EFI vs. Carb Exhaust Options

[zenBD]

I've been looking for a k9 for awhile, missed a couple opportunities & declined a couple more. Right now I have two in the running which are priced within a couple grand of each other....comparable miles/condition. One is EFI and the other carbureted. I'm leaning toward the EFI, but I heard that you are mostly limited to slip-ons with the EFI (although I've seen listings for EFI bikes with big radius pipes). Is that true, or are there other good pipe options for EFI bikes? Can you use a power commander with an EFI K9? Does it make sense to go carbureted just to have more performance options?


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[Mr4500dodge]

Go carbureted!!!! Alot easier to mess with and a hell of a lot easier to make some real power with.

 

[Brew]

I too am partial to the carb, as mentioned easier to mod if you put on pipes and air cleaner just plop in jets and tune the carb... That's JMHO

 

[08mastiff]

I have an EFI with big radius pipes and a dual runner. Runs like a top. The computer is able to handle that and self tune itself. Anything more than that you will need a programmable module.

 

[Nukeranger]

I am also partial to carburetor.

 

[zenBD]

I have an EFI with big radius pipes and a dual runner. Runs like a top. The computer is able to handle that and self tune itself. Anything more than that you will need a programmable module.

Can you use a power commander or something of that ilk? Are they made to plug into the K9 system?


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[08mastiff]

Can you use a power commander or something of that ilk? Are they made to plug into the K9 system?


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That I could not help you with because I just don't know. Call the people at S&S. Their customer service is excellent. Talk to one if their EFI guys.

 

[zenBD]

That I could not help you with because I just don't know. Call the people at S&S. Their customer service is excellent. Talk to one if their EFI guys.

Cool...good advice. It is really only the scarcity of options that would keep me from the EFI. I have an EFI fxdb, and it works well. Not that I have any problem with the carb bikes either... Super G is a good carb...ran one on my 104ci 1985 fxrs.

I'm sure I'd be happy either way... I just don want to run into a situation where I unknowingly limited my performance options from the start. Anyone know if you can still get brand new sets of exhaust from the big manufacturers for the k9.... Like v&h, supertrapp, etc. Or have they stopped making them new?


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[RCAdd1ct]

Efi is locked from big dog.

S&S has a plug in ecu that is unlocked and you mod to your hearts content.

Although both efi have narrow band sensors and it really only tunes down low in the rpm range.

You can swap and rewire to a thundermax. That would have wide band feedback and auto tune throughout the rpm range, but it will always leave some power on the table compared to a dyno tune.

A dyno tune you jet(tune) for max power. The t-max you set the fuel ratio to what you want.

You can dyno tune an S&S and t-max, but if you auto tune after that the dyno power might be lost.

I do not think a power commander would be a good option.

 

[Nukeranger]

Just a question. Why do you think you need a power commander on a Big Dog?

 

[zenBD]

Just a question. Why do you think you need a power commander on a Big Dog?

It's not that I think I need a power commander, just that I want to know what my options are. Power commander is just the first ecu tuner that came to mind. I was basically just worried about having some way to dial in for the best performance with any air cleaner/pipe combination...much like the right jets for any set up on a carb. Sounds like the S&S drop in or thunder max set up would do that. I have heard that the BD units "self-tune", but I am skeptical as to the efficiency of its self -tuning capability on the stock set up. I don't have any experience with a BD EFI, but I hear people say that Harley EFIs will "self-tune", and I know form personal experience that they certainly do not.


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[RCAdd1ct]

It's not that I think I need a power commander, just that I want to know what my options are. Power commander is just the first ecu tuner that came to mind. I was basically just worried about having some way to dial in for the best performance with any air cleaner/pipe combination...much like the right jets for any set up on a carb. Sounds like the S&S drop in or thunder max set up would do that. I have heard that the BD units "self-tune", but I am skeptical as to the efficiency of its self -tuning capability on the stock set up. I don't have any experience with a BD EFI, but I hear people say that Harley EFIs will "self-tune", and I know form personal experience that they certainly do not.


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From my research anything narrow band (HD, Big Dog, S&S) can only adjust from idle to about 2500. The sensors just do not have the range to get into the power band.

The main issue is that big dogs are long and they do not fit on all dynos. T-max will help with that or go carb and read plugs.

IMHO, a carb is best for something simple like a chopper. Less wiring on a BD is a good thing.

 

[Nukeranger]

Oops,

Sorry about that. I also believe Big Dogs do better with less electronics though.

Huw

 

[zenBD]

Yeah, I'm getting the sense that the carb is the safest best...never thought about the fact that a K9 has a hard time fitting on a dyno!

Plus, there must be a ton of proven air/exhaust/ jetting set ups for the carb models.

 

[Moespeeds]

You are out of your mind if you get EFI. If it works well, then you're good, but if it has a problem, you are completely screwed. Nobody wants to work on them, nobody knows how to work on them, the guys who say they know how to work on them are lying, and it's next to impossible to get parts. This I know from direct, firsthand experience. Stay far far away from it, it's nothing like the HD EFI. Carb is the only way to go.

 

[zenBD]

You are out of your mind if you get EFI. If it works well, then you're good, but if it has a problem, you are completely screwed. Nobody wants to work on them, nobody knows how to work on them, the guys who say they know how to work on them are lying, and it's next to impossible to get parts. This I know from direct, firsthand experience. Stay far far away from it, it's nothing like the HD EFI. Carb is the only way to go.

Yeah... if they were still in business, then it would be a different story... I'm inclined to agree.