V-Twin Forum banner

1 - 20 of 27 Posts

·
Registered
Joined
·
250 Posts
Discussion Starter #1
Here is the new info:

1. HD has now released a custom calibration cartridge for the new EFI SE103 Road King Stage I. It is rated at 92HP @5500 and nothing at 6500.

2. HD has now published the ratings for a stroked 103 EFI high output touring model - guess what? - 92 HP @ 5500 and nothing at 6500.

3. HP continues to publish the stroked 103 carbed touring TC88 at 112HP at 5500 and 118HP @ 6500 with the 45mm carb kit et.al.

Mystery where is the 20 -30 missing HP on the EFI vs Carb for the 103 - all other things being the same?

Answer:
1. The EFI Induction Module at 40mm can't compete with the 45mm flatside carb. And there is no upgrade for it.

2. The EFI injectors at 4.35gm/sec 360cc/min are maxed out with the SE EFI Tuner at a 20ms duty cycle at 5500RPM so it is impossible to get enough fuel to the motor.

Conclusion: You won't see 120HP on any 103 or larger Harley EFI motor any time soon until a 550cc/min injector makes an appearance ($75) and you still may need a fatter Induction Module (big bucks).

The good news: Anyone who looks at HD's new performance configurations posted this month will easily spot the 20-30 HP difference between the carbed and EFI 103 and ask what the @#[email protected]? is going on at 5000RPM! Why does the EFI 103 go in the dumper at 5000 while the carb pulls strong to 6500? They won't even sell them until this is solved. You can get the same from a EFI high output 1550 - and that you can feed with the stock injectors.

You better believe they are on it!!!

Dealer meeting in January!!!! Stay Tuned!
 

·
Registered
Joined
·
2,300 Posts
Maybe so. This run is of a stroked 02 Delphi RoadGlide, stock throttle body, stock injectors, stock ECM and even stock flash as you can see from the rev limit. Sure it had a few things done to it, but it's pretty close to the carb numbers you post and way above of what they theorize the limit of the stock EFI parts is.

 

·
Registered
Joined
·
250 Posts
Discussion Starter #3
You can do the same things to the carbed 103 and push the curve up well beyond the factory chart. The point is the shape of the curve. In the EFI you run outa gas and air at 5000 and it basically flattens off whereas the carb keeps going.
Here is the math. At 6000RPM, that is 100revs per second or .010 seconds or 10ms. At alternate strokes that is 20ms per combustion cycle.
That is all the time you got for the fuel - actually you got less time.
Now go in your SE EFI Tuner and chark your Front and Rear Injector Pulse Width. At idle it should be 2-4 MS. It should never be more that 75-80% of your available time. At 3000 RPM you got 40ms. It'll be at 10-14 ms. Easy to inject. At 6000RM you got 20MS and you're done. Injectors are opening up to 20MS well before 6000 in the 103 to feed it.
Look and see what yours are running on the graph and you'll see the problem.
The other problem is air flow. No matter what you do, that flatside carb is 45mm and the EFI Induction Module is not. Nothing can compensate for that difference in available air flow. Not porting - not nothing.

I'm a big fan of EFI . But I want it to run in the big motors 103/107/116/124/131. For that we need a fatter induction modiule and 550cc./min injectors.
 

·
Registered
Joined
·
250 Posts
Discussion Starter #4
Hippo- What do you thhink about this?
We get the RSR 200i induction module from RB Racing with their low impedance injectors. That thing has a 56mm Throttle body measured at the butterfly. Then we use the HD ECM EFI system for all the electronics. We don't use RSR control system or software only their hardware for the induction module and injectors.
As you know I only use SE and HD parts but in this case an exception may be warranted and it would retain all the SE EFI Tuner benefits as well as all HD sensors and electronics.
Something I might even fund.
I won't move my 1550 to 103 until there is a techical solution.
 

·
Registered
Joined
·
2,300 Posts
Don't know if they still are in business, but see if you find one of the throttle bodies from EMC (Eagle Motor Co)
One of their engineers just moved to Phoenix and we have been going over his bike discussing a few things. It's a RoadGlide with a 135 ci engine.

As an addition the bike on the dyno chart was done just before the EFI tuner came out. We were running an adjustable fuel pressure regulator and a DFO. The pressure was set higher then stock. The 135 also runs higher pressure and a Ford Mustang pump.
 

·
Registered
Joined
·
250 Posts
Discussion Starter #7
RC Engineering (Russ Collins) makes the injectors used in RSR EFI systems in cohoots with RB Racing. I'm having a conversation with RB Racing right now. They don't sell "upgrades" - normally just the whole system from RC Injectors, throttle body, wiring harnesses, sensors, software. Their fuel regulators run 57lbs so that is the same. It takes a lot of additional fuel pressure to increase flow by 50%. I'm sending SBC some mail re this. He'll get it you.
 

·
Registered
Joined
·
250 Posts
Discussion Starter #9
Checked with EMC. They still live and breath. Even got a retrofit for the IAC stepper motor on their Throttle bodies. I don't see that on RB Racings RSR EFI . And I don't plan to lose half my electronics and be fooling with an idle mixture adjusting screw- haven't done that in years. Year 2002/2003 solutions are unknown.
 

