Triumph Rat Motorcycle Forums banner

1 - 13 of 13 Posts

·
Registered
Joined
·
5 Posts
Discussion Starter #1
After lurking here for a few years the first thing to do is to thank the following guys here:
@DEcosse @andrewed1 @Will and all the others with helpful inputs.

You have helped me a long way: stator & R/R, cabling, speedo sensor, ECU maps to name a few. Also with courage to make my hands oily and reduce anxiety towards multimeters :)

Pre-requisites:
- Speed Four 2004
- low speed jerking in slow turns, city traffic
- desire for a smoother power delivery
- stock air filter and exhaust
- no exact results from google: triumph speed four low speed tuneecu stock exhaust air filter

There was no precise information about how to solve low speed jerkiness between 2500 - 4000 rpm, so here is what I tried:
1. Got TuneECU and a suitable cable (TuneECU site will have more information: http://www.tuneecu.com)
2. Determined that I have map no 10167 (http://www.tuneecu.com/Tunes_in_Hex_and_dat/All_Tunes_sorted_by_model/SpeedFour/10167Map.zip)
3. Downloaded and compared with map no 10164 + PCtrim + i Limit (http://www.tuneecu.com/Tunes_in_Hex_and_dat/All_Tunes_sorted_by_model/SpeedFour/10164+PCtrim+iLimit.zip)
4. Replaced the part on "I Limit" map with values from modified 10164 like shown in attachments: new vs orig


So far I've done just one minor test ride and it was better. I'll continue testing and post here if something will be changed or reverted. Any advice or considerations are also highly appreciated.

Disclaimer about something something non-native english speakers and don't try this at home
 

Attachments

·
Super Moderator
Joined
·
21,500 Posts
Thanks for the shout-out! :thumb

- low speed jerking in slow turns, city traffic

There was no precise information about how to solve low speed jerkiness between 2500 - 4000 rpm....
The 'jerky' behaviour (also called 'surging') is caused because it's lean (high air/fuel ratio i.e insufficient fuel mass)
The best way to resolve is not to adjust the timing map, but the fuel (F) map - try adding 5-10% in the trouble zone group of cells (1000-4000 rpm range identified and low 0-10%$ throttle openings)
- that should resolve your issue
(you can use the F TRIM map for this as opposed to changing the core values in the Fuel Map Table itself - result is the same)
 

·
Super Moderator
Joined
·
8,631 Posts
Beat me to it - F Trim is also called Fuel Idle Trim in TuneBoy. Use that to enrich the mix down low and it smooths things out off idle and reduces snatch at small throttle openings. I adjusted the timing map on my Sagem injected bikes with good results, but as Decosse points out, the real issue is that it has a lean mix at low rpm.
 

·
Registered
Joined
·
5 Posts
Discussion Starter #4
Thanks for the input!

Beat me to it - F Trim is also called Fuel Idle Trim in TuneBoy.
(you can use the F TRIM map for this as opposed to changing the core values in the Fuel Map Table itself - result is the same)
In the tunes available on TuneECU website for both Speed Four and TT600 F Trim tables are zeroed out. There are no values to follow suite so I'd rather prevent testing on animals.

The uneducated guess to change timing is based on the comparison of 2 known good map sets: 10164 (with custom filter & exhaust) and 10167 (stock). One of the maps is opaque to show the difference.
Fuel maps: https://plot.ly/~radjiv/2/ (throttle position has logarithmic axis, so it's a bit cramped, check the values)
Ignition limit maps: https://plot.ly/~radjiv/7/

Since 10164 with add-ons is different from my bike (less restricted airflow) then the maps should differ on most occasions which also makes sense when comparing the amount of fuel. On the 10167 ignition timing map there is a very distinctive area (40-80% load and 0-4500 rpm) which is straightened out on 10164+.

Real life has been better – significantly less surging than before but not completely gone. I'll keep driving and probably make another minor test with 10164+ tune and then try to adjust 10167 fuel values up to the range seen on 10164+ in the lower RPM range.
 

·
Super Moderator
Joined
·
21,500 Posts
Again, for your symptom you absolutely need to do as suggested and adjust the fueling in that area.

