Tony D

Well, the diagrams in the FSM are identical, and the explanation of their operations are identical in the FSM's. From this, i took a four channel O-Scope, and went to comparing the waveforms between the two units when I was having "problems" with my install. They were identical. I have several 82/83 ZXT CAS units that I powered up and tested both by spinning by my fingers and by an electric drill to simulate actual engine running conditions. My Milwaukee Magnum turns 500rpm, so it was very nice for approximating the waveform at 1000rpm engine speed. JeffP had told me they were the same an interchangable, and from the O-Scoping, I tend to agree that there is not difference in the output from the modules. HOW they derive the information is VERY different, but the waveforms on the output are identical. As for RPMS, make sure you set your hard limiter and soft limiter up before your first drive. The thing will pull in first like it never has before! Go MS, you will be glad you did! I think you can even run an "emissions program" that will get your through CA Smog if you keep the stock wiring look about the engine bay when you do the conversion.

It depends... I used the 81 CAS to prove you could, because nobody else had... From what I could tell the most advance you can get on the stock CAS adjustment bracket is about 35 to 40 degrees. This is 10 to 15 degrees too little for "full" N/A mode advance. During boost it shouldn't matter as you are only running around 25 degrees BTDC, so a max advance of 30 degrees should be fine... BUT... For cruise and partial throttle coasting, you want bins that may be as high as the low 40's BTDC for maximum fuel economy and response. To accomplish that you have two choices with an 81 CAS. 1) modify the bracket. I was not about to take all the bracketry off and see if I could make something work or 2) Take the front pulley off, drill ONE hole, and bolt it back together after aligning the trigger wheel using the new hole. The modification is VERY easy, and you should check your damper ANYWAY because the thing revs to 7K EASILY in the first two gears, and doing that will eat up the rubber in the dampener. By doing the modification, you will get full N/A advance, and allow full advance under all conditions. The engine RUNS with the 81CAS fully advanced, but you never really know where it is running, and I didn't like that. With the five bolts holding the timing disc to the pulley, the math was easy. Move it one bolt in any direction and you alter timeing 365/5 degrees. Or 73 degrees. If you take your original timing set at 24 degrees, and DON'T CHANGE ANYTHING, and do this modification, your spark angle should be VERY CLOSE to 97 degrees. I moved my CAS 8 "bumps" off of dead true (for some stupid reason), which is supposed to be 24 degrees. So add that to the 97 I already screwed into it, and it comes out to almost EXACTLY the 120 I put into the offset window on the setup screen for megasquirt. With that setting, when I fired the car, it took right off, idled correctly, and when I hooked up the timing light the mark was DEAD ON to the spark table for the rpm I was supposed to be switching between (9 and 14 BTDC). I have played with the numbers and it introduces an error in the timing light for initial timing and how the engine runs, so it must be correct. It is a VERY easy modification, and FAR easier than swapping the spindle and over to the 82/83 CAS... At least IMO... The CAS is identical in output between models, so it's up to you which one you want to use.

I'll agree, I converted mine some time ago using a 200SX throttle cable. When I drilled out the ball on the end of hte throttle pedal and bent it 90 degrees, it lined right up like it was made for the conversion. I will have to take photos and post them on my cardomain site. The 200ZX cable "pull clip" went right in the hole vacated by the old bellcrank pivot ball's stem! Just like on the 200SX pedal! I was amazed. Have not converted the EFI car as of yet. No time.

L20ET is the ZX and Skyline "Tax Beater" JDM 6. In 89 when I left Japan, it was common for guys with L28's to have them removed and have the L20ET installed in it's place to take advantage of the lower "2-Liter Tax Class" which was considerably cheaper when it came to registraion and insurance time. The power was comparable with N/A L28, so it was a "win-win" situation.

because the power source for the heated O2 is jumpered under the board to S1-5 on the Relay board, and if the straightthrough connector was used, the "jumpers" on the board, would feed back to the ECU... I jumped wires from their "Assigned Spots" in the interconnect cable to other spots for the relay board attachments. Hey, it's open arc, right?

