Cylinder numbering?

I feel almost embarrassed to ask but I just can’t find it anywhere. Not in the workshop manual or elsewhere, so here it comes... How do you go by numbering the cylinders on a 355? (and is there any layout for the ignition wires from the coils anywhere?)

 

On my 348 the cylinders are numbered as such:

Front of car
---------------
| (8) | | (4) |
| (7) | | (3) |
| (6) | | (2) |
| (5) | | (1) |
---------------
Rear of car

If you were to lay the coils down with the plugs laying facing up they order is:

for bank 1-4 (right side looking in from the rear)
1,2
4,3
^
wiring loom connector

for bank 5-8 (left side looking in from the rear)
7,8
6,5
^
wiring loom connector

I don't know for sure if it's the same for a 355, but it could be. Hope this helps?

 

Thanks for the help, really appreciate it!

 

I do think that, even on a 348, the numbering is the following:

Front of car
---------------
| (8) | | (1) |
| (7) | | (2) |
| (6) | | (3) |
| (5) | | (4) |
---------------
Rear of car

With a " 1 - 5 - 3 - 7 - 4 - 8 - 2 - 6 " firing order, it balances the firings left/right but also front/rear.

 

Hi eric
That actually makes more sense and correspond with what I can see by looking at the left cylinder bank wiring. Wasn’t sure though because of the wasted spark set up which I assume can result in two different wiring and still work, right? Since I know that you are good electronics, have you been looking into the coil-on-plug conversion? I am looking into this and am trying to se if I can use an 8 channel AEM Twin-Fire solution. I am trying to get som help from the AEM forum but no luck yet...

http://forum.aempower.com/forum/index.php/topic,7141.msg130171.html#msg130171

 

Hi Johan

I followed the coil-on-plug conversion thread even before I took delivery of my 355. I was very interested on it but have always been concerned by the need to connect 2 coils together whatever it is in serie or in parallel. Depending on the balancing of the coils it may works well or ... not so well.
I do prefer your AEM solution and, starting with the 8 cylinders diagram, I think the only change you have to implement is to connect together, on each side, the white and yellow wires then the green and violet wires. So you have only 4 inputs to connect to the Motronic, triggering the coils in a wasted spark mode and in such a way that the coils which are fired simultaneously do not share the same capacitor.
Also, I think that it would be better to use two 4-channels modules because they can be installed exactly where are the original coils, minimizing the harness work.
One thing which is not clear in their documentation, is the capability of the system to fire an engine in the wasted-spark mode at 8600 RPM. Indeed, each coil and each capacitor are triggered 2 times more per cycle, so as often as on an engine at 17200 RPM in normal mode (single spark per cycle). That seems to exceed their 14000 RPM limit.

 

Thanks eric, great input as always! The change you suggest is exactly what I was thinking about, just not sure if it will work and if it is the way to go... Your point about the setup exceeding the 14000 RPM limit is interesting and as you say it might be better to go for two 4 channel units. The price of two isn’t that much more and might actually be a reasonable way to do it. Mille grazie

 

OH CRAP!!!

You are totally correct! Thanks for catching that Eric, and for correcting my mistake.

I'll go sit in the corner now with a dunce hat on. LOL!
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That is the direction I'm going, once I actually start this project.

 

The more I think about it the better a 2 unit setup sounds. And the AEM Twin-Fire unit is only 14 x 12 x 3.5 cm and would probably fit nicely in the space where the coils is today. And as eric points out, will result in a much nicer and simpler wireing to the coils... Done! This is what I will try to go for

The only problem now is to find the cheapest place to buy it. The US seems to be a lot cheaper than here in Sweden, almost three times actually... But it is always the problem with customs and tax that is added :-(

 

Friend of mine is a certified AEM tech and dealer. If you think we can somehow sneak this to you under the radar, I can have him check prices.

 

You are now the honorary "Sparky" of the Stooges. Plugzit, you are relieved.

 

lol...that pic is hilarious.

 

Thanks man, that would be great! Sneaking it under the radar i usually not a problem if it can be sent as a private package ;-) Could you check the price for two 4 channel unit and PM me?

 

No problem, I need a pair too so I'll see if I can get a quantity discount

It may not be until Monday due to the holiday weekend until I talk to him.

 

Havind read their documentation, I am not really sure anymore that the original coil area is the best place. It is written that the system does not like the engine bay environment, and we all know how it is around a 355 engine. OE coils are above the headers, any piece of electronics will have a very hard time there. The extreme rear corners of the car are probably better, but not as good as close to the motronic. Harness work from the rear corners is still easy, from the motronic it is much more demanding and I don't know if the length of the wires between the module and the coils would be acceptable.

 

I read the same but I guess there should be some place where you could fit it. Guess the rear corners should be on posible place... Maybe install challenge rear grille och try to get extra cooling some other way...

 

Got an answer from AEM last night and they say that there should be NO problem using a 4 channel Twin-Fire unit to drive all 8 COPS as long as they are wired in series. Maybe try that first and see if a second unit is necessary after all…

This is the basic idea they are recomending.

"A single 4-channel can be used to waste fire 8 cylinders COP. However, the coils for the paired cylinders MUST (just to repeat, MUST ) be wired in series. Check out the diagram on page 16 of the instruction manual. The diagram is for an MK-IV supra, not a ferrari, but it is a good example of how to wire the coils in series. Obviously you will need to pair the coils as needed for your engine. "
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I'll be at the dyno with the 355 tomorrow, should have a price on the AEM box.

 

Sorry, I am just getting on to this "box" issue.
What is AEM? Is that an alternative to MSD?
And, if so, what makes one better than the other? Thanks