White_FC

Oh.. My... God....

I'm not talking about which 'end' is the smallest, have a look in the middle.. I can't see the smallest section IN THE MIDDLE OF THE CARB being 48mm... but hey I don't know very much and have only looked at a handful of IDA's so what would I know.

anyway re: the throttle bodies..

You said:
"However, a stock 13B TB has two of those butterflies closed throughout the low RPM range" yes?

ok.. good..

I said:
"And the three throttle butterflys on the 13b's all open up at exactly the same RPM.... you can have them all 100% open at 0-RPM if you want.."

Can anyone spot the difference In these two statements? I know I can.


The only reason I mention the 6-port system was because that it what it sounded like you were talking about.


So.. Now getting back slightly more on topic here..
The 13b throttle body system.. has three butterflys.. the 'single' one that goes to the center two ports is the only butterfly moving until ~15% throttle is applied (This _IS_ to do with fuel consumption and light load emmisions) then the other two start to move until they all reach 100%... now.. you see how you can have 0-rpm and still 100% WOT?

RoninAutoBoX

Do you undertsand how VE works at all? Do you honestly think that you can bolt a 1000 mm throttle body to any engine and all of a sudden its VE will increase just because of throttle size? Throttle size is such a tiny part (just as with venturis) in the ultimate equation which will determine VE. If you are measuring throttle size to determine what the VE of an engine will be, you are only adressing 1% of the issue. Do some reasearch if you don't know what you are talking about. Don't keep hitting your head on the table. You can have a two manifolds with every specification exactly the same, and watch one's VE go straight down the toilet just by extending its runner length.


The venturis are designed to improve air velocity through the carb, one can just make the venturis larger to make up the difference in size that it would be without the venturis with little effect on performance if any at all.

I hear you telling me that I am wrong, but I have yet to see one single relevant fact telling me that I am wrong. You seem to know as little about EFI as you do carbs.

A step is only a step backwards if no improvement is made, which is why a an EFI car running 15 seconds in the quarter mile is the bitch of a carb running 9 seconds, or why a car running faster around the roadcourse with a carb owns an EFI car runnning slower.

One only takes a step backwards if the car becomes worse at the application in which the driver intends the car to perfom for. When it comes to money, ease or repair, replacement, troubleshooting, and maintinence, a carb will offer many advantages. Deepending on the application, a carb can be to a great advantage.

Very simple, I can't take up any type of project on my car right now because I only have one. I haven't even gotten it repainted yet. With time, we will see what happens to my car. I'm not quite sure where I want to go with it yet.

If I go carb, I will probably run Edelbrock or Holley. predator parts are not so easy to acquire in an emergency situation, Edelbrock and Holley parts fall out of the sky. If there is a Discount Auto, (we have a 24 hour one here) pep Boys, Bennett, Advanced Auto, or just about any parts shop open, then I will not be without parts to perform any repair, replacement or maintinence. I would never have to worry about what-ifs with my fuel system. Much more than I can say for any of the OEM EFI components.

NZConvertible

Damn, can't resist! OK, so maybe VE was the wrong term to use in this discussion. Fact is, any reduction in restriction improves VE. But to make you happy, instead I'll say that because there's no need to have a venturi in the airflow, an EFI TB will pose less restriction to the air than a similarly-sized carb. It may not be much, but it's there.

I'm fully aware you can oversize an EFI TB. But you can go a lot bigger than you can with a carb before you compromise low/mid-range performance. And of course a bigger TB increases VE. Yes, there are obviously many other factors that influence VE (you keep mentioning obvious facts), but throttle size is an important one. Anything that changes how much work the engine has to do to overcome airflow restrictions influences VE.
Up until now I figured you had a pretty good knowledge of carbs, but after this statement I'm not so sure. Still, at least you knew the venturi existed...

The venturi is fundamental to the operation of a carb. It's the air accelerated by the venturi that causes the vacuum that pulls the fuel through the jet. It's the most basic principle of how a carb works. The narrower the venturi, the less airflow is required for good fuel flow, but the higher the restriction it causes. The bigger the venturi, the greater the airflow must be for good fuel flow, but the smaller the restriction it causes. So the more airflow you want to get through the carb, the bigger the venturi needs to be. But this has a obvious negative effect in lower-rpm operation because the amount of vacuum generated at the jet is reduced.

