TheSamba.com :: View topic - "New" Kind of Throttle for your Rail..Hydraulic?

Mon Aug 24, 2009 9:49 pm

I was checking out another post, when this gent was asking about a hydraulic throttle... Hmmm.

Hydraulic throttle? I haven't heard of that. Is it like a brake pedal? Is it like a Hydraulic clutch.... is the actuation swift or is it slow and thick? Can you use a clutch type master and slave, and put the slave actuator arm on a v shaped pivot, where the slave attaches to the short leg of the v, and the other end of the v is longer.... this attaches to the pivot point on the hex bar to your dual carbs... if even with a short cable that cannot be caught up in debris or any kind of obstruction. As I am typing this.... it sounds very doable and like a very good idea..... has anyone done this?

I hope that the above simple explanation is understandable enough. I am seriously thinking about trying this and would like some criticism... or advice.... or suggestions. I think I ruined a good set of heads because of my engine racing away with me recently from a stuck cable. I have heard of the push pull morse style and the open cable and pulley style, and the cable inside of a plastic sleeve, and one in a soft metal sleeve like a brake line. And the problems are lubrication... and sand sticking from using lubrication... kinked lines, and debris. So a better mousetrap is definitely in order... we have all seen each of these types work... and fail.. there is always the exception (some folks never have a problem). lol.... so what do ya think about this hydraulic type? Don't feel stupid.. just throw it out there... I really want your ideas.

I have just discovered that their is a hydraulic throttle somewhere out there... ever heard of it?

Thanks,
Travis

Mon Aug 24, 2009 10:08 pm

Just thinking out loud...

If the bore of the master and slave are different, you'd run into a situation where you'd make the pedal too sensitive (ie: large master fills/actuates a small slave faster - increased throttle movement); or too sluggish (ie: small master moves less fluid to slave - reduces movement of throttle).

I'd also imagine you'd need a hefty return spring to close the throttle, since you'd have to push all the fluid back to the master at the front of the car.

Hydraulics are a force multiplier... if the linkage does not account for the full movement of the slave, you may damage/break the carburetor at wide open throttle since it applies much more force than a cable will. The slave would attempt to open the carb further than the butterfly can physically rotate.

Thoughts?...

Tue Aug 25, 2009 1:28 am

I was imagining your typical hydraulic clutch system as a model... since that is all that I have experience with. .... coming off of the "Y" shaped cam/fulcrum point with the downstream leg being longer, it would multiply or exaggerate the short movement of the slave piston to give a long enough stroke or draw length....also, at this point, I would try possibly a twelve inch piece of cable to the final connection, instead of solid hydraulic all the way through. Maybe some modification to the size of the holes where the fluid returns to the master cylinder... making it larger so that there would be less resistance to flow, and leave the valving alone. I can see in my mind the clutch slave working back and forth... although it moves in a too small amount, putting it on the "Y" shaped cam would overcome the travel limitation of the slave cylinder... (of course you would have to adjust for limiting its action on the crossbar to the carbs.) I would have to figure out how to push the fluid back home though...(At the slave) Not at the carbs or linkage bar. The linkage would be left alone... I don't think it would be a good idea to mess with it any further downstream.

So You/I /Us/ We lolz would need some sort of bracket to hold the Y, the slave cylinder, and a place for the "spring" to return the piston back to its "short" position. Maybe something like what we are already used to seeing on the side of the transmission already... I am only using that for a refference point for showing that it can be done as far as a complete assembly, but from that point ....exactly how it is on your trans, add the "Y" shaped cam to exagerate the piston movement, and then add a short length of cable to finish it up, I may even figure out some way to "Purge" the pressure in case of emergency and the pressure won't disengage, or some kind of quick release on the short piece of cable..... that would be my fear, is if the slave went bad. and stuck it the extended/full throttle position.... (Depending on the setup, you could have it push or pull the cam to goto WOT of course).

I can really see some trouble free operation here though. I imagine it being very reliable.... although, I know nothing about hydraulics. I do get the principal. I really see this as something that can be accomplished as an alternative to what is already out there.

Tue Aug 25, 2009 7:05 am

Nothing can be simpler and more effective than a simple wire...

