anyone running AU 5litre's carbied?

[5.0 ED]

Just curious if anyone has just gone the way of putting a carb on there AU v8 instead of doing the whole ECU/bigger injectors and so on way. If so how are they going? Fuel economy?

[RG]

Originally Posted by 5.0whiteaughia

Just curious if anyone has just gone the way of putting a carb on there AU v8 instead of doing the whole ECU/bigger injectors and so on way. If so how are they going? Fuel economy?

Doubt it as it wouldn't be legal.

[naughtyfalcon]

Originally Posted by Russell

Doubt it as it wouldn't be legal.

yeah,highly illegal,but some track cars have them instead of injection

[EvilChief]

and why would you sacrifice better fuel economy and performance for a carby, besides being illegal?

[aye you]

Originally Posted by EvilChief

and why would you sacrifice better fuel economy and performance for a carby, besides being illegal?

so you can have da fully chromie air cleaner bro

[Cam]

I must say now that my AU (347ci) never gets driven, the idea of a huge(er) cam, stally, and 4.11's converting it to carby fed has crossed my mind as an option..

Am awaiting Sledgehammers input....

[24 coldies]

bigger injectors, maf sensor, cold air intake, pod filter, bigger throttle body, intake plenum, flash tuner, dyno tuned ? around $4000
vs
carby, intake manifold, dizzy the ability to fine tune using a screwdriver ? around $1500
are any mods legal ?

mate of mine picked up a low kms 5ltr from the wreakers cheep. removed efi gear, bolted on old school, a bigger cam,allready has roller lifters, then droped it into a xt fairmont. in front of a top loader and nine inch. it runs sweet and smooth, a totaly practical street car

[bodes-sh]

^^that's great and all, but i'd like to see you pass any random emissions test that gets done. they are saying it's illegal because the car has to comply with certain emissions regulations. as well as that, at least with a tune, etc you are still using all the original emission equipment fitted to the vehicle. that's why you can't put an older motor into a newer car unless it meets the emissions requirements of the vehicle it is being fitted to

this gives you an idea of what i mean http://www.infrastructure.gov.au/roa.../emission.aspx see the difference between 86 and now?

[JC]

I believe Moffat ran a carbied EB at Bathurst one year (the Cenovis falcon) and it lacked power compared to its injected brethren.

[5.0 ED]

I was not asking about the legal side of it, i was just posing the question as to wether or not someone had just gone, stuff this injected stuff and put a carb on, pretty much for reasons 24coldies mentions, to note using a flash tuner on your car is illegal too, unless you get it EPA tested. Just about any mod you do to your car is illegal, what you think your aloud to change the cam without getting proper testing? even custom extractors are illegal.

As for fuel economy what makes you think a fuel injected car is so much better in this department, fuel injection tunes for 14.7 at cruise, carby can be tuned for 17 to 1 and so on. secondly standard engine managements are programmed to run a slightly retarded timing at cruise in order to burn the fuel better to reduce emissions and so that the catylitic converters work better doing so, most flash tunes increase this timing to give better fuel economy therefore taking away the factory tune designed for less pollution.

The biggest problem that ever faced carbies was all the people who didn't know what they were doing with them, or dirt and so on blocking them up, if you get a good carby tuned 100% to suit, and the only thing it wouldn't do to meet EPA is self calibrate to suit changing conditions.

I for one have thought about it a lot, thinking to myself, well for me to go the next step i need bigger injectors $200 s/h /maf $300 /tune $1500 /intake manifold $900, yet for $250 you can get a power plus hurricane and for $650 a speed demon and be done with it. And if i change anything in the future then big deal it won't matter i'd now have a carby instead of fuel injection that would now need a retune.

[Sox]

Originally Posted by 5.0whiteaughia

I was not asking about the legal side of it, i was just posing the question as to wether or not someone had just gone, stuff this injected stuff and put a carb on, pretty much for reasons 24coldies mentions, to note using a flash tuner on your car is illegal too, unless you get it EPA tested. Just about any mod you do to your car is illegal, what you think your aloud to change the cam without getting proper testing? even custom extractors are illegal.

Actually, many items are also legal, as they have little effect on emissions. It's typically not the item itself which is the problem, it's what the item does to emissions, and items like extractors/exhaust don't have much effect.

As for fuel economy what makes you think a fuel injected car is so much better in this department, fuel injection tunes for 14.7 at cruise, carby can be tuned for 17 to 1 and so on.

And deal with the associated surge, stumbles etc, that comes with such a lean condition.

secondly standard engine managements are programmed to run a slightly retarded timing at cruise in order to burn the fuel better to reduce emissions and so that the catylitic converters work better doing so, most flash tunes increase this timing to give better fuel economy therefore taking away the factory tune designed for less pollution.

And your point is? I'm not sure whether you think this a win for EFI or not?

