Carbs vs EFI

Engine, Transmission and related drivetrain.
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James
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Re: Carbs vs EFI

Post by James » 11 Oct 2015 18:15

I have one of those coils in my car as well…..
Finished is better than perfect......

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bertvorgon
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Re: Carbs vs EFI

Post by bertvorgon » 12 Oct 2015 09:58

Morning World, I hope every ones turkey day was good!

I'm surprised that coil is still available. What is interesting is that it has lasted this long, when I consider the heat and vibration cycles that have happened under that hood for the last 30+ years. I mounted my coil on the passenger fire wall just to get it away from any exhaust manifold/turbo heat, let alone space limitations. Something was made right the first time.

I hear you about working on cars, I'm done too. I started when I was 15 years old, so 50 years ago, with 30 years of very hard core racing thrown in there for good measure. I just like to "fiddle" with small things in the morning, BRIGHT lights to illuminate things and not too many contortions. Other than that, it is off to Specialty.

My next project is to drag my vintage Boler into work so I can dismantle on hopefully get the furnace working, something that is going to require me to lay on the floor and stare into a very dark place, due to space limitations, not looking forward to that.
"Racing makes heroin addiction look like a vague wish for something salty" - Peter Egan

Keith Law
1973 2Door Slalom/hill climb/road race / canyon carver /Giant Killer 510
1968 Vintage 3HP Mini Bike
1971 Vintage 13' BOLER trailer

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Byron510
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Re: Carbs vs EFI

Post by Byron510 » 07 Dec 2015 12:06

So Richard - any progress on the Haltech (??) EFI project on the 280?

Byron
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because the opposite never works.

Chickenman
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Re: Carbs vs EFI

Post by Chickenman » 07 Dec 2015 13:03

Not really. It's been too darned cold to do anything. Have gathered a few more parts though. Just bought some new injectors.

And I've gathered some parts for a rear disc conversion. And some spare front struts and TT coil over kits. Audi needs some TLC too.

Probably start tinkering after New Years. Hard to get motivated in winter...
Last edited by Chickenman on 07 Dec 2015 17:26, edited 1 time in total.

Chickenman
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Re: Carbs vs EFI

Post by Chickenman » 27 Feb 2016 09:43


inokaya
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Re: Carbs vs EFI

Post by inokaya » 28 Feb 2016 22:36

Hey guys, I wanted to chime in on this one... I'm going to speak on the perspective on an NA engine right now and chime in later on turbo's as they are a different beast altogether.

One of the key aspects that people forget in this discussion is drivability and application, I don't see it as just a just a HP/power discussion. From a road racers perspective there area a couple key things that EFI lets you do that carbs don't. You have much better throttle response (control) and get more accurate fuel delivery at an given throttle position. Carbs (even webers and mikuni's as greats as they are) are flawed in that the only have limited throttle progression points in comparison to EFI. I have literally driven two nearly identically prepared L28 race engines one with EFI and one with Mikuki's and the biggest difference was drivability, you could do so much more with the throttle especially in longer sweeping corners.

Also, there are some amazing power advantages... I never got to this point myself but i know of some racers in australia that were using specific fuel injectors with a very narrow misting pattern and blowing them on the dead side of the throttle plate. Put the motor on the dyno and extracted 10 more HP on an L28 by moving the injector position from the vacuum side of the throttle plate to in front of it. I love creative stuff like this.

Lastly, there are varying schools of thought on how engine management systems fire. Some, or most, fire fuel on both the compression and exhaust stroke. The best solutions fire on just the compression stroke as this the only time you need fuel buy they are more sophisticated in their triggering This is then exacerbated by whether you are running a OHC or DOHC engine. With a DOHC engine you have two cam center-lines to manipulate and can do some interesting things with cam timing to scavenge fuel and time injectors and unlock more power and specifically more power at a given RPM range. With an OHC engine you are limited on what you can do for cam overlap by the camshaft design alone.

That said, it depends on what you want to do. I am in consensus with an earlier poster, Duke, i believe. Carbs are half or less of the price and much easier to tune. The difference would be virtually unnoticeable unless you spend lots of track time on your car. On a street car I would carb anything that is NA. Even a DOHC like a KA24de. Personally I don't want to mess around for hours tuning efi. I would consider doing a really simple EFI like SDS on a serious track day car, and If i was building a serious road race car and time and budget were not a factor i would look at going nuts with EFI to get every last bit of drivability and power out of the car. I'm currently done with that phase of life, so for the financial and time cost difference for me, on a 510 it would be Carbs on anything but a ultra serious race car.

Chickenman
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Re: Carbs vs EFI

Post by Chickenman » 29 Feb 2016 00:06

I have to agree 100%. I do find carbs so much easier to tune, and if this was a 240Z it would be getting Triple Mikuni's . However, being a 280Z and already having EFI I decided things were already halfway there. Plus I got a great deal on the used HalTech.

As far as Tuning, I've got my work cut out for me. This is an older unit ( E11-V1 ) and the software isn't nearly as user friendly as the more modern stuff. One of the biggest challenges with this software is that selection of Cells in 3D and 2D Maps has to be done with Keystrokes... no Mouse selection. That is just a royal PITA and makes things so much more difficult. I have to have a bloomin' list of Keystroke combinations printed just to remember how to manipulate Maps. Dumb design.

Hardware surprisingly hasn't advanced that much in the last 10 years. It's the software that has really changed. New software programs that are VE based, can auto calculate IPW based on injector size and other engine parameters, will put you in the ballpark so much faster. And the ability Auto Tune to define fuel Maps based on requested AFR certainly makes tuning much, much easier than the older styles that rely on manually inputted Injector Pulse Width calculations.

However if this all goes to isht in a hand basket I will be looking for a set of Triples.

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