I tried those old mothballs in some stationary powerplants and was amazed by the blue flames emitting out of the exhausts afterwards. No scientific, but an interesting thing of note for a 14 year old who was curious about "mothballs in the gas tank seizing an engine" theory. Mothballs didn't do it, and sugar had tobe mixed VERY well in HIGH CONCENTRATIONS to actually effect anything... But I digress. The reason for no acetone in modern fuels may simply be cost economics. How much does cost to add it in such a high concentration? A fraction (we're talking added cost in the area of 0.000001) of a dollar added to each gallon refined would mean a decreased profit of Millions of not tens of millions a year. While not the "insidious conspiracy" favored by most, lots of "potentially beneficial things" are left out of ANY consumer commodity simply because most people are too cheap to pay a single cent more! With the talk of the gas prices projected this summer, can you see anyone actuall believing that they can save 10% (maybe) if they pay a penny more per gallon? For me and my F250 that would mean 16.5mpg instead of 15 on the freeway. Three gallons per tankful. I could do that math, and might try this out on the company truck (muahahaha, like Canola oil in the Diesel one time... just to see "what happens") but given most of the public's attitude at this time, some slick marketing would need to happen to make it fly IMO. Maybe a patriotic angle. But what kind of long-term effects on plastic fuel system components will this concentration of acetone have? The way I read that Acetone Formula, it lookde similar to Nitromethane, so that's good enough for me to give it a try... But a lot of petro refiners have to satisfy the Big Three in their fuel demands. If Ford GM and Dalimer decide they all want to run a plastic that is .02 cents per component cheaper in their vehicle fuel systems and it's not Acetone Resistant, I suppose they would probably put pressure on the refiners to keep the stuff out rather than THEM pay the costs up front to use the petro that could save their customers money. Now if they make a retrofit fuel system component that IS resistant, and let the customer buy it as an UPGRADE to be able to use this "wonder-formulation" then the cost is totally on the consumer for the usage, and they make money on both ends... I digress even further, and on a tangent.... But am thinking some Acetone is on the back shelf from the last FRP extravaganza I had... and I do have to take the Company truck out otday to get the Bridgeport... Hmmmmmm Decisions Decisions! Interesting thought. Post experiments. I can see how this might help with some of the "EFI Syrup" they sell today when run in a carburetted car...

Yes, I remember well. It was before the rage with Hondas. When nice rust free 240's would show up in the junkyards by the SCORE... WE had a chocolate river that ran through town, and little orange men who dumped sugar into it to make it sweet. Because as you all know, memories filtered through a choclate river are oh, so bittersweet! BWAHAHAHAHAHAHAHAHAHAHAHAHAHA! Someone can slap me for being off-topic when they see me! I hereby give you permission for that comment! LOL But yeah, I was suprised by his comments. And still shudder at the thought of having something like that and trashing it---such is the nature of the business during experimentation I suppose! In 30 years some people will lament what we are doing for our rides I suppose...

PCV is always a good idea, especially under boost where there is a lot of blowby... I run PCV on all engine I have built. If the NHRA runs it, there's a reason...

Move the PCV to the same location as the turbo PCV. I drilled mine and threaded it directly into the manifold. I believe that "Blue's Links" at ZCar.Com shows my PCV relocation. The photos have been posted there a few times, if you search the Tech Forum there they should pop up. I don't have them on my hosting site yet (probably should put them up there) so I don't know the link offhand. If you see the photos, it's pretty self explanatory. It's no biggie, really easy to do. I just plugged the original PCV hole in the bottom of the manifold with a flush mounted socket headed NPT Plug---do not recall if I ran a chaser tap down the hole or if it went in on it's own. I do know I used Loctite PST on it, used a Brass Plug, and then Staked it around the periphery in three or four places. That relocation will also allow you to keep the stock Turbo PCV line which is important, as heater hose tends to collapse... Good Luck. It's easy to fix, don't sweat it!

