Getting ready to install stand-alone engine management...
10-26-2004, 06:46 PM
#1
AudiWorld Super User
Thread Starter
Getting ready to install stand-alone engine management...
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With the HallTech engine management going in over the next two weeks I started dabbling today with a way to convert my engine to direct fire sequential ignition with six coils instead of the stock setup's remote 3 coils with spark plug wires driving a "wasted spark" ignition method.
The big problem with wasted spark ignition is it fires twice per engine revolution, ie; once on compression stroke where combustion occurs and then the "wasted" spark on the exhaust stroke. The problem with this is coil dwell and energy buildup times are half what they could be if they only fired once. Compounded by the fact that there are only 3 coils and 6 cylinders. This means the buildup time for the coil to store energy to fire a spark plug is cut in half again.
With direct fire I eliminate all spark plug wires and the 3-coil bank that sits over the power steering pump and fires 6 plugs. I eliminate the possibility of spark plug wire leakages and shorts as well as never having to buy one (or 6) ever again. All I need do is add a second ignition module so that each coil has its own circuit then run a low voltage harness to each coil that will be almost identical in size to an injector wire harness. The results: far hotter and more precise spark with no wasted spark discharge weakening'reducing the subsequent spark (ad infinitum). Plenty of time for the coils to build a charge between discharges to the plug. Four times more time in fact, Makes for cooler coil temps, hotter spark, longer spark duration and longer coil life. The coils only working 1/4 as hard as on the stock system.
I was considering running my old coils from my UrS4 car but I'd need to buy an extra coil for the 6th cylinder. Those are older generation and probably 400% larger/heavier than these new generation coils. I never could've gotten the old ones to sit directly on the spark plugs as these do and I would've had to mount them remotely and run plug wires from each coil to it's respective spark plug. Defeats the purpose and not my style.
I stumbled on these at Champagne today and found they just snick right on to the plugs like they were made for 2.8 12V. Now all I need to do is buy 6 of these, add a second ignition module or 1 single one if thats how it comes from the factory on the new cars and make (or buy outright from the dealer) a wiring harness almost identical to the fuel injector harness and VOILA! Direct Fire Ignition!! Just like that!
But without stand-alone engine management you cant have it, or I should say you cant have it "all." You can have direct fire ignition. I started wondering how it could be adapted to a stock ECU 12V and while it cant be single spark it can "direct fire." It will still have the wasted spark on the exhaust stroke but each coil will only be firing one spark plug instead of two. That will allow 50% faster coil energy buildup and an accompanying hotter spark. This setup will also run cooler and could make as much as 50% hotter spark. It should increase coil life as each coil will only have to work 50% as hard as stock coils do now. It would also eliminate your existing coil packs and all spark plug wires. It would KILL such things as Nology wires for spark enhancement... I mean COMPLETELY BLOW THEM AWAY! But yes, all this hi-tech does come at a price... it will be expensive. Maybe as little as $350 but probably no more than $500 or so. But you can replace a coil for $40 (new) and you never buy ignition wires again or worry about a mis-fire associated with one or all of them. And you have better, hotter, more precise ignition spark than a set of $200+? Nology's or anything else in the same price range can ever give you. And everything fits neatly under the engine cover. No one will ever know unless you run "topless."
I'll put in more time over the next two weeks on this while doing mine and let everyone know how it unfolds and show you picturs of how mine turns out. My set-up with stand-alone engine management will be 100% identical to to the the stock ECU car. The difference is purely the ECU's used and not one item that fires a sparkplug will be different.
With the HallTech engine management going in over the next two weeks I started dabbling today with a way to convert my engine to direct fire sequential ignition with six coils instead of the stock setup's remote 3 coils with spark plug wires driving a "wasted spark" ignition method.
The big problem with wasted spark ignition is it fires twice per engine revolution, ie; once on compression stroke where combustion occurs and then the "wasted" spark on the exhaust stroke. The problem with this is coil dwell and energy buildup times are half what they could be if they only fired once. Compounded by the fact that there are only 3 coils and 6 cylinders. This means the buildup time for the coil to store energy to fire a spark plug is cut in half again.
With direct fire I eliminate all spark plug wires and the 3-coil bank that sits over the power steering pump and fires 6 plugs. I eliminate the possibility of spark plug wire leakages and shorts as well as never having to buy one (or 6) ever again. All I need do is add a second ignition module so that each coil has its own circuit then run a low voltage harness to each coil that will be almost identical in size to an injector wire harness. The results: far hotter and more precise spark with no wasted spark discharge weakening'reducing the subsequent spark (ad infinitum). Plenty of time for the coils to build a charge between discharges to the plug. Four times more time in fact, Makes for cooler coil temps, hotter spark, longer spark duration and longer coil life. The coils only working 1/4 as hard as on the stock system.
