Tony D
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Posts posted by Tony D
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I used a pertronix flamethrower offroad HEI module. that baby throws a 4" long spark to the PCV HOSE! (Did you know the PCV Hose is conductive rubber? Neither did I!) Makes a nice "poof" of smoke when it does so.
I am using an 87 Z31 Turbo Coil. The guys at Nissan Comp Department told me it was the hottest coil Nissan Made, and it's what thye use in most every stock configured racer they field.
Thusfar I have been VERY happy about the performance. I think I paid $45 at a local speed shop because I had to have it NOW (ironic, isn't it given my circumstances...) because I didn't like the orangeish spark given to me by the Autozone / Wells Stocker that was $13. I like bluewhite with a POP! Not orange-ish with a "Fitz!"
I figured I can always use the spare Wells unit if the 81 CAS didn't work out, and I needed another unit to trigger from a magnet or hall effect sensor...
I would order from Summitt Racing Online, or Jegs. They are V8 parts, and those places are GIVING the V-8 Crap away!
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mario, that is an anti-backfire and fuel economy measure. You have settings basically approximating the last scenario, which is the only one you really needed to worry about.
The other two are anti-HC spiking control algorithms to lower emissions. If you aren't really coasting much or heavily decelerating constantly it will make little difference.
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Yep! It's getting it to the ground, not hazing the tires thorugh second gear that makes for quick times!
Though for spectators it sure is entertaining!
Yeah, John, he was in your group! He was probably hiding in the shadow of one of my legs...
But I thought it was Ian who got sick from the fumes... he sure played it off big to suck sodas from the "blue chest of plenty at Spa Dighera" up on the front straightaway! LOL
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"The 432R models were very stout engines indeed. I would not be so quick to disparage a factory sponsored racer with well over 240+ hp in conservative tune (on carburettors) against an L24 with only 150..."
Here you have completely ignored what I said. I was comparing the engines stock to stock. If you want to talk about race cars lets bring out the BRE car of John Morton which was putting down 290hp from the L24. Now' date=' as to the first question of where I got the comparison info. Several years ago I picked up a book on classic Japanese cars. Obviously I can only make out a few things in the desriptions, but the charts are fairly easy. They took all of the factory ratings and listed them. Here is what it showed.
The Fairlady Z had a peak of 150ps at 5600 and a torque rating of 21.0 at 4800. The car was also equipped with a 3.9 rear end. It ran the 400m (1/4 mile) at 15.8.
The 432 had a peak of 160ps at 7000 with torque at 18.0 at 5600. This car was equipped with a 4.44 rear end. It ran the 1/4 in 16.0.
Both cars had the same tranny ratios. 2/10 of a second may not seem like much, but it is. Not to mention that the 432 had a 4.44 rear end. Imagine if the Fairlady had that rear end too. I would imagine the gap would be a bit larger.
When I mentioned the price of $15k I was going off my personal experience. When I bought my '71 Skyline last year I was offered an S20 as well. The motor was used but complete with tranny and carbs w/factory air cleaner. $15k was the sticker. Tempting for sure, but not really practical so I passed.
Brian[/quote']
Uh, no, the comment was about the 432R model. (Now whos' not listening?) This is not the plain jane 432! The plane jane 432 was rated at 160ps, sure, as was the L24 at 150.
The 432R model on the other hand was a FACTORY EQUIPPED RACING VEHICLE! It is NOT a consumer grade 432. Comparing or even using 432 and 432R interchangably is a SERIOUS faux pax! THEY ARE DIFFERENT BEASTS, and my statement stands on the horsepower rating of the R-Models. Depending on "High Test" or "Regular" gas engines you specified, there were many tuned power levels. Up to 320+ horsepower!
The 432 was a Homologation model for the Japanese market, but it was a FAR different animal the 432R!
The 432R model WAS available for purchase FROM THE FACTORY and was similar to the Ford Thunderbolt, or any other "Factory Racer" of the day! Go in, place your money down, and take delivery.