The biggest problem that ever faced carbies was all the people who didn't know what they were doing with them, or dirt and so on blocking them up, if you get a good carby tuned 100% to suit, and the only thing it wouldn't do to meet EPA is self calibrate to suit changing conditions.

Not quite, idle quality and 'cleanliness' is never a strong point on a modified engine as carbs rely on engine vacuum to work properly. High lift cams with a lot of overlap reduce vacuum, hence idle quality suffers real quick.
Also an unnecessarily large pump shot is needed to overcome the somewhat slow metering of all carbs when the throttle is cracked to WOT quickly.
These two things alone will have the EPA screaming blue murder, and economy suffering.

Both of which EFI have no problem with.

I for one have thought about it a lot, thinking to myself, well for me to go the next step i need bigger injectors $200 s/h /maf $300 /tune $1500 /intake manifold $900, yet for $250 you can get a power plus hurricane and for $650 a speed demon and be done with it. And if i change anything in the future then big deal it won't matter i'd now have a carby instead of fuel injection that would now need a retune.

But you would have a more reliable, more economical, FAR better idling, better performing engine with EFI.
Sure, carbs ain't all that bad, and can even be made to produce the same power at WOT, however they also have many inherent problems which can't be ignored.

Rick.

[FGII-XR6]

stupid question of the month maybe ? why would you do it EFI = smoother running more power better economy lower emmisions easier starting . yea lets ditch that for 20th ( or 19th if you really want to be pedantic) century technology:

[StealthAu]

It is rare that the cheaper option is the best. A bit off topic, but does anyone know if using the capa flash tuner can the au v8's be tuned to run without the maf sensor?

[5.0 ED]

Still i have to say that the comments still bagging the carburetor are still bias at poor setups, you say stumble/surge i say poor ignition system, you bring up excellerator pumps, fuel injection systems still use an accelerator pump function, giving an increase pulse width when the pedal is applied, except oh whats that this happens how many ms later cause the computer has to calculate it then hold the injector open longer?

As for more power and better fuel economy it is not necessarilly the case, more consistant power yes fuel injection has. But not necessarilly an increase in power or better fuel economy, most of these comments seem to be based off experience with poorer quality and old untuned carby's. do you think that an air fuel ratio of 15 to 1 is putting in a different amount of fuel from a carby motor to a fuel injected one?

Talking about idle quality personally im yet to see a high duration cam idle better in a fuel injected car then in a carbied car, the results will see soon, cause i have access to a manifold/carb that will be put on for a couple weeks of experimenting, only cause were going to the drag's and my efi system is all over the place, but hey well see how she goes.

And yet still this thread has been totally off my original question, has anyone run there AU v8 with a carby? Im after facts not opinions here.

[FGII-XR6]

you will never get a well tuned carby to run as well as a well tuned EFI system all other things being equal

[RG]

Originally Posted by au3xr6

you will never get a well tuned carby to run as well as a well tuned EFI system all other things being equal

Exactly. Don't you think if the pros of a carby over EFI outweighed the cons that we'd all be running them?

[JC]

Originally Posted by 5.0whiteaughia

.........And yet still this thread has been totally off my original question, has anyone run there AU v8 with a carby? Im after facts not opinions here.

With the responses so far, I think you can work out the answer. "No" it would be. There is no benefit in doing it, therefore it's not been done.

[GreenMachine]

Doesn't Sledgehammer from the forums run an AU V8 with a Holley? Fairly sure it isn;t a street car though...

[RG]

Originally Posted by GreenMachine

Doesn't Sledgehammer from the forums run an AU V8 with a Holley? Fairly sure it isn;t a street car though...

His is also a 351.

[Gambit]

Originally Posted by Russell

His is also a 351.

It was injected with a vortec at one time tho... It's an awesome car either way.

[Sox]

Originally Posted by 5.0whiteaughia

Still i have to say that the comments still bagging the carburetor are still bias at poor setups,

I'm not bagging them, I personally think they are great, and they do a fantastic job considering how basic they are. As good as a carburettor is though, the fact is, EFI is superior on almost every level.

you say stumble/surge i say poor ignition system,

Good for you, I think you're wrong.
Sometimes it is almost impossible to tune out certain flat spots from carbs. Nature of the beast, they are a compromise.

you bring up excellerator pumps, fuel injection systems still use an accelerator pump function, giving an increase pulse width when the pedal is applied, except oh whats that this happens how many ms later cause the computer has to calculate it then hold the injector open longer?

Of course, however the 'ms' delay is not noticed in a well set up EFI system.
Throttle response is never an issue with a well done EFI system.
It is also MUCH more accurate than the mechanical pump on a carb.