I was considering running my old coils from my UrS4 car but I'd need to buy an extra coil for the 6th cylinder. Those are older generation and probably 400% larger/heavier than these new generation coils. I never could've gotten the old ones to sit directly on the spark plugs as these do and I would've had to mount them remotely and run plug wires from each coil to it's respective spark plug. Defeats the purpose and not my style.
I stumbled on these at Champagne today and found they just snick right on to the plugs like they were made for 2.8 12V. Now all I need to do is buy 6 of these, add a second ignition module or 1 single one if thats how it comes from the factory on the new cars and make (or buy outright from the dealer) a wiring harness almost identical to the fuel injector harness and VOILA! Direct Fire Ignition!! Just like that!
But without stand-alone engine management you cant have it, or I should say you cant have it "all." You can have direct fire ignition. I started wondering how it could be adapted to a stock ECU 12V and while it cant be single spark it can "direct fire." It will still have the wasted spark on the exhaust stroke but each coil will only be firing one spark plug instead of two. That will allow 50% faster coil energy buildup and an accompanying hotter spark. This setup will also run cooler and could make as much as 50% hotter spark. It should increase coil life as each coil will only have to work 50% as hard as stock coils do now. It would also eliminate your existing coil packs and all spark plug wires. It would KILL such things as Nology wires for spark enhancement... I mean COMPLETELY BLOW THEM AWAY! But yes, all this hi-tech does come at a price... it will be expensive. Maybe as little as $350 but probably no more than $500 or so. But you can replace a coil for $40 (new) and you never buy ignition wires again or worry about a mis-fire associated with one or all of them. And you have better, hotter, more precise ignition spark than a set of $200+? Nology's or anything else in the same price range can ever give you. And everything fits neatly under the engine cover. No one will ever know unless you run "topless."
I'll put in more time over the next two weeks on this while doing mine and let everyone know how it unfolds and show you picturs of how mine turns out. My set-up with stand-alone engine management will be 100% identical to to the the stock ECU car. The difference is purely the ECU's used and not one item that fires a sparkplug will be different.
10-27-2004, 04:10 AM
#5
AudiWorld Super User
Thread Starter
that would be the "back right" spark plug... just cuz one stands outside the car to see something...
doesnt change the compass orientation which is "always" referenced as if sitting in the driver seat.
10-27-2004, 06:00 AM
#7
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Mance, how do you intend to secure the coils? Do they fit as snuggly as the plug wires?
I ask because, I recall (perhaps incorrectly) seeing some models with he coils screwed into the head. Additionally, all the 5v models have the spark plug in the center of the head and use a gasket to seal the access hole and keep the coil centered. Does everything look secure enough on our 12v?
Also, you appear absolutely right regarding the wiring; it should go seamlessly if you can get matching plug connectors for the coils and just wire the connectors to the power wires coming from the ignition amplifier and the ECU. It looks like a great idea. I hope it works out.
Also, you appear absolutely right regarding the wiring; it should go seamlessly if you can get matching plug connectors for the coils and just wire the connectors to the power wires coming from the ignition amplifier and the ECU. It looks like a great idea. I hope it works out.
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10-27-2004, 06:08 AM
#8
AudiWorld Super User
Thread Starter
These are the new style coils that dont require screws...
they lock on to the spark plugs and are made even more secure by 4 rubber tabs near their base that center them and keep em locked into place. They are fretfully tight and secure with no other fastening required. They dont budge axially/laterally at the top end and no way they could ever work themselves loose.
Since the 12V is an "open plug" design there's no need for any upper seal. Thats why we dont have them from the factory. There is a "drain area" on our cars so spark plug chambers dont fill up with liquids or debris. The heads you're referring to dont have that feature and water must be kept out. These coils do have seals located under the coils but are not needed for our engine.
I'm going to try and locate a "used" wiring harness from a salvage yard from a late 2.8/3.0 car rather than make something. If I cant find one I'll likely opt for the complete harness from the dealer.
This all looks far more complicated than it is. Truth is it should literally be a "walk in the park."
Since the 12V is an "open plug" design there's no need for any upper seal. Thats why we dont have them from the factory. There is a "drain area" on our cars so spark plug chambers dont fill up with liquids or debris. The heads you're referring to dont have that feature and water must be kept out. These coils do have seals located under the coils but are not needed for our engine.
I'm going to try and locate a "used" wiring harness from a salvage yard from a late 2.8/3.0 car rather than make something. If I cant find one I'll likely opt for the complete harness from the dealer.
This all looks far more complicated than it is. Truth is it should literally be a "walk in the park."
10-27-2004, 06:14 AM
#9
AudiWorld Super User
Thread Starter
I did... but "maybe" others reading "may" not so I have to keep you honest....
no such thing as "passenger" and "left side" in the same sentence. Least on left-hand drive cars. Right-hand drive cars swap passenger side for driver side but not the L vs R orientation.
It can get complicated if protocol is not follwed. But with it its easy-peasy.
;-)
It can get complicated if protocol is not follwed. But with it its easy-peasy.
;-)
