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Engine Specific Info and Questions => IDI Engine => Topic started by: ejust on March 23, 2005, 09:52:54 am
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ive been reading preivous posts on this govenor (spring rate) mod. Question i have is how bad does it affect fuel milage. i would like more driveability, not if its gonna kill my milage. At @2.39/gal (US), i cant afford sacrifing too much. And does anyone have pics of this mod by chance??
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Try this thread[/u] (http://www.vwdiesel.net/phpBB/viewtopic.php?t=579).
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Will this work on N/A engines?
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I haven't really been able to ascertain what exactly the goal is of the governor mod? What are we trying to do within the pump?
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the govenor start tapering off fuel at about 3500 rpm iirc. by modding it you are able to get full fueling up to redline then it starts to taper it off then. or just remove it and rev to 6000+ rpm. and hp is toque x rpm/5252 so therefore you are able to get more power.
hope this helps
Mark
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the govenor start tapering off fuel at about 3500 rpm iirc. by modding it you are able to get full fueling up to redline then it starts to taper it off then. or just remove it and rev to 6000+ rpm. and hp is toque x rpm/5252 so therefore you are able to get more power.
hope this helps
Mark
Ok, how does the governor work exactly? What are we doing by increasing spring tension?
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increase tension makes it withstand more, so the governor doesnt kick in until higher rpm's :D
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there are lttle flywieghts in the pump...the faster the engine turns the more pressure it puts on the springs and when they start to move it decreases the fuel. becasue it works like this it cant just cut out the fuel all at once, so to have it cut out at where it does it starts tapering it off way earlier. so by shimming the spring you basically increase the amount of force it takes to start moving the spring, so it take a higher rpm before it takes away the fuel. if you are going to try this i recomend you find an old scrap pump and take it apart to see how it works, so you dont screw up your good one.
good luck
Mark
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yes, it will work an all rotary pumps.
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I'll have to take a bit closer look. I have several pumps. I just like to have a clear understanding of how everything works. I not only want to know what the mods are, but how and why they work. I find that the first step to improving any system is understanding how it works in the first place. :wink:
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if i find the time, ill go mod one tonite and post a pic by pic explanation on how to do it.
as far as how it works, basically what u are doing when u push on the gas, is pull a spring. at lower rpm's that spring just acts as a conector hooking the throttle are to the actual internal linkage. there are flyweights pushing a rod at the linkage. when the engine speeds up the flyweights push out harder and harder till the rod's force will overcome the spring tension. once this happens the rod starts moving the throttle linkage back farther and farther untill it's not putting out enough fuel to turn the motor any faster, another way to move the linkage back is to take your foot off the gas. anyway, because this all relys on centrifugal force, it happens in a linear motion due to rpm. so in oreder for it to take away all the fuel so it only revs to 4800 rpm, it has to strat cutting it out at 3500 rpm.
anyone correct me if i'm wrong, but i think i got it.
hope this helps
Mark
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So what would be the disadvantage of making the internal linkage peice solid (like welding it all together or machining a replacement)?
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So, I've been doing some searching and reading and I see tha Jake says it would cause some issues with the LDA to have a solid linkage. One of the other things was the an old thread on here about the governor mods and travel of the timing advance plunger. It was noted that the 1.5 had a more aggressive advance, so why not use the 1.5 spring in the 1.6 pump?
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im not too sure of what would happen if it were all one peice, but all i can say is don't try it. anyway now your talking about a whole different spring with the timing advance. you can use the 1.5 spring in it i guess, but im not too sure of how much better it would be.
i didnt have time to take a pump apart, but i found these pics.
(http://i2.photobucket.com/albums/y46/heizler_99/govenor.jpg)
basically, this is how the govenor works except the spring at the top, the one we are concerned about, is a little different.
(http://i2.photobucket.com/albums/y46/heizler_99/govenor2.jpg)
this is a pic of how the spring you have looks like. what you want to do is shim the main spring or replace it with something solid.
here are some pics of the springs and the pump i have.
http://www.cardomain.com/memberpage/418501/3
Mark
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hmm...so I guess our goal with all of this is just to raise spring pressure so that the counterweights that swing out due to centrifugal force cannot push the metering pin (of sorts) back toward the lever which is controlled through the throttle shaft. I'll have to go play with my pumps tomorrow. :D
Thank you for the explanation!
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had ago myself from a previous thread by DVST8R , sorry don't know how to put a link to this topic. My engine is a 1.6td in a 1989 Jetta which I have for spares, thought I would give it ago , nothing to loose. The engine runs fine and revs freely, unfortunatly the car is not road worthy so a full test cannot be carried out. I will have to wait until I fit the engine to my caddy. Here are a few pics I took whilst doing the job.
http://homepage.mac.com/keithsasha/
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Has anyone had an issue with the pump lid sealing back on top of the pump? I haven't attempted this mod, I was just curious if it was a concern.
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it shouldn't be a problem the top has a square section 'o' ring fitted and if you are careful should go back together ok. the seal is very cheep to buy if you wanted to replace it.
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So let me get this strait.....
You want to shim up the MAIN spring ONLY? (or is there others to shim?)
What would shimming it up do such that it only has half the compression travel it used to have do for drivability??? (ie - spring can compress 1" (2.54cm) and you shim it so that its precompressed down to a 1/2" (1.27cm) already) <--would that be adequate????
Also, does anyone thats done this mod have any idea of its side effects like fuel milage, drivability, long term effects, etc...??
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ejust, the governor mod raises the rpm at which the governor begins to cut off fuel, so will not by itself affect low rpm performance at all.
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Has anyone had an issue with the pump lid sealing back on top of the pump? I haven't attempted this mod, I was just curious if it was a concern.
I would be concerned about disturbing and then relying on a 20+ year old seal. That's why I would recommend buying a bosch pump rebuild kit, which contains all the seals, gaskets, and o-rings, and are available cheap (like around $20). Then whatever seal you touch when working inside the pump, replace. All the rubber parts, including those governor lid seals and also any o-rings (like the throttle input shaft o-ring, and the full load adjust screw o-ring) can get quite flattened and loose their resilience over 20+ years.
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Has anyone had an issue with the pump lid sealing back on top of the pump? I haven't attempted this mod, I was just curious if it was a concern.
I would be concerned about disturbing and then relying on a 20+ year old seal. That's why I would recommend buying a bosch pump rebuild kit, which contains all the seals, gaskets, and o-rings, and are available cheap (like around $20). Then whatever seal you touch when working inside the pump, replace. All the rubber parts, including those governor lid seals and also any o-rings (like the throttle input shaft o-ring, and the full load adjust screw o-ring) can get quite flattened and loose their resilience over 20+ years.
Nobody here(Winnipeg) will sell a kit like that: you have any leads in your neck of the woods?
N.
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Buried in the archives somewhere, I have posted this... ah yeah here it is: http://www.vwdiesel.net/phpBB/viewtopic.php?t=39
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Buried in the archives somewhere, I have posted this... ah yeah here it is: http://www.vwdiesel.net/phpBB/viewtopic.php?t=39
Much obliged!! 8) 8) 8)