[quote name='tomwal' timestamp='1355828532' post='260726']
It would be really useful to get a conclusive report from some owners who have installed this device. Does it smooth out the slow running/snatchiness ? What is the effect on fuel consumption ? Is there general performance improvement ? I am sure I am not the only one who would really appreciate this information before deciding to purchase.
Thanks, Tom
[/quote]
G'day Tom,
(hope you're not colour blind; it's late and I'm going to answer lazily)
Yes; most of the 900's suffering snatchiness in the lower RPM are doing so because of too leaner AFR or/and O2 sensors that are not working correctly.
Minimal to negligible; you will likely see some increase around town but highway and mixed cycle mileage do not suffer significantly. The 900 will still be a miser by comparison to any similarly sized bike, and you'll get still 350-400+kms per tank when touring fully loaded with 3 boxes and a fully kitted 110kg+ nut screwed to the seat.
From idle to ~4000RPM there is a definite improvement in performance... I have no idea what a dynamometer might show but... the throttle response becomes more linear and low end torque feels much stronger. The bike is more tractable, at lower RPM, and far better behaved at low/town speeds and there is no detriment to highway performance. You won't break any records at Nürburgring but you'll enjoy the tour there much more and arrive less stressed.
My results are based on my experience with a 2009 model, but most of this will hold true for any EFI bike:
Things like the TFI and EJK aren't always going to fix every ill behaving bike; there are other considerations that you should attend to first.
LIke:
1. check your throttle cable free-play...set it as per the manual... but, I have found, a little more than the manual says can help.
2. Use the right fuel. The TDM isn't a high tuned race engine; it wont make use of high RON (premium) fuels and they can cause poor low RPM running. I have found the local 91 RON to be best all-round... 95RON can get more miles per tank on the highway but can run rough around town... 98RON is as per 95 but with even worse low RPM running (and the bike can stink of un-burnt fuel). The higher RON premium fuels are more viscous and, unless the engine is made for them, will not mix and burn as they should which causes rich running and can foul ignition plugs. The TDM was designed for low RON fuels so run it on them; the only time to go higher is if nothing else is available or the ambient temperature is often around 40 degrees C (this will prevent pre-detonation or pinking). (There's lots of information to support what I've just said, you'll even find it at the fuel manufacturers websites.)
3. balance throttle bodies. Fine tuning here can do wonders, but I've not read of a 900 that was ever much out of balance. Try to set the vacuum at the highest possible level within spec'; this does (as you'll find mentioned on Carpe several times) make the most difference to low end behaviour that the OEM tuning method can give.
4. set the correct final drive chain tension/slack... too much slack can exaggerate the snatching.
5. get more exhaust flow. either buy and fit a good after-market muffler set or modify the OEM mufflers. More flow definitely helps with low RPM torque delivery, and you don't need something loud to make a huge difference. (The cheapest option seems to be the Fuel Exhausts for a new purchase, but second-hand can be good too, shop around.)
6. air filter... K&N is a popular fit/mod... but, to be honest I doubt there is any real benefit to performance on the TDM. Certainly nothing that will alter low RPM running. (I've only added this line for completeness.)
7. Air-box mod... post ~2007 bikes, don't do it; it won't help (unless you're susceptible to the placebo effect)... pre 2006 bikes, it's said to help and may well do so (but if you add a TFI I would try removing the airbox mod and then tuning the bike... or, you could try it both ways and settle for the better).
8. Fit and tune a TFI/EJK/PCIII and tune it. Which device you chose will be based on budget and your own DIY abilities.
The TFI-1025 suits the TDM900 best IMHO; it gives the range of adjustment needed, is relatively cheap, and any half decent DIY'er can fit and tune it.
So much for me giving a lazy answer.... I must suffer keyboardiarrhea... and I shouldn't have had that nanna-nap after work.
"conclusive report"... not sure where you'll ever get one of these unless you're prepared to try something for yourself or have a close relationship with someone that does try it.
I will give you the most objective report I can... and it'll probably far too wordy, by half... but conclusive is a tall order.
From my participation in this thread, we've had a few owners install the TFI-1025 and they're sounding happy with them; if they weren't they'd be posting more often, of that I'm sure.
