Lotus Elan and Lotus Elan Plus 2 Forums

I have a Petronix electronic ignition set which I would like to fit on my S1
Old posts suggest it may interfere with the Tach (Rev Counter if you like).What is the latest thoughts please.
I have converted to -ve Ground and Tach works OK.
With the carbs off I can actually reach the distributor!
Ken B
64 S1 Wannabe racer

From what I can gather from this and other Forums, you may be lucky and it'll work fine. Try it and see!
Neither my Elan nor Europa TC worked well with Pertronix, though. The Europa seemed OK to start with, then the tach started "jumping" and was only cured when it was converted. The Elan never worked - it just sulked and wouldn't move at all.

I installed a Pertronix when I converted from a generator to an alternator. Had the tach converted to negative ground, and it has worked just fine for the past 5 years. The only problem I had with the tach was when one of the grounds to the instrument came loose and it started acting funny. Fixed the ground and it has been great since

Rob Walker
26-4889

Salut


This informative post may be of interest if you have problems:

elan-mods-f31/rvi-tachometer-conversion-t26919.html#p180291

@+

Vernon

So far I can recommend the Ultraspark unit from Ignition Car Parts Ltd in the UK ( part no ICPEK018). I fitted one in 2011 with no issues. It just worked, although with quite low mileage so far. A friend has just fitted the same kit to a Plus 2, also with no tachometer problems. One point though, we do not know which country you are in.
Eric in Burnley
1967 S3SE Type 45 (ready for the glorious spring coming soon)

I have a Pertronix ignition system and it works just fine. I've never had to touch it since purchasing the car a couple of years ago. Which is just as well because the dizzy looks to be a bit bigger than the standard one and a heck of a tight fit under the carbs.

My tacho works, but it is bouncy. I am currently working on the solution proposed by rjaxe (mentioned above). I don't really see this as being related to the Pertronix, I think it's just a case of the tacho components being 40 years old and past their best.

I know nothing about electronic ignition, aside from the obvious, but I assume that one of its benefits is that it can create a very large dwell angle, allowing the coil to saturate nicely and produce a nice fat spark. I guess the downside of this is that the "points open" time is so small that the smoothing circuit in the tacho views it as mere noise and ignores it. This, of course, isn't the problem that I'm working on.

By the way, does anybody have a manual for a Pertronix system? I would really appreciate a copy for when the time comes....

Nick

Their support page might have the info you need?

http://www.pertronix.com/support/manuals/default.aspx

Duh. Oh yeah - thanks! I'll claim that it wasn't there when I had a brief search a couple of years ago.....

Nick

Hi All

the RV1 tacho's dont like the small current that flows to power the various type of electronic ignition. I have scanned the petronix connection info and marked up how I think the red wires should go. Only put the loop through the tacho to the ignition coil. I have found this fix works on several ignition units using RV1 type tacho's though not tried it with petronix. I guess it is down to how much current flows in the red wire.

hope this helps

Best of luck

Bob

Clever. This is clearly a great tip to help a current driven tacho that is struggling with electronic ignition work properly.

My Pertronix gets its 12v from the coil, so I quickly tried this wiring change over the weekend to see if it would help my bouncy tacho. I didn't think it would, and it didn't - the tacho electronics is clearly at fault. So my project to convert to the voltage triggered electronics that rjaxe describes continues.....

Nick