craig1410
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| posted on 28/3/10 at 07:32 PM |
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Acewell Dash RPM pickup with V8 engine? How?
Hi,
I've had an Acewell 37xx series computer for a few years now but have never managed to get a stable RPM reading from it. Due to the fact the V8
has 4 sparks per rev at the coil I am forced to use the spark plug lead with the sensor wire coiled around it several times to get a signal.
I've tried between 1 and 10 coils, I've tried 1 Meg resistor in series, I've tried shielded coax wire and all the combinations of
these and nothing gives me a stable signal. This bugs me and I want to fix it this year...
Has anyone managed to get a good RPM signal with a V8 engine and if so, how did you do it? I've emailed Acewell as well and will post here if I
hear from them.
Thanks,
Craig.
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Paul (Notts)
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| posted on 28/3/10 at 07:49 PM |
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I have run my Veypor 2 dash from the coil on my V8 when I had a single coiul and dizzy. Then from a single coil when I switched to twin coil packs
and EDDIS.
just had to play around with the settings to get a good rpm reading.(It had a multiplier setting and a filter setting)
Paul
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craig1410
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| posted on 28/3/10 at 07:59 PM |
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Hi,
The problem I'm having is that the RPM is unstable - it bounces around between what I think is half the true reading and what I think is double
the true reading. Noise or harmonics perhaps.
I think I might try running the feed from the coil low voltage "CB" connection even though this will give me a reading of 2x actual revs,
at least it might be stable.
Just thought I'd ask first if anyone has got the Acewell working with a V8.
Thanks,
Craig.
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loggyboy
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| posted on 28/3/10 at 08:10 PM |
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Pulse converter? MIght allow you to get a signal from a another point on the igniton and tune to the dash.
I used one of these to calibrate my speedo when fitting a VX220 dash in my Nova.
A chap called Dom makes them on Migweb
PM here:
http://www.migweb.co.uk/forums/items-sale/262397-speedometer-rev-counter-pulse-adjusters-9.html
They used to be on this site http://www.picbits.co.uk
but i cant seem them now, so try an enquiry here:
http://www.picbits.co.uk/catalog/contact_us.php
[Edited on 28/3/10 by loggyboy]
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DavidW
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| posted on 28/3/10 at 08:13 PM |
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I had a problem with an unstable reading so swapped the wire which goes from the Megajolt to the acewell for shielded microphone cable which improved
the situation significantly. It's now not quite perfect but now acceptable.
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02GF74
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| posted on 28/3/10 at 09:21 PM |
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I don't run your guage but think it is TIM.
there is a button 4-6-8 that allows use with that number of cylinders.
it is connected to the switched coil LT side.
as you have tried, that is where yours should be connected - but I wold have excpected you tacho to have some sort of adjuster for number of
cylinders?
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craig1410
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| posted on 28/3/10 at 09:40 PM |
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quote:
Originally posted by 02GF74
I don't run your guage but think it is TIM.
there is a button 4-6-8 that allows use with that number of cylinders.
it is connected to the switched coil LT side.
as you have tried, that is where yours should be connected - but I wold have excpected you tacho to have some sort of adjuster for number of
cylinders?
Yes mine has a setting to select the number of engine revolutions per signal. The options are 0.5, 1.0, 2.0 and 3.0
What I need is 0.25 but it doesn't have this.
Thanks,
Craig.
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turbodisplay
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| posted on 29/3/10 at 07:51 AM |
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If you want to keep trying the pickup route try getting a ferrite snap on filter, wrap arrround the core, connect one wire to -ve, other to dash. Then
clip around the plug.
Darren
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NOTE:This user is registered as a LocostBuilders trader and may offer commercial services to other users
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russbost
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| posted on 29/3/10 at 09:23 AM |
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Hi Craig
It's very unusual not to be able to get a stable reading with the Acewell. Usually doing the various experimentation you've described will
sort the problem out, you could try increasing the resistance above the 1meg, or indeed try a reduced resistance - maybe get a 0 -10M ohm variable
potentiometer so you can play with that.
Another possibility is that the HT lead you're picking up from may be knackered (ie VERY high resistance) - have you tried runnng the pickup on
a different lead?
If you do as you've suggested & run from the coil CB so you get a stable reading but double the revs IIRC you can set the 37xx series to 0 -
16,000 instead of 0 - 8,000 in which case althought the no.s would still be wrong the bar graphic would at least look right if you follow me.
If all else fails, you could use the method used for old diesels, which is to add a magnet & speed sensor to the crankshaft pulley & run the
tacho wire from that with the cycles per spark set to 1
Regards Russ
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NOTE:This user is registered as a LocostBuilders trader and may offer commercial services to other users
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