We've had someone source a similar TFI, but not the 1025, and they managed to get good results with it after some slight wiring changes.
Danresh has had a bad run with an EJK for his later (2009?) model TDM... it's our opinion that the base tune on the EJK is not good for the post 2007 bikes (due to changes in the ECU and air-box flap etc). Dobeck only list them for 2002-2007 and the sales advice given to Danresh was IMHO just plain uninformed wrong. I'm sure Danresh will let us know how he goes with the TFI-1025, but I suspect he'll have a positive experience this time around (I've got my fingers crossed for him).
But, what we haven't seen is anyone having had any bad experiences with the TFI-1025 thus far. I'm sure members would be telling us if they did. There's been well over 2500 reads of this thread so it not like it's obscure or hidden on the forum. <img src='http://www.carpe-tdm.net/ipb/public/style_emoticons/<#EMO_DIR#>/smile.png' class='bbc_emoticon' alt='
' />
If you Google around you'll find the Dobeck TFI's being used on Harleys and all sorts of other twin bikes. There's also a number of other similar products that do exactly the same thing, the same way, but with different names and price tags. Most of these products are sold for specific models of bikes.
As owners of TDM's we suffer a unique problem in that the bike we own and love has not proliferated in the US market; it's a niche product, and a bloody good one, but that means we don't have the mainstream after-market manufacturers developing lots of alternate products for us. We do see some great bolt-on products coming from Germany, France, and the UK etc. but the local laws there mean that performance products, that alter engine management, are few and far between. Dobeck are in the US where laws vary widely from state to state but, on the whole, are more relaxed than EU... but Dobeck don't have direct access to the TDM for R&D... the TFI-1025 is a generic product that can be used on a number of twin cylinder EFI engines, so we TDM owners can use this product (it's not a simple plug-in but works very well none the less)... the EJK (plug-in) is a product for a specific model, so Dobeck need to work with partners with access to the TDM and they've done this for the pre-2008 bikes and are in the process of trying to include the whole TDM900 range. I'm sure they'll get it sorted but, until they do, the TFI-1025 will work for all TDM900's.
TLDR?... sorry.
It would be really useful to get a conclusive report from some owners who have installed this device. Does it smooth out the slow running/snatchiness ? What is the effect on fuel consumption ? Is there general performance improvement ? I am sure I am not the only one who would really appreciate this information before deciding to purchase.
Thanks, Tom
[/quote]
G'day Tom,
(hope you're not colour blind; it's late and I'm going to answer lazily)
Yes; most of the 900's suffering snatchiness in the lower RPM are doing so because of too leaner AFR or/and O2 sensors that are not working correctly.
Minimal to negligible; you will likely see some increase around town but highway and mixed cycle mileage do not suffer significantly. The 900 will still be a miser by comparison to any similarly sized bike, and you'll get still 350-400+kms per tank when touring fully loaded with 3 boxes and a fully kitted 110kg+ nut screwed to the seat.
From idle to ~4000RPM there is a definite improvement in performance... I have no idea what a dynamometer might show but... the throttle response becomes more linear and low end torque feels much stronger. The bike is more tractable, at lower RPM, and far better behaved at low/town speeds and there is no detriment to highway performance. You won't break any records at Nürburgring but you'll enjoy the tour there much more and arrive less stressed.
My results are based on my experience with a 2009 model, but most of this will hold true for any EFI bike:
Things like the TFI and EJK aren't always going to fix every ill behaving bike; there are other considerations that you should attend to first.
LIke:
1. check your throttle cable free-play...set it as per the manual... but, I have found, a little more than the manual says can help.
2. Use the right fuel. The TDM isn't a high tuned race engine; it wont make use of high RON (premium) fuels and they can cause poor low RPM running. I have found the local 91 RON to be best all-round... 95RON can get more miles per tank on the highway but can run rough around town... 98RON is as per 95 but with even worse low RPM running (and the bike can stink of un-burnt fuel). The higher RON premium fuels are more viscous and, unless the engine is made for them, will not mix and burn as they should which causes rich running and can foul ignition plugs. The TDM was designed for low RON fuels so run it on them; the only time to go higher is if nothing else is available or the ambient temperature is often around 40 degrees C (this will prevent pre-detonation or pinking). (There's lots of information to support what I've just said, you'll even find it at the fuel manufacturers websites.)
