Where to get coils...
Discussion
I'm after some small(ish) individual plug coils.
There's not really room for the usual coil-over-plug type as found in Subarus and VWs etc, so something vaguely cube shaped (for packaging reasons) with HT lead connectors on one end and an easily obtainable LT connector on the other would be good.
I'd prefer not to have a wasted spark system (I have reasons...)
The ECU should be flexible enough to drive most things.
Can anyone suggest anything that might be suitable? Not bothered about them being new etc, as long as they're an easy-to-get part!
Thanks!
There's not really room for the usual coil-over-plug type as found in Subarus and VWs etc, so something vaguely cube shaped (for packaging reasons) with HT lead connectors on one end and an easily obtainable LT connector on the other would be good.
I'd prefer not to have a wasted spark system (I have reasons...)
The ECU should be flexible enough to drive most things.
Can anyone suggest anything that might be suitable? Not bothered about them being new etc, as long as they're an easy-to-get part!
Thanks!
BoostedLS1 The triggering of the LS1 coil is not straightforward.
It is a 4 wire, amplified coil. I ditched mine in favour is more simle Bosch coils for this reason, as I couldnt get my ecu to work with them easily and it wasnt worth the hassle trying.
I have no idea if thay would be any use to you.
there are 4 wires
+12v
-ve switch
ground
0v ecu reference, which nobody can give me a definative answer as to what it does.
If you could make use of them, they wouldnt be expensive, although some of the wires on the plugs may be a bit short, as I cut them all off. I think I still have the plugs though. ( might have thrown them out, I'll check later )
The Bosch MEC723 or HEC716 are a simple straightforward coil, as I mentioned elsewhere...
It is a 4 wire, amplified coil. I ditched mine in favour is more simle Bosch coils for this reason, as I couldnt get my ecu to work with them easily and it wasnt worth the hassle trying.
I have no idea if thay would be any use to you.
there are 4 wires
+12v
-ve switch
ground
0v ecu reference, which nobody can give me a definative answer as to what it does.
If you could make use of them, they wouldnt be expensive, although some of the wires on the plugs may be a bit short, as I cut them all off. I think I still have the plugs though. ( might have thrown them out, I'll check later )
The Bosch MEC723 or HEC716 are a simple straightforward coil, as I mentioned elsewhere...
dnb said:
I'd prefer not to have a wasted spark system (I have reasons...)
Mind if I ask what they are?
(My worry is that the wasted spark occurs in a cylinder of lightly compressed air/fuel mixture connected (by the inlet valve) to more of the same in the inlet manifold. I've already had a couple of blow-backs and don't want to blow the whole thing up.)
dnb said:
The ECU I'm looking at has the potential for individual cylinder trimming of fuel and ignition. This is more difficult with wasted spark.
I also plan to have some form of traction control at some point so want to keep my options open.
What's the betting it's an M8 Pro
Boosted
If you have a sequential system ( ie running a cam sensor ) then you can still have individual cylinder control, even with wasted spark.
It may fire a spark on the exhaust cycle too, but the ecu will still know when a particular cylinder number is firing, so it does allow you to adjust that particular cylinders timing.
The whole issue about igniting mixture on a waste spark IMO is very very unlikely to ever happen, unless cam choice is very wild.
Because I dont use a cam sensor on my engine, I have to operate it in twin spark mode to fire 8 seperate coils. Basically the same as wasted spark, although I do not have the option of individual cylinder control, as I dont have a cam sensor to tell the ecu where no1 cylinder is. With a crank sensor only, it would see either 1 or 6 just the same way.
The only reason I used 8 coils, as it made plug lead routes neater, otherwise I'd probably have went for coil packs.
It may fire a spark on the exhaust cycle too, but the ecu will still know when a particular cylinder number is firing, so it does allow you to adjust that particular cylinders timing.
The whole issue about igniting mixture on a waste spark IMO is very very unlikely to ever happen, unless cam choice is very wild.
Because I dont use a cam sensor on my engine, I have to operate it in twin spark mode to fire 8 seperate coils. Basically the same as wasted spark, although I do not have the option of individual cylinder control, as I dont have a cam sensor to tell the ecu where no1 cylinder is. With a crank sensor only, it would see either 1 or 6 just the same way.
The only reason I used 8 coils, as it made plug lead routes neater, otherwise I'd probably have went for coil packs.
stevieturbo said:
The whole issue about igniting mixture on a waste spark IMO is very very unlikely to ever happen, unless cam choice is very wild.
Yeah, it *must* be safe normally because it's so widely used that we'd certainly know if there was a problem. But what would it take to produce conditions in the chamber capable of being lit by a spark, during the overlap period? With forced induction producing massive scavenging at low RPM, and retarded ignition putting the spark nicely into the overlap period, all the ingredients seem to be there for a bonfire in the inlet manifold.
by forced induction, I assume you refer to supercharging ?? I doubt turbocharging could produce this massive scavenging at low rpm that you refer to.
Also, seeing as most FI cams do not need, or indeed like large overlap, the chances of this problem arising are low.
Also, why would you have this retarded ignition that you talk of ?? It simply isnt necessary, unless you are producing serious amounts of boost at low rpm's, which in most cases, doesnt happen, either with SC or with turbos.
Im not saying such an explosion cant occur, but it would take a strange set of circumstances for it to happen.
Also, seeing as most FI cams do not need, or indeed like large overlap, the chances of this problem arising are low.
Also, why would you have this retarded ignition that you talk of ?? It simply isnt necessary, unless you are producing serious amounts of boost at low rpm's, which in most cases, doesnt happen, either with SC or with turbos.
Im not saying such an explosion cant occur, but it would take a strange set of circumstances for it to happen.
stevieturbo said:
by forced induction, I assume you refer to supercharging ?? I doubt turbocharging could produce this massive scavenging at low rpm that you refer to.
Also, seeing as most FI cams do not need, or indeed like large overlap, the chances of this problem arising are low.
Also, why would you have this retarded ignition that you talk of ?? It simply isnt necessary, unless you are producing serious amounts of boost at low rpm's, which in most cases, doesnt happen, either with SC or with turbos.
Im not saying such an explosion cant occur, but it would take a strange set of circumstances for it to happen.
Quite right, I'm talking about a supercharged installation. Turbos don't suffer from the same scavenging effects, but I think we've had this conversation before!
I didn't mean a massively retarded ignition, just that ignition advance increases with revs so the ignition will be most retarded at low rpm. Assuming a fairly conventional cam (not a zero overlap supercharger special), it seems to me that the wasted spark could well occur during the overlap period. If this happens, then given a cylinder full of fuel/air (due to blow-through) how safe is it to throw a spark into the mixture at this point?
There can't possibly be a cylinder full of mixture at that point as the piston is approaching TDC on the exhaust stroke. I can see where you are comming from though, but I think this is most unlikely to be a problem with the mild cam timing normaly used in forced induction applications.
MR2Mike said:
There can't possibly be a cylinder full of mixture at that point as the piston is approaching TDC on the exhaust stroke. I can see where you are comming from though, but I think this is most unlikely to be a problem with the mild cam timing normaly used in forced induction applications.
You'd think so wouldn't you? But at low RPM with +5 psi in the inlet manifold and normal atmospheric pressure in the exhaust, the boost from the inlet manifold pours straight into the chamber the moment the inlet valve cracks open - which is some way before tdc.
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