Go Alan! Mack, he's got valid points. The quote was referring to LY -vs- L on the 4-6% range. The OS claimed 12% bolt on in literature of the day compared to L. This is akin to Mikuini claiming 22% by a set of 44PHH's on the L24, and 12% on the 280 mill running EFI (they even had dyno graphs with no scales on them to prove the point!) But as for this quote: "The fact of the matter is that I am 99.999999% sure that NO ONE on this board has ever owned or worked on an O.S. giken head, so its all speculation anyway." I would take the member list, divide that number into at least TWO and revise that ".999999%" figure to more accurately reflect the realities of the situation. Just as an aside, the TC24B1 that was tested at JG Engine Dynamics in Alhambra actually made less horsepower than the JG-Ported head on a similar engine. This was using a SOHC cam grind similar to what the two OS cams were ground to---they did have the advantage of trimming lobe separation easily on the dyno. Cam figures are about usless unless you ahve the cam in front of you and measure it yourself. Who is to say they were measured at 1mm valve lift, .015 or .050" valve lift or in CAMSHAFT lift. I have seen many cams advertised at 304 duration that when measured at .015 or .050" lift at the valve were only in the 280 range. So a 304 may sound radical or insane, it really only is a number. I have had real world 290 duration cams in vehicles, and they in no way compare with some advertised "310" grinds. At least nobody called it a 3/4 Race cam... :Rolls Eyes" Get it? 3/4 Race because it's 270 degrees duration... now you know the rest of the story! But I digress... Now keep in mind, Javier used one of his 3.2L engines, and that required changing pistons and rings between the tests. I begged Javier for the old head, but unfortunately he tried porting the OS head to get comparable numbers and found the casting was much thinner than stock Nissan parts, and the ports could not be reshaped for better flow or horsepower. Reading that, you can infer that he trashed the head cutting through the ports in more than one place. But L-Engines were on the decline, and Hondas were taking up more and more time in his shop... I still wish I had the old OS head just as an ornament. Cut ports or not...

I used each of the following at one time or another: 91 Stanza TPS (Potentiometer) from an SR20 240SX TPS (Potentiometer) from a KA24 91, 92, 93 Mazda 929 TPS (Potentiometer) Some Ford TPS on a 70mm Throttle Body A GM TPS (Potentiometer) Whatever throttle body you choose to use, the later the vehicle the better, as the chances are good it will have a TPS and not just a switch. The Mazda was the only odd man out, as it had more wires than the rest... But the Mazda Throttle Body also had an integrated ADJUSTABLE idle air bypass circuit! Same as the Ford unit.

The relay box is set up for engine room usage, the MS is not. Had my interconenct sensor cables been long enough I suppose I could have moved that into the kick panel also, but one way or the other you will have to make a harness longer. So either your sensor harnesses are longer, or the pigtail moves you remote. Not everyone is installing these in Z's. A VW Bus would be better served with the ECU up front, where you can monitor it, hook up to it, smell it burining while the relays are all out back where they need to be. Another thought would be that with a pigtail, it allows you flexibility in routing where stuff goes. The way I wired some stuff, that straight through connector would send some wierd signals to the box from what I did underneath the relay board conecrning power taps for the heated O2 sensor, CSV, etc! Also, remember you will have to run your power wires to the relay board, meaning power wires through the firewall.

A L O D I N E That is the trade name of the stuff, and just about any place that does any sort of small aircraft engine work will be able to give you a small vial to touch up what you need to do. It is the stuff that gives aircraft aluminum that off-color tan gold look. Alodine. Aircraft Spruce Co in Corona sells it by the gallon... But you only need a bit to touch up what you did. FYI, I redid the entire upper throat area including the fuel distribution "trees" in the throats of my Corvair almost 15 years ago now (hacked up NOS Carbs, believe it or not!) and to this day I have not gone in and retreated with Alodine. I have no corrosion yet. But this is SoCal... and the car has sat for extended periods, so I dont' thing the corrosion will be a big deal. But if you "want it to look sotck and untouched" then alodine is the way to go! You can stick the whole thing in there and boil the whole carb so it all looks like new... You went this far, why not! LOL Oh, and as for a 2" hole only being a 2" hole, to visualize it look crossways at the plate: The turbulence caused by the SHARP EDGE of the hole will make the air at the upper edge tumble towards the center of the orifice, with fluid flow only happening across about 1.750" of the orifice. When you add the velocity stack, you get linear flow through the WHOLE orifice since there is no tumbling of the air around the outer edges. In reality, a 2" hole in a flat plate, is actually quite a bit smaller due to the turbulence. One with a velocity stack is actually a full 2" of useable, unturbulated space.