Hydraulic and Morse cable (though good concept) are complication multipliers.....

A simple wire run through a few "guides" is almost foolproof and easiest to repair under worst conditions....

If your are seriously off roading you should carry a spare throttle cable and clutch cable and enough basic tools to replace them...

I doubt seriously if you have a broken hydraulic throttle you are going to be able to repair it in the field, and of course the break down will be 10 miles from nearest rescue (tow or run to autoparts) vehicle....

Dale

Tue Aug 25, 2009 8:50 am

I understand your statement dale... I suppose in a pinch, a person could tie their shoelaces together and connect it to the twelve inch piece of cable and pull their ass home with it. lol. But, I have seen people complain about the single cable and pulley systems too with sticks and weeds getting caught in the pulleys... That is why I am trying to see if this will come together as something feasible as an alternative. Of course, a person can use that in their buggy.(The cable and pulley type) I only want to offer an alternative that should be reliable. (with no real load on the hydraulics, other than the return spring, it should last as long as natural deterioration from weather/cold, hot, and UV will allow. Maybe there is a reason that people don't have them in their rides. Maybe it doesn't work well. I don't know. I only want to give everyone an option. Plus for me, it will be fun to try to make it work and see how it turns out. Maybe, for those that have top of the line fancy this and that.....Maybe it will only be for that person. Maybe for the person that thinks that morse cables suck and for some reason can't use the pulley system.... I was just thinking about it, and thought hey, this could work, I wonder why no one has it. I haven't seen it for sale anywhere, but I did see a post where someone bought one off of ebay. So, I suppose that you can buy them somewhere..... But I would love to make one with my hands and see how it works out. With the present systems that are out there though. I will use a straight cable and pulley system till I can get this worked out... right now I have a sleeved cable, and it is sticking, periodically.

Tue Aug 25, 2009 9:05 am

Do not mistake the word "guides" in my statement for pulleys.... Pulleys jam, they go beyond KISS principle...

Guides are simply a 1 inch piece of tubing to controls cable route from accelerator pedal to carb... If you cant keep a 1 inch length of tube clear, or cleaned it out with stick from along side of trail, you are in wrong sport....

If you go beyond KISS ( Keep It Simple Stupid) you are setting your self form more problems than fun out on trail....

If you don't like the simple wire concept, then use MORSE cable.....

I have twice had throttle cable fail on me in buggies, I have been able to pull cable out of tube and reattach cable at carb (thanks to Swiss Army Knife) , thread other end between body lip and pan and into drivers area and was able to pull throttle with left hand while steering and shifting with right hand.... Not best concept, but it got buggies home so they were not left beside road.... Do that with hydraulic system....

Dale

Tue Aug 25, 2009 11:53 am

Innovative, but a terrible idea. The force needed to overcome the linkage spring is minimal at worst. Also, as someone said, you have to overcome the reverse force pressure to bring the engine back to idle, something that would require a heavy spring (And about 10 more factors that can cause the throttle to stick wide open).

A question:

Why??

Tue Aug 25, 2009 12:28 pm

They are hardly new.

I had one 20+ years ago on a mid engine sandrail.
Hated it.
Way too sensitive and as Dale pointed out hard to field fix.
All racing sanctioning bodies I know of have rules against those setups.
Probably for good reason.

Morse cables are the shnitz.
Sinple, sealed and rarely ever hear of one breaking.
If it does it's usually an end that is easy to field change.

Tue Aug 25, 2009 1:45 pm

tundrawolf wrote: Innovative, but a terrible idea. The force needed to overcome the linkage spring is minimal at worst. Also, as someone said, you have to overcome the reverse force pressure to bring the engine back to idle, something that would require a heavy spring (And about 10 more factors that can cause the throttle to stick wide open).

A question:

Why??

