Tony D
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Posts posted by Tony D
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TonyD, I have no idea what your getting at with your jeffp comment, can you elaborate a bit?
Some time ago there was a protracted debate over wether JeffP's 3" downpipe and exhaust 'really' added 20HP. It devolved into 'what really caused the increase in HP' some thinking the freer flowing exhaust made more boost, etc etc etc...
Parsed and rationalized to death
End result was Jeff simply claimed he put the exhaust on first, before changing anything else, in order to see what the HP increase would be.
This is kind of a similar suituation, I was just waiting for the 'what really caused more horsepower, it can't just be the bolted-on exhaust' conversation to start!
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"Black Magic" the black slag/aluminum oxide blasting grit makes for a pretty agressive finish. Monitor blasting pressure and distance and you can get quite a range of finishes. You can even overwhelm the stock as-cast and massage it. Afterwords, you might consider shotpeening at a lower pressure to 'knock over the high sharp edges' from the more agressive media for a more muted satin look.
Rough becomes hard to keep clean, so maybe straight shotpeening to texture everything so it's somewhat 'wipeable'...
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The aluminum bodied AMOT thermostat will allow FULL bypass from the head back to the inlet of the pump until cracked open and you start running water through the radiator. The opening for the AMOT will be radiator hose size when fully open.
The flow improvement using the AMOT will be the total elimination of the external bypass lines and internal passages. Jeff has found already what I noticed long ago...there is a shunt from the head to the inlet to the pump that is almost 10mm in diameter that goes from the hot side of the engine straight back to the inlet of the water pump. Add to that the external bypass line which is anywhere from 8mm to 10mm, and on earlier engines there are sometimes two internal bypasses of identical diameter at the front of the engine.
This is a considerable amount of flow that is stopped from going through the engine instead of the radiator. Plug those holes, give the water some place to go while warming up, and you get more flow through the block when you need it.
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Maybe peak, but that doesn't tell much of the story. Look at your curves again!
You made almost 30rwhp from 4800rpm to redline, and 20rwhp at 3400rpm from a much quicker spoolup. Noticeable gains from 2800rpm to redline, serious area under the curve added on the HP side.
On the torque side at 5200rpm and higher you picked up 25ft-lbs, no wonder you need more fuel!! Substantial gains from 2800rpm and up.
Once again proving, a good exhaust system is the best bang for your buck on the Z turbo motors, and in general, most turbo motors.
Does this mean we should reference this point in the future when there are arguments about JeffP's dyno runs on his 3" system improving by 20HP?
The next step is a flury of rationalizations about 'how' the HP was made...
Good Information! Another chink in the armor of 'loosing your bottom end' argument when you add a big tube to an otherwise stock ZXT...
And the revelation of the stock downpipe....WOAH! Surprising tidbit there!
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Flowing 270 per runner would outflow most race ported L28 heads, making any aftermarket manifold unrequired...
I think the important thing to come away from the 'runner diameter' discussion is that things in the US Market may have been quite different indeed than what was available in Japan and worldwide. I have seen people swear there were no N42 Heads on 82 280ZX's... Well in Japan there were... And all those import engines sold years ago? Not one came with a P79 or P90... Japan didn't get them! And the N42 casting? Different than what we got here due to different emissions requirements.
Point being keeping one's mouth shut sometimes is the best course because you don't know all the combinations possible---the best course may be to clarify the situation with something like 'here we've found only 36mm OD runners, what's your runner O.D. if you plan to go to 35mm ID?'
If you read the FIA Homogolation Sheets for the L28E, the manifold specified I.D. for the runner was 35mm, as I recall. Might say something about what they were designed to take?
And worst case, you weld at the last portion of it.
Really, 35mm at the gasket surface would not be the ideal setup anyway, unless you are a big turbular log manifold afficinado... a tapered runner somewhere slightly larger or possibly 35mm ID at the PLENUM end, TAPERING to a given diameter at the gasket surface would be nice for velocity. And then as Daeron says: having a head ported to 35mm would leave "a nice anti-reversionary step at that point"---which may even have merit in a Turbo Engine.
As for 350HP at 15psi... with the right cam, turbo, and porting on a stock manifold 350 to the rear wheels should easily be accomplished below 15psi. To bring out JeffP's engine in different tunes, he was making 380Ft-Lbs of torque to the rear wheels at 4500rpms at 8.39psi of boost some years ago. His last run with a bone-stock L28ET bottom end was over 300RWHP at 10psi, and 460+ around 20psi.
My stocker with blowthrough mikuini carbs was in that general area when I ran 17-20/21psi (EFI has the advantage hands-down in this regard, though I wouldn't complain too much about 17mpg in that trim in daily driving!)
The goals as stated originally are eminently reachable. The big point I was making was the goals were stated clearly enough that it was more a design exercise than anything on the manifold, trying to improve what was there without an aftermarket piece. Hell, they are reachable without porting the stock manifold!
