BSR GTU E31 Head Images

[Tony D]

I read things like large injectors are hard to control at low RPM, so you run the smaller set like you said for lower RPM and switch to large ones after a certain point. For my N/A application, my largest injector would be 450-ish I think I saw, for a 3.1L 8000RPM max therefore I wouldn't need 3 injectors since the gap between my smallest to the biggest isn't that big...?

 

Don't believe everything you read. For a race setup, especially with a large cam with lots of overlap, alpha-n is the easiest way to go. Guys with tuning problems are running on the street and lugging the engine below the point where there is a good vacuum signal for the MAP sensor.

 

For an engine like that the old TEC2 by Electramotive had a 'PAFZZ Blend' software package that let you run alpha-n at idle, and then blend the mixture of pure throttle position/engine rpm based fueling into a MAP based control once the RPMs got high enough and the cam made vacuum. This makes even the wildest of cams run smoothly---we could idle our Bonny engine to 400rpms using it. Bang Bang Bang Bang... thought the engine would die, but it would tick over reliably just above the cranking setpoint of 300 rpms like clockwork. Try that with carbs of MFI! Our 45 Webers wouldn't idle reliably with the same cam below 1700rpms, a centermount four barrel wouldn't idle below 2200 rpms. Power came on aroudn 5000 and pulled above there, with the engine really liking it above 6K.

 

With a cam like that, you have to select the right gear for the corner and know how to drive to keep the engine making power. With a 3.1 it may have more bottome end, but it won't have idle vacuum if you are contemplating the cams you discussed in another thread. And that really puts you into Alpha-N control for the reliable off-idle (even if it is 1700 rpms!) ability to get the engine accelerated without bucking and spitting.

 

Thing is, with EFI you can blend Alpha N and MAP based control techniques. With MFI you will always have Alpha-N---it will always be based on continually injecting fuel based on a fuel pump that makes flow and pressure based on engine rpm, and a bypass pressure control (that dictated volume through the nozzle) that is solely based on throttle position. Hillborn and Kinsler do make some vacuum anneroid items that allow it to drop pressure a bit under vacuum conditions and lean out the setup at partial throttle, but again that is another mechanical tuning process. It all seems so easy at forst because it's mechanical. But when you get into it, the more you want, the more adjustments you have to make. And in the end every mechanical adjustment is subject to plugging with dirt, loosening and changing, or simply downright failing when a spring breaks or takes a set. With electronics, it's the exact same process, except your hands don't get drenched in methanol and crack from lack of skin oil, you simply arrow up or arrow down.

 

The largest issue people have with tuning EFI is they don't understand what an engine does or how it really works. Once you realize what the engine needs, the tuning becomes logical. Then it's a matter of doing the tune one portion at a time. It's just easier for me on EFI because I can do it FASTER than having to take something apart, reassemble it, then go test.

 

It's my ADDHD side. I can get instantaneous feedback on what the adjustment did with electronics---and therefore go in the right direction faster.

 

If you have ever had to tune PID loops on industrial controllers you will understand what I mean. Oldtimers used pneumatics. There were kids who HATED pneumatics because of the constant hassle of calibrating them every quarter, they were subject to dirt, water in the air, etc... And tuning them was a chore. But old timers would come in and seemingly twist the dials like crazy and in a few adjustments be finished. They knew that changes on mechnical devices needed to be radical so you knew right away which way you needed to go. Once you knew that, you make fine adjustments. Kids usually took the opposite approach tuning in fine increments and never seeing a change---then it just 'went haywire'... Same oldtimers usually picked up on electronics and found the same techniques worked there as well, just punched in numbers instead of twisting dials. Double the Porportional and see what it does, double it again till it's in Hystersis, then go back 50% from where you were. Same for Resets a minute. BIG changes and then fine. I watch guys make 10 or 20% changes all day playing around with electronic tuners on our equipment to no avail. I go in there, go from 150% to 450% then back to 275% and BANG done. They can't figure it out. I tell them, it's a LONG way from 150 to 275 at a 5% increment when you have to WAIT HALF AN HOUR between adjustments to see if it worked.

 

MFI is like old Pneumatic controllers--they work almost as good as electronics, but you have all the pittfals of mechanical devices. If it gets dirty, it poops, if it's hot, it may poop. If it's loose it poops. If the thing is too tight it poops. And every time it poops it's 30 minutes to get it back to where it was.

