F355 coil-on-plug conversion | FerrariChat

F355 coil-on-plug conversion

Discussion in 'Technical Q&A' started by jeffdavison, Oct 22, 2004.

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  1. jeffdavison

    jeffdavison F1 Rookie
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    This is also an update on a couple of other threads I have out there.....

    Getting things prepared to install the DIS-4 in the 355. A bit of a discovery regarding the 5.2 lost spark igntion, flat crank, and firing order.

    It appears that the cylinder pairs 1/4, 2/3, 6/7, and 5/8 ignition are fired at the same time instead of one spark per each single cylinder. When one of the pair is at TDC the other is on the exhaust. Hence, one spark is "lost". The coil has a an add on sticker that shows the pairs and that is how the wires are attached, even though the molded in numbers in the coils body are different I'm assuming this is because of the flat crank.

    This caught me just a little off guard. Just want to be sure before I actually hook up everything and fire it for the first time.

    On an aside, as noted in a previuos thread, I was looking into alternate plug wires. On the 355 just before the 4 hole grommet the cables pass through before they exit the back of the cylinder head is a narrowed passage way. While 8.5 mm wires will clear the area where the grommet was (can't use the grommet becuase of wire diameter) the 4 wires will not fit in the narrowed passage way and have the cover fully screwed down. Maybe 7 mm wires will fit and have the cover close (that's the stock cable diameter), but most "performance" spark plug wires I've seen don't come that small.

    Since I'll be using "coil-on-plugs" from a Suzuki GSXR, I dont have to worry about this diameter. I do have something else to address however. The GSXR are the shortest c-o-p's I could find, but they sit 1/2" higher than the stock Beru plug connector. I could elect not to use the cover, but I'd like a cleaner look and still be able to use the stock "Ferrari" labeld cover. I'll be fabricating a spacer that will go between the cover and head so that the C-o-p's will have the clearence they need while retaing a stock look.

    Will up date as this proceeds.

    JD
     
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  2. FL 355

    FL 355 Formula 3

    Nov 3, 2002
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    Jeff thanks for the update. I may follow in your footsteps. As you go along can you also include some pix? For example the spacer...I want to keep a clean and stock lookk also. Would appreciate a breakdown of cost for the project as well.

    Look forward to your results.
     
  3. ferrarifixer

    ferrarifixer F1 Veteran
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    I was surprised how "cheap" 360 ones are....around AUS$140 each list.

    I'm intrigued as to WHY? for 355
     
  4. jeffdavison

    jeffdavison F1 Rookie
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    Update:

    Installed ignition box installed in tail of 355.. Fabbed up wiring harnesses & connectors.
    About 2 weeks out for the cover spacers, but should be testing early next week as time and weather permit.

    JD
     
  5. fatbillybob

    fatbillybob Two Time F1 World Champ
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    Jeff,

    I missed the story... Why are you doing this? How do you trigger the cop's? Are these stock suzuki parts or do you have to make plug extenders? Are you using the stock motronic which triggers the ingitor which triggers the dis-4 to trigger the cop's? I'm confused as to how you trigger these and interface with the motronics.
     
  6. jeffdavison

    jeffdavison F1 Rookie
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    Simple...

    the connector that went into the coil pack, now goes into the MSD DIS-4. Motronic is a lost spark setup and has a total of 4 channels driven. 1 coil pack per bank of cylinders.

    In turn the MSD then fires two of the coils in parallel 1/4, 2/3, 5/8 and 6/7 according to firing order.

    The Motronic sees the DIS-4 as it would normally see the coil packs, then the DIS-4 triggers the coils.

    I'm tossing the stock coil packs and spark plug cables.

    Stock Suzuki GSXR coils. no extenders needed, but they are longer than the stock plug boots so I'll be machining a spacer for the cover to fit over (1/2" thick). Honda cops can work also but are another 3/4" longer (I'll be using those on a 308QV I'm building for my Stratos replica as they are the perfect height).

    MSD is a multi spark high output ignition box. Give a multi low & mid rpm spark as well as a higher output high rpm spark.

    Better performance at 1/3 the cost of new FNA supplied plug wires.

    JD

     
  7. fatbillybob

    fatbillybob Two Time F1 World Champ
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    Jeff,

    I love your idea! I'm a great part replacer but not an inovator. How do you know which ferrari wires that go into the ignitor go to which DIS-4 wires? I also assume you are using one DIS-4 to control both sides when you have two ECU's so does that mean you are taking the passenger side ferrari wires going into the ignitor and splicing those into the same place on the DIS-4? Sorry I'm a bit clueless.
     