What the stock 240 system did through it's diverter vavle was to allow pressure to build in the tank (say from expansion on a hot day) to a set pressure of water column pressure. It then discharged to the vehicle's crankcase. While cuel got sucked out of the tank on a drive, the same diverter valve vould allow filtered air from the air cleaner back into the tank while driving along. We just had a club member go on a drive after finally replacing all his vent hoses in the back of the car. He ended up sucking the filler neck flat! Come to find out for years he had been running the little vapor line up front with a nice sanitary vacuum cap on it, and with all the leaks in the vapor hoses, it never made any difference. The Carbon Cannister used the Charcoal as the storage medium, until startup and that flapper valve opened to let it purge into the manifold. Similarly, the vapor return line to the back of the car did the same function on the vehicle when driving down the road: let air into the tank to keep a vacuum from being pulled as the fuel was pulled out of it by the fuel pump. Keeping fuel system integrity is easy if you know how they test the tanks. A small series of check valves (I despise PCV valves, they almost universally leak!) works to keep the "test pressure" on the tank during a fuel system pump up at check time (if the garage actually has the tank adapter!) If anything , the easiest way to make sure it all works is to simply relocate the carbon cannister to the rear of the vehicle. Some other vehicles have smaller cannisters that would make packaging easier, but "may not" adequately provide for enough storage capacity for vapors. This will have to be your decision. In many cases as long as it's all hooked up and in place, they will let it go through the system on a check. If only functional stuff is required, then mixing and matching components will make for easier packaging. The vent line for the EVAP comes off the top of the phase separator annyway from what I recall, so as long as it's hooked up so that it only gets gasseous fumes, you should be fine. But for the effort of relocating it to the rear of the vehicle, sticking it out in the fenderwell behind the headlight, or in the back portion of the wing behind the wheel would be just as easy, and require far less custom tubing to be done. I agree, all PCV systems are a metered vacuum leak, this is why it's important to let it distribute evenly to all cylinders! In many cases with total closure systems (Think ITB's with an IAC motor on a log) the PCV may need to be restricted by an orifice as small as .050" to keep from the high vacuum incidents (snap throttle closed) from sucking oil out of the crankcase and into the manifold! I have a Mitsubishi PCV that fits in the hole int he side of the block, it has an .063" orifice built in (sorry, been almost 15 years since I installed it, no model information or tech specs) and it distributes through a 1/4" line manifolded into each intake runner, off my 3/8" balance tube. Hope this helped in some measure...

Ugly Car Club Charter Member #2 here, after Moby, of course! LOL Actually, most of my cars are ugly. Who has time to paint?

FYI don't get hung up on the semantics of what Nissan calls a "Head Temperature Sensor". It is a glorified WATER TEMPERATURE SENSOR, and has the EXACT same response curve. I have used the CHT and WTS interchangably in Megasquirt applications, as well as when retrofitting Earlier ECUS in earlier S30's with later engines. The only difference is that the CHT is a little slower to respond initially, and once warmed to operating temperature reads a bit hotter than the WTS (but only on the line of 5 to 15 degrees F). I would not make someone get a CHT and install it, in my experience using the stock Water Temperature Sensor for the original ECU pickup in the Thermostat housing works just as well, and the ECU never knows the difference. Perhaps you could take my readings into account, and if a customer specifies he's using the Thermostat Mounted Sensor, you could skew the CHT tables 10 degrees F colder and therefore get the same curve as from the CHT. Realistically, I dont' even think that will be necessary. What I have noticed is that at idle, the CHT normally reads in the 140-150 degree range with a 160 degree thermostat, so maybe warmup may need some redefining. it is not a problem with my setup, (MS-n-S) as all my warmup enrichments are out by 130 degrees F anyway.

