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Old 8th January 2011, 20:35   #16
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Default Re: Accelerator (pedal travel ) meter

Uh oh... the kind of things you can make a rheostat do for you!! Genius!

But I'm curious - if the last 1/3 of pedal travel is pretty much useless and just increases fuel consumption, why not put in a little adjustment bolt there under the accelerator pedal, to prevent the pedal from being depressed so far (say the last 1/4th of pedal travel)? Like the old-time "jugaad" that Ambys and Fiats used to come with, for the running-in period?

I wonder if you could hook up a rheostat (or two), to indicate the gear you are slotted into? In the heat of the moment, slotting into 3rd instead of 1st, or 2nd instead of 4th, could be quite detrimental to both engine and transmission...
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Old 8th January 2011, 21:47   #17
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Default Re: Accelerator (pedal travel ) meter

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Originally Posted by SS-Traveller View Post
Uh oh... the kind of things you can make a rheostat do for you!! Genius!

But I'm curious - if the last 1/3 of pedal travel is pretty much useless and just increases fuel consumption, why not put in a little adjustment bolt there under the accelerator pedal, to prevent the pedal from being depressed so far (say the last 1/4th of pedal travel)? Like the old-time "jugaad" that Ambys and Fiats used to come with, for the running-in period?
yes I did this for the 540 way back , I placed another gundi( a cable end used in two wheelers which has a skrew on top ,remember the old scooter clutch /gear inner ? ) I used to lock the last 20% of the pedal travel , It helped me to get the vehicle pass the PUC test , which was not otherwise possible .

Quote:
I wonder if you could hook up a rheostat (or two), to indicate the gear you are slotted into? In the heat of the moment, slotting into 3rd instead of 1st, or 2nd instead of 4th, could be quite detrimental to both engine and transmission...
Oh come on you dont belive that do you ? But its true ,I floored the pedal quite often .

Anyways , let me explain your 1st Q as to blocking pedal travel or doing it on dist.pump
The service shops ( who adjust/overhaul the distributer pump) do that on their machine according to the deta they have of a particular engine ( BMC,Peugot,etc ) So they adjust the pumps pressure, volume, Auto advance etc . But most importantly Idle & max RPM is set on 'their ' machine ( A lathe like jig/fixture, you see ) & not on the vehicle ( our )

Now many times I had to adjust the Idle even after they set it .Suppose standard 2112 peugeot idle rpm is say 700 +/- 20 , it is set on their test bench ,so one needs to adjust that according to vehicle condition (wear etc ) I do it by using a non contact RPM meter .This depends on adv/ret timing too.

Now about max RPM , again its set at the shop ( in ref to ideal engine condition & rpm ) . In practice your engine may not need the volume or simply cannot take it because of its mechanical wear/conditions /lack of compression etc.

That is the reason why I say that the last 1/4 ( as shown on my meter ) is useless & waste of fuel . In theory I am totally wrong BUT in practice I hold to be correct

I have tried so many things on the landy regarding the pump timing (advance /retard ) volume , nosel pressure etc because its my vehicle (Totally ) ,the 540 was owned by Dad so I had limitations on experiments till lately ( now he is 80 & I dont listen to him anymore ) so now I am gona try few things on Jeep too

hope you understand ( thease doubts make me feel better as I start to remember so many things which I almost fogot )

its all potatos & tomatos in my head ( remember ?) since last 12 years , now BHP has put me on track

Sudarshan

PS thanks for Compliments

Last edited by Sudarshan : 8th January 2011 at 21:54.
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Old 8th January 2011, 22:33   #18
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Default Re: Accelerator (pedal travel ) meter

thhere is another issue I tried to incrporate it the last post ( via edit ) but failed .
@ SS traveller
There is one more thing , you may have observed that there are tamper proof seals on distributor pump done by the service guys .Particularly You can find that the Max rpm setting skrew is sealed after their own setting is done . Every pump service shop has their own marking/punchings(date) on thease seals .

Now if you try & adjust anything (including max rpm ) by breaking their seals ,their warrenty becomes void . its usually 6 months ( varies according to dealer ) . In my case I used to go to one particular guy/shop ,so next time if he finds his seals broken ,he treats the pump as tamperd /fouled & that reflects in charges & results in unnecessary Q&A with him .

thats the reason why I or you shouldn't do any adjustment on pumps .

this is OT please bear with me.
I used to take the Landy pump ( cav ) to an elderly person ,with whom I had a good repo developed , I tried to learn few things but found it to be a very specialised job which needs some special tooling & test beds . But I did learn few things which were easy & practical ,can be a subject of another thread though

Sudarshan
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Old 8th January 2011, 22:39   #19
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Default Re: Accelerator (pedal travel ) meter

Sudarshan JEE , you continue to impress me. Kudos!

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Old 8th January 2011, 22:40   #20
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Default Re: Accelerator (pedal travel ) meter

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Originally Posted by Sudarshan View Post
...I or you shouldn't do any adjustment on pumps .
I totally agree. Been through the diesel pump and injector calibration equipment and training many years ago, just for the heck of it. Without the test bench, fiddling around with the pump settings is like handing a kid a box of matches - you don't know when something will catch fire.
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Old 13th January 2011, 11:46   #21
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Default Re: Accelerator (pedal travel ) meter

Hi Sudarshan,

Interesting little rig you've got there.

