Aim with a coil

[John Robinson II]

is anything required to use an aim data system with standard blue coil?
john

[emackey]

I use the AIM RPM Signal Filter with the blue coil. Without the filter, the RPM signal was erratic, but after installing the filter the signal was clean and accurate. I've used the filter with both the Mychron3 and the Evo4.

https://www.pegasusautoracing.com/pr...asp?RecID=5476

[Rick Kirchner]

also, if you don't use the filter the coil eventually destroys the dash. Also, you need to ensure the battery voltage doesn't drop below 9v when cranking or it kills the filter. I have a shutoff switch and a big capacitor/zener diode to hold the voltage up.

[S. Frebert]

also, if you don't use the filter the coil eventually destroys the dash. Also, you need to ensure the battery voltage doesn't drop below 9v when cranking or it kills the filter. I have a shutoff switch and a big capacitor/zener diode to hold the voltage up.

You have pictures of the install? I have the filter, but interested in the capacitor/diode setup to hold voltage up.

[Rick Kirchner]

it will take me several days...

[S. Frebert]

it will take me several days...

Ah understandable. Any reference to specific parts you suggest? Especially manufacture that you felt was reliable?

[DanW]

Ah understandable. Any reference to specific parts you suggest? Especially manufacture that you felt was reliable?

The rpm signal from the coil is very noisy and "dirty". Its hard to get a clean signal from the coil for the AIM dash.

An alternative is an adapted wheel speed sensor originally designed by Ron Chisholm of Cypress Lane Racing. Now David and Ellen Ferguson make and sell the crank speed sensor with a collar that clamps to the front pulley. The sensor makes a clean, consistent rpm signal.

https://veracitydata.com/products/ve...cing-products/

[S. Frebert]

The rpm signal from the coil is very noisy and "dirty". Its hard to get a clean signal from the coil for the AIM dash.

An alternative is an adapted wheel speed sensor originally designed by Ron Chisholm of Cypress Lane Racing. Now David and Ellen Ferguson make and sell the crank speed sensor with a collar that clamps to the front pulley. The sensor makes a clean, consistent rpm signal.

https://veracitydata.com/products/ve...cing-products/

Appreciate it Dan. I experienced what you're describing. I ending up wiring up the filter myself. I do like the idea of the crank speed sensor style though..... That may be on the list instead of this diode setup....


Thanks for the info!

[Dave Harmison]

Thanks for the mag pick up referral.

Besides cleaning up the rpm I like that it isolates the data from the engine. No chance of the data system causing a misfire.

[TimH]

also, if you don't use the filter the coil eventually destroys the dash. Also, you need to ensure the battery voltage doesn't drop below 9v when cranking or it kills the filter. I have a shutoff switch and a big capacitor/zener diode to hold the voltage up.

I have the AIM switched. Never crank the starter with the AIM on. Too many times seeing the dash get scrambled.

[BorkRacing]

I have the AIM switched. Never crank the starter with the AIM on. Too many times seeing the dash get scrambled.

Are you connecting the white lead to coil negative and the black lead to chassis ground?

[TimH]

Are you connecting the white lead to coil negative and the black lead to chassis ground?

Umm...

Can I get back to you in a couple of weeks? Things are pretty buttoned up for transport right now.

IIRC the filter is hooked in according to directions (white to coil, probably red to power, black to ground and ? to AIM). The AIM power input, not the ground, is switched.

[BorkRacing]

Thanks for the mag pick up referral.

Besides cleaning up the rpm I like that it isolates the data from the engine. No chance of the data system causing a misfire.

I am curious how the data system can cause a misfire. isn't it reading the low voltage spikes. I don't think it sends anything down the wire...

[Dave Harmison]

If the AIM somehow shorted, either totally, partially or intermittently, that would cause a misfire.

[BorkRacing]

If the AIM somehow shorted, either totally, partially or intermittently, that would cause a misfire.

I really doubt it. It just reads the voltage spike that will continue happening as long as there is a signal from your distributor. It can short or turn itself off, you are not grounding your ignition through it.

[Matt Clark]

I hate to piggyback onto someone elses thread, but I assume the info about the the AIM dashes & using a coil are universal, correct?

I ask because the MyChron3 in my FV is a bit erratic at times. Obviously I am running a coil in that car, and with a Pertronix ignition.
I was looking & found the AIM ARP03 Filter on my own as well, but decided to ask once I saw this thread. All I have to do it splice the filter inline?

[TimH]

I hate to piggyback onto someone elses thread, but I assume the info about the the AIM dashes & using a coil are universal, correct?

I ask because the MyChron3 in my FV is a bit erratic at times. Obviously I am running a coil in that car, and with a Pertronix ignition.
I was looking & found the AIM ARP03 Filter on my own as well, but decided to ask once I saw this thread. All I have to do it splice the filter inline?

Yep. Also comes with instructions.

[Matt Clark]

Cool, thanks Tim.

[JHerscher]

Matt, the filter comes with instructions.

Blue is tach signal, red +9 - 12 vDC, Black ground. On the coil side, white is for a coil, blue is for ECU.

I did chase a misfire over the winter that was traced to a bad filter. I guess what killed it is what killed the dash. I found a bad ground on the dash power which meant the dash was finding ground through the signal filter. Had strange dash output, sent it to AiM, they confirmed it was fried. Replaced the dash but not the signal filter. Was convinced the dash was somehow causing the miss. Eventually I unhooked the tach signal input and the filter from the coil and with a new coil the misfire was cleared.

Took forever to troubleshoot.

Have a new filter. Hope no more issues

John

[Matt Clark]

luckily I haven't had any major issues like that yet, but I have barely used it so far after switching from standard gauges.

I *really* do not want to get into all those headaches.... else I may just go back to plain gauges. if I do end up with problems, I definitely will be making a post as I rip my hair out chasing it.

[JHerscher]

I'm an analog man in a digital world.
If I had room I would use gauges with needles and circular faces.