turbo and you are instantly at 400 horse.

How much do you think you could charge for someone to dip their car, though? if it WORKS, something like that could potentially pay for itself. at least, you can rationalize it that way

Well, it was something of a comparison between our Horny Hero and the methodical, precise, determined work done by the men to get those guys BACK that I had in mind.. plus, Gene Kranz is pretty much my default "mission control" guy in my head.

Does that price include intake/injectors/exhaust manifold/turbo?? L28ET can easily get you to 300-350 horses without going inside the motor at all. Best way is to look into building a megasquirt system, (you can buy them assembled or solder it yourself and save some cash) get a good T3/T4 hybrid turbocharger, a good intercooler, proper exhaust and the right injectors and you are pretty much there. If you have stock electronics, its easy to put on a good intercooler, throw on a rising rate fuel pressure regulator, get the upgraded turbo and maybe some injectors (tuning with stock electronics is a very subtle art of fooling an antiquated computer and its programming; the computer has to think everything is stock, and you are limited to a fuel delivery pattern that parallels stock) and you get upwards of 200 rather rapidly. Once you get there its time to do some suspension, braking, and tire upgrades anyhow. I used to live in North Wilkesboro

yikes...

Afraid of the boogeyman? I call that "stealth mode."

Many thanks for the Vizard article!! I think I have heard this referenced but I have yet to find it. It is well worth jumping through the hoops to register to download it!!

Lets not forget that 3.545 was also stock rear end ratio for the 280Z originally, I am not 100% certain how broad the application is but I know my 75 has one. I realize that the engine and transmission are TOTALLY different from stock S30 (duh) but still, my point is that a 3.545 isn't some crazy tall diff ratio for a Z-car.

Good luck, and Godspeed!!!

He is right; virtually all of the comments made to the effect that "triples are over-doing it" are only intended in the sense that, you do not NEED to go to triple to reach your power goals. Modest power goals can be well tuned in with modestly sized mikuni/webers and run at least as well as SUs; however, the tuning complications of matching six carburetors are still there.

I saved alot of those pictures on my hard drive and have been looking at them wondering where the head went, but wasn't going to say anything. Awesome to see the computer modeling you've done, as usual. Your head looks rather alot like one posted elsewhere; tomorrow when I have a moment I will search for the thread and show you the pictures I mean. I like the look of the chambers you mocked up, and have for some time now. Can't wait to see it all added together. Some Sum!! EDIT One BIG issue I see in that last video though.. only half of the chambers are swirling in a "z" shape. The other half are swirling in an "S" shape. It isn't an S, its a Z. if you don't have them all balanced, this motor is sure to eat muffler bearings for lunch.

JM hit the nail on the head: stick with SUs, build a mild/hot head, and stick with your own gut on putting the rest of the budget towards suspension. It is hard to disagree with someone dead set on going triples... but SUs are almost always enough, at least as a beginning. The SUs can be replaced once everything ELSE is done, and be a final power bonus.

What did you do to pre-lube the assembly before your initial start-up?