This is one the main downsides to EFI over carbs. EFI can be tuned to suit many, many individual load and rpm points, whereas a carb is basically tuned to work perfectly at a few points and everywhere else is a compromise. It's all about accuracy. I know that carbs have worked well for decades, and still do work well, but EFI does the same job better, plus a whole bunch of other stuff at the same time.
When in the paragraph you quoted did I say you were wrong? Exactly why do you think I know nothing about EFI? Why do you feel the need for hostile such statements?
Funny how quarter mile times always seem so important in carb discussions. Drag racing is mainly about peak power. Peak power is about airflow. If your carb or EFI system has the necessary airflow, and is well tuned, you can make whatever power you want. The method of fuel delivery is largely irrelevant. I could reverse your statement and say "a carb'd car running 15 seconds in the quarter mile is the bitch of an EFI running 9 seconds." Doesn't prove anything, does it? What we're talking about using either a carb or EFI on the same engine.
You are entirely correct. For me the primary application of my car is as a street car. For a street car, there are other considerations besides how well the engine runs at WOT. It should have good throttle response, good mid-range, run well regardless of changes in temperature, start and idle easily when stone cold or heat-soaked, etc, etc. I know that in general a carb will not do these things as well as EFI, which is why for a street car I would always choose to upgrade the EFI system than swap to a carb.

For a racecar I'd consider a carb but would still rather run EFI if the budget and rules allowed it. The advantages aren't quite as significant, but they're there, which is proven by how popular EFI is on racecars. Well, at this end of the world anyway.

And I have absolutely no interest is building a drag car...

White_FC

Yeah I agree, EFI is crap, carbs are Muuuch better..


hehe sorry.. couldn't resist

NZConvertible

Oops! Damn...

I'm sure you know what I mean.

RoninAutoBoX

And just how much restriction do you think that venturi causes? Answer: Not much at all. certainly not enough to avoid carbs like the plague.

Yes indeed, and having a manifold that delivers a straight shot to the rotors rather than a bunch of bends, three throttle plates with poor transitions from the TB, a restrictive AFM, and rods poking through 2 of the ports will deliver better VE.


So basically what you are saying is that a venturi improves air velocity through through the carbs barrels. I figured it was a given at this point that the carb was dependent upon the air velocity to draw fuel through through the jets, but obviously it was necessary for me to have to explain that to you.

How can someone who claims to have even the most basic understanding of a Predator carb even make this argument anyway? Don't you know that even the simple ones sold in a Summit catalog have variable venturis, therefore making this argument apply only to specific carbs and not all carbs in general?

EFI obviously does things better, but not all things, coming back to what I had said about application once again. As much as you claim to grasp this topic, it seems you only want to be right.

Hostile? hardly. I say what i say because you keep arguing every point I make using facts that don't exist in a path that doesn't exist. Most of the stuff that you are saying about carbs applies to EFI. Do you think that our engines have variable intake paths at 3 points and dual fuel rails with seperate activation points because EFI alone is so much more adjustable than carbs? maybe more than your standard Holley, but not all.

Funny how you cut out the comment I made about road racing in order to make a non-existant point about how I consider quarter mile times to be sooooo important. I mentioned it only as a part of this discussion. in case you could not tell, my last post went a lot fruther than that one sentence. It is only an example of many applications that a car may find itself in.

What it proves is that whatever setup best fits the application is the superior format, which is why cars vary so much, and even the tiniest parts made for our cars can come in hundreds of thousands of configurations. Sometimes simpler works better, sometimes something more complicated can deliver a better advantage. A step forward is an improvement in the car's ability at its application. If I change out an anything to any anything, and a car becomes faster, more reliable, easier to maintain, or whatever the goal of the car may be, it is a step forward. Simple as that. A car that loses or exhibits poor abilites compared to another car of lesser technology, is not therefore better just because it uses better technology. The Honda Insight is a far more advanced car that a Turbo RX-7, but I don't think you'll see anybody rocking one of those in Super Stock any time soon.


You said it in the first sentence of this paragraph. Even you admit that this is your opinion and your goals. For others, their street cars will be better street cars with carbs. You have mentioned some of the things that a street car needs at the age of our cars, but not all of them.

