Go with Hall or VR?

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MadMax78
MegaSquirt Newbie
Posts: 27
Joined: Sat Jun 27, 2009 9:06 am

Go with Hall or VR?

Post by MadMax78 »

Hi Guys,

I'm in the process of installing a MegaSquirt system in my 78 VW Bus. The stock aircooled engine has a point based triggering system. However, for the 79 Californian models VW used different dizzies, these are electronic ignition units and they use a hall sensor. See image below:

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Now I'm a bit hesitant on what system to go with. Originally I planned to use a VR sensor with a 36-1 trigger wheel. I actually already got the sensor and trigger wheel, trigger wheel just needs machining to make it fit. Problem with this VR setup is that it will be way harder to service. Basically when it is installed there is no way to get to the sensor. So if it fails I need to drop the engine and it would take hours of work to get to it after I dropped the engine. Needless to say it will also be a whole lot more complicated to install. Advantage would be that I could maybe some day install EDIS which I already got lying around also.

Advantage of the Hall dizzy would be a very easy installation and easy to get to for maintenance. Also it will be less prone to contamination since it is inside the dizzy.

What to do, what to do? Which way would you go? Which one is easier to set up with MS? Is there a difference in spark accuracy? Which system is more reliable?
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PSIG
Helpful Squirter
Posts: 69
Joined: Fri Jun 11, 2004 11:02 pm
Location: Seattle, WA area

Re: Go with Hall or VR?

Post by PSIG »

Both systems are reliable. The crank-triggered setup will be slightly more accurate due to less mechanical tolerance (slop), but more than adequate for most purposes, if your parts are not worn excessively. Personally, I would plug-in the dizzy and get it running well, and save the extra EDIS work for when and if you really want it.
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David
-=If it was easy, everyone would do it.=-
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MadMax78
MegaSquirt Newbie
Posts: 27
Joined: Sat Jun 27, 2009 9:06 am

Re: Go with Hall or VR?

Post by MadMax78 »

Thanks for the opinion. I just bought the dizzy. If the dizzy has little wear I think I'll go that route. That'll save me a lot of work, that's for sure. :)
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