Bosch Coil Pack Conversion - Help Needed

[Lazy-Bastard]

I am looking at doing a Bosch coil pack conversion and am a bit stumped on the wiring side.

I was thinking of taking the easy way out (no idea if it would work or not) and just hacking the factory coils off at each connector and then connecting the wiring for each one to the Bosch coils. Obviously the wiring would be a bit of a mess but once I get it working I can tidy/shorten it all up later.

The problem I have is that the Bosch coils I have seen just have a '+' and '-' terminal, whereas the factory coils have '+', '-' and 'E'.

So my question is...Is this going to work and what do I do with the 'E' wire for each coil?

Please no posts like "If you don't know what to do then you shouldn't be doing it". Where's the fun in that?!

I have read the other couple of threads on ths topic and, yes, there is a wiring diagram, but for those of us not so electrically minded (but still wanting to have a go) it would be nice if someone would just say "this wire goes there, etc."

I will try to post some pics soon to clarify things.

Any help would be much appreciated.

*Edit* This is for a Series 1 R33 with external igniter

Edited December 7, 2006 by Lazy-Bastard

[Skas33]

Hey Lazy Bastard,

I have been having the same problem. Help given was wire them in place of standard coils which is all well and good but the bosh coils have 2 terminals where as the standard coils have 3!

I've been wondering if i should just have a go, i am assuming that the E may be the earthing wire ( could be very wrong )

I too would love a hand with this conversion, miss firing sucks.

Please let me know if you get anywhere

[NathR32]

I have had Bosch coils recently fitted to my car but my mechanic did it for me, I don't know what happened to the third wire. I could ring him tomorrow and find out for you if you want?

Nath

Edited November 29, 2005 by NathR32

[Lazy-Bastard]

I have had Bosch coils recently fitted to my car but my mechanic did it for me, I don't know what happened to the third wire. I could ring him tomorrow and find out for you if you want?

Nath

<{POST_SNAPBACK}>

That would be very helpful, thanks

[NathR32]

The RB coils have '+', '-' and ground. When connecting the Bosch coils, there are only 2 terminals, '+' and '-'. Just hook these two up, the Bosch coils do not have to have a ground to each coil.

Nath

[RB30-POWER]

Give you a tip as well.

Only works with RB20DET ignitors. (Weird i know, but must be different)

If you can't get it working with R33 ignitors, don't say i didn't tell you so!

Not to bad if you have a series 2 RB25DET as you will need to buy an external ignitor pack anyway. (As series 2 is built into coils)

[NathR32]

Ahh ok I didn't know that, Mine is an RB20 so I know it works on them. But hope it works for you on the RB25.

Nath

[Lazy-Bastard]

Interesting tip on the RB20 igniter, thanks

I would have thought the RB20 and series 1 RB25 igniters would be almost identical.....oh well

[Sydneykid]

What ECU are you using?

You have to match the ignitors with the ECU. Not all aftermarket ECU's work with all ignitors.

I haven't seen a singe pack aftermarket ignitor for aftermarket ECU's that runs 6 cylinders. Most likely you will need 2 X 3 cylinder ignitors.

Unless you are going to run wasted spark, in which case you will only need 1 X 3 cylinder ignitor

Last time I priced a 2 ignitor 6 coil (with leads) system retail, it worked out at (200 +200 + 65 X 6 + 5 X 6) = $820. Which is a pretty expensive solution compared to the alternatives. Personally I would replace the faulty ones with used standard coils or buy a set of Splitfires and save some money.

cheers

[xr8eater]

SK are you saying that there isnt enough power to run the bosh coils?

nath what part number coil did you use?

[Sydneykid]

SK are you saying that there isnt enough power to run the bosh coils?

"Power" isn't really the right description, the ECU expects to see a particular load (impedance) and a certain dwell time for the ccil. There are also negative switched and postitive switched and high and low voltage switched ignitors. All up there are about 30 possible combinations.

If you don't have the right ignitor for the ECU, you will either fry the ignitor or the ECU or it simply won't work at all. If the dwell time doesn't match the coil, they won't fire either.

That's why I would always suggest using the ECU manufacturer's recommendations for ignitor and, to a lesser extent, coils.

cheers

[xr8eater]

cheers SK

[RB30-POWER]

Once you do this mod, you usually wire them so its runs waste spark mode. (i.e. one coil fires two cylinders - one on power and one on exhaust stroke)

You don't need two sets of coils or two ignitors.

Here is a link with the guy in NZ that preety much started the modification and promoted how easy and sucessful it works if you use the correct coil pack set. (which he happens to sell)

http://gdz1la.kol.co.nz/prod01.htm

the coil is from a circa 1988 turbo buick v6 motor (in various models released in USA).

i have also now found out that if you want to use an easier to find coil pack set. get them off an AU Series 1 6cyl Falcon. Seen these working a treat. but remember the rb20 ignitor is still required

Edited December 2, 2005 by RB30-POWER

[NathR32]

Part no. is HEC716. Usually can be bought for around $40-$60 each.

[xr8eater]

thanks lads i have seen thoes NZ ones and was a bit concerned about choping up my loom and it not working as well as he said it would

[xr8eater]

AU Series 1 6cyl Falcon bosch coil part no.9220061800

if any one is game enough to do the pinout on it

i wouldent know where to start they retail for $80 cheep as chips

[Lazy-Bastard]

SK, I am using a series 1 R33 ecu.

I have heard there are issues with the dwell time from someone else, but other people who have done the conversion don't seem to have an issue.

http://www.skylinesaustralia.com/forums/in...topic=89824&hl=

I believe the bosch mec717 are a single coil, so would I be right in assuming that this is NOT a wasted spark setup?

[Sydneykid]

Ok I'm confused;

1. The RB20 ignitor is designed for 6 coils, so if you use it for 3 coils you are feeding its own trigger voltage back through the wasted spark coil. This is not good for ignitor life, it might work for a while, but........

2. Why would I want to convert a 6 coil on plug system to one running wasted spark with 3 coils? You loose 50% of the coil recovery time, plus you have ignition leads with 2 connections.

3. I am not so sure that it's a good idea to use a coil pack designed for an engine with a 5,000 rpm rev limit on an engine that standard revs to 7,500 rpm easily.

Personally I don't see that it is a worthwhile modification, it looks to me like a downgrade/price trade off.

cheers

[Lazy-Bastard]

SK, If you check the link in my last post, the guy is using 6 coils (different to the option the NZ guy is offering).

So I presume the 6 coil configuration is not a wasted spark setup.

I get what you mean about the AU coil pack and the falcon having a ~5K rev limit, but I would have thought the individual Bosch coils, being fairly generic, would have to be able to cater for a higher RPM.

[Lazy-Bastard]

BTW RB30-POWER, thanks for the link.

I had seen it a while ago, but have been searching for it for the last 2 weeks.

He makes the wiring part sound pretty easy, but auto electrics and I are not the best of friends, so I would like someone else to be the guinea pig