It is currently Sat Oct 20, 2018 10:54 pm



Post new topic Reply to topic  [ 5 posts ] 
Author Message
 Post subject: S40 + 3 wire bosch coils
PostPosted: Tue Oct 16, 2018 2:17 pm 
Offline

Joined: Thu Jul 28, 2011 4:10 am
Posts: 856
ECU Model: S100 Pro
I've not used active coils before and I think these 3 wire bosch are? Any reason why I can't run 2 coils from one output of an s40 on a 4 cylinder. If that is ok do I just check the external amplifier box, no need for pull up resistors or anything else?. What worries me is that the loom the coils came from had a fairly thick wire that is the trigger wire.
Worried also of damaging something, I'll definitely wire coils +12v via fuel pump relay.
I can't find any info on the coils.


Attachments:
Bosch CoP.jpg
Bosch CoP.jpg [ 240.75 KiB | Viewed 92 times ]
Top
 Profile  
 
 Post subject: Re: S40 + 3 wire bosch coils
PostPosted: Tue Oct 16, 2018 3:36 pm 
Offline

Joined: Tue Aug 02, 2011 12:08 pm
Posts: 2901
Location: Norn Iron
ECU Model: No ECU
If you test with a current clamp/scope, you'll soon know with a brief test as to what mode of charging is correct.

Problem with 3 wire...it could be either. And as you say a heavy trigger wire might seem a little out of place for a coil with an internal ignitor.

Do you get a resistance reading between that trigger and any other terminals ? I dont think you should get a reading if it has an ignitor inside.

Regular inductive you'd defo get a reading.


Top
 Profile  
 
 Post subject: Re: S40 + 3 wire bosch coils
PostPosted: Wed Oct 17, 2018 2:13 am 
Offline

Joined: Thu Jul 28, 2011 4:10 am
Posts: 856
ECU Model: S100 Pro
Thanks, yes silly me, 1st thing to do is put a meter on them! They were definitely fed with an earth and 12v and the 3rd wire. So if they are passive can I hang 2 on one output? I guess I need to find how much current they draw.


Top
 Profile  
 
 Post subject: Re: S40 + 3 wire bosch coils
PostPosted: Wed Oct 17, 2018 3:24 am 
Offline

Joined: Fri Feb 28, 2014 1:03 pm
Posts: 1119
ECU Model: S40 Pro
Distributor: DTA
Firmware Version: 79
Bosch 3 wire tend to be inductive.

There are a number of people running S40s with paired active coils. It does work, but puts a lot of strain on the coil drivers as there's no heat sink on them. The S40 has thermistors to monitor coil temps under normal operating conditions for this reason.

Most of them are fine just being paired up, no pull ups required.


Top
 Profile  
 
 Post subject: Re: S40 + 3 wire bosch coils
PostPosted: Sat Oct 20, 2018 12:38 pm 
Offline

Joined: Thu Jul 28, 2011 4:10 am
Posts: 856
ECU Model: S100 Pro
As Alex suggested they are passive coils but with an extra earth for something or other. The primary resistance is 0.8 ohm and 2 of those would be 0.4 ohm,
So I chickened out and got one of those ford wasted spark coils.
Started up first time :)


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 5 posts ] 

Who is online

Users browsing this forum: No registered users and 2 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
cron
Theme designed by stylerbb.net © 2008
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group
All times are UTC - 5 hours