Carbs aren't just for drag cars. carbs are for all cars, which is why edelbrock and Holley haven't sunk yet.

Makenzie71

told ya so

Donn Hecht

Gentelman MPO is carbs are a beautiful setup like the webber downdraft, also the Holley with the blow through box is a beauty as well, but lets face it thats old school technology. As far as a daily driven Rotary you cant go wrong with a "Haltech" or Microtech, or any after market EFI system for that matter. You cant compare the gas mileage you get with a after market EFI system compared to a carb. As well as the tuning is concerned it's much more better, not to mention the fact that every time the weather changes you have to get your *** out of the car, and jet it, also at the track same thing. I rather sit in my car and fiddle with my laptop, or microtech hand held, and tune it from the inside. My friend has a Holley 650 double pumper with a blow through box on his T-II,
and homeboy is only getting like 10 miles a gallon, with gas prices on the rise thats obsurd if not ridiculous gas mileage for a daily driven T-II. My case is closed. EFI all the way for ever.

RoninAutoBoX

You didn't read the entire post, did you now? I only have 2 things to say:

1. Try to find a part for your aftermarket EFI system in less than 3 business days.

2. If you are concerned about gas mileage, just stop driving a rotary.

Besides that, you pretty much repeated all of the same carbeurator stereotypes that we know aren't true. Maybe its because the weather doesn't change that much down here, but nobody I know has ever had to re-jet their carb because of the weather. Heck, i have known people who have driven cross country and haven't had to make any adjustments to their carbs.

NZConvertible

I don't know about Holley sizes, but as an example a Weber 48IDA would probably use 41-42mm venturis depending on tune. Even when smoothly shaped like a venturi, a 25% reduction in cross-sectional area is not a small restriction.
You're right, it's not. It's just one of many reasons that I prefer EFI.
So we're back to the stock system? Like I said earlier, if your EFI manifold is too restrictive, replace it with a better one. It was designed to improve torque and drivability (and it does), so if all-out power is your goal then it will eventually need to be replaced.
No! The venturi increases velocity at that one point only, but it does not improve airflow though the carb. It is required to make the carb work at all. No venturi = no fuel flow! You tell me I don't know about carbs, yet you don't seem to understand this basic concept. It should be obvious that (for example) a 48mm bore without a venturi in it will flow better than a 48mm bore with one in it. Do you agree?
Um, I explained it to you in my last post. If you think any of that explanation was incorrect, then say why.
Predators again? From what I've seen, conventional carbs outnumber variable venturi carbs by a huge amount. You even said yourself you probably won't use one. I've never seen anyone run one on a rotary. Maybe you have, but it would be a rare exception. So if hardly anybody uses them (and we are talking about rotaries here), then there's not much point in repeatedly bringing them up.
So what does a carb do better than EFI? I'm not talking about how simple they may be to install, or how easy it is to get parts. What do they do better?
Um, what?
No, they have those features to broaden the engine's power band, just like most modern engines. Simple as that. Mazda rotaries actually had sequential throttles and staged induction (6PI) before they had EFI. Any significant upgrade to the intake system, whether by using a carb or an aftermarket EFI TB, will place much more emphasis on high-rpm tuning at the expense of other areas.
I did that deliberately because I specifically mentioned track racing later on, and didn't feel I needed to make the point twice. It would be ludicrous to think that one circuit car is better than the other just because it's got EFI. Despite what you might think, I'm not trying to twist your words.
Again you're trying to prove your point using completely irrelevant comparisons. How can two completely different types of cars nearly 20 years apart have any bearing on this discussion?
Sure you can slap a carb on anything. Never said you couldn't. Edelbrock and Holley survive because for some reason the US has a carb culture. US development and use of aftermarket EFI is miles behind other countries where car modification is popular. All of the world's leading brands of aftermarket programmable ECU's are from Australia (Haltech, MicroTech, MoTeC, Autronic and others), and their popularity there (and here) is huge. You may say that's because it's cheap, but that's wrong. It's cheap because these companies have been developing and selling these units for years, and they're now produced in large numbers, which brings costs down.
If EFI was as troublesome and difficult as you claim, it wouldn't be nearly as popular. You seem really paranoid about this without any logical reason to be.
That's a dumb attitude. I'm perfectly happy to accept the rotary's thirst, but I see no need to make it worse than it could be. No matter how well you tune a carb, it's light-load fuel consumption will be considerably higher than even stock EFI, let alone a well-tuned programmable system. I'd rather my money went towards all the other features of a decent ECU than into the tank and staight out the tail pipe. That's just a waste.