So don't confuse the terminology. The BRE car was a PRIVATELY EQUIPPED Race Vehicle. You coulnd't normally get one delivered through distribution.
The 432R was available by placing an order at any Prince Dealer that handled the 432 line (at the time PMC Dealerships dealt with the "performance lines" that Nissan had to offer domestically. As of 1990 to get parts and service on Z-Cars in Okinawa, you still had to go to "Naha Prince" as they were still the performance dealer on the island!)
This is no different than comparing a COPO Camaro with the six cylinder 250CIS base model you got at your corner Dealership in the 60's /70's.
Like many things, there were trim levels people simply don't knwo about, the differenitation between GTO and Tempest is a good example.
I am talking about running a GTo against a stock 4 cylinder Tempest here.
They are BOTH STOCK! You just had to order the GTO in the configuration you wanted, and you got it if you paid your money!
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Oh, and in my defense about leaving DLP out of my little book...
Last dealings I had with DLP had to be 9 or 10 years ago when he recurved a distributor for me.
While I know people who accepted delivery of a custom cam grids from Isky within the last month or so (in the same price range mentioned)...
So I claim "most recent memory syndrome"! DLP totally slipped my mind, and I should have known better.
Don can be...uh....well, some people take him wrong when they first meet him. I like him, but can see why he is the way he is, and I can accept that. De did not dub himself "The Curmudgeon" from lack of other terms used to describe him by others! LOL
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P.S. You wouldn't be interested in my Twin Turbo Kit for one of your RHD Z? I've got that plus 36 other parts up on EBay now..
You bastard! You are the devil incarnate!
Now I know how Ian feels when I danlge tidbits I find on E-Bay in front of him all the time!
You are not in collusion with Ian to stop me from this tendency, are you? LOL
Right now, I am in Venezuela, and up to my ankles in funeral trip debt, and nephew graduation trip debt, so no goodies for Tony until I get some of it knocked down to a managable level...
Good luck on the auction, though, that is a nice piece, and would look good in the 71, 75, or 78 RHD vehicle..... Muahahaha!
Why on earth did you sell the Box? I would have lost nuts to keep that. And my friend working in Aberdeen right now would have probably traded you his three Z's and his girlfriend as well as ex wife for that car!
Now I have to "cut and paste" you post into an e-mail and send it to him to let him know a Box Skyline was in Md, and he didn't even know about it!
LOL
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Another innovator Tony left out of his dissertation is Don Potter
OMFG! YOU ARE DEADLY RIGHT!
I hope he still returns my calls! DLP Engineering IS one of the innovators!
ABSOLUTELY CORRECT! A BIG (HUGE) OMISSION on my part! Sorry!
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WHAT YEAR ZXT?
If the donor engine is an 81, you can crank and twist the distributor all you want, and it won't do a darned bit of good as the CAS is triggered on an 81 from the front pulley and a different CAS pickup point!
So before I went down any road, I'd clarify which engine it is! Even though you say it's an 82, it's not some strange NY titled beast that sat on the lot for a year before being sold, and is a "closet 81"? IS there a CAS under the cover inside the distributor, and IS there NO CAS bracket under the AC idler pullley?
If that is the case, and you truly DO have a distributor mounted CAS, you should be able to gain approx 60 degrees advance by tweaking the dizzy. If you are not sure, just start with the basics, make sure it's set up with the Rotor Cap Pahsing hole aligned.
If the engine is not at 20 then, start looking for why, because it shouldbe very close. a 10 degree move of that dizzy is a 20 degree move on the spark timing trigger point!
The possibility exists that it may be off a tooth, but verify placement of the TIMING MARK on your pulley, and make sure the ELASTOMER has not shifted giving you spurious readings!
So yes, set it to TDC, if for nothing else, to VERIFY your timing mark! THAT is your first step!
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what's and arm, leg and firstborn child going for in NorCal these days?
Here in SoCal Autozone asks around $240 for a reconditioned CAS for an 83, and the dizzy shaft may still be available from Nissan for all that's worth!