As for more power and better fuel economy it is not necessarilly the case, more consistant power yes fuel injection has. But not necessarilly an increase in power or better fuel economy, most of these comments seem to be based off experience with poorer quality and old untuned carby's. do you think that an air fuel ratio of 15 to 1 is putting in a different amount of fuel from a carby motor to a fuel injected one?

Of course not. However, you seem to be forgetting that EFI can deliver much greater accuracy from idle to redline / part throttle to WOT. As I said in my last post, a well setup carb will perform equally as good as EFI at WOT, and perhaps at several points in between, however it will never match the EFI for OVERALL performance and economy.

Talking about idle quality personally im yet to see a high duration cam idle better in a fuel injected car then in a carbied car,

Then you haven't seen enough of either.
Radical engines have difficulty idling at low RPM's with carbs because of large cam overlap, hence low vacuum.
EFI does not rely on engine vacuum for metering, the same engine can idle like a pussy cat if adjusted properly.

the results will see soon, cause i have access to a manifold/carb that will be put on for a couple weeks of experimenting, only cause were going to the drag's and my efi system is all over the place, but hey well see how she goes.

Knock yourself out.
3 points though.

Carbs actually work very well on the drag strip, mainly because all you're really using is WOT. If the accelerator pump is adjusted correctly for a good launch, their ain't much else to go wrong.

Secondly, if your EFI system is 'all over the place', then it ain't tuned properly. So by then comparing it to a carb which you may tune properly, ain't comparing apples with apples.

Thirdly, you have to compare the 2 systems with an economy run, driveability, emissions, and idle quality before you make any claim that carbs are as good as EFI. Drag racing alone ain't quite enough.

And yet still this thread has been totally off my original question, has anyone run there AU v8 with a carby? Im after facts not opinions here.

The facts are everywhere, if you take the time to look around.

Rick.

[EvilChief]

I must admit the design of standard efi intake manifolds arent the greatest, compared to some of the carby or even aftermarket efi intake manifold. however due to more accurate fuel control in an efi system, taking into account air temp, cool temp, baromtric adjustment, refined throttle pump setup etc, outweighs the accuracy of cold and hot start, throttle response, closed loop, etc etc a carby type system.

second efi has better fuel economy, because of close loop control, which carby cannot employ, as it targets specific AFRs during specific conditions, second it is able to increase ignition advance during cruise (close loop) mode, which subsequently gives better fuel economy.

I have owned well tuned carby cars, but none were or can live up to the fuel economy of my efi ones.
one thing i grant: efi is more expensive, a good carby for 700, good manifold for another 700, new dizzy for 150, new coil for 120, electronic ignition control for 350
makes a sum of $2000 (without a dyno tune)

efi: high flowed injectors: $400, fuel pressure regulator: $120, POD filter $100, SS intake ducting: $120, forget about MAF and TB until u exceed 250kw, flash tuner $850 and tune $1000 = $2600 (with a dyno tune)

thats not even considering a good exhaust system which would be identical for both types of fuel delivery

now for $600 extra id keep the comfort of a cold start ;)

[Sox]

Originally Posted by EvilChief

I must admit the design of standard efi intake manifolds arent the greatest, compared to some of the carby or even aftermarket efi intake manifold.

Exactly, we're comparing the fuel delivery method, not the manifolds. As you said, their are just as many aftermarket EFI manifolds as their are normal ones. In any case, ANY manifold can easily be adapted for EFI.

one thing i grant: efi is more expensive, a good carby for 700, good manifold for another 700, new dizzy for 150, new coil for 120, electronic ignition control for 350
makes a sum of $2000 (without a dyno tune)

efi: high flowed injectors: $400, fuel pressure regulator: $120, POD filter $100, SS intake ducting: $120, forget about MAF and TB until u exceed 250kw, flash tuner $850 and tune $1000 = $2600 (with a dyno tune)

now for $600 extra id keep the comfort of a cold start ;)

What extra $600?
Your figures EXCLUDE a dyno tune for the carbed setup, so there's your $600 and then some.

Rick.

[EvilChief]

Originally Posted by Sox

Exactly, we're comparing the fuel delivery method, not the manifolds. As you said, their are just as many aftermarket EFI manifolds as their are normal ones. In any case, ANY manifold can easily be adapted for EFI.

What extra $600?
Your figures EXCLUDE a dyno tune for the carbed setup, so there's your $600 and then some.

Rick.

yer tuning a carby car on the dyno doesnt take quite as long as an efi one. it took me around 6h to put together a complete new fuel map from scratch on a NA V8 car, plus cold start idle setup. flash tuner i did a few weeks ago took around same, that was including setting up cold start and idle, fuel adjustment and ignition adjustments, which at $120 p/h equates to around $720 plus flash tuner. that didnt take into account redoing fuel injector rescaling for bigger injectors.