Makenzie71

NZ...again the narrowist point in the 48 is...according to my caliper that I bought just to measure this in case I was wrong...is actually just over 47mm...the manifold side is just over 48mm...barely...

And I have to kinna disagree with this as well. Again you're saying that carbs are about as advanced as a rock with a stick leaning on it. Many companies and throughout the world have been using carbs since their beginning and continue to do so. Mostly anymore it's limited to smaller engines but carbs have advanced with the industry, as well as EFI. Again, there are setups out there that are just as efficient and effective as your typical EFI setup...****...I should have abandoned this...you should have too, NZ...

NZConvertible

Dude, without a venturi, a carb won't work. It's as simple as that. Are you sure that's a complete carb?
I really wish you'd stop sticking words in my mounth. Where in the paragraph you quoted did I say anything like that?
How about we just stick to cars. What new production cars are still using carbs? What major car manufacturer is still developing them?
And again I challenge you to present them. And be very careful how you use the word "efficient".

RoninAutoBoX

41-42mm? What the hell kind of venturis are those for? A diesel truck? I have never looked down a carb that had venturis that restrictive.


Suit yourself. You're presenting an opinion. In reality, having venturis is not a serious detriment to a carb, so the point is actually not much of one at all.

back to the stock system? We were in the stock system in the first place. You have been mentioning all along parts of the stock system, and price comparisons using the stock system, and all. I hope those prices you quoted weren't actually supposed to include a wild EFI manifold and all of the custom parts you would have to run to do that one too. Otherwise, your argument really flies out the window when it comes to drivability, fuel economy or otherwise.

That one point of the carb is called the barrel, just like I said!

I keep using references exactly to how a carb works and yet you keep telling me that I am not explaining it correctly. I am saying exactly the same things you are, yet you do not seem to totally grasp it. The barrelof the carb is that single point in which the venturi and the jet live. The venturi ramps inward to improve air velocity in the barrel in order for that air to draw the fuel from the jet. Get it?

I am not saying it is incorrect. I am saying that you elaborated on something that we already agreed on, simply because you did not understand what I was saying without typing out the entire process of how a venturi works.

If you want to make blanket statements about carbs in general, then it is going to come up.

If you are refrring to engine management and fuel delivery functions, then the answer is really nothing, but it does a good 90+% of what fuel injection does with a lot less parts, points of failure, and better reliability, and ease of replacement and repair.

OK, you're starting to get it.

OK, so then we agree that drivability, fuel economy, and other things typically sacrificed for performance is going away with a high performance setup regardless of EFI or carb. Thank you.

Then why the whole rant about drag racing when I was very careful to point out that that there was much more to my argument than strictly peakpower even before your ranting? You spend as much time making my points as you do arguing them.

Their seperation is the most relevant part of this discussion. Point is, just because its newer, and better technology, doesn't mean its going to give you the best car in every case.

I think you are the only person who would use those names and the word cheap in the same sentence, especially TEC.

I never said EFI was unreliable in general, just extremely hard to diagnose in comparison, and harder to get parts for on a rotary. Can you name one EFI part that isn't a special order everywhere? Want me to start quoting prices too? WE can start with the TPS.

When it comes to our systems, an EFI system that is 12 years old at best is going to have problems. That is simply a fact no matter what is said. These parts are not going to be in the same condition after such a long time.

How is it a dumb attitude? Half of the guys on this forum have a seperate car for a daily driver because of the caveats of an older rotary engine.....maybe more.

Into the tank and straight out the tail is exactly what you will get with a rotary engine, that is how they are supposed to run, and even with your EFI, no matter it be a stock computer, or aftermarket, that is how it will be tuned: Rich rich rich. Standing behind a modified turbo rotary is poison death by gas chamber. You know that as well as I do.

Light load fuel consumption? Just howoften is a car with a heavily modified or totally redone engine management and fuel delivery going to see light load anyway? On top of that, carbs really aren't that bad during light loads. They shut down their largest jets, barrels, and slow down just like any fuel delivery system.