I would bet the conversion can be done using "new and warranted parts" for under $300!
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common to keep vacuum systems segregated from boost.
Your setup should be easy enough, find the FSM, and then copy the checkvalve placement for the Turbo Version 200SX!
I mean, you already got a diagram from the factory engineers, what more could you ask for?
For me and my 260Z with factory Air, the standard check valves worked fine, and the larger vacuum reservoir held more than enough vacuum to sustain heater control position under periods of extended boost. If you get paranoid about boost and vacuum, you can always add the vacuum pump and supplementary reservior from an 82/83ZXT if you can find a place under the hood for it!
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"but for decent parts id have to buy from a group of different people..."
And the problem with buying the best parts from the best suppliers of each individual part is what exactly?
LOL
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What is their definition of "Differential Gain" as I'm betting it's somehow the same as Integral.
If they don't have some sort of intgral compensation, it's why the pressure-based algorithm will never work. PWM may be the Time-Based "I" in the equation, but it would be a strange way of doing it. Normally PWM is the output.
On a PID controller, the OUTPUT is affected by the loops. And I suspect the PWM is changed by P+I+D=O
BAH! RESET RATE will be your INTEGRAL! They are using mixed Pneumatic and Electronic Terminology! On a PNEUMATIC controller, you have Porp, Reset, and Anti-Windup Reset (lets not go down this path!)
Anyway, What I said about Integral applies to Reset Rate in an inverse fashion. Instead of being Offset from Setpoint/Time you simply ramp up the Reset Rate to make the Porportional Reset close on the target setpoint faster, and use the Differential as you would Integral to close the final "differential gap" once the Porportional controls to the always-present offset point I mentioned earlier!
I'll lay money that is how they are controlling it! They are basically all the same, there are only so many things you can do to the thing to control it...
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Here in Venezuela the Sin Plomb gas is 77 octane and costs about 20 cents per gallon......
There are lost of Impalas, Torinos, and Dodge Darts here...
But I digress. There is the argument of "low compression" versus "high compression"...
Most people use the argument that lower compression allows you to "run more boost" to make horsepower. This is true.
But to what extremes are we going to take the argument. An 8 or 8.5:1 compression engine will easily take 20psi of boost. And what are we making by that point? 350, 400HP? E'motive in 1983 with stone age electronics made 580HP at 7500rpm, on 20.6 pounds of boost, using racing gas, and a compression ratio ABOVE the stock ZXT of the day (considerably more if you talk with the people involved).
So the question becomes, in my mind at least, "How much money do you want to spend?" If you spend the money on head work and a cam, 580HP is waiting at 20-psi, but ASSUREDLY NOT at 7.4:1 compression ratio! You can get decent performance from a stock compression turbo, but for the money the drivability and spooling capabilities of a higher compression engine seem to win out when you weigh it. There really should be no trade-off in the octane scare between 7.4 and 8.5. I would personally waste my time with anything below 8.0!
The naysayers about "higher boost levels" might want to do a reality check and actually ask "how much boost do I terminally want to run?" For someoen going with 45psi, then yeah, I might say 7's would be in order. For someone with an inefficient intercooler? Maybe no more than 8:1. But for someone pushing a hybrid turbo and a decent intercooler on even 90 octane, I would shoot for the stock N/A drivability that 8.5:1 offers off-boost. Nothing is more discouraging to hear than some idiot with a well-tuned stocker say "I got him out of the hole till the boost come on!" Lets' not let those N.A. guys ever have the ability to say that!
In a roundabout way what I am trying to say isn't really about boost. It's about total mass flow through the engine. The power is, and always will be, in the HEAD of the L-Engine. A properly ported L-Head running 17# of boost will make more power than an unported engine running 20+. I have an acquaintance that did a before and after dyno test (headwork only). After retuning the TEC2 for the new flowing configuration, the SAME engine using the SAME turbo, and basically the SAME everything save for the portwork and runners in the intake manifold made more HP at 17# than he did at 21# before! (BTW, this was on an engine with 8:5:1 Slugs) So the "More Boost means more power" line of thinking is a bit corrupted. My training has (since I work in Compressed Air and Gasses for a living) always been that "pressure is the resistance to flow! The less resistance you have to flow, the more efficiently you transport air... So in some cases, LESS boost means MORE power! On the test vehicle, it assuredly did!
