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Another quick DIY, I looked at installing a 993 twin coil setup into my 964, couldn't find it in any threads, sorry if it has already been covered.
This started out because I have one black and one silver coil, so one replacement from Brazil? anyway reading about the possible issues i wanted to get them out of there.
2 things come out of this upgrade;
- 993 coils are cheaper to replace and by all accounts more reliable
- they weigh 1.1kg half the weight of the 964 pair (I am always looking to save weight)
You will need
a 993 coil assembly either new or used,
2x rubber dust boots for the top of the coils/terminals
2x 993 HT leads coil to distributor middle connection
The change can be made without any special brackets or mounts, just a 30mm M6 bolt.
Step 1
Remove the engine heater elctric fan assembly and pipework.
Step 2
The 964 coils and 993 coils have different HT connections so you need to swap the Beru HT lead coil ends from the 993 leads over to the 964 leads. The Beru cables screw into the connectors, this is the tricky bit as they can be damaged and then you could end up with no working leads! I found it doesnt matter with the 993 leads if you twist off the threaded fitting as you can get it out of the connector by removing the outer rubber cover.
The best way to get the leads out is to spray some penetrating oil in past the cable to ease things up, then gently unscrew the leads.
See the final pics - you need to unscrew the brass fitting from the HT connector not unscrew/pull the cable out of the brass fitting as in second pic. If it is difficult to unscrew try to pull the outer rubber cover off of the HT connector to expose the brass fitting (it will come off with some effort).
Screw the 993 connectors onto the 964 leads and put them back on the distributors.
Step3
Unbolt the old coils from the car, there are 2x 6mm hex bolts, one at the top and one is accessed through the hole betwwen the ignition modules. Unplug the ignition modules and unbolt the coil connections. Undo the 2 ignition modules from the heatsink and unbolt the heatsink from the coils. Bolt the ignition modules back onto the heatsink, you may wish to apply some heatsink compound under each.
Step 4
Drill a 6mm hole in the 993 coil assembly along the centre line, 35mm from the top of the large metal plate. In the engine bay remove the plastic cable strap from the wiring loom just below where the coils were, this is to make space for the coils. Place the 993 coils where the old ones were and insert a 30mm bolt with a lock washer through the new hole into the lower threaded fixing. You may want to add some padding behind the coils where they rest on the body of the car. I used some velcro adhesive strips.
Step 5
Place the heatsink with ignition modules upward onto the threaded stud that used to have the cable tie strap on it. Plug in the modules so that the loom runs over the yop of the modules. I added a 964 trim plastc nut to hold this in place (not shown in the pics)
Connect up the coils 8mm and 10mm nuts being carful the connectors do not touch once tightened. Add the rubber dust covers and plug in the HT leads.
I bought the 993 coils complete with 2x HT leads and the rubber dust covers from a breakers, a bargain at £35! and the best way to go I think, I don't have the 993 parts list (only 964 PET) so maybe someone else can help? The coils are on the bay and very cheap at about £110 I think for new.
See you tomorrow Seb yep will show you the goods, went for a long thrash and it feels better, pretty sure those old 964 oil filled coils were past their best.
Have run the car hard for a couple of days now, honestly feels stronger. It is completely reversable, doesnot damage any existing components and is a more up to date, lighter, servicable and reliable solution.
The only risk is the possible damage to one end of your existing HT lead from the coils if you dont get the cable to unscrew cleanly from the connector. And then the only result is the cost of a new lead, mine unscrewed easily.
You can eliminate this question by going out to the car before ordering any parts and proving the connectors unscrew from the exisiting leads - pull off the HT leads from the coils, lift the edge of the connector rubber and spray some penetrating fluid/plus gas etc down into the connector past the cable, then very gently unscrew the cable, if it comes out you are all good to go. Just screw them back in (not too tightly) until the parts turn up.
Parts list is,
1x 993 dual coil,
2x rubber dust covers (optional),
2x 993 coil HT leads - to steal the end connectors from
1x M6 30mm bolt and a bit of tape/velcro backing
1x plastic threaded trim nut to hold the heatsink down (same type used throughout the 964)
Last edited by tdiquattro; 07-13-2015 at 04:07 AM.
The 964 coils and 993 coils have different HT connections so you need to swap the Beru HT lead coil ends from the 993 leads over to the 964 leads. The Beru cables screw into the connectors,
....
There's one caveat in this process. To fix coil ends you'll need to use obscure and $$$ Beru crimp tool:
out of 7 leads I have unscrewed only one was difficult and that came undone by pulling back the rubber outer cover and accessing the brass end. So I would say there is no issue here.
Yep they come apart pretty easy. The trick I use is to carefully slide the prong of a fork (the kind you eat with) into the rubber boot where the cable exits. Open it out a fraction and squirt in some washing-up liquid. Run the prong around the circumference of the cable under the boot to spread the liquid about. You should then find they unscrew. This has work successfully on the plug and dizzy ends.
07-11-2015, 03:26 PM
DIY - 993 coils into 964
yep will show you the goods, went for a long thrash and it feels better, pretty sure those old 964 oil filled coils were past their best. 