I think you are really bringing up the wrong arguments for a mod that is designed with serious performance in mind. Once you get into aftermarket throttles and manifolds, bigger injectors, etc etc, you don't have a lot of drivability, fuel economy, light load crusing capabilities, or any convenint operation left to work with.

These areguments may work for OEM EFI, but considering development of the last OEM carbs ended years and years ago, a slight advantage in these areas is to be expected when compared with a performance carb and manifold. The last of the OEM carbs however, did indeed carry variable venturi design, among other things, that really evened up the score to enough of a point. But, then again, we really aren't talking about OEM stuff are we(or at least shouldn't be anyway )

NZConvertible

This is fun. I haven't quoted a single price yet... And a manifold for an IDA-style TB is the same as one for an IDA Weber, which isn't really all that wild.

I'll give you a price if you want though. Injection Perfection in Australia do a 13B EFI kit that comprises a 50mm IDA throttle body, Malpassi FPR, four Bosch 600cc/min injectors, Bosch fuel pump, fuel rail, TPS, fuel filter, pre-filter, Microtech MT-8 fuel/ignition ECU and Microtech hand controller for A$3,052 (US$2,070). This will support a big bridgeport. Some of these parts may not even be required, depending on what you've already got.

Compare that to the prices of brand new components for a complete carb conversion. Even if it's half as much, it still makes EFI a lot more affordable than many seen to think.
Most EFI systems control fuel injection, ignition control, idle control, fuel pump, variable intakes, thermofans, boost control, emissions control, air-conditioning, and more, and can often diagnose themselves. What carb can do 10% of that, let alone 90%.
Yes, but because of the higher precision of EFI, those sacrifices aren't as great as with a carb. Anybody who's converted an engine from carb to EFI, particularly a highly-modified one, will tell you that. You can argue that all you want, but it's fact.
What I meant was cheaper in Australia than in the US.
Is that how you tune engines? Geez... Rich mixtures are only during for full load. The rest of the time very rich mixtures are not required or wanted. No respectible EFI tuner would ever tune that way. Full-load mixtures are only used for a small fraction of the engine's running time. If you want to continously **** good fuel out the tail pipe, you're welcome. Not me.
So you drive around with your foot to the floor all the time? You don't ever lift off? Interesting...

I dunno what you use your car for, but even if mine wasn't a daily driver, it would still be used often for normal street driving. Anywhere I went on the weekend would probably be in the 7. I often to go for long drives as part of a car club event. This is the sort of driving that most people here do. You exactly can't drive around the suburbs like you're on a racetrack. Whether you realise it or not, most of the driving you do is light-load. I'm amazed you'd think anything else.
But EFI does it a lot better. Can a carb retune itself hundreds of times per second to achieve perfect mixtures?
As I said above, even with serious performance, EFI doesn't sacrifice drivability, fuel economy, light load crusing as much as a carb does.

RoninAutoBoX

When you consider all of the supporting components that must be purchased, it actually is quite wild.

Yes, you actually quoted a few prices in the beginning of those secondhand EFI computers.

$2000? I could get a full carb setup with a supercharger for that price.

$2000? That's a giant chunk of change. About the same as a lot of second gens themselves are worth, or more.

I was referring to fuel delivery capabilities.

It is not as good, but there is not a drastic difference.


fair enough, but don't think that Americans know little or less of aftermarket fuel injection. I recall Hibborn having been around a lot longer than any of the companies you mentioned.

When did I ever say that the engine must run rich full time? Rotaries run richer than your standard engine, but under full load, yes it is extreme.

Depends on your definition of it. Under normal street driving conditions, a carb is not going to just dump fuel uncontrollably into the manifold. It will meet the demand of the engine, just as it was deigned to. A carb is not a single stage fuel delivery system, it is progressive just like EFI fuel delivery.

Does it really matter to an extreme amount if it can't? You say that EFI is much better, how much better is much better? What are the amazing results of running EFI over carb?

Of course it does not, but you act as if a carb totally throws it out the window and just dumps fuel straight out of the pipes. I don't know how much dyno tuning of carbs you have watched, but the AFRs are similar if not the same. I have never noticed a carb all of a sudden just start dumping excess fuel into the exhaust just because it wasn't at full go. What exactly is this action of a carb that you are describing? If you see a carb engine that is just dumping fuel under normal driving conditions, then you need to advise the owner to get that thing back on the dyno and tune it right this time.

