Triumphrat

britrich · 01-31-2010, 08:49 PM

I'd really appreciate some advice. I have an 09 T100 EFI with NH Togas and the Arrow 2-1 map. The bike runs beautifully through out the range with the exception of snatchiness at low revs as many others here have commented on before. I really want to try to get rid of this since it's annoying and from what I've read here, it's not something I should have to put up with. I'm also thinking about removing the airbox soon so what I want to know is what would be the best thing to do post-airbox removal? I have read quite a few comments here in favor of dyno runs. Would this be able to sort out the snatchiness as well as optimize things throughout the range? I'd rather do that than get a Power Commander or Tuneboy and do it my self. What sort of cost would I be looking at to get this done and what sort of shop does this? Any recommendations of a trustworthy place in the Puget Sound area?
Thanks in advance,
Rich

Forchetto · 02-01-2010, 05:14 AM

I don't think anyone has really cured the snatchiness. A lot of it is subjective, some people put up with it or adapt to it.

Tuneboy or Power Commander plus rolling road tests can sort out the fueling to such an extent that any surging and flat spots are eliminated.

Removal of the AI helps a bit, but doesn't cure the on-off throttle snatchiness completely.

Also, fiddling with the closed loop mixture by manipulating the output of the O2 sensors virtually eliminates the surging you get when running on a steady low throttle at low speeds, such as keeping up with dense traffic, pottering around in a high gear on country roads or manouvering in car parks, etc. Snatching is still there though.

My next experiment to eliminate that is somehow damping the throttle stop. I can't think of a way to do it mechanically, so I might have a go at introducing some electronic damping by modifying the signal from the TPS (throttle position sensor).

I suspect it'll be a failure, and that snatchiness is inherent on intake systems that use a butterfly-type valve, i.e. CV carbs or EFI throttle bodies. Not so noticeable on cars due to their softer power delivery characteristics, heavier flywheels, etc.

BluprintZ · 02-01-2010, 06:32 AM

Hmm, interesting.
The only mod i have done, is fitted the TORS system and i've never really noticed any snatchiness.
Compared to the 900 Duc Monster i owned for a few years, the Thrux is as smooth as silk, the Duc was a nightmare in town.

G ; )

Slinky · 02-01-2010, 06:46 AM

I can't say I've experienced any snatchiness or surging either, the EFI throttle response seems just fine to me (on a standard bike).

I always thought CV carbs smoothed out throttle response, because of the way the slide takes a while to catch up with the butterfly opening. I would expect the link between throttle and fuel inectors is more direct, more like the old slide carbs.

Maybe it is just a question of adapting throttle technique? I don't know for sure, just thinking out loud.

IAmTheDoGMaN · 02-01-2010, 11:08 AM

After removing the AI on my 09 EFI Speedy I noticed that some of the snatchiness is gone. Certainly feels a lot softer onset then before. I used I think it was Forchetto's ball bearing method to test it out before I pulled it completely. Takes all of 5 minutes and is easily reversible.

LuckyBonnie · 02-02-2010, 06:19 AM

Gotta say that I was having big "problems" with snatchy throttle when I first got my efi Bonnie, however after raising my idle from its initial dealer set 900 rpm to 1100-1150 the bike has been superb, completely solved the problem for me.

Forchetto, there is a small company on the internet that makes an excellent product (as reviewed by one of the better bike gear review sites); it is a throttle handle that has a cam thingy in it that causes the initial throttle opening to require a greater twist of the handle compared to how much twist is needed beyond initial opening.
I believe it is called the "Thottle Tamer", I will have to check. I contacted the 'inventor' last year to see if he would manufacture a model for the Bonnie and he sounded keen. Once I solved my jerky throttle response by raising the idle I never bothered to follow up and see if he did a model for the Bonnie. His site has interesting info on how he created his "Throttle Tamer" (cams, etc., pics.)
They were approx $100. He had models available for a few different bikes at that time.
Will check and post the link when I can find it.
Ted

Forchetto · 02-02-2010, 06:47 AM

Thanks Ted. I'd love a "mechanical" solution rather than the electronic ones I'm investigating now, like electronic damping of the TPS signal, Fuel cut eliminators, etc.

Mine has the Arrow 2-2 map, AI removed, The signal from the O2 sensors modified to give a richer mixture in closed loop mode, etc.

I just have a little bit of snatch left but I'm pursuing perfection...

britrich · 02-02-2010, 12:13 PM

After removing the AI on my 09 EFI Speedy I noticed that some of the snatchiness is gone.

So what's the consensus on removing the AI on EFI bikes, or isn't there one yet? I thought this was supposed to be bad for the pre-CATs in the headers.

Lucky, thanks for the idling suggestion but my bike's already idling around 1100-1200. perhaps I just ened to work on my throttle technique as Slinky suggested!

IAmTheDoGMaN · 02-02-2010, 12:17 PM

My bike didn't have pre-CATs. So I had no issue there.

Calliway · 02-03-2010, 01:45 AM

Triumph fuel injected bikes are snatchy. Get used to it, you can't really change it. They do not have secondary butterflies or a off idle circuit so your throttle is either open or closed.

If you think your Bonnie is snatchy, try a new TBird. It takes some getting used to but with a little clutch work and supple wrist you can tame the snatchiness.