As an option to cutting apart and porting a manifold, always remember Extrude-Hone makes a quick job of it as well. I mean, in this application how much flow do you really need---and that is the key question. Hands down the answer is 'nothing' when you can make 350 on boost alone. So at that point arguing over what the engine 'needs' becomes a bit foolish. It doesn't 'need' any of it. That he wants to do it is all the justification he needs to proceed. Who am I to give anything but encouragement. The more people making 350+ on stock components, the more people who can combat those insisting the 'need' for this component or that!
Perying on the ignorant can be seen as bad marketing, or great marketing...in either case, it's not marketing I would choose to be party to, regardless of the customer or vendor!
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Like I mentioned, I like the Auto-Tune feature of the Autronic. It incorporates a lot of OEM-Style Technology.
Frankly, if someone were to have a GM OEM ECU and that software (like Tunercat) it would be as robust as many of the Aftermarket ECU's available, the fuel trim makes for great drivability on your particular car--- the difference between the Autronic and a GM ECU with long term and short term fuel trim is the ability to incorporate the Long Term and Short Term Fuel Trim into the basic map permanently with a keystroke. On the GM's you store it in RAM which is volatile, and when you disconnect power to the ECU it looses it, and starts learning all over.
I would NOT be in a hurry to buy an EMS system. The Self-Tune technology is progressing QUICKLY in the aftermarket. Autronic makes the second manufacturer that I know of that has incorporated the OEM style trim as an option for talioring the Mapping of the ECU.
There will be only more of this in the coming year or two. Turbocharger technology is static for the time being, same as head and intake technology. Those are something you can do now that you will not have a surprise in a 'great leap forward technologically' within the next month, or even year of construction.
Frankly, if building an engine, I'd buy the EMS system last, after it was all asssembled or close to it. Some of these assemblies can take years when other things get involved. The last thing you want is a smokin' brand new, never been in the car, ready for action Second Group Buy MS-1 sitting in your shed waiting for installation 7 years later when you get the time to put the car on the road (speaking from experience, I now have one in a car and 'two fully operational spares'...)
The next one will have either Autronic, or another box produced locally here in SoCal by a group of guys in Corona. Yeah, it's $1200, but I understand and trust the Fuel Trim functions as I have investigated them. It's truly OEM technology, and makes for a great driving car...quickly!
As for big injectors and poor drivability...the type of injector can be as important as the size in drivability. JeffP had crap idle with some 600CC units, but ended up going with 720's which idled as good as his 450's did years ago. Latency, opening and closing speed, can radically effect the idle quality. It it's not a quick switch, and they dribble or are sluggish, idle can go down the tubes quickly! It's not just the size.
I'm not going for mongo-horsepower where I would need anything over 450 or 550 CC's in a street car, so I wouldn't really be concerned with sequential in my application. If you were planning on 500+ and running 700CC+ injectors, I might agree that sequential might clean up the idle depending on the injectors used...but even then 'semi-sequential' is probably all that is needed. By boost threshold (say 3500) you will want to swap over to batch and start laying on the fuel for power.
I digress...
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Check for a leaking system reservoir check valve. If the system check valve leaks, when you go into boost the reservoir should have more than enough capacity to hold the doors in their positions even with some leaks.
If it starts blowing hot air, that is a vacuum dashpot going away because you have no vacuum in the reservoir. And the most likely canidate is a leaiking check valve.
The 83's have the little 'bullfrog' pump that will turn on and off to maintain vacuum in the HVAC system while under boost for sustained periods of time.
If your system started blowing hot air, but out of the same vents (like Ford's do...) then it's a compressor cutout switch under boost. If your doors change position its because boost is blowing into your vacuum system due to either a leaking check valve or some really mazzive leaks in the tubing/switches that bleed out all vacuum in the reservoir tank almost immdeiately. But generally that would happen at partial throttle cruise without heading into boost, they would change state on lo vacuum situations as well, not just under boost...(with massive leaks, that is!)
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Good luck on those parts! I'm to the point where I will fabricate mine...
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So do I...
As Peggy Hill would have said: "I did not know that!"
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Posting number... I've been a proponent of that 'elsewhere' with the number at 100 posts. 40 is not that much for an active, contributing member. Did someone come here to participate or just sell parts?
The higher the number, the more participative the member, and the more interaction others will have had with him (as far as that is possible online)...
Trends show up early. They rarely change...
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I'd parrot Geezers commentary. Ive helped with scads of Turbo conversions to Maximas, and even a couple of earlier Z's (after being duly impressed by Randy's car at an MSA show years ago...) I have been contemplating an early 90's LT swap into a ZX. Having assisted my bud in New Jersey do a 94 LT into his 74 Camaro and then get it through their cursory check, I learned a lot about the wiring harness, and the wonderful program TunerCat that lets you access the engine parameters and mapping through the OBD2 port. Almost like having a standalone EFI.