I've seen carb engine that run so rich they blow black smoke, and some that are tuned to run ultra lean for their applications. If you tune a carb right, it will be perfectly drivable, get excellent fuel economy, and it should expecially have no trouble cruising, since the throttle remains in a single position during cruising.

I keep hearing this reference to how EFI doesn't sacrifice "as much" as carb, but to what extent do you speak of? I have never noticed any big difference at all, driving the cars, watching the dyno sheets, or the fuel gauges, so just how much of a difference are you seeing in your vast experience with carbed rotaries?

God only knows that EFI is better at fuel delivery than carbs, but carbs can do anything that EFI can. Air conditioning? Fuel pumps? other acessories? Believe it or not, these existed and operated perfectly before the advent of aftermarket EFI. I don't think a carb owner has much to worry about in the operation of any of those acessories. The thing is that carbs offer better acessibility to parts, ease of maintinence, and reliability due to less stuff to go wrong, and that will make all of the difference depending on the application, as many race teams that have rejected EFI have proven time and time again, and raced successfully.

Boy, this is fun.

13B2QuIcKNy

first of all i wanna post, weber carbs are garbage on fc's and fb's... at least in my opinion.. holleys are way better if u ask me
currently i just rebuilt my engine..91na... did street port.. didnt go carb... but eliminated all emissions and lots of vacuum lines.. all i have is 2 lines.. one for the FPR and one for the Pressure sensor.. very simple setup yet still fuel injection... turboII secondaries because of the added street port.. car runs beautiful to 8200 rpm...

Second of all.. coming from having an 84 13b(12a side housings) 4 port bridge port with a HOLLEY 650 setup racing beat intake manifold and complete exhaust.. i was running 13.4'swith stock tires and diff.... thats about tha same thing t2's with bolt on's are doing ... except T2's DO IT WITH WAY MORE TORQUE! dont get me wrong i loved my bridge ported 13b but it wasnt much fun around 2-3-4000 rpm's.. it did spank lots of cars... but essentially with the carb setup... maybe it is easier to tune sometimes.. but its like going back in techonology...fuel injection is much more smoother and sophisticated...and sure it does require re-mapping and adding better secondaries... but its much easier than keeping up with a carb... also.. there is no way i would ever see a carb setup with stock ports running 250 hp at the wheels or even close.... not with stock ports.. i dont even think i was making 250 with the bridge setup!.. and thats FULL BRIDGE!

just thought this could help...


Chris

MPM

roninautobox said - The thing is that carbs offer better acessibility to parts, ease of maintinence, and reliability due to less stuff to go wrong

I'd have to disagree with this somewhat. Many of the aftermarket stand alone EMS systems utilize very affordable and available GM style sensors. It only takes a water temp sensor, air temp sensor, MAP sensor and a throttle position sensor(TPS) to control fuel delivery. All these sensors can be bought at the same part stores like Advanced Auto Parts or AutoZone that you might find the carb parts at. And from experience those sensors usually take less than 10 minutes to replace if bad. Unplug the connector, remove sensor by unscrewing it or removing 2 screws, replace with new and plug back up. No adjusting as the EMS hasn't changed at all.

Ofcourse I'm saying all this after having dealt with carbs for the last 4 years and finally went FI utilizing the factory intake and a used EMS for only $350. Runs better than it ever has.

RoninAutoBoX

Gm sensors are extemely easy to acquire, and SOME systems do use them, but certain other parts, like the MAP sensors, TPSs, and especially injectors are less than generic to be sure.

NZConvertible

Wild? Now it just sounds like you're scared of EFI. If you think something as simple as an IDA TB set-up is wild, perhaps you should stick to carbs...
That wasn't me...
Maybe it's a lot to you, but I see giant chunks of change like that thrown around all the time on this forum, on everything from engines, suspension, body, interior, etc. The car's purchase price is irrelevant when you start modifying for performance.