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Tuned the boost controller using the Duty Cycle table for about 12psi. I found that I had to ramp up the duty cycle as rpm's increased.
Also' date=' the duty cycle vs. boost amount is NOT LINEAR! Upping duty cycle from 25% to 30% may increase boost by 2 psi. Increasing from 30% to 35% may increase as much as 4 psi. This is something to consider when tuning your boost controller!
I'll post up my duty cycle table later on, right now I am headed to the strip.[/quote']
This makes sense. The air production from the turbo is not linear, either. And the PWM equating to a larger waste gate opening as RPMS rise is also logical. The reason is the flow coefficient across the valve is non-linear. In the controllers I work on they have a "valve characterization screen" that allows you to plot flows from the actual positioning of the valve so you can normalize the blowoff valve on a non-linear cage to ACT like it has a linear cage installed.... Odd trivia fact, when I went for initial roll-out training on this thing in April 2002, it became clear they were using a MOTOROLA chip in the control computer. Then later this year going for advanced controls school, I was able to cut apart the training center's potting compound to reveal...... Guess what Processor? How to tell the instructor about Ver2.1.1 and Ver2.55 being incompatible with V3.2.1 and Ver 3.2.1 not having to use a bootloader jumper because the software now allows that! Sound familiar? I passed...LOL And he wanted a photo of my Megasquirt!
I would try the Target KPA Table. I will bet the reason nobody got it to work is they don't understand the PID loop requirements and how the porportional and Integral interact over time. What exactly was it doing? Overboosting liek your P was too small? What are the maximum values available for the range, and what are they based upon?
I should go take a look at this code and how the user interface is set up. I am not a fan of the electronic controllers, but this would give me another gadget to play with (like I need any more complexity, eh? LOL)
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Do you have any idea what pulse rate this solenoid needs? I think it may be 31hz, but cannot find anything definite. There are basically four settings for 'tuning' the valve, PULSE/HZ, update rate, proportional gain, and differential gain. From there you can choose to use a target KPA table or duty cycle table. I would prefer to use the target KPA table. Have any suggestions?
Do you understand how a basic control loop functions?
You usually have
(R) Reset (times the controller looks at the Set Point in a given timeframe---usually per minute) This sounds like "Update Rate" in this application
(P)Porportional Gain (the user-set percentage of the scale the controller will move the control valve when looking at the "offset from SP". For best and most hair-left-in-your-head methodology you need to know how they define P... Is it 1/P or is it P/1? Usually it's 1/P meaning P is the divisor, so with a bandwith of 10psi, and a setting of P=1, with an SP of say 7, and a real measured value of PA, your offset is 3, so what your controller woudl do is move 3/10 of it's travel, then look at the reset rate, and then make another adjustemnt. With PORPORTIONAL ONLY Control, you will NEVER reach your setpoint! You will ALWAYS have an offset equal to your Poprortional band below or above your setpoint.
(I) Integral Gain (don't know if this is the "differential gain they speak of, but it probably is...) is another divisor setup that is equal to time. So the longer you have a setpoint offset, the more this will take into account and make an additional correction to the move size of the control valve.
In the above case where you would have a porportional offset, the integral will let you close that gap to exactly setpoint in a very short order.
(D) Derivative. This is a rate of change correction factor. "Derivitave" and "Devil" both start with the same letter for the same reason "Despicable", "Destruction", & "Debauchery" do, they all connotate that bad things are happening, and you best stay clear from it. Derivative can send even the most carefully tuned system into Hysterisis from even the smallest jump... Be glad it was not included (or at least I think it wasn't included)...