 

With electronics you eliminate a lot of that. Sure there are electrical stuff that can screw with you, but on a race car especially there is no great electric load, so power should be good. Wiring should not be an issue as it's all dedicated. What it ends up coming down to is what the class rules dictate. If they allow EFI I would run it over the other choices. If they mandate 'period correct induction' I would haul out photos of the 1971 240Z running EFI on ITB's and argue like CRAZY for it to be allowed (and really piss off the Porsche guys who were running Kugelfischer MFI!)

 

If it came down to it, and you have never worked with MFI before, this is likely not the best place to learn! I would tend to run the Lucas Slide Valve system as it was OEM available on many cars in Europe, and has refinements for running in mid throttle. It will be a more tractable system than a Hillborn, IMO. But finding one and setting it up will not be a cheap prospect. I would tend to steer you towards carbs (big ones) but with the cost involved in them you're into EFI teritory.

 

Again, the reason we went to Tec2 and TWM ITB's on the Bonny car was that a new manifold and set of 55 Webers (which is what we needed to get the horsepower we wanted) was going to be as much as the EFI setup. And we would still have a damned distributor! What sold us was the ability to control timing precisely...and in the end that will KILL a high rpm engine. A couple of degrees of spark scatter at 8000 rpms and you detonate. Bang. Done.

 

Even if you run carbs, I would SERIOUSLY recommend you get something like an Electromotive HPV1 Ignition setup and eliminate your distributor entirely as a source of failure. SCCA even now allows this from what I'm understanding. But if you can program that, you're well on your way to mapping fuel.

 

As for injector sizing, you have to keep your injector pulsewidth within the available time of the valve opening (usually). This means larger than you think injectors so they can deliver the fuel with a shortest pulsewidth available. At 8000 rpms we are running 550cc injectors on a 320HP engine. And the same injectors worked perfectly on the 2 liter making 2/3's that amount. The 'control at idle' is terribly subjective and many times the interweb is bogged down in myths, legends and people who put to much goddamned emphasis on THEORETICAL arguments. Yes, fuel puddling can occur. In practical application does it make a difference???? For them it will be something to rail on about everytime they see an 'oversized injector applied' and out comes this argument or that. But in reality there is little to no PRACTICAL effect to the phenomenon (whatever they may be railing on about) and you can disregard the bluster. It just becomes hard to know what is what sometimes.

 

I watched an unemployed guy (acquaintance of mine) walk into a successful well known Datsun Restoration Shop in SoCal, and after he looked around a bit, he said to the owner...his FIRST words to the guy were: "What you gotta do is..."

 

A guy who's UNEMPLOYED, NEVER ran his own business, NEVER ran a restoration business, NEVER EVEN FINISHED HIS CAR (been sitting in primer and bondo since 1986!) deigns to tell a guy with 11+ years as a successful operating business how he needs to straighten up his act and fly straight.

 

These are the guys on the internet arguing points that in practical application have no real meaning or affect. Ask them what they run, and when the reply starts "I read" throw it out, or ask for references so you can read it yourself. Usually it's a reference to someone else who "read" somewhere that something could maybe cause a problem when the moon aligns in the 12th trimester of a pregnant elephant that kneels on the Mekong Delta to get a drink of water while a monkey poops from a vine swinging nearby... Like that happens all the time right? Yeah, that's real applicable to me and my Datsun.

 

Some of the Bob Sharp cars did use MFI BTW... Wonder where those setups went...

[Gollum]

That post should be it's own sticky tony!

 

Regarding my first hand experience, injectors don't get really hard to handle at idle unless 1 of 2 possible things are happening:

 

1. The injectors are cheap, and just plain suck at being consistant at low pulse widths, which means you don't want them anyways

 

2. They're insanely large, like over 1000cc large

 

That being said I've witnessed AEM systems running over 2,000cc idling wonderfully. It just takes a decent injector and a decent EFI system that's tuned well. I was actually just talking today with drummingpariah about this same issue. He's 100% a carb guy and loves how well motorbike carbs work for their application. And in many ways I understand where he's coming from, but I also think that EFI is much more well rounded. You CAN tune a car to take to a race track and still drive home, without sacrificing much along the way, except for "complexity" that I think EFI much more than makes up for when it comes to ease of tuning it RIGHT.

[josh817]

I don't want to be a jackass but the question, is twin injection needed for something like my setup, was never really answered. The conclusion was you can run decent sized injectors for my power output and still get good idle/low end control, therefore no need for staged injection (use only one set of injectors?!). From what I've read I want a low impedance injector and the charts show I needed 450cc but you said 550cc will run well. Oringed or barbed, thats easy enough to answer, just get the fuel rail to match. Then comes the difficult part. I remember on 280z's they had something with 2 screw holes in it the hold the injector into the manifold. Am I lucky enough to avoid this and have some sort of snap in bungs/injectors. I will read.