  8. jeffdavison

    jeffdavison F1 Rookie
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    Drawing shows stock coil packs. In my application I'm using 4 c-o-p's instead of one coil pack per cylinder bank. Picture is worth 100 words:
    Not rocket science...This is really a no brainer.
    JD

     
  9. Harta320

    Harta320 Karting

    Nov 6, 2003
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    Hey Jeff, Nice work.

    I see that you plan on making this set up for the QV engine. I would love to do something like this for my QV. How tough would this mod be and can you give some details. Thanks!

    Bill
     
  10. jeffdavison

    jeffdavison F1 Rookie
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    The one I'm doing for the QV on my Stratos replica will have a Motec. THe only way to do the c-o-p is to use an aftermarket igntion system. I'm not at all familiar with any other system other than Motec or F.A.S.T/ (aka "Speedpro - on my turbo Lancia Scorpion).

    Jeff


     
  11. Harta320

    Harta320 Karting

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    Thanks Jeff.

    I thought the trigger would be a problem with the stock system. I am guessing you are making the eng. EFI. That might be my next project so please keep the updates coming. Thanks again.

    Bill
     
  12. jeffdavison

    jeffdavison F1 Rookie
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    Stock trigger on the 355 should not be a problem. The stock coils are "dumb". The stock trigger (embedded in the 5.2 motronic ecu's) simply send the signal to the DIS-4 which then in turn drives the coils. Simple in-line setup.
    Here's a pic of the left bank. I should get my cover spacers in about 2 weeks from my machinist to keep the stock appearence.

    JD




     
  13. jeffdavison

    jeffdavison F1 Rookie
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    OH BABY! LIGHT MY FIRE!!!!!

    Just did an initial shake down. Great results. Start up is faster, idle is much smoother, off idle acceleration smoother. overall the engine has much crisper acceleration at all rpms. NO check engine lights. Bosch 5.2 Motronic is happy.
    Comes "on song" quicker and sings in a purer tone! Maybe a few, seat of the pants, horsepower as well

    I have one minor tweek to do on the box. Seems I forgot to change the RPM limiter on the DIS-4 from 6250 to 8500. Final shake down tomorrow, weather pending.

    me so happy :)

    Any one want to buy a good set of stock 355 coils and plug wires? I'll make you a deal ;^P

    JD
     
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  14. Harta320

    Harta320 Karting

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    Sorry Jeff, I did not explain to well. My post was refering to the converted 308 engine that you are also working on. I have an 83 QV and would love to convert it to the COP setup. I kind of guessed that the stock trigger system would not work. I am guessing that you will make the 308 engine EFI or do you just plan on using the Motec for ignition.
     
  15. jeffdavison

    jeffdavison F1 Rookie
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    I understood you perfectly :)

    The 355 is using the stock electronics. No modification (other than tossing out the old coil packs and plug wires) at all. No aftermarket ecu. Just the MSD DIS-4 amplifier as described above. Very simple and straight forward.


    To do my 308QV, I'll be going the aftermarket ECU route. I'll be using the Motec for the 308, that's the only way for the individual coil-on-plugs. The Motec needs a trigger for the coils and I''ll be using a pair of Bosch triggers from an Audi 1.8T to fire the individual cops. The system will be using 8 channels, one for each cylinder and not a lost / wasted spark as the 355. I had a couple of the Bosch triggers from my last daily driver ('98 A4 1.8t) and they were described in the Motec "Grail" (downloaded literature). To do 8 seperate channels I'd have to use 2 DIS-4's. Don't need to spend the money when the parts I have on hand will work the way I need them to.

    Alas I don't think it possible to do the cop on a stock QV setup.

    JD

     
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  16. fatbillybob

    fatbillybob Two Time F1 World Champ
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    Jeff,

    VERY CLEAN! Also are you dumping a 308QV motor in a Lancia beta scorpion or are you building some kind of lancia stratos from a lancia scorpion?
     
  17. fatbillybob

    fatbillybob Two Time F1 World Champ
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    Oh...why do you need to set the rpm limit in the dis4. Isn't that still controled by motronic 5.2?
     