For your best response fastest, I would use a Quick Reset Rate, initially a Large Porportional Band (move wise, not necessarily numerically!), and a somewhat medium Integral Rate. From this if you are seeing boost overshoots and undershoots on recovery, start slowing your porportional rate, till the overshoots go away. if that does not do anything, go back to your initial setting, and halve your reset rate. If it cuts it out, you will have to determine if you want a quick reset rate, or one that only makes slow porportional corrections. I prefer to keep P and I to the smallest numbers possible for finest control, and to do this a quick reset rate is usually required, ESPECIALLY when you have fast varying load conditions (like in an automotive turbocharger!)After you are satisfied with your P response, Then find a hill and see what happens when you stay in boost for a while. If it "creeps" and it's not mechanically caused then play with integral by lessengin it's correction factor.
Basically in any tuning loop you first make it unstable, then make it stable. Then upset it and check for response. Tuning the control loops on Centrifugal Compressors can be rather daunting. They pay me pretty well to do it on large stationary turbocompressors. Remember if you can have the luxury of a variable reset rate, USE IT. Start fast and over responsive, and work to the stable end of the spectrum. Basically start jittery and go towards null response.
I hope some of that made some sense!
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There is NO turbo distributor!
On a US specification ZXT, the easiest method is to simply go with MSS from the start!
Of course, if you want to source a European or JDM distributor for the turbo L-6, THEN you could use it as MS alone, with the vacuum/boost cannister taking care of retard in the stock zone.
Of course when you later converted to MSS, you would end up going to a fixed trigger, and negating that neato Euro Dizzy to begin with.
The 81-83 Turbo Distributor is just that, it distributes the spark (on an 81 that's ALL it does! There ain't but a rotor in there!). It has absolutely nothing to do with spark production in relation to engine speed like a conventional distributor.
It is a dumb box, it does nothing but shoot the sparks. It doesn't advance, it doesn't retard, and without an interface to read the pulses from an 82/83 CAS housed inside there, it won't even give you a timing pulse!
Now, for a conversion of an 81 to MS alone, you most likely would simply install a convetional ZX Distributor, along with it's support, into the place where the 81 Dizzy went. It is the ONLY turbo engine in the US that will do that easily. (The 82/83 have a different spline configuration and will need to have the oil pump dropped, and the dizzy shaft rephased and reinstalled with one compatible with a distributor.) After you have a conventional distributor in there, you can use an MSD box, have it fire the coil and do whatever you like with the spark as far as retard. Advance you are limited by centrifugal in the mechanisim, along with vacuum advance canister limitations, of course.
For all the hassle, simply use the tables Moby has for the spark. I have mine working again. I made a miscalculation on the number of degrees I was advanced, and had entered the wrong numbers. Under high vacuum conditions the spark was "jumping" one terminal in the firing order (at least that is what I think was happening) I have now made successful pulls in fourth up to 4500rpms (3.36 rear end) with no surging, no popping, no spark knock, nothing.
Though now upon having my 81 CAS unit off the car and looking closely again, I may be able to do another mod that will not entail removal of the front pulley and rotating it for maximum advance. I had misinterpreted the timing information given in the FSM, and with a bit of work with adremel tool it MAY be possible to get just enough advance for the 81 CAS to work without pulling the pulley off, and drilling the second hole.
Just for information, I will probably use my spare 81 CAS for a N/A conversion to MSS, and my spare 83 CAS/Driveshaft combo for another conversion of an N/A engine. The real advantage of standalone is being able to tailor your spark curve. Mobys timing is safe and works, you can always tune it later on. But there is really only so much you can do with fuel alone. And spark advance available in Moby's tables should add up to far better cruise and partial throttle economy than the stock system had!
Can you tell I'm in a hotel room now with time on my hands? LOL
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I would have to agree with Alan on the cost aspect for sure!
I rue the day I made the statement "I'm not paying $3500 for any damn Z-Car with a fancy engine when I can get one just as nice from the used car lot for $2400!"