 

I can't see anything more then 350hp at the wheels from a race 3.1L. My cam grind idea was perhaps something slightly smaller then a 306º duration, 102º lobe center, and .610" lift. I don't want something as radical as I just mentioned. I'll be giving Isky a call when I'm ready to play.

 

Isky's Z-273 (710127) looked to be around what I want, if he can do it with the right lobe centers.

Edited October 20, 2010 by josh817

[Tony D]

"I can't see anything more then 350hp at the wheels from a race 3.1L"

 

Then son, you need to open your eyes!

 

To be pedantic: No you don't need dual staged injection, you aren't going to make enough horsepower to require it. I thought I said that right off. 720CC injectors will run fine. It's not the injector, it's the circuit driving them and it's ability to control it.

[josh817]

Lol sorry about that Tony, look at the time I made that post!

 

I'm just saying no more then 350hp because I don't have the money or the knowledge to do something like that. Remember how I was raving about the Japanese making that sort of power? I may have a nice cam, exhaust, and intake, but I don't see my headwork performing as well as theirs. I'll leave it all up in the air though. It sounds like I can get away with an injector substantially larger than necessary and it won't kill performance.

 

This setup, since I'm going with a Hillborn or Kinsler manifold will be more like Dereks home made manifold. Point being, I wonder if I will need air bleeders to sync. the runners since its one long throttle shaft, unlike Webers where you can adjust the idle open on each body to sync. I should probably start another thread so we don't fog up Z-ya's original post. D: Sorry!

[Tony D]

Curious you should mention that: 7 hours ago it was 5PM here, so what's your excuse again?

Second, perusing the November "L-Engine Special" Magazine here outside Tokyo I found something interesting in one of the hard parts ads: ISKY CAMS!

 

Yes, that's right, ISKY RACING CAMS advertized in a Japanese Hard Parts Ad by a local speed shop. Hmmmmmmmmmmmm what was that I was saying about engineering excellence in that other thread?

 

EFI idles with the throttles CLOSED. This maximizes vacuum signals if you are running a MAP based system, and allows for FAR more precise air metering to the cylinders via a single 'idle bypass screw' with individual hoses to each runner (or a log like balance tube linking the runners).

 

Using a Hillborn setup, I'd put the injectors in the air horns, and use the mechanical injector ports for the idle air bypass and balance tube connection...

 

First thing you learn on EFI: Don't open the throttle plates to set your idle! Ask Frank 280ZX about it!

[josh817]

It would be really easy to mount the injectors/fuel rail outside the horns, like a staged injection system (but only 1 set of injectors) instead of having to weld bungs and ****! That's what I was initially wanting to do and was why I was asking if an injector before the throttle plate would work at idle and stuff, since the plate would be closed. Now that I think about it though I remember this video. Slide valve injection on a rotary, injector is before the slide:

 

Almost like this, but not really because he is running injectors before and after the throttle plate.

This is perfect, its going to be fun doing this! I'm all excited now, I may squeal like a girl.

Edited October 20, 2010 by josh817

[Tony D]

No son...that's...

 

 

 

SQUEAL LIKE A PIG!

[josh817]

Wait a second, Tony. I think I see twin injectors on the first video too....

 

Seriously now, will it work the way I described?! Injector before the throttle plate only, no injectors after the throttle plate to spray when the plate is closed? Grrr

[Tony D]

How many different languages do I know to say this in an alternate fashion?

 

Hai

Si

Ja

Ya

Yes

Yep

Yerp

Yah, eh?

Affirmative

 

This is a good indication for what I said in the Forum Ettiquette Thread. Explicit answers are what people need, there is no effort to read and get the context it has to be pedantically written out three times at least before most people will get it.

[Xnke]

Really, the large injector problems are a non-issue except on a street driven car; especially for N/A applications. On a track only car, who cares if the idle is rough, as long as it doesn't bog on takeoff or die on throttle lift, most of your time will be spent in the upper range anyway! No need for double sets of injectors.

 

EFI is the way to go; as long as your class rules allow it.

[josh817]

Sorry Tony. My mind was running a muck. Had a hurray moment, then was like :/ wait what if its realistic, then was like wait we just discussed, then was like wait what?