The F Trim tables are always 0 - until you add (or subtract) trim - that is why it is called a TRIM table. As delivered. most maps have zero trim.
The trim is exactly that - adjust the corresponding cell in main F table by the amount of trim
So - you can make changes in the F table directly OR changes in the Trim table - the Trim table is much easier to keep track of what you are doing.
i.e. if you add 10% in a trim table cell, you can go back and make it 5% or 0 again to arrive back at the original value
If you change an F table value by 10%, if you go to adjust it back again it will deduct 10% from the NEW value - so you don't end up where you started.
Also you can see instantly how much change you have made at ANY cell with changes in the trim table - when you change the actual values in the F table, it is much harder to see what you've done without studying a copy of the original table before changes.
After testing and you are satisfied, there is an option to commit the trims to the F table - which will apply the changes into the F values and zero out the trim table - makes no difference in net result, will be the same even if not committed.

Note that you cannot just compare the F tables between maps either - the actual Fuel delivered is derived from both the A/F table and the F table (and the Trim if appropriate) - so unless the A/F tables are identical, you cannot compare one F table cell with one from another map and determine if richer or leaner.

Also note that the A/F table values will need to be less than 14.5 in order for the values to 'stick' - otherwise the O2 sensor will just over-ride the Fuel values
 

·
Registered
Joined
·
5 Posts
Discussion Starter #6
Again, for your symptom you absolutely need to do as suggested and adjust the fueling in that area.

The F Trim tables are always 0 - until you add (or subtract) trim - that is why it is called a TRIM table. As delivered. most maps have zero trim.
The trim is exactly that - adjust the corresponding cell in main F table by the amount of trim
So - you can make changes in the F table directly OR changes in the Trim table - the Trim table is much easier to keep track of what you are doing.
i.e. if you add 10% in a trim table cell, you can go back and make it 5% or 0 again to arrive back at the original value
If you change an F table value by 10%, if you go to adjust it back again it will deduct 10% from the NEW value - so you don't end up where you started.
Also you can see instantly how much change you have made at ANY cell with changes in the trim table - when you change the actual values in the F table, it is much harder to see what you've done without studying a copy of the original table before changes.
After testing and you are satisfied, there is an option to commit the trims to the F table - which will apply the changes into the F values and zero out the trim table - makes no difference in net result, will be the same even if not committed.
This is a good example of educated vs non-educated guesses :notworthy I got caught in mixed terms in searches regarding "Fuel Trim tables". Adjusting process in percentages makes sense.

Note that you cannot just compare the F tables between maps either - the actual Fuel delivered is derived from both the A/F table and the F table (and the Trim if appropriate) - so unless the A/F tables are identical, you cannot compare one F table cell with one from another map and determine if richer or leaner.

Also note that the A/F table values will need to be less than 14.5 in order for the values to 'stick' - otherwise the O2 sensor will just over-ride the Fuel values

In current case the A/F tables were identical. Also noteworthy: both tunes have 15,5 values in AF table up to 29% and 2000 RPM. There is no O2 sensor present on Speed Four to my knowledge.
 

·
Registered
Joined
·
48 Posts
Hi I hope this ok to post here, I had a thread with the same problem and I tried almost everything. The only thing that helped me was instead of increasing fuel in the trouble areas I took fuel out. I came to this conclusion because my problem got worse when the bike warmed up. This told me it was too rich in them areas. Another thing I did was I ripped the dreaded IVAC out and blocked off the holes on the intake rubbers(this was done before I did the last tweak on map). I may try putting the IVAC on again. This worked for me.
 

·
Super Moderator
Joined
·
8,631 Posts
As long as it worked. I would be interested in knowing what the fuel values were to begin with and whether the IACV was sealed and the vacuum hoses were in decent condition. I never tried starting a TT600 without the IACV hooked up, which makes me wonder if you have an excessively rich map already loaded or if there's some other issue going on. It would be a bit like running with the choke pulled even when the bike is warm if that was what as going on.
 

·
Registered
Joined
·
48 Posts
Will I loaded the stock map then took that back a notch. I came to this discision also because it ran worse with the baffle in. Don't get me wrong it does do it very slightly but in a manageable rev range.
 

·
Registered
Joined
·
5 Posts
Discussion Starter #12
@Brett8206 From the other thread you seem to have an aftermarket can? Mine is the stock one.

Since air/fuel ratio was discussed here's the map from stock tune (10167). It is also the same on 10164+air+ex+I limit tune. Out of curiosity I checked that 10089 (TT600 + exhaust) map has values up to 17.0 and other member have been happy without any changes to this :)
 

Attachments

·
Registered
Joined
·
48 Posts
Well i did want a stock can to see if it sorted my problem out, as others have said it did for them. I can't remember what number map mine was but it was the same as what is on the ecu label. I think i smoothed out the fuel trim. I changed it to graphic mode and smoothed out the graph. Im no expert, this is what worked for me.
 
1 - 13 of 13 Posts
Top