DME Too Hot?
05-09-2004, 09:17 PM
#31
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i have a list of things that i'm going to tie into on the 951 in a week or two - this just got added. thanks so much for your follow-through on this issue. as you said - the information and smarts on this list is simply amazing.
thanks again.
thanks again.
05-10-2004, 04:43 AM
#33
Race Director
Avoid anything with "Nology" in the name... 
Snake oil has evolved in the modern high-tech world.
A very simple upgrade can be done with a capacitor to power the coil. These are the old-style condensers used on points ignition. In that role, they serve to absorb the initial high-current voltage-spikes when the points closed. You can use one on the coil to provide a quick recharge after the spark had been lit off. To connect, connect the body underneath the bolt that clamps the coil. Then extend the wire upward and hook it to the power side of the coil. This is the larger post with the 10mm nut.
How this works is that during the charge-phase of the coil, the battery also charges up the condenser. Then after the coil is dumped to fire the plugs, the coil needs to be charged up gain. The condensor then discharges its stored current into the coil much faster than the battery can flow. At high-RPMs when little time is available to charge the coil, this extra fraction of quicker charge helps ward off high-RPM misfires. This typically occurs around 350-375rwhp.
Snake oil has evolved in the modern high-tech world.A very simple upgrade can be done with a capacitor to power the coil. These are the old-style condensers used on points ignition. In that role, they serve to absorb the initial high-current voltage-spikes when the points closed. You can use one on the coil to provide a quick recharge after the spark had been lit off. To connect, connect the body underneath the bolt that clamps the coil. Then extend the wire upward and hook it to the power side of the coil. This is the larger post with the 10mm nut.
How this works is that during the charge-phase of the coil, the battery also charges up the condenser. Then after the coil is dumped to fire the plugs, the coil needs to be charged up gain. The condensor then discharges its stored current into the coil much faster than the battery can flow. At high-RPMs when little time is available to charge the coil, this extra fraction of quicker charge helps ward off high-RPM misfires. This typically occurs around 350-375rwhp.
05-20-2004, 02:12 PM
#34
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TT wrote:
"The specs look good for the BU941Z, but it only has two pins and case compared to the DME ignition driver's 3 pins and case."
True enough... the "third" lead from the 1012 is the case, so to use a BU941Z I soldered a wire directly to the 941's case to get that third lead. I scratched the nickel plating to get to the "solderable" metal below (brass/copper/whatever) and attached the wire. Been working a few years now. :-)
I had posted photos in my write-up, but they were pulled...too bad. Now I gotta look for them.
"The specs look good for the BU941Z, but it only has two pins and case compared to the DME ignition driver's 3 pins and case."
True enough... the "third" lead from the 1012 is the case, so to use a BU941Z I soldered a wire directly to the 941's case to get that third lead. I scratched the nickel plating to get to the "solderable" metal below (brass/copper/whatever) and attached the wire. Been working a few years now. :-)
I had posted photos in my write-up, but they were pulled...too bad. Now I gotta look for them.
05-20-2004, 02:59 PM
#35
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Join Date: Mar 2002
Location: Union Mi
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If anybody is wondering about the suitability of replacement transistors for either the ignition or injector driver I would be happy to runs some tests on them at work. I can evaluate their gain and sat voltages at various temperatures on our curve tracers (Tek 370 and 371) along with some other dynamic properties. But I will need a known good device to compare it too.
I have quite a supply of similar T03 and TO220 parts
Ben
I have quite a supply of similar T03 and TO220 parts
Ben