 

I will make up for it by presenting this idea to you:

http://teamc.com/i-4554532-moroso-performance-63765-air-bleed-valve.html

 

Assuming the Hilborn or Kinsler manifolds have 1/8" NPT nozzle threads, screw one of these in each and twist the knob to sync. Seems to work in my head. I looked back at Derek's manifold build thread and he uses a log he made himself but he is running MAP. I don't think I will run MAP at all, so unless I have brake booster issues where I lose a lot of brake pedal from serious cams and little vacuum, then I won't use a vacuum log. The description says its for cooling systems but I saw the same product on another website for CO2 bottles. I have an old paintball gun and I remember having air adjust things on it. I'm wondering if a paintball supply shop will have a product I could use. I'll need something that won't twist under vibration.

 

Edit:

Simple PM to Derek and I now have a very clear idea of how this will work. He directed me to Clippard.com and said he used the 1 series. Found a 1/8" thread with knob:

http://www.clippard.com/store/display_details.asp?sku=MNV-1KP

 

May choose a knobless, to utilize a flat head screw driver.

Edited October 21, 2010 by josh817

[Tony D]

It's 'running amok' it's an Indonesian term when you get wild eyed and have no control. Indonesians in colonial times were known to 'run amok' and hack their Ducth Opressors to death with large cane knives and other items of farming.

You can see it today in the lower provinces during the water buffalo races where they run for the whole day over a long course from town to town and province to province. The riders wildly flailing a stick with a spike in the end to urge the buffaloes along faster. They have special racing buffalo, devoid of hair and almost pink! They will be streaming blood from the flailing, and there are people on bamboo platforms who jump onto and knock off the drivers at the finish line. They are all wild-eyed and it takes a few minutes in some cases before they realize the race is over and they aren't on the back of the buffalo any more!

 

RUN AMOK

 

Sorry, it's up there with "Freeze Plug", "Irregardless", "Suposably",and "Mute Point" ...

 

I digress...

[josh817]

I have found your list of things that bug/piss you off is rather long.

[Tony D]

There was a commedian (Daymon Wayans) who performed a hilarious sketch on "In Living Color" of a "Nation of Islam" inmate who continually used words improperly.

 

That was hilarious, because it was a comedy act lampooing people in the real world who do it. They use the words improperly (or grossly out of the proper context) and end up showing their true ignorance.

 

"The Baginification of the, wait. Let me reconsummate. The ***inafication of the moment is overwhelmed by the viliscimitude of the cortex in which it is being eaten!"

 

A mind is a terrible thing to waste.

 

"A Muck" is right up there with "Baginification"...

 

In it's right context it hilarious. Outside of it..."not so much."

[Tony D]

It's just that the word is not "Mute" (that means silent) it's "MOOT" (meaning the point is no longer an issue, or fake)!

It's not "A Muck" (something akin to mud), it's "AMOK" (insane ranting and out of control actions).

 

If it was a mispelling, it's one thing, but it's the totally wrong word.

 

It can be summed up like this:

 

The ants are my friends, they're blowing in the wind.

 

The girl with colitis goes by.

 

No, its

 

"The answer, my friend, is blowing in the wind."

 

And

 

"The girl with Kaliedoscope eyes."

 

DIFFERENT MEANINGS ALTOGETHER!

[Tony D]

Oh, and my tastes in music are pretty wide.

Ted is a mainstay, but they range from the above mentioned Gollumisim to Onedakoza and various indegenious beats from the jungle (akin to strangling a cat manually with percussion accompaniment.) I can usually select something that will keep me enthiused but drive off just about most people.

 

I don't do Country, Western, or any combination thereof.

 

That does not include Bluegrass...

[z-ya]

 

Some of the Bob Sharp cars did use MFI BTW... Wonder where those setups went...

 

I know exactly where they are:

 

 

This is one of the spare Nissan V8s used in the Newman-Sharp 280ZXTT IMSA car. It uses Kinsler MFI. It's a ***** to tune. An expert is required. We had it on the track at the National convention this year in Nashville. It's sounds awesome, but wasn't really running right.

 

The other Bob Sharp cars to use injection were the Z31 single turbo cars driven by Newman and the Z32 twin turbo. The single turbo Z31 cars used a heavily modified stock ECU. JR Mitchell told me it was a real hack, it it took them forever to get it running right. Good enough to win 2 or three championships though. He said that if someone was to run it again, they shoudl just swap in a Motech system (or other aftermarket ECU).

[josh817]

Tomorrow I'm going home so I can remeasure the ports and take more pictures. Do you have any videos of the V8 and the Z31/32's, Z-ya?

[z-ya]

Tomorrow I'm going home so I can remeasure the ports and take more pictures. Do you have any videos of the V8 and the Z31/32's, Z-ya?

 

Sounds like a top fuel car:

 

 

As of this year the car hasn't run for 30 years.