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Discussion Starter · #1 ·
After being held up for 2 weeks by the UK postal system I have my DFC unit. It comes with 2 maps 1 stock and 1 for Two Brothers end can.

There are some puzzling aspects which are not explained by the scant documentation ( the software help button doesn't do anything!). There are in theory three ways to adjust the fueling.
1) The map values
2) The low medium and high rpm screw adjusters ( potentiometers?)
3) The closed loop rich/weak adjuster which presumably intercepts and changes the O2 sensor feedback.

The installation instructions say that the bike runs in closed loop mode up to 85% throttle and if this is the case only the 80% and 100% fuel map columns are going to have any permanent effect. This probably applies to the screw adjusters as well so only the high r.p.m. one is worth adjusting.

The supplied maps have a nominal 8% adjustment value in all columns except the full throttle one and I suspect this confirms the above.

The attached chart ignores the vaues below 80% throttle and shows the difference between the 2 maps.

Notwithstanding the above reservations the proof of the pudding is in the eating - I'll report backup after testing.

Regards Roadster
 

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Discussion Starter · #3 ·
DFC Update

I have the unit installed and working.

My bike:-
LV stainless full system with reduce outlet pipe ( 29mm inside dia.)
Foam air filter in standard airbox.
Air injection removed and blanked off.
Crankcase breather redirected and air cleaner entry blanked.

DFC Installation:-
This is straightforward but watch out for connection tap to throttle position sensor. The instruction say yellow wire but there are 2 yellow wires. I have connected to yellow with grey tracer and this is giving correct throttle position calibration in the Dynojet software.

Tuning:-
2 maps delivered with the unit. map 1 decribed as stock gave in immediate noticeable improvement. Map 2 for Two Brothers end can was not as good.
I have set the closed loop adjustment to +5 and this gave a big improvement from 3500 r.p.m. to 8000 r.p.m. The map I have worked on so far is a variation on map 1. I am concentrating on full throttle behaviour and trying to get the most resilience when trying to hold top (8000 to 10000 rpm) speed in varying conditions. The comparison with the original map 1 can be seen attached. I haven't made any changes below 8000 r.pm.

Is anyone interested in exchanging maps or is there some way we could collect them on the site?

Regards Roadster
 

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Were you able to get the bike dyno'd after installing the DFC? I believe there wouldn't be any noticeable difference on the top end right? BTW, what's the comfortable top end you're able to reach (assume its MC41 engine) at any point in time?
 

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Were you able to get the bike dyno'd after installing the DFC? I believe there wouldn't be any noticeable difference on the top end right? BTW, what's the comfortable top end you're able to reach (assume its MC41 engine) at any point in time?
Aargee there will be big difference in top end as well as HONDA map is running really lean at high RPM.. Dnyo Jet works through O2 sensor but there are other devices that directly taps in to ECU.

roadster can u post the fuel map stock and urs ?? it will really help
 

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The two bros map is the exact map that I have in my bike. My bike was the doner bike used for R&D for the DFC. My tuner makes a good 80% of the maps for dynojet.
Here is my sheet. The lowest number is stock tune with a pipe and the highest is a pipe and tuned " two bro's tune"
I noticed the bike felt healthier and pulled harder from mid to top. i'm happy with it expecially when I paid nothing :)

 

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Aargee there will be big difference in top end as well as HONDA map is running really lean at high RPM.. Dnyo Jet works through O2 sensor but there are other devices that directly taps in to ECU.

roadster can u post the fuel map stock and urs ?? it will really help
Im not sure if I understand this properly? I thought the Honda stock tune was very lean at LOW rpm, and these DFC's only have real benefits at low-mid rpm's but less so at high rpm?

Dave
 

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Had mine dyno'd yesterday.. The end result with stock air filter, lv complete exhaust, and dfc 25.85 HP .... Gained about 3HP at 5k RPMs.. Overall there was a gain across the range.
 
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Thought I'd put up the Dyno sheets



Check the ARF
 

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Discussion Starter · #10 ·
Thought I'd put up the Dyno sheets
Thanks.

Those dyno curves have a much better correspondence to what I get on the road compared to previous ones published. They seem to have captured what happens above 9000 r.pm. I would be interested in the dynojet maps if you can find a way of pasting them to a spreadsheet. I haven't found much need to add fuel at high r.p.m. but I am sticking with +3 on the closed loop adjustment and +5 on the device's high end trim pot.

This gives a robust mid-range and an engine thats willing (in top gear) to reach about 9500 r.p.m. in slightly favourable conditions and 10,000 downhill. I am still getting about 70 miles per UK gallon which is astounding considering that I use at least 9000 r.pm. whenever I can.

Regards Roadster
 

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Had mine dyno'd yesterday.. The end result with stock air filter, lv complete exhaust, and dfc 25.85 HP .... Gained about 3HP at 5k RPMs.. Overall there was a gain across the range.
It's unusual that they were able to hold onto the power all the way to redline. Normally this falls off above 9,500 unless you change the tuned intake runner in the air box for a vel stack.
 

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It's unusual that they were able to hold onto the power all the way to redline. Normally this falls off above 9,500 unless you change the tuned intake runner in the air box for a vel stack.
Yeah the guy that tuned it spent 3hrs tuning it.. He's a perfectionist..lol The AFR on the graph are some of the best I've seen on anything, car or bike.

Cool thing is I'm sure they didn't charge me for 3 hours of tuning. They also told me that my base line with no mods put out more power than a cbr250r they ran on the dyno with a slip on:eek: I've seen freak motors before in some of the honda cars I've worked on in the past..

Any way.. They seemed to really be impressed with the bike, as soon as I went to pick it up my friend was smiling and said it wheelies now...lol I don't plan on trying to though...:)
 

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Thanks.

Those dyno curves have a much better correspondence to what I get on the road compared to previous ones published. They seem to have captured what happens above 9000 r.pm. I would be interested in the dynojet maps if you can find a way of pasting them to a spreadsheet. I haven't found much need to add fuel at high r.p.m. but I am sticking with +3 on the closed loop adjustment and +5 on the device's high end trim pot.

This gives a robust mid-range and an engine thats willing (in top gear) to reach about 9500 r.p.m. in slightly favourable conditions and 10,000 downhill. I am still getting about 70 miles per UK gallon which is astounding considering that I use at least 9000 r.pm. whenever I can.

Regards Roadster

I'd have to plug it in and pull off the map or see if my friend can email it to me. It was tuned through the usb port. I'm at sea level so depending where you are they might not work with out being modified.
 
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