Opinions on EFI system

[olddog]

Originally Posted by hauss

carbs are easier to tune efi takes computers and expensive sensors to many things to go wrong after market not as good as factory lots of folks can tune carbs not many can tune efi

"Easier" is a variable factor based on what you are familiar with.

As for computers and expensive sensors, any professional today is tuning a carb or efi on a chassis dyno using a wide band O2 sensor. Leaded fuel and reading spark plugs are long gone.

Factory EFI systems can be used to very high Hp levels.

A new car with a Carb has not been sold since, what, mid 1980's. Well over 30 years. Most certified master mechanics today have little experience with a carb. Some have never seen a carb on a car, short of going to an antique car show. I think you meant you personally know lots of people who can tune a carb, but few who know what an EFI system is.

Bottom line: if you use all modern expensive computers and sensors on a chassis dyno and tune your carb as close as you can get it, which close is the best you can do, it is only good for that day, assuming the weather does not change. The more the weather changes and time moves on the further from close that reliable old carb will be. Drive up a mountain and all bets are off. EFI will be much closer to spot on at all of these conditions. This is fact.

However a carb typically fails much more slowly and rarely in a catastrophic engine stops kind of way. Not sure if they allow EFI on single engine air craft, but likely not. I think they may still be running points in a distributor, but I have no idea what they really do.

[PaulProe]

On a recent outing, (Thanks again, Bob Cowan) we ran our cars to the top of Pikes Peak. Some carb'd, some factory ECU's and a couple aftermarket ECU's.

My system uses a Performance Electronics PE3-8400 ECU and incorporates both a MAP sensor and a separate barometer sensor. It was tuned for local altitudes (Saint Louis area, 500' ASL) (EightStack system on an FE)

We ran to the top, 14,115 ASL. The carb guys had issues. They made it but their engines were not happy. The other Factory ECU guys made it fine, but Ford has invested a lot of money into tuning and they benefited from it. My car ran to the top, stopped, started, cruised, pulled, etc without issue, performing as well at 14,000 ft as at 500'

The injection learning curve is kind of steep, but once you've learned and set the system properly, it really makes huge difference, compensating all the time for Air Density. Cold start, hot start, high altitude, doesn't matter, it just works.

Don't think you can just put an injection system on and it will run great from day one - it needs tuning, and with the infinite adjustment, it takes a fair amount of work. Most systems 'self learn', but that only covers the fuel tables, you still have to manually tweak cold start, hot start, acceleration and de-accel. But once you get it set, you'll be one happy camper.

Paul

[MKS427]

Originally Posted by PaulProe

The injection learning curve is kind of steep, but once you've learned and set the system properly, it really makes huge difference, compensating all the time for Air Density. Cold start, hot start, high altitude, doesn't matter, it just works.

Don't think you can just put an injection system on and it will run great from day one - it needs tuning, and with the infinite adjustment, it takes a fair amount of work. Most systems 'self learn', but that only covers the fuel tables, you still have to manually tweak cold start, hot start, acceleration and de-accel. But once you get it set, you'll be one happy camper.

Paul

That's been my experience. Well worth it.

[ERA 626]

Originally Posted by olddog

"Easier" is a variable factor based on what you are familiar with.

As for computers and expensive sensors, any professional today is tuning a carb or efi on a chassis dyno using a wide band O2 sensor. Leaded fuel and reading spark plugs are long gone.

Factory EFI systems can be used to very high Hp levels.

A new car with a Carb has not been sold since, what, mid 1980's. Well over 30 years. Most certified master mechanics today have little experience with a carb. Some have never seen a carb on a car, short of going to an antique car show. I think you meant you personally know lots of people who can tune a carb, but few who know what an EFI system is.

Bottom line: if you use all modern expensive computers and sensors on a chassis dyno and tune your carb as close as you can get it, which close is the best you can do, it is only good for that day, assuming the weather does not change. The more the weather changes and time moves on the further from close that reliable old carb will be. Drive up a mountain and all bets are off. EFI will be much closer to spot on at all of these conditions. This is fact.

However a carb typically fails much more slowly and rarely in a catastrophic engine stops kind of way. Not sure if they allow EFI on single engine air craft, but likely not. I think they may still be running points in a distributor, but I have no idea what they really do.

well said