The cylinders are different than a brake or clutch setup, since the pressure doesn't need to be nearly as high. My setup used a 1 to 1 ratio. 2 to 1 ratios are available as well.
I used the original return spring with no issues. There is not really any friction in the system to overcome, just the weight of the gas pedal itself.
I love it. Never gets jammed with sand. Plus one can move the pedals back and forth without having to readjust the throttle cable. :)

Tue Aug 25, 2009 9:07 pm

I am ok with someone saying bad idea, I asked for that... note the pole at the top of the page. I don't do this for sport. I do it for fun. I wanted a motorcycle, but the wife talked me out of having a bike like when I was young.That's why I now have a buggy, it has all of the open feeling and the safety of a full cage and harness around me and a passenger. Also, lets not forget the coolness factor, I am a freakin celebrity when I drive my vw... I swear, and last, when I was a teen, my best friend that lived next door had a cherry red Gia for his first car. (This 1835 served and lugged my ass for many years coming up. Now, I have my rail and am teaching my children how to be as passionate as I am about a vw.

Sorry for mistaking guide for pulley, the pulley and the tubing style and the morse are the only styles that I am familiar with. As stated before, I have heard someone say that they have bought one off of eBay (hydraulic)... I have never seen one. So, I do what I do know how to do..... I ask the members of this great forum.... and with the knowledgeable masses at hand available to me/us here... I get years of hands on experience that you cannot get from a book and very candid responses. The only thing that is asked in these forums is that we all keep our class and tact. I believe so far.... that we all are, and would like to keep it that way..... No question is a bad question. Although, this may be a bad idea.

Quote: The cylinders are different than a brake or clutch setup, since the pressure doesn't need to be nearly as high. My setup used a 1 to 1 ratio. 2 to 1 ratios are available as well.
I used the original return spring with no issues. There is not really any friction in the system to overcome, just the weight of the gas pedal itself.
I love it. Never gets jammed with sand. Plus one can move the pedals back and forth without having to readjust the throttle cable. :)

So this gentleman likes the system. I do notice that he said "used" like he no longer has the system or the vehicle. I would love to hear where I can buy it. I would like to compare it to mine... I have metal brake line sleeves that my cable runs through, and am looking for alternatives. Maybe I can cut allot of the tubing out of it and only have it at the points where the cable changes direction.... I believe that is what Dale is suggesting to use.... unless I am mistaken. I had kinked the end of the tubing where it ends at the pedal and caused it to bind at full throttle. I think that I have damaged a set of heads now. I just bought a leak down tester to check it all out. if anyone knows where to get the throttle type of hydraulics let me know please... I would like to at least price it and see how the setup looks....

As far as the voting goes..... BAD IDEA........ LMAO.

OH Well...

If I thought it was the greatest thing I wouldn't have put the poll there. Thanks for voting guys. !

Tue Aug 25, 2009 9:18 pm

Looks to me like the poll at the top says that the hydrolic throttle has little following. It is hardly a new concept, but why mess with a tried and true reliable system that is simple and easy to fix. Dale Is right. Why mess with something so easy. There are plenty of ways to things, just some work better than others over the long haul.

Tue Aug 25, 2009 9:32 pm

Well... the damage to my heads is why... in part. lol. "Why" seems to be a popular topic. Sigh, I guess other than my heads being possibly damaged and almost sh*tting myself when it happened. If you knew me in the real world, you wouldn't have to ask. I am just that type of person that tinkers and tries different things.

I also, not too long ago received shipment of my 2276 stroker longblock and I don't want to mess it up... You know how much money that is without me even saying.... so, added all together, that is the reason for the question.... when I saw another member in a different thread asking about a hydraulic throttle website... it just got me to thinking is all..... That is all it took to get me in the groove for information gathering like this. That about sums it up. It isn't an invention of mine or anything that I am trying to patent. He He...

No way. It just initially sounded easy and reliable. So I wanted to ask around about the pros and cons as a 3rd or 4th option to what we typically use.

Tue Aug 25, 2009 10:22 pm

TravisChattin wrote: I wanted a motorcycle, but the wife talked me out of having a bike like when I was young.That's why I now have a buggy, it has all of the open feeling and the safety of a full cage and harness around me and a passenger.

You CAN have a full harness, a full safety cage around you and your passenger both on a motorcycle. It'll just look funny. You'll be a celebrity for the wrong reasons, then. :P

Wed Aug 26, 2009 8:16 am

I recently sold the sandrail because I upgraded to a baja with a 2.3 turbo.