3. balance throttle bodies. Fine tuning here can do wonders, but I've not read of a 900 that was ever much out of balance. Try to set the vacuum at the highest possible level within spec'; this does (as you'll find mentioned on Carpe several times) make the most difference to low end behaviour that the OEM tuning method can give.
4. set the correct final drive chain tension/slack... too much slack can exaggerate the snatching.
5. get more exhaust flow. either buy and fit a good after-market muffler set or modify the OEM mufflers. More flow definitely helps with low RPM torque delivery, and you don't need something loud to make a huge difference. (The cheapest option seems to be the Fuel Exhausts for a new purchase, but second-hand can be good too, shop around.)
6. air filter... K&N is a popular fit/mod... but, to be honest I doubt there is any real benefit to performance on the TDM. Certainly nothing that will alter low RPM running. (I've only added this line for completeness.)
7. Air-box mod... post ~2007 bikes, don't do it; it won't help (unless you're susceptible to the placebo effect)... pre 2006 bikes, it's said to help and may well do so (but if you add a TFI I would try removing the airbox mod and then tuning the bike... or, you could try it both ways and settle for the better).
8. Fit and tune a TFI/EJK/PCIII and tune it. Which device you chose will be based on budget and your own DIY abilities.
The TFI-1025 suits the TDM900 best IMHO; it gives the range of adjustment needed, is relatively cheap, and any half decent DIY'er can fit and tune it.
So much for me giving a lazy answer.... I must suffer keyboardiarrhea... and I shouldn't have had that nanna-nap after work.
"conclusive report"... not sure where you'll ever get one of these unless you're prepared to try something for yourself or have a close relationship with someone that does try it.
I will give you the most objective report I can... and it'll probably far too wordy, by half... but conclusive is a tall order.
From my participation in this thread, we've had a few owners install the TFI-1025 and they're sounding happy with them; if they weren't they'd be posting more often, of that I'm sure.
We've had someone source a similar TFI, but not the 1025, and they managed to get good results with it after some slight wiring changes.
Danresh has had a bad run with an EJK for his later (2009?) model TDM... it's our opinion that the base tune on the EJK is not good for the post 2007 bikes (due to changes in the ECU and air-box flap etc). Dobeck only list them for 2002-2007 and the sales advice given to Danresh was IMHO just plain uninformed wrong. I'm sure Danresh will let us know how he goes with the TFI-1025, but I suspect he'll have a positive experience this time around (I've got my fingers crossed for him).
But, what we haven't seen is anyone having had any bad experiences with the TFI-1025 thus far. I'm sure members would be telling us if they did. There's been well over 2500 reads of this thread so it not like it's obscure or hidden on the forum. <img src='http://www.carpe-tdm.net/ipb/public/style_emoticons/<#EMO_DIR#>/smile.png' class='bbc_emoticon' alt='
' />If you Google around you'll find the Dobeck TFI's being used on Harleys and all sorts of other twin bikes. There's also a number of other similar products that do exactly the same thing, the same way, but with different names and price tags. Most of these products are sold for specific models of bikes.
As owners of TDM's we suffer a unique problem in that the bike we own and love has not proliferated in the US market; it's a niche product, and a bloody good one, but that means we don't have the mainstream after-market manufacturers developing lots of alternate products for us. We do see some great bolt-on products coming from Germany, France, and the UK etc. but the local laws there mean that performance products, that alter engine management, are few and far between. Dobeck are in the US where laws vary widely from state to state but, on the whole, are more relaxed than EU... but Dobeck don't have direct access to the TDM for R&D... the TFI-1025 is a generic product that can be used on a number of twin cylinder EFI engines, so we TDM owners can use this product (it's not a simple plug-in but works very well none the less)... the EJK (plug-in) is a product for a specific model, so Dobeck need to work with partners with access to the TDM and they've done this for the pre-2008 bikes and are in the process of trying to include the whole TDM900 range. I'm sure they'll get it sorted but, until they do, the TFI-1025 will work for all TDM900's.
TLDR?... sorry.
![[Image: gallery_10460_302_12664.png]](http://www.carpe-tdm.net/ipb/uploads/gallery/album_302/gallery_10460_302_12664.png)