Just a Bizzare second thought I have had while observing the modified plate in action. Seems Nissan put the TDC mark at a different place than their paddles. The paddles were advanced for the CAS in the first place. But while your TDC mark that I made actually reflects piston position, I ended up sing the paddle position for timing on the other side. THAT is why the timing is dead on with the paddle, and wherenver I try to trim to the TDC mark I made (like Nissan) I can't get the thing to run! It is better using a paddle for timing readings anyway---it's far easier to read. Unless you make two marks reflective of TDC, and the exact same offset on the CAS side of the pulley it's almost impossible to tell where the timing mark will end up. My advice from this point would be to mark the TDC simply for reference in the future, but know that timing directly off the paddle over on the CAS side of things will make your life easier. Even if it does look like you are firing 60 degrees advanced based on your TDC mark... :rolls eyes: I may play some more, but it works all as written, maybe I'm overthinking the mechanics involved here anyway...

Went for a drive today, got tons of intermittent ping while on boost. Thought for a while it was soething "too good to be true" on the conversion, then looked at my spark bins, and found an alternating "36" in every other bin along the full load (170KPA) line! D'OH! Went back and made one pull with the laptop on in "follow mode" and sure nuff, rrrrrrPing! rrrrrrPing! rrrrrPing! changed the bins to the "24" and "26" they should have been, and on the return trip pulled hard, and not a hint of spark knock! Like I tell everyone, always start tuning a system at low boost, and on the stock bottom end, one error like that on high boost and it would have been BOOM! LOL How they got changed I have no idea, I must have had them in ther for a test earlier, and forgot to change them back after the test. Whew!

I would agree with ZCar Nut. My first thought was 1) that your VR might be bad 2) that you have corrosion on your sensing wire. I recently replaced a "new" VR because it fried. Remember that you can have NO POWER applied unless the case of the external regulator is GROUNDED! What I did was to run a separate line (#12) fromthe case of the external voltage regulator to the star ground point on the chassis just below the battery. This modification ALONE stopped my voltage seeking problem. Before depending on what accessories I was runnning, the voltage out of the alternator would be anywhere from 12.9 to 15.3 VDC+!!! After the addition of this ONE ground line, the voltage dropped to an almost universal 13.8-14.5VDC no matter WHAT accessories were on the circuit. After finding some corrosion on the sensing lines, and making some corrections and cleanings, the voltage stabilized even further to closer to 13.8 - 14.2 VDC. The big thing is that now I have 13.8 at IDLE as opposed to 12.9 or lower before! Sensing wires and bad grounds kill electrical components. Make sure they are all up to snuff. And if you have a 260 or 280Z with the external regulator, my little #12 wire for the ground is ESSENTIAL to you not frying your reg! The thing mounts to a bracket that mounts to the chassis. That's two junctions of bolts and painted metal to corrode causing this drift. Not to mention that if you remove the bracket and it's powered on the battery (like for troubleshooting) POOF! There went that NEW VR! That Pigtail I added allows you to remove the battery and gain access to the regulator and not loose it's ground path. Preserving it for another week at least! LOL Good Luck!

Moby, you may want to consult JeffP's Extreme 280ZXT Webpage on Anglefire for his older turbine specifications. I know when rolling in second gear at 3000rpms, when he nailed it 23# was instantaneous. He was getting boost around 2500 if I recall. http://www.angelfire.com/extreme/280zxt/ And it incorporated a cut stock turbine housing, with some other center section and compressor section. I believe he actually has one or two of those housing still laying around his garage still. He held on to the stock manifold (with some hand porting to the inlets and turbo flange area) to 450HP. His last tests indicated 23psi exhaust manifold backpressure at the turbine inlet, to 23psi intake manifold plenum pressure at 7000rpms in second gear. Testing those numbers in anythign but second would be suicide! LOL He had a really boosty-responsive setup and used that log manifold to 450HP... Now you want to make some real power, snag one of those Euro Manifolds! They have internal passages bigger than the 1 5/8" Tube Headers SoFla Performance was making! The only restriction on that unit seemed to be head port exit, and that was easily portable to help with the flow! But I digress... Good Luck!

