Switching to coil packs?

Switching to coil packs?

Author
Discussion

Lesliehedley

Original Poster:

216 posts

240 months

Wednesday 3rd August
quotequote all
I've currently got a 400SE running an Emerald K3 ECU. My current set up uses the original coil controlled by the ECU and the distributor is used purely to distribute the spark. I am thinking of changing to coil packs as I think this will eliminate any wear or play in the distributor. But will I notice any difference? Is the difference between coil packs and a distributor going to be big enough for me to make the change worthwhile? Anyone done this that can give me any advice before I dive headlong into this?TIA

spitfire4v8

3,840 posts

161 months

Wednesday 3rd August
quotequote all
If you have a crank sensor then the dizzy play is not an issue .. if you are using the dizzy as the engine trigger then you might see a minor improvement but it all depends how bad the dizzy / cam chain play is anyway as regards how much timing scatter you have. You could always put a strobe light on it , lock the advance in the ign offset setup bit of the ecu, and see if the timing marks jump around much with the engine running.

If it were me though I'd probably leave it as is .. I'd wager that if it made a big enough difference to notice from the driving seat you have other issues which need fixing. eg dizzy falling apart or cam chain stretched massively, in which case fix the cam chain and/or dizzy (which also drives the oil pump on the pre serp so as I say if you notice a difference in driving manners going to coil packs you have other more pressing engine issues!)

Panamax

1,557 posts

14 months

Wednesday 3rd August
quotequote all
I don't really understand what's going on here. Unless you lose the distributor completely I don't see how moving the coil(s) from before the distributor to after the distributor is going to make any worthwhile difference. You'll have the potential for a heftier spark but not much else.

Lesliehedley

Original Poster:

216 posts

240 months

Thursday 4th August
quotequote all
Panamax, Moving to coil packs would eliminate the distributor because the coil packs would be connected directly to the plugs rather than the distributor distributing the spark.

My reason for the change is that the idle rpm is a little rough and I thought that might be due to wear in the distributor advance weights system giving me spark scatter. From what Jules says, it looks like it won't make any noticeable difference so I reckon I'll it as is for the present. Thanks for the advice Jules.

350Matt

3,665 posts

259 months

Thursday 4th August
quotequote all
I actually carried out the 1st rover v8 to coil packs with an Emerald ECU some 21 years ago on my wedge

the biggest advantage to moving over to coil packs from a single coil is you increase the amount of allowable spark timing
as with the distributor you may request 35 degrees for example in the map , but unless the rotor arm is anywhere near the dizzy post you will not get this figure, you will only get the spark travelling to the plug when the rotor arm orientation allows it by which time its typically reduced to about 28 -30 degrees at most

not only that, even with a dizzy drive in good condition there is several degrees of slack in the system between true TDC and when the dizzy arm flies past the cap post
plus the rotor arm moves about at high rpm so if you request 30 degrees say you might get 33 or 28 depending on what rpm etc

I found with the coil packs I could generally run larger spark advance numbers and pick up power and improve fuel consumption too at part load

its very worthwhile, do it

I managed 283 bhp from my 4 ltr v8 on Emeralds rollers back in the day

Lesliehedley

Original Poster:

216 posts

240 months

Thursday 4th August
quotequote all
Thanks 350Matt. That's very interesting. It's that sort of slack in the distributor that I thought might be worth eliminating. My Emerald was tuned by Jules and gives 273 bhp with 280 lb ft of torque, and that's with the distributor distributing the spark. So it seems that the coil packs will give a more accurate ignition figure than the distributor. Do you think it would need to be retuned by Jules to get the best out of the coil packs?

350Matt

3,665 posts

259 months

Friday 5th August
quotequote all
yes it will although I'd be surprised if you didn't feel some benefit right away

you will need a crank trigger wheel too, if you don't have one , then most of the distributor can be removed. I turned mine down to just leave the shaft so it still drove the oil pump and used it for a cam sensor to do injection timing

http://trigger-wheels.com/store/contents/en-uk/d14...

gmw9666

2,721 posts

180 months

Friday 5th August
quotequote all
Dizzy removed, coil packs (same as cerb if memory serves me right) + Emerald on mine…….makes for a neat install


Polly Grigora

10,229 posts

89 months

Friday 5th August
quotequote all
gmw9666 said:
Dizzy removed, coil packs (same as cerb if memory serves me right) + Emerald on mine…….makes for a neat install

Wow that looks the part

Thundered

29 posts

20 months

Friday 5th August
quotequote all
I'm using a 123 dsitrubutor with bluetooth connection - best thing I ever did in terms of being able to programme one's ignition timing. Don't know much about coil packs in terms of what they would offer over a standard distributor but would think a 123 Distributor IMO is the best way forward in terms of swapping from an old lucus type to something 21st century - without the aggro of setting up coil packs.

adam quantrill

11,454 posts

222 months

Friday 5th August
quotequote all
Wow - I just had to google the 123 ignition kit. It does look like a way of keeping semi original look.

What's inside the cap - does it dispense with a rotor arm completely?

It will be interesting to see if these new-fangled things can withstand underbonnet temperatures over extended use. God knows we have had enough over the years with ignition amps playing up!

Lesliehedley

Original Poster:

216 posts

240 months

Wednesday 10th August
quotequote all
Does anyone know if this coil pack works with the Emerald ECU?
https://efi-parts.co.uk/product/wasted-spark-coil-...

spitfire4v8

3,840 posts

161 months

Thursday 11th August
quotequote all
It will need a change to the config to run that style of amplified coil, it can be done with a relatively straightforward update and you really need to run the power for that coil through a relay triggered by the main relay control from the ecu to avoid all the coils firing at ignition-on which causes a backfire into the plenum.
But better still you can run a std non amplified coil pack a-la cerbera (peugeot 106) .. You will also need to update the configuration in the ecu to tell it to run 4 ign signals and their offset relative to cyl 1 TDC, and wire in those 4 signal wires of course, and change the ht leads ends at the coil end.

KKson

3,275 posts

105 months

Thursday 11th August
quotequote all
gmw9666 said:
Dizzy removed, coil packs (same as cerb if memory serves me right) + Emerald on mine…….makes for a neat install

Stunning engine bay. Can't wait to see it up and running. Cheers.

KelWedge

1,267 posts

165 months

Tuesday
quotequote all
350Matt said:
I actually carried out the 1st rover v8 to coil packs with an Emerald ECU some 21 years ago on my wedge

the biggest advantage to moving over to coil packs from a single coil is you increase the amount of allowable spark timing
as with the distributor you may request 35 degrees for example in the map , but unless the rotor arm is anywhere near the dizzy post you will not get this figure, you will only get the spark travelling to the plug when the rotor arm orientation allows it by which time its typically reduced to about 28 -30 degrees at most

not only that, even with a dizzy drive in good condition there is several degrees of slack in the system between true TDC and when the dizzy arm flies past the cap post
plus the rotor arm moves about at high rpm so if you request 30 degrees say you might get 33 or 28 depending on what rpm etc

I found with the coil packs I could generally run larger spark advance numbers and pick up power and improve fuel consumption too at part load

its very worthwhile, do it

I managed 283 bhp from my 4 ltr v8 on Emeralds rollers back in the day
And it still has the same Emerald Unit and Coil packs fitted, but it got remapped at Emerald when the RPI 4.6 replaced the 4 ltr smile

Hi Matt, No you still cant buy it back !