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 Post subject: Re: Reduce pedal travel?
PostPosted: June 18, 2016, 9:07 pm 
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Joined: October 13, 2011, 9:19 am
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Location: Denver Co
So now that I have the car back, I measured the throttle pedal travel and it's at 6". That's way too much!

I am going to machine up a pulley to cut the pedal trave in half or more too see how it feels before making an eccentric one.

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 Post subject: Re: Reduce pedal travel?
PostPosted: June 19, 2016, 12:02 am 
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Joined: August 27, 2005, 1:04 am
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Location: Kamloops, BC, Canada
I made a progressive one for my car from 3 layers of aluminum sheet that I cut out with a jig saw. The middle piece was a bit smaller than the two outer ones so the cable had somewhere to sit. The whole works was held together by two bolts that also held it on the carb linkage. I never did take any pictures of it though.
Kristian

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 Post subject: Re: Reduce pedal travel?
PostPosted: June 29, 2016, 1:14 pm 
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ok so someone stop me if i am wrong. I calculated that if i needed half the pedal travel I need half the arc length (cable pull length). See below. Seem right? For the eccentric pulley, I would want the arc between the full and half size pulleys while maintaining the arch length or cable pull length.


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 Post subject: Re: Reduce pedal travel?
PostPosted: June 30, 2016, 1:36 am 
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Makes sense to me, although when I did my progressive one I used a decreasing radius curve instead of a constant radius that was just offset. Think of it as a section of a spiral. Keep in mind I'm no engineer though.
Kristian

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 Post subject: Re: Reduce pedal travel?
PostPosted: June 30, 2016, 8:10 am 
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turbo_bird wrote:
Makes sense to me, although when I did my progressive one I used a decreasing radius curve instead of a constant radius that was just offset. Think of it as a section of a spiral. Keep in mind I'm no engineer though.
Kristian


i will look into that but i think my eccentric version will be much easier to make. I actually already made the above configuration but i forgot to take pics of it yesterday. here is a pic of the model. I will snap some pics tonight.


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 Post subject: Re: Reduce pedal travel?
PostPosted: June 30, 2016, 10:28 pm 
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If you're making the wheel on a lathe it definitely would be easier to have a constant curve. I didn't have access to a lathe, so I cut the pulley out of aluminum with a jig saw and did the rest with a hacksaw and file.
Kristian

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 Post subject: Re: Reduce pedal travel?
PostPosted: July 1, 2016, 9:43 am 
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Joined: March 30, 2011, 7:18 am
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Location: central Arkansas
> 6"

Most cars, it's closer to 3". Some late models are as little as 2". That's *effective* travel, not the slack and do-nothing at each end.

Too much travel and you have to relocate your foot if you need full travel. Too little and it's hard to control RPM, particularly on a rough road. The cam or snail type cable throttles work really well for that sort of thing; you need the most sensititivity at low throttle settings, but for most cases you can go from 50% to 100% throttle without needing much modulation.

Don't forget that there should be some slack between the butterfly and the pedal when the pedal is all the way down. You don't want the butterfly to be the throttle stop.

[you've been through all this already, I'm just rambling]


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 Post subject: Re: Reduce pedal travel?
PostPosted: July 1, 2016, 9:56 am 
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Joined: October 13, 2011, 9:19 am
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The adapter i made works perfect. I wasn't able to test it on a working engine but the i was able to hook everything up and test the pedal travel and movement.

i know someone is going to comment about that throttle cable angle... its straight.. dont ask me why the pic looks like that.


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