Three years later, I was again taunted when the inspection rules changed and the current owner of that 432 wanted to trade me even-steven for my 73 LHD 240Z Turbo with full flares and all, along with a spare engine, and several rocket boxes full of spares.
Thanks to the US Governments' forms in triplicate, and already having them filled out for shipping, I would have done that deal in a quick second!
Now, it's a pipe dream unless there is some sort of insurance settlement or lotto winning! LOL
The 432R models were very stout engines indeed. I would not be so quick to disparage a factory sponsored racer with well over 240+ hp in conservative tune (on carburettors) against an L24 with only 150...
Lets' not even throw in the Mechanical Slide Valve Fi version seen in some places...
The Z432R was a badass vehicle, engineered with no holds barred towards performance. It has been said that the specific output was over 150HP / Liter in some engines...
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What did I say about "forged pistons" when we got that Megasquirt fired up?
LOL
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im not a pro in the area of cams. but in my opinion schneider cams are the way to go. most of their cams have an asymetrical grind' date=' which is better for the valve train. i called them up and a cam goes for like $175. i believe MSA sells schneider cams. schneider provides cams for many race cars on the west coast and they have a real good reputation.
although i have not looked into isky cams as much so my vote is fairly biased.[/quote']
I will chime in and say that Isky is probably one of the few originators of the Assymetric Cam grind for the Datsun developed by Ron Iskendarian when he returned from the service and started working on R&D in conjunction with E'motive team at the time.
The others would be Racer Brown, and from what I uderstand now, Sunbelt.
Most Z-Car cam grinds are simple copies of the original Billets Isky ground in the early seventies, which were based on BMW Cams, and were not a real "priority" for the company at the time. Rons uncle took something that looked like it would work, ground it, it performed decently, and it went from there until Ron came back from the service, with his engineering degree, and started working in earnest on the cams for E'motive. Nissan was at the time as secretive about their assymetric grinds and they are today, and even to top competitors in the field of racing was not forthcoming with information on why the cam was ground the way it was. Ron had to work backwards on his own to figure it all out.
For the money, I would talk with Ron, tell him what you want, and they will grind it for you on proper billet, with proper profile, for a reasonable cost.
The stock of Racer Brown is in the hands of JWT (Jim Wolf Technology) and are excellent cams. Racer Brown was another engineer (see a pattern here) that could actually explain WHY he ground his cams the way he did, and not just say "we did a bunch and this is what worked the best for us"...
When Isky and Racer Brown ground an experimental cam, they knew what they were doing beforehand.
They were the innovators, not the immitators. Many times you can bring a cam into Ron and Isky, and he can profile it, and tell you if it is a generational knockoff of one of their original BMW grinds.
Sunbelt seems to be the latest group of people with a cam machine that have "rediscovered" what Racer Brown knew in the 70's, and what Ron Iskendarian reverse-engineered and knew in the 80's... They are doing things with lower vavlespring pressures due to proprietary assymetrical ramp designs from what I understand.
I'm not saying anything bad about Schneider mind you, I'm just stating some facts about Nissan Cam Development.
For the money on an N/A engine, I would buy and old Racer Brown Cam, or one from Isky. For a turbo, since the development work Ron did was 10 years more advanced from what RB did in the 70's, I would go with an Isky, hands down. RB did have some turbo cams... But I think the Isky will work just fine given IMO more development time with better turbos and not the stuff available when the first units were out there (580HP at 20.6 psi on a .040 280 engine at 7500 rpms ain't all that bad!)
Ron at Isky will tell you all you could ever want to know about a cam, and same for Jim Wolf. Both those guys know their stuff.
From what I have seen, Schneider sells because it's inexpensive, and performs decently. For the small outlay of the camshaft proper (the big cost is in the lash pads, springs, and new rockers) I myself would spend the extra $5 (Last Isky Cam I know that was bought was $180 on a CUSTOM GRIND L7/L9 split configuration timed per customer specs.) and get the billett from Isky.
BTW I have an Isky cam in my turbo Corvair, too! Now you know why!