[5.0 ED]

At no point am i saying that efi systems arnt great as an all over, and i would prefer to stick with it, but from my point of view, to get my car running 100% nice with the extra power i would have to spend $4000 on it, to me spending $4000 on a $10,000 car that isn't going to be worth anymore after i do, is a bit of a waste.

Your talk of big cams and low vacuum with carbs, mate i can take you and show ya an XW that i built the engine for that has a 236 degree duration at 50thou and 590thou lift, you get in it pump the pedal once and bang starts straight away and idles perfectly, from cold to hot. The carb is a speed demon was bolted straight on, mixtures check all through out, and was spot on, we didn't even have to touch the idle screws. Carb's too have improved a lot in the past years.

Now i will say that with a very good hi energy ignition system in perfect order, a motor will not stumble it will not surge, if mixtures go lean, it will infact just loose power, I have done engines with killer ignition systems on them and can lean them out until they will not accelerate, and yet no stumble no surging, why cause the ignition has still be good enough to ignite the mix.

My previous windsor was in an XF running straight gas with a gas mixer i built, i could lean it out completely till it made no power and yet still no stumble no surge, and no backfiring.

[naughtyfalcon]

it don't matter how well you can get the carby to run you can not run an au on australian roads with a carburettor full stop.

its illegal.

[Sox]

Originally Posted by 5.0whiteaughia

At no point am i saying that efi systems arnt great as an all over, and i would prefer to stick with it, but from my point of view, to get my car running 100% nice with the extra power i would have to spend $4000 on it, to me spending $4000 on a $10,000 car that isn't going to be worth anymore after i do, is a bit of a waste.

And you think that by throwing a carby on a ~2000 model car, that you will hold it's value? I think you'd have better luck spending 4k on an improved EFI system and increasing the value by a small amount, than spending even 2k on a carb setup and holding it's value.
And to top it off, you would have a better performing and more economical car.
Seems like 4k well spent to me.

Your talk of big cams and low vacuum with carbs, mate i can take you and show ya an XW that i built the engine for that has a 236 degree duration at 50thou and 590thou lift, you get in it pump the pedal once and bang starts straight away and idles perfectly, from cold to hot. The carb is a speed demon was bolted straight on, mixtures check all through out, and was spot on, we didn't even have to touch the idle screws. Carb's too have improved a lot in the past years.

Sure they have, and I'm sure your mates XW is just fine and dandy.
I'm also sure that with an appropriate EFI system installed, he would improve performance, driveability, and economy. That's a given.

Remember, I never said carbs can't work well, what I am saying is that EFI simply works better.

BTW, what RPM does it idle at?

Now i will say that with a very good hi energy ignition system in perfect order, a motor will not stumble it will not surge, if mixtures go lean, it will infact just loose power, I have done engines with killer ignition systems on them and can lean them out until they will not accelerate, and yet no stumble no surging, why cause the ignition has still be good enough to ignite the mix.

Perhaps so, however as I said in my last post, much of the time these stumbles can not be ironed out. And even if the ignition does eliminate the stumble, the lean condition will still cause a lack of power at that point, and this can be perceived as a stumble. Carbs are notorious for this, even good ones. As I said, they can work well, however they are still a major compromise.

Rick.

[howesy]

You can do anything you like if you want to risk getting caught and paying the consequences.
Thats exactly why the modification industry thrives. if we simply said it's illegal so you cant do it then every car with an exhaust system or a flash tune or any other modification should immediately be taken off the road as the would breach emission laws therefore they are illegal.
You want to go carb the do it you will get s@#t loads of grunt for a fraction of the cost.
HOWEVER- be prepared to have the book thrown at you if you get caught and it doesn't comply with emissions

P.S My old school 351 (just under 2000kg on road) easily flogged Krapout of any of this new school stuff and was economical and easy to start but the motor was purpose built and had high energy ign.

Also if you remove fuel lines and run stright LPG with a big gas cam ,regraphed dizzy and big carb and twin converters you may still comply with emissions if you lean the mixture when its checked, but then the dollars are mounting up also.

[StealthAu]

On the topic of value, I think you will find running a carby setup will result in a rather cunky decrease in value. Cars sold with a roadworthy always seem to fetch better dollars then those that need rather expensive mechanical alterations to get on the road.

[FGII-XR6]

Originally Posted by howesy

P.S My old school 351 (just under 2000kg on road) easily flogged Krapout of any of this new school stuff and was economical and easy to start but the motor was purpose built and had high energy ign.

and the tooth fairy , easter bunny & santa are real too. all things being equal ( important to remember that point) the modern engine will flog the carby engine . put up a pourpose built fire breather against a stock EFI sure the fire breather will win . but pourpose build an EFI firebreather and hold on. problem is we still have too many technophobes around. the man who pulls off a good functioning EFI system on a modern car and replaces it with carby and dizzy is a fool . sorry to be blunt but it needs to be said