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Location:
Canberra
Registered:
April 2003
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Dizzy Vs. DLI
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Thu, 27 January 2005 10:06
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Just curious what the pros and cons are between these two.
I know DLI is more reliable in theory, due to no moving parts. But i've some big numbers of dizzied engines and i haven't seen much info at all on engines with DLI.
Just trying to set some info before deciding on which engine to get.
Thanks
Steve
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Toymods Social Secretary
Location:
Sydney
Registered:
July 2002
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Re: Dizzy Vs. DLI
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Thu, 27 January 2005 10:16
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in reference to what exactly are we talking about?
there is more to consider with an engine than just the ignition system!
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Location:
Canberra
Registered:
April 2003
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Re: Dizzy Vs. DLI
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Thu, 27 January 2005 10:22
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Well, I'm looking at 4a's and theres both these types of ignition. I'll be using an aftermarket computer and the usual bolt on mods.
I'm asking which ignition is better? or if there fairly even, what are the pro's and cons.
Steve
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Location:
The Eastwood MASSIVE !
Registered:
May 2003
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Re: Dizzy Vs. DLI
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Thu, 27 January 2005 10:47
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DLI is better in the fact that it can output a higher voltage and sustain a larger primary current , hence produing a more powerfulk spark that isnt compromised at higher rpm from the effects of reduced dwell time.
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Location:
Gympie Qld
Registered:
December 2004
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Re: Dizzy Vs. DLI
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Thu, 27 January 2005 10:47
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Steve for what it's worth I'm almost certainly going DLI with my 20 valve. I'm actually going to use a trigger disk off the crank pulley with an ABS sensor as the sensor. Primarily as I want more space around the back of the motor (non toyota recipiant car).
To provide food for thought (and I can't comment with first hand experience on this comment) my tuning person (or should be) said that a crank system will work better than the crank sensor in the dizzy because the trigger in the dizzy is quite small and running at half crank speed so at low revs does not provide a vey strong signal (remember the signal is triggered by the solid tooth running past the sensor depending on type of system) which can upset the computer and cause rough running. Whereas the crank trigger is running at crank speed and is quite large so goes past the trigger fairly quickly at idle to supply a strong signal.
This makes sense to me when you think about magnets and electric current etc but of course there are heaps of variables out there the least of which are what type of system eg hall effect, magnetic, optic and what brand of computer etc.
Gavin
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Location:
Montrose, VIC
Registered:
May 2002
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Re: Dizzy Vs. DLI
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Thu, 27 January 2005 11:52
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Also remember that running off the crank, there can be no 'home' signal, so you have to run a waste spark system, as well as no sequential injection.
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Location:
Kita-Ku, Sapporo, Japan
Registered:
January 2003
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Re: Dizzy Vs. DLI
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Thu, 27 January 2005 12:30
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and what of the coils on waste spark systems not putting out equal sparks??
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Location:
Montrose, VIC
Registered:
May 2002
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Re: Dizzy Vs. DLI
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Thu, 27 January 2005 12:57
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Crikeys, wouldn't want it to end up running like a Buick V6!
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Location:
Kita-Ku, Sapporo, Japan
Registered:
January 2003
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Re: Dizzy Vs. DLI
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Thu, 27 January 2005 13:15
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you mean horribly unbalanced and about to fall apart?
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Location:
Gympie Qld
Registered:
December 2004
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Re: Dizzy Vs. DLI
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Thu, 27 January 2005 13:27
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MRSHIN - I am looking at running the latest Wolf 3D and have been assured we can still run it in full sequential mode.
Not sure about your comments about no "home" signal but if you mean piston/tdc references etc I've been told that the trigger disk is to have 2 teeth/references 180 degrees apart one being tdc no 1 piston and the other 180 degrees out and a trailing tooth which trails number one cylinder past tdc. EG there will onyl be 3 teeth/reference points on the disk. This stuff I'