Very technical electrical modification to the throttle peddle question !

[richj]

I would guess there are two sensors, one for down, and one for up. That way, it doesn't matter if the input voltage changes because the ecu can 'work out' 1/4 down + 3/4 up, 1/2down 1/2 up etc. Probably vastly more complicated than that, but there my ten pence worth

this is the reason.

 

[MSG2]

Arnold, thanks mate, as I said I have come on here to help too, I am an electronics engineer, and have been making designing and manufacturing various electrical gadgets that I have sold all over the world, and I am indeed very cool about the whole issue, time and again I have tried explaining as best as I could but obviously if Ed or richj don't want to agree with my idea and heavily criticise it then there is very little I can do about it.

So I rest my case now and see if Ed or Richj can come up with alternative ideas and deliver the products.

I have delivered a solution and know it will work, but the engine needs to be under a slight load such as you would get some loading on the engine when trying to balance the car around a biting point. Blazerboy has alraedy stated that there is a marked difference now in the response than before.

So I am calm, I have no problems or any personality issues either.

 

[Blazerfrazer]

Yes, i don't think the graph is that accurate, as the car did feel better with 4 diodes, but i am thinking that the reason could be because the part of the trac now in use ( the bit after 2mm) might have a shallower curve on it? poss, i dont know. at one point ( dont laugh ) i considered scraping some of the outer edges of the track to raise the resistance at the start... lol but i am sure it wouldn't work and i would damage the pedal!!

but the engine needs to be under a slight load such as you would get some loading on the engine when trying to balance the car around a biting point.

Hi, i must make this clear, the problem i have is WITHOUT load.... the problem is the revs before the clutch comes up. i need to calm it down with free reving of the engine, the way i show the the biting point for the first time is "Press the clutch all the way down, set the gas a little, then slowly, very slowly rase the clutch pedal. This is where the problem is BEFOER the bite is found... they either find the bite with no revs and stall it or rev it right up 5000. Frazer

 

[MSG2]

Yes, i don't think the graph is that accurate, as the car did feel better with 4 diodes, but i am thinking that the reason could be because the part of the trac now in use ( the bit after 2mm) might have a shallower curve on it? poss, i dont know. at one point ( dont laugh ) i considered scraping some of the outer edges of the track to raise the resistance at the start... lol but i am sure it wouldn't work and i would damage the pedal!!

you seem to really know what you are doing, but my advise is not to tamper with the actual layer of those resistive tracks, and yes of course the resitive track can be a log scale as opposed to a linear.

Overall, the best solution would be the one that achieves a performance as per the bottom graph, which according to me can be achieved through ecu remap itself. and who does it or who could do it I don't know.

 

[richj]

I get these as the default values:

travel (mm) v1 v2
0 - 0.38 - 4.5
1 - 0.97 - 3.92
2 - 1.55 - 3.32
3 - 2.15 - 2.73
4 - 2.73 - 2.15
5 - 3.32 - 1.55
6 - 3.92 - 0.97
7 - 4.5 - 0.38

and these as the required values:

0 - 0.38 - 4.5
1 - 0.65 - 4.23
2 - 0.92 - 3.96
3 - 1.19 - 3.69
4 - 1.46 - 3.42
5 - 1.73 - 3.15
6 - 2.2 - 2.68
7 - 2.25 - 2.63


are these correct?

 

[Blazerfrazer]

Hi Rich, i think so?!?? Boys? is the 1-7 representing full travel up and down or mm? not sure i understand.
Frazer

 

[MSG2]

I can't tell if the values you have come up with correct, basically if you look at the V1 voltages for now, what you need is a very slow increas in the value from the minimum 0.38V and all the way up to 4.5, that is the ideal solution, so if I may state what i think the values should look like going up exponetially.

1 0.38
2 0.50
3 0.75
4 1.25
5 2.00
6 3.00
7 4.50

these are just suggestive figures for demonstarting the required effect from the pedal and not actual or calculated figures, and they are there to show how the pedal needs to slowly increase the voltage for the first few mm of travel and then after it has travelled half way its scale the engine can then reach its peak designed revs.

 

[Blazerfrazer]

I have a bit more time to have a play, then i must put it back and try to reset the engine light as i have a test on Monday in Dorchester

 

[richj]

blazerboy - the values 0 -7 are mm taken from the graphs you produced. I don't know what the full travel is in mm so I used 7 from the graphs.


These values emulate
0/7 down 7/7 up
1/7 down 6/7 up : 0.5/7 down 6.5/7 up
2/7 down 5/7 up : 1/7 down 6/7 up etc...
3/7 down 4/7 up
4/7 down 3/7 up
5/7 down 2/7 up
6/7 down 1/7 up
7/7 down 0/7 up

They are calculated using the specification documented in the link i posted.

Appologies for the poor table - the forum removed the spaces.

For the modification to work properly, those are the required values (unless I made a mistake in my calculations which I may have done).

so 2 mm of pedal travel will have the throttle result of 1mm of travel (as per the first post..)