However, if its basically measuring real-time fuel efficiency that you are after, i think a better (and still fairly low-tech) way of doing it would be by measuring the vacuum in the intake manifold!

A lot of older cars used straight-forward pressure gauges to monitor manifold pressure while driving. If the manifold pressure is ___, that means you are using less fuel, and the gauge points to green, if its ___ the gauge points towards red.

This is still an approximation, but its much more accurate than just "throttle position" in my opinion. Do consider it.

Regards,
R

PS - Its this manifold vacuum that also powers the brake booster / "power brake"! Very convenient, since when you're braking you take your foot off the throttle - and that causes a higher manifold vacuum = more power for the booster!
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Old 13th January 2011, 12:04   #22
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Default Re: Accelerator (pedal travel ) meter

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...measuring the vacuum in the intake manifold!
Vacuum meter won't work for a diesel, where the intake manifold is not controlled by a butterfly valve.
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Old 13th January 2011, 14:56   #23
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Default Re: Accelerator (pedal travel ) meter

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Originally Posted by Rehaan View Post

However, if its basically measuring real-time fuel efficiency that you are after,
Yes ,correct

Quote:
A lot of older cars used straight-forward pressure gauges to monitor manifold pressure while driving. If the manifold pressure is ___, that means you are using less fuel, and the gauge points to green, if its ___ the gauge points towards red.
I have seen that in my friends old Fiats/Ambys .I remember it was connected after butterfly ( towards manifold )

Quote:
PS - Its this manifold vacuum that also powers the brake booster / "power brake"! Very convenient, since when you're braking you take your foot off the throttle - and that causes a higher manifold vacuum = more power for the booster!
It was in my first Landy ( series 3 ) the acceleration was through pump lever only ( not vacuum controlled diesel delivery ) but there was a butterfly valve linked to the accelerator pedal which controlled it & created more vacuum when the pedal was let off ( as you have said ).That adjustment was critical & people have damaged their heads ( If the valve closed earlier / or accidentally due to linkage failure )

But now there is no such thing in this ( its a series 2a ) so now I will have to locate a position & tap for it .

anyways thanks for compliments .

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Vacuum meter won't work for a diesel, where the intake manifold is not controlled by a butterfly valve.
I also feel so but need to think how to apply this

Sudarshan
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Old 16th January 2011, 12:42   #24
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Default Re: Accelerator (pedal travel ) meter

Interesting DIY sir,

I've had the same requirement in the older cars of mine,

I have used my uncle's petrol amby 1489cc, that had a vacuum gauge to show the same data. If we manage to keep the gauge in the green zone, we'd get 12+ kpl!!!

Cheers
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Old 20th July 2011, 08:53   #25
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Talking Re: Accelerator (pedal travel ) meter

Update ;

I have recently fitted a RPM meter to the Landy , I think mine is the only old 4x4 vehicle on 'BHP' having such feature

Have a look

Accelerator (pedal travel ) meter-dscn2785a.jpg

Sudarshan
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Old 20th July 2011, 09:30   #26
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Default Re: Accelerator (pedal travel ) meter

You never cease to amaze me!

Nice DIY. I liked the way you used the variable resistor to measure throttle position. I liked the DIY battery disconnect switch of your Landy too.
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Old 22nd July 2011, 11:47   #27
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Default Re: Accelerator (pedal travel ) meter

Update ;

Finished re calibrating the meter with the help of a non contact RPM meter ; checked the RPM at crank pulley & marked on the sticker pasted on the dial . Now hoping to find a good mileage spot with -- RPM > actual throttle position > road speed

have a look

Accelerator (pedal travel ) meter-dscn2795a.jpg

Sudarshan
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Old 22nd July 2011, 12:18   #28
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Default Re: Accelerator (pedal travel ) meter

What is the sweet spot for your engine? Is the mark showing the same?

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Old 22nd July 2011, 12:29   #29
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Default Re: Accelerator (pedal travel ) meter

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What is the sweet spot for your engine?
Actually this will need some trials ( & errors ) I think I will be able to perfectly locate it, say after a 1000 km of mixed run

Quote:
Is the mark showing the same?

Spike
Nope ; this mark is for reference , this indicates the area around 1800 rpm ( which indicates max torque ,according to manufacturer ie 1750 or 1800 rpm )

I am yet to find a torque / bhp curve for this engine ,if anyone ( particularly Jeepster ) finds it will be rewarded accordingly

Sudarshan
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Old 10th August 2011, 16:31   #30
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Originally Posted by SPIKE ARRESTOR View Post
What is the sweet spot for your engine? Is the mark showing the same?

Spike
Update ;

haven't found a 'torque / bhp ' graph yet

had a brief trial --Findings

On highway

In 4 th ( top ) gear ,at 1/3 rd accelerator , engine rpm was 2200 & road speed 65 kmph approx ( the speedo is not calibrated- so may not be accurate )--- vehicle ran smoothly

After this spot any increase in accelerator didn't give much ( significant ) gain in rpm ( & road speed ) . compared to the first 1/3 rd of accelerator travel.

I think this is the sweet spot I was looking for .


On Internal winding roads & steep hill climbs-- the range of 2000 to 2500 rpm in any gear was found to be comfortable WRT engine temperature , maintaining momentum & road behaviour, roll ,cornering etc ( not so fast or slow to handle )

Sudarshan

Last edited by Sudarshan : 10th August 2011 at 16:56.
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