·
IronButt
Joined
·
6,364 Posts
I am in the same boat. 107 inch Axtell motor and the EFI system. I had the TB opened up 3 MM new butterfly and blended the TB to the intake. now for injectors. All the Delphi TC 88's have the large injectors. I am thinking about finding a larger injector and fitting it to the intake. Plenty of room to do so. Any others have a better idea??
 

·
Registered
Joined
·
2,300 Posts
Higher pressure, depending on how much more fuel you need.

It will be into the new year before we have more regulators as right now the CNC's are making Hummer parts.
 

·
Registered
Joined
·
250 Posts
Discussion Starter #12
I think the problem with the 103 and larger EFI motors is lack of fuel AND lack of air.
Hippo, what is the size of the butterfly in the single throat throttle body?The two channel ones claimed 38mm with an SE Induction module upgrade to 434mm.
These twin channels didn't work so they are now back to single channel/throat but what size? There is also no SE upgrade for the new single throat throttle body - at least not yet.
Regarding fuel pressure - it takes a lot. Injector Flow increases as the square root of the change in pressure. So if you up pressure from say 60 to 90 a 50% increase, Fuel flow is up only 22%. Since I'm seeing pretty long duty cycles on the stock injectors at 5000RPM and up I'm looking for a 50% increase in flow.
 

·
Registered
Joined
·
2,300 Posts
I'm under the impression it's 45 mm but I would have to measure one to see what it really is.

I understand your reasoning but from time to time you just slap things that are available on and see what happens. It looks like the Delphi throttle body works fine as is with the valve sizes we run.
We built 117's with the stock Delphi throttle body and they worked well and the factory runs the 103's with it and they make very good power once they have been remapped and with good pipes and air cleaner assembly despite the low CR they run.
Even the dual 43 MM throttle bodies don't work all that well. Hard to say what the real reason is, configuration, MM mapping (doubt it), etc.

I'm sure there is more to be found in particular by the guys that like the larger ports and valves but right now the economy is going south and the big engine projects have dried up and we have to survive building inexpensive upgrades and wait to play another day.

Just received an offer from someone with a track record that has some sort of upgraded Delphi throttle body of his own manufacture to run some tests on. Right now I don't have a prospective customer for a really large stroker, if you do let me know and I'll ask him if he wants me to give you his e-mail.
 

·
Banned
Joined
·
999 Posts
tsuter said:
Here is the new info:


Mystery where is the 20 -30 missing HP on the EFI vs Carb for the 103 - all other things being the same?


[/QUOTE

Harley wants it to stay together, consequently it gets detuned.
 

·
Registered
Joined
·
250 Posts
Discussion Starter #15
The dual 43mm runner throttle bodies don't work too well because they found that air doesn't like to do a hard 90 degree turn into the intakes. Slowed the air velocity etc. Some engineer thought having completely separate intake events was a good idea - it wasn't at least not in that tight of a space. So back to the single channel but until someone measures the butterfly - how big?. The SE breather is 54mm but I'm sure things neck down.
When you look at the HD published charts for 103 Carb verus 103 EFI, they are pretty much the same under 4500 or so . From 5000 on up there is no comparison.
I've tried to solve some of it with the EFI Tuner on the 103 and you can get a bit but it stills starts to die at 5500 and nothing at 6000+. Actually unless your're really on a dyno or racing what happens over 5000 doesn't matter much but I'm still certain you can get 120 HP out of the EFI 103. just a matter of air and fuel.
 

·
Registered
Joined
·
287 Posts
Just a thought: They add compression releases to the heads, why not put the injectors right into the heads? They are doing it on newest diesels.
 

·
Registered
Joined
·
2,300 Posts
The MM mixture assembly is different in the sense it has individual runners but the Delphi two part throttle body/intake manifold is quite similar in configuration to a carb/manifold assembly. The air still has to make the turn, carb or EFI.
I would wager that the airflow isn't that different. Might even match the ports and throw them on the flowbench for shits and giggles after the new year.
 

·
Registered
Joined
·
250 Posts
Discussion Starter #18
45MM on the SE flat side carb seems to get plenty of air. That and the jets - the fuel is good.
EFI may have 45MM in the single throat body and if so then air is less the issue than fuel. Above 5000RPM the fuel isn't getting in there fast enough.
It sure is cheaper to upgrade an injector but I haven't seen a "plug and play" injector upgrade for the one in there.
I'll have to stop by a dealer and get the butterfly dimensions off a 02 throttle body if they got a bike apart.
 

·
Registered
Joined
·
2,300 Posts
The one difference is that with the Delphi throttle body you have the butterfly and the shaft in the airflow while with the flatslide all that is there is the needle. That's why I wpuld like to flow them.

With a flatslide you also have a very nice and clean variable orifice while the butterflies could have a ramp effect that could disrupt flow just before the turn. Just guessing here but based on stuff we have seen in the past.

It just seems curious that some very high performance world class japanese racebikes are using computer controlled secondary throttles on their EFI throttle bodies to mimic the effect of a flatslide or even better a CV slide and have achieved quantum drivability improvements with it.
 
1 - 20 of 27 Posts
Top