The baja has been eating transaxles so I haven't had a chance to worry about upgrading the throttle system (currently a piece of copper tube and a thin cable).

So I have used one, and liked it. Take that for what it's worth.

Wed Aug 26, 2009 9:08 am

Does anyone have photos of cable/wire setup with hexbar linkage?

Wed Aug 26, 2009 9:12 am

Quote: I had kinked the end of the tubing where it ends at the pedal and caused it to bind at full throttle. I think that I have damaged a set of heads now.

Very odd failure..... Generally what happens is "Z" bend breaks off end of cable and throttle usually goes to idle..... But as you say you kinked end of tube..... The fault is not with design but human intervention......

If you have trouble with simple system a more complex system (hydraulic) is going to drive you nutz............

A Morse cable is probably you best solution. But it has to be setup right, have free movement, wide turns and free pivoting anchor points... More complex than simple cable but less complicated than hydraulic....

Morse cables are widely used for controls in boating industry....

Dale

Wed Aug 26, 2009 9:15 am

Thunderbug4U wrote: Does anyone have photos of cable/wire setup with hexbar linkage?

Look at any VW motor with dual Webers or Dellorots....... Its the MOST COMMON system out there...

Dale

Wed Aug 26, 2009 2:55 pm

The cable and tubing system was set up from the PO. Some things that need improvement aren't noticeable to me until something happens because this is my first rail. It's not that I am having trouble with the simple system.... it is a sliding pedal assembly, and I had moved it back towards me, closer to the end of the tube and the final strap holding it down - which ended up being very close to the heel of my foot. I just didn't foresee the problem till it had happened. During all of the sliding and bouncing and jumping and whoops and berms....... I stomped the damned thing or something, still not quite sure what I did to bend it, but it was my foot that did it. (That, I am sure of) Just because I live in the south .... it doesn't make me stupid. Now that I know what the problem is, I know I have to do something about it. Because I ask questions doesn't make me stupid either. Intelligence and ignorance/inexperience are 2 different things... Intelligence is your God given ability to learn, and ignorance is experience based. I have never had that happen before and didn't foresee it in my future. So, I started asking. It is not that I cannot handle a simple system, it's not that I am in the wrong sport, it's not that I have any faults at all. ...................... . This post is based on opinions about throttle systems, Not about opinions of my ability or my intelligence. We all know, VWs are basic and easy, but experience rules here on The Samba. If people knew everything to know about these things, this site would have no use or purpose and you might as well be using Craigs list or Ebay. I do thank all that have answered my silly vw based questions and offered your opinions. It is YOUR humble opinions that have given me and those like me who keep these cars alive and breath life back into these wrecks the courage to take on such great tasks, like performing a complete restoration. I am so amazed at the skill, talent, time, and money invested. A VW isn't a car... to many of us, they are dreams that have finally matured and manifest before us...... and now people like me have the opportunity to actually own one and finally make that small boys dream a reality. I thank the creators of this site and all of the local club members that freely share their knowledge just because they have it to give. I seldom hear that anything asked on here is a stupid question. From what I have seen, there are no stupid questions.

But there are stupid actions. LOL.

Thank you Tampabay buggy club (Tampa, fl)
Thank you Five wide club (frostproof, fl)

Wed Aug 26, 2009 5:18 pm

Funny how bits of information leak out over time and many messages.... Sliding pedal assembly!....

You need Morse cable......

Dale

Wed Aug 26, 2009 7:33 pm

I'm going to respectfully disagree with all the "experts." I've had a hydraulic accelerator on my car for 19 years, and wouldn't take a cable of any kind if you paid me. I used to race the car at Glen Helen (sand drags) and never had a tech issue. Problems: after about three years, on one trip I had a zip tie holding the hydraulic hose to the frame break, allowing the plastic hydraulic hose to melt on the exhaust...My weekend was done. I replaces it with a steel braided line, and have NEVER had a problem since. Also, I used to do most of my duning at Glamis. One extremely hot Easter weekend (above 100 degrees) the fluid expanded in the system causing the car to idle high. I just turned the bleeder valve, relieved the pressure, and continued to dune on my merry way. It's cleaner, easier to route, and can be bracketed to fit at any angle. JMHO I'll send pics if you want..