I am replacing my ignition system and thinking about adding a VOES. I have an Ultima 113" that I have been running with a Crane hi 4 in race mode without a VOES. I recently took this motor off of a light rigid and put it on a heavy dresser. I have searched this here and find that some of you highly recommend running a VOES . I have also seen it said that a VOES is not recommended for a big inch high compression motor. I understand the advantages of the VOES . What would be the disadvantage ? Right now I am more concerned with long term reliability , low end torque and fuel mileage.
Looking for any and all opinions.
Thanks , Evan D.

 

if you read the ultima instructions for the ignition it says do not use the voes with there engines. running without a voes is safer than running with one less chance of detonation.

 

It's entirely down to what the ignition system is designed to work with. When I changed my stock module for a Crane, that was intended to be used with the VOES, but as Dg says, check your instructions! There may be no way of connecting a VOES up to it.

 

It sounds like you want ignition curves for both acceleration and gas milage. That means two different curves and the VOES gives you those two curves.

 

Running with might get some low end or roll on ping,

Running without might leave some performance and mpg on the table.

You could even run a switch on the VOES input and have the option on the fly, 'coarse idle speed will change.

Only one way to know if it will work for you, the VOES is adjustable too.

I thought the Ultima and Dyna ignitions were the same, after looking at the Ultima instructions, the curves are different, Ultima table is first.

My lower compression(9.7 with a 585 cam, 195psi CC)111 runs with the VOES and Dyna2000 on curve #4, hover around 40mpg.

 

Interesting! My 585 cam 107" with S&S IST ignition doesn't use a VOES - runs like a steam loco! There is more than one way to skin this cat....

 

GB, your timing curves are dictated by crank sensor, map sensor and knock sensor inputs, much more versatile.

Your map would look something like the DTT ignition I use on my sporty.

 

How much alcohol do you have in your petrol ???? Plus you are running IST !!

John

 

Schex, my engine is covered with sensors!

 

Look guys, this is simple. The VOES retards the timing under load/low vacuum preventing pinging/detonation. When the vacuum returns the timing advances. with todays fuel, you really want the VOES. As most of you know I run Ultima gear and I use a VOES !! You've seen my dyno sheets and the engine is not lacking in torque or HP. Why take a chance on damaging your engine??? We even started putting them on the high compression shovels we built. VOES does not make your engine ping unless it isn't working or set way too low. If you adjust it you need to reseal the adjustment screw recess or it may not work as intended. If it didn't work Harley would not have put it on millions of bike, they could have saved a boatload of money. It is not like the smog equipment on your car engines. Just my two cents worth !!
John