Look for a complete donor car that has been heavily rolled or something along those lines. The 94 that my bud got his donor from cost a whopping $1800 because it was wrapped around a pole. Only after digging through the documentation in the glove box did the engine block with no serial number make any sense: P.O. had put a new LT Service Replacement in, along with a Goodwrench Remanufactured transmission...18 miles before he totalled it wrapping it around a telephone pole!
The newer stuff I'm not up on, but the GM Manuals are darned good at explaining the functions of the ECU and vehicle systems/computer function. You want that manual from your donor, it will save you time and headache in the long run...and you will know what the Smog Guys are going to be looking for since you read the book before taking it to them! Right? You will read the book...please say yes! LOL
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For those Americans Unawares of English, I suggest "Snatch" with Brad Pitt, or "Lock, Stock, and Two Smoking Barrels" at their local DVD Emporium.
My fave is Bricktop walking in on the black dudes in the back of the pawn shop...and the attendant long speech thereafter "Do you know who I am?" "Do you know what 'Nemesis' is?" "The best way to dispose of a human body, so I'm told is to feed it to pigs..."
ROMAFLOL!
I can watch those two all day long. Hell, I don't even need the Subtitles! LOL
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What have you been reading? As long as your V8 comes from a light duty vehicle (not a truck) and is of 1981 vintage or newer, all you have to do is make sure all applicable smog devices present on the original engine are there in the ZX.
Most of the stuff is already in the ZX, you just have to pick it up.
For that matter, the IDEAL swap for this situation would be to simply go find a wrecked LT1 out of an early 90's Camaro, and put that EFI and everything into the ZX and go run it through the Smog/BAR Referee. The EFI is supersimple to understand, the GM technical manuals are great, and with TunerCat, you can log into the ECU through the OBD2 port and change just about any configuration within the GM program you want so you don't throw codes for things you didn't install in the car...
Were I to do a V8 Swap, I would take a 79ZX and get that engine. The whole car can be had for under $2000, and the emissions hookups are Datsun Friendly.
I helped my bud in Jersey with long-distance technical support as he put a 94 LT into his 74 Camaro. Learnt me a lot about the GM setup, and for the conversion hassles, I'd not mess with a carbbed engine for smog compliance in SoCal. Especially on a ZX.
Good Luck!
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It all depends on where your power band will lie with the cam you select.
If you are running an L28 Cam in the L20A head, you will get great bottom end, but be out of breath by 5500. No matter what you do. Those valves are small. But as stated the port velocity of the larger cylinders combined with the well-unshrouded dinky valves will flow that head to it's maximum potential. It just won't be that much.
The complete EFI head will make decent horsepower and pull harder on the upper ranges of the rpm range (from 3500 on up) that the L20A head, but the L20A will have a 'grunt advantage'... especially since the combustion chambers are so small, you will have quite a bit of compression. I think that may be more of a limiting factor: compression ratio with the L20A. It will fit, but likely it has Comb Chambers sized for the drastically smaller L20A bore as well, and consequently may have way too much compression for practical driver usage. E31 on flat top block anybody, off the top of your head remember the CR? The Y20 head from a LATE skyline L20E with the BIG combustion chamber is SMALLER than an E31 chamber...meaning HIGHER compression...
As mentioned, it's also about your gearing, and what you intend to do with the car...neither of which you have revealed...
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So this is the prompting of the bright-green 'forum rules' in the banner up top...
and the 'you need to click and accept' at the bottom of the page...
Was it a test, all I could think of was 'Oh, looks like they changed classifieds to being here for a while...' did I pass?
For a second, I thought I was being 'reminded' of the rules because of some malfesance! Perish the thought...
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I can see these polished up really nicely and staying shiny under the car for years afterwards...
Mmmmmmm, Shiny!
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There is only one tank for a 75 EFI car. If you had a 75 260Z tank, it would have a 5/16" (8mm) feed line, and not the 12mm line of the EFI tank.
Tanks didn't change for the US Market till around 6/76 when they started using the space saver spare and a much larger tank. It is quite different, I don't think it would fit the earlier chassis at all...
Maybe you just didn't get everything situated on the mounts up top properly?
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Age has very little to do with engineering principles or the construction of a 30 year old vehicle. If it was true in '05, it's likely still true today, especially physical placement of compoentry! LOL
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Yep, when you datalog your MS, watch your battery voltage, that is a big jump running and not...the charging system may be marginal, and that can cause delivery problems if the pump is not getting sufficent voltage under highest load conditions.