That price is for a near-complete set-up using all new parts. Where are you going to get a complete new carb'd supercharger set-up from for $2000? I know the Atkins one is a helluva lot more than that. And as I said, you may not even need some of those parts, and some would be easy to source second-hand.
I was referring to the complete abilities of an EFI system. Even a bottom-end ECU can do a whole lot more than just squirt fuel.
I can't believe you'd even mention mechanical injection. How is that even slightly relevant? The point is there don't appear to be any US companies pushing full-featured programmable electronic fuel injection systems. Why not?
That would be when you said "Into the tank and straight out the tail is exactly what you will get with a rotary engine, that is how they are supposed to run, and even with your EFI, no matter it be a stock computer, or aftermarket, that is how it will be tuned: Rich rich rich."
Again you mention other engines. Once again, we're comparing carbs and EFI on the same engine!
It's progressive sure, but it isn't as accurate.
Carbs can do anything that EFI can? That's a laughable statement. A carb can't give you exactly the same smooth idle no matter what the temperature or load on the engine, a carb can't give you precise control over spark at all loads and engine speeds (and neither can a dizzy), a carb can't be tuned while under load on a dyno or while driving, a carb can't do closed-loop mixture control, a carb can't turn your A/C off under load, a carb can't turn your fuel pump off if you crash, a carb can't self-diagnose or datalog, etc, etc. You may think these things are unnecessary, but the point is it's all these things as well as the greater precision of fuel delivery that makes EFI worth every cent you pay for it.
You sound as if you expect your car to break down every week, whether it has a carb or EFI. If the cars you work on are so unreliable that you're scared to drive too far from a parts store then perhaps you're doing something wrong. Just because EFI relies on a handful of external devices doesn't mean it's a ticking timebomb. And even if something does go wrong, if you are knowledgeable about the EFI system on your car then fault diagnosis is not nearly as hard as you make out. There's no great mystery to it.

Funny thing is, in this part of the world we think the exact opposite. Almost nobody in NZ or Oz uses Holleys on rotaries. Webers (and the odd Dellorto) are the only ones considered.
What about the air bleeds for the injectors and oil nozzles?
You don't need them. There's no way a streetport would need that much fuel. Without some way of tuning them, you'll be running very rich and making less power as a result.

Makenzie71

The thing is that most of us have not had the best of luck with our cars and good number of us expect them to not start every time we turn the key...that's where that frame of mind comes from, and at least that you have to have a little understanding.

Ditto. I'm not saying that a Holley isn't good for the rotory but think about their intended purpose...have you ever seen a 9000rpm V8? With a Holley downdraft 4brl? I use a holley but onyl because they're free...after I get my chance at a webber setup there'll be no turning back. The stock Nikkis off a 12A are more suited for the rotory than a Holley...

The air bleeds for the injectors? What are you talking about? The only vac line coming anywhere near the fuel injectors is the line that goes to the FPR...which is needed. The oil nozzles can be plugged with a bolt, then run premix.

ditto...****...why am I back in here???

White_FC

Umm something is seriously wrong with you car if you can't expect it to start everytime you turn the key.. i know my car is far from stock, I still expect it to start everytime. and start it does, everytime, with even better cold idle/cranking than the stock computer ever had
Bzzzzzt! wrong answer!
The injector air bleed line is a little nipple in the manifold just before the primary injectors. Which, strangely enough bleeds air into the injector fuel spray (can't think of a better way to word that??) to atomise it better.




Edited because i'm a **** that can't spell properly.

NZConvertible

What he said, both things.

MPM

I never said they were generic. Just readily available. When you go to an auto parts store wanting carb parts do you walk in and say "I need some carb parts. Got any?" No you don't. You know what you need and ask for it. Same goes for the TPS or MAP. You have the part number(off the part) and you give it to them. Most computer systems in use will let them cross reference and find you the correct part. As far as injectors are concerned, I'd acquire a set of used N/A or TII injectors and have them cleaned. Your making this much to hard.

Makenzie71

geee...I wish we all had that security...

Okay...I know what you're talking about here, but it's not a necessary vac line. The rex I had than went the longest didn't have anything but the FPR and boost sensor and brakes hooked to the intake...




Edited because i'm a **** that can't spell properly. [/B][/QUOTE]

White_FC

My point basically was that you can't blame EFI at all for your car being a shitbox. Try fixing the problems first, then you should be able to have as much security in your car as I do in mine?

Well.. just to be ****, it IS a vac line.. theres a pressure difference over the line. Although no it is definatly not absolutly nessesary to being able to drive the car, but I know im certainly keeping mine on there