  18. jeffdavison

    jeffdavison F1 Rookie
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    I'm putting the QV into a Stratos Replica. Complete kit from Hawk Cars UK (I'm their U.S. Agent). Turbo Scorpion is my other toy (besides the 355). They are seperate projects Yes, there is a Fiat twin cam burried in there somewhere!

    JD

     
  19. jeffdavison

    jeffdavison F1 Rookie
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    It has a built in limiter that is defaulted to 6250. 5.2 has it's own limiter but the DIS-4 is built in and not bypassable so it has to be set.

    jd
     
  20. FL 355

    FL 355 Formula 3

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    Nice going Jeff!

    Sounds like a great improvement. Post again after rev limiter has been reset.
    I'm really interested...
     
  21. davehelms

    davehelms F1 Rookie

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    Very nice work! I have often wondered if the multiple spark would help on these.
    Dave
     
  22. jeffdavison

    jeffdavison F1 Rookie
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    Just like before! THIS is the setup to have on a 355! SMOOOOTH right up to redline.

    Smother Idle, much better off idle acceleration, crisper acceleration better running through all gears and more seat of the pants power. Burns the fuel more efficiently and I seem to get less of the usualy "Tubi" backfire noise than before. Well worth the effort. Absolutely no problems with the factory ECU's.

    With K&N's, Tubi & Dis-4, this 355 is much better than when I drove her stock.

    I'm going to look into what it will take to outsource the wiring sub-harness that I had to fabricate, if anyone else is interested as this took me about 3 hours to fabricate using recycled motorcycle coil connectors (had to rebuild them to re-use). I need to find where I can source new ones as these seem propriatory to the Desno c-o-p's. The MSD box comes with a harness that need cutting to length and adding connectors (Bosch & weatherPak).

    A handy DIYer could do this themselves, but it's much easier to just plug and play. Also, I was at FOA the other day and the older 355's may need another place to mount the box as the space I used in my '97 (5.2) is filled with other goodies in the 2.7. I only had to drill one small very inconspicuouse hole for a mounting bracket on the back side of the MSD. I used existing hole & fasteners to secure a front mounting bracket. I hate to drill holes in my car If I dont have to.


    Here's the final cost tally:
    DIS-4...........$330 Summit
    connectors.....100 Bosch / WeatherPax / Amp
    wire................25 McMaster Carr
    Coils...............75 Suzuki GSXR on eBay (around $400 new retail)
    Spacers.........150 E-Machine Shop
    Spark Plugs......60 NGK Iridiums (COPS need the 4mm threaded end)
    ------------------------

    Total............$740


    This doesn't include my labor for parts fabbing, (wiring harness, mounting brackets, and secondaries i.e. hole drilling on the spacer)

    Need to mention also that the Coil On Plugs NEED the 4mm threaded contact. They won't work with the solid non-removable ends. That's ok with the availability of the new less expensive NGK CR7IEX Iridiums plugs.

    Best of all, NO SPARK PLUG WIRES!!!! @$150 per cylinder
    At this price, it's worth it just for the cost benefit, but if cost and performance is an issue, then there is absolutely no excuse not to do this mod.


    JD
     
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  23. tbakowsky

    tbakowsky F1 World Champ
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    This is fantastic!! What a great mod for the 355..I always wonder why Ferrari never went this route to begin with on the 355.

    Will you be offering this in a kit for sale..If not I would really be interest in a "how to" type instruction. If at all possiable could you post or e-mail me they way you did it? I would love to do somthing like this for a customers 355 but time is money in a shop..and I can't be tying up peoples cars experimenting. Thanks so much for this thread very informative and extremly useful info..in a word..awsome!!

    Tom
     
  24. Birdman

    Birdman F1 Veteran

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    Which Honda model COPs fit the 308?? Has anyone done this for a 308 yet? Seems like a great way to get a hotter spark with good reliability.

    Birdman
     
  25. jeffdavison

    jeffdavison F1 Rookie
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    As soon as I can source the conectors and find a subcontractor to make the harnesses and get a quantity pricing on the spacers and mounting brackets, I'll probably kit it out. Now if there's a volunteer 2.7 355 owner in the Atlanta area who would like one, I'll work with you on the install, that way I can determine a good mounting location for the early 355's. More than likely this will cause the wiring harness to either be shorter or longer. I'd also probably kit it with new coils instead of sourcing used ones on eBay. That would drive the price higher and make this a less cost effective mod, but still worth the perfomance upgrade.

    Once all the parts are fabricated the install itself is about an hour. The time killer is making the parts.

    JD



     

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