I finally had a chance to do my pulley mod as in the sticky. Linky: http://www.cardomain.com/memberpage/735451/9 FINALLY I have a timing mark that MATCHES my timing light! WooHoo! Finally I am getting a full 40 degrees advance during the high vacuum, high rpms sections of the map. The engine is MUCH freer on the top end of the rev range as the adjustability of the CAS screw only allowed me to get maybe a total of 28 to 30 degrees total advance. So I moved the pin hole to line up the Timing Wheel one bolt rotation advanced. I found that a 13/64'th transfer punch will work perfectly for transferring the hole from one timing wheel to the other (I sandwiched two together, one in the stock position, the other advanced on top of it, bolted to an old pulley), and using the same sized drill bit also allowed a nice tight fit on the factory Nissan Dowel in the back of the pulley. The ONLY thing I did differently, was I lined up the trigger to the CAS line 8 "nubs" off from the place it set after finding TDC and marking it on the other side of the pulley. This 8 "nub" offset allowed me to set "120" on the spark Trigger Angle (what I figured was it was the roughly 72 degrees difference, plus the 30 degrees from the 8 "nubs" and some Kentucky Windage in aligning the CAS on the Bracket). This puts the timing mark RIGHT at 9 degrees at an 850rpm idle speed, and well in advance of the scale's 30 degrees during a rev-up. I have set no offset in the other screen. I will now work on the lights to get legal, and then start doing some road trimming. For once I can do something on the car, and it is actually verifiably tracked in the MSSTune. Again, WOO HOO! IMO, I would not even TRY to dick around with adjusting the 81CAS, while the engine is out of the car, pull and modify the pulley, get your TDC marks set up on the altered timing plate, and bolt it all together before installing it in the car. I pulled the radiator to get to this stuff because I did it in-car. Putting the 81 CAS back to "TDC" is something you will have to do BEFORE you pull the pulley off also. Marking it after the mod is easy using typical TDC finding methodologies. I am really suprised by how much better the car runs with the extra advance available! Moby, feel free to use as you see fit to incorporate the photos in your sticky if you want...

NOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO! The wiring of the + side DOES NOT CONNECT TO THE FIDLE! The + ONLY connects to the B terminal on the GMHEI setup. You wre SHORTING THE MODULE!!! You will BLOW something in the FIDLE driver circuit trying to hammer the MS with the current draw of a coil! The + Terminal will also have a 12V supplied to it, from the ign switch... Why didn't you wire it like the Moby Stickie?!?!?!?!?!?

240zprace... Do you have any photos of your setup. I have NEVER seen an AFM in a boost area. EVER. The airfolw would logically be Air Filter, AFM, Turbo, Piping, FMIC, BOV (to ATM or recirc), Throttle Body. EVERY setup I have seen in the past 20+ years has been set up in that configuration. I need to see your setup to see how you converted it to Pressurized Airfolw through a box with no in-to-out sealing capabilities.

Alan Pegged It, this is a post of dubious heritage, and that's being extremely charitable. "L" was a simple configuration designation, you are crossing VIN designations into the Engine Classifications. Amongst other things. This will become one of those "reference posts" that will perpetuate evil internet myths ad nauseaum. Not even close! As for LD28, That's a DIESEL. Now if someone converted it to EFI and Gasoline, then that wouldbe one thing, but its' still an LD28. The manufacturer sets the engine designations, not aftermarket builders. L31 anyone? it tells you what it is, but it's not a Nissan Designation. As for the RB-S motor connection, I'm getting charged up and will stop now, before I go off the deep end. There is not a connection, one did not evolve to the other. Not even close. :rolls eyes:

blower, supercharger, turbo... Both a blower and a turbo are superchargers... They are all forced induction engines. A turbo will use a different piston than a blower. I would go with the second piston with the first ring pulled away from the combustion chamber, and a dish to concentrate the fuel air mix at ignition into a central turbulent area.