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Oh, forgot to mention. The price point was not conducive for sales in the Z-Car marketplace.
Originally the second generation kit was around $3400. The firstgen as closer to $2800.
When they went back into production, the manifold and supercharger cost alone, retail was close to the cost of the complete analog EFI kit: $3400!
So then is when Sandy decided to split the stuff up. The Holley system added another $1500, to $2000 Retail cost to the kit complete. Imagine the overwhelming response for a $5000 supercharger kit for vehicles that sell for under $1500 complete...
Most people by the time it went back into production had aftermarket ECU preferences, and they were smart to realize that and offer the components.
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Jim Cook Kit hasn't had a carburettor offered in the kis since the 80's!
They went to the Holley Pro-Jection (or whatever the first generation four-barrel throttle body system was called, it was Analog) early in the 90's (90 I believe).
Then the kit went out of production for a while, and when it came back they split the kit in to supercharger and manifold, and the injection kit, after finding no interest inthe components combined. The digital Holley system worked much better then the old system, but so many other alternatives for EFI existed aftermarket, Sandy figured it wasn't worth their effort to package it together---with all the liability of selling a "complete kit" entailed.
So JCR does produce a kit that mounts the supercharger on a dedicated manifold that fits under the hood. The EFI is up to you! The Supercharger does utilize a four-barrel mating flange simply as a holdover from the early design of the kit, and the second generation of the kit using the Holley Throttle Body.
Many of the successful campaigners of that kid use an 80mm T/B from a Q-Car or whatever mounted on a simple adapter plate. Simple is as simple does! LOL
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There is a bit of a misonception there!
The 81CAS sends 3 pulses per crankshaft revolution (120 degrees apart).
The Distributor Mounted Optical unit from the 82/83's gives the SAME output, becasue it is driven halfspeed, from the drive gear in the front cover.
What you have to realize is that the timing of the trigger wheel on the 81 CAS is already set for some initial advance from TDC, and is then trimmed with the physical movement of the CAS pickup within it's bracket.
Depending on how much advance you want, that may or may not be a problem.
Altering the trigger wheel on the 81 is a simple matter, there is a link to my cardomain page in the "megasquirt" forum in Moby's sticky.
The alteration of hte 82/83 units is like twisting the distributor and has limits also due to captive bolts limiting travel, but that is easily fixed also.
What are your plans for the systems? The outputs from both the CAS units are identical, even though the way they are triggered is different (81 uses Magnetic pulses shaped in the CAS unit to look like the optical's triggering!)
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would that be akin to "RTV" on your head gasket, "BubbleNorm"? LOL
;^P
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yep, I would try for some compressed air in the cylinders that have "0" compression and do a leakdown check. Find out where it's coming out...
I wouldn't crack anything open until contacting the builder with the update and get his take on it IN WRITING.
Normally two cylinders adjacent with low compression is indicative of a blown head gasket channelling between the cylinders but that third one in there makes me think of either bent valves, or a valve job so bad, the exhaust seats aren't sealing (akin to bent vavles). So I would keep from starting it until that leakdown test is performed!
Good Luck!
Adding Boost Control
in MegaSquirt
Posted
I hate to say this, but after the "help" I recieved when it was a Yahoo Groups site, I'm not too keen about going there any more...
In any case, I would bend over, as from what I read on EFHAL's post on Pg4, it's a PD controller, and he has a good explanation of what it'd doing there.
The Differential Gain setpoint indeed is a derivitave setpoint, and therfore will be VERY touchy and jittery to minute changes. The concept seems to be to use P and then D to slow the response to prevent overshoot.
I would read EFHAL's post on Pg 4
GMHeinrik on the same page, specifically the post on dutycycle
MattDupis on Pg 8
GMHeinrik on Page 10
For me, giving up the failsafe of INJ2 channel for Boost control doesn't look to be in the cards for me. I know a Z will run on three cylinders and get me home, but not on zero cylinders!
Like I said, I like pneumatic boost controllers! LOL