I ran a #8 line and used the stock relay to control switching of the power to the pump at the back. It gave me a large enough line for all sorts of power accessories at the back of the car from a common hot stud terminal...not that anything but the pump is back there right now...but it's well supplied off a #8 line from the battery, and then a short run of #10 from the terminal, to the relay, to the pump and then a large ground that is run similarly. It is not chassis grounded, there is a companion #8 wire (black) that goes along the frame rails front to back paired with the hot wire. What can I say? I'm paranoid about the drop. Plus, I kept thinking 'man, if I'd put my battery back here all this wouldn't be an issue...while I'm at all this, I should probably relocate it...
About that time the wife yelled 'STOP THAT WHILE YOU'RE AT IT STUFF'... apparently my thoughts were also freely running out my mouth in stream of conciousness and she heard me. She knows what 'while I'm at it means'---two weeks over christmas vacation with no living room floor because I didn't like the floor crossbracing on the 4X4 section I was supposed to splice in and repair in a day...
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I didn't see much discussion just acerbic commentary.
When the aftermarket heads make the 850 HP at 26psi that the good old L-Series N42 Head did waaaay back in 1983...maybe I'll take notice.
But till then, it's just sounding like beating one's own chest over trodden territory.
Most of this is done because we can... making a negative statement like you're wasting your time is not a discussion, it's chucking stones. Especially when we can see here clearly the resultant response. Jab, jab, no discussion. I think the O.P. handled his last thread in the negative exactly the right way: I'm not picking your decisions apart, don't do the same to mine, thanyouverymuch! Which is a fair assessment of what was happening. The merits of the project were not discussed, the decision was put into question, and that goes along the lines of 'What is BEST'...
Asking for rationale or something else is one thing, chucking a negative attitude into the mix on an otherwise upward beat post is something altogether different and not needed. I didn't see any 'constructive' criticisim, just a terrible misreading of post context, and total disregard for the O.P. originally stated intentions for the build. The decision to do the build in the way it was done was basically called ''not the best''...
Like the forum rules say: "There is no best" coming in with factual commentary after starting on a premise totally fabricated out of cloth is just bad form, regardless of what the 'facts' may be.
I took it for what the O.P. stated he wanted to do: a study of the intake to meet his set criteria. I simply came in to give some rationalised numbers so there would be a clear understanding of what could be expected, and where to expend efforts in the future. Nowhere did I come in with an intimation that it was a waste of time. Frankly any of this work is a waste of time and frivolous, there are much better things we ALL could be doing for humanity with the money, time, and effort.
That all being said screw the rest of the world, I'm going to work on WHAT I WANT TO WORK ON: My Z Car!
The manifold looks like it's progressing nicely, and I for one would be interested in the results being quantified. For ANY of the manifolds being chucked out as superior, inferior, or a waste of time. NUMBERS not opinion sway my judgement when someone undertakes a project. And for that, the best course of action is help along the way and see what comes out at the end of it. That, I would see as a positive way to approach this build as an observer (and I think a couple of people have!)
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No rollerskates, just do like Frank280ZX did and put a BMW M5 V-8 in the chassis along with the six speed manual and BMW Diffy! (Ad can help with that as well...he he he)
Did he supply your chassis as well? Or did you send your existing chassis to him for the cage work?
We DEFINATELY need photos of clutch explosions! PHO-TO! PHO-TO! PHO-TO!
(Natives are restless, now it's off to Hooter's Shanghai for Hootie Hour. I will return and post inebriated later this evening! LOL)
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ONE nozzle stuck in the down position will drop my 260 from 22-26 to 11-15 mpg. Similar for both nozzles stuck just partially down. Fully down...
Geee, I wonder what two fully down would do? Bables slipped of their holders, frozen down by years of sludge and disrepair, pulling the lever only moves the cables now, instead of the nozzles which a stuck, frozen, bending the light metal levers attaching them to the bellcranks of the lever actuating wires...
"None are as blind as those who won't see..."
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No, I was just around in 'the bad old days' of HEI.
Apparently not much has changed until they went to the new crankfire systems.
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I'd go get a mechanical gauge, stick it in a 't' where the stock sensor goes, and VERIFY the pressure reading. 5-10 psi at idle, and around 10 psi per 1000 rpms is considered normal. The FSM has a spec of something like 45psi by 3000rpms or something like that, and in many cases they are well up around 90+psi at 6K...
If it's 5-10 at idle, and 45 at 3K, I'd vote for the sensor going kaput. They do it oftener and oftener as these cars age.
4n71b post mortem
in Drivetrain
Posted
I picked up a couple of remote filter assemblies from Autobacs when they were closing the store. Got em for about $30 each. Looks just like the standard automotive filter for oil, just made for Transmission Lines. Had some holes in the housing for thermo probes, etc...
That would kind of keep the stuff coming back and contaminating your new tranny from the old cooler/radiator. Olberg makes a nice filter that would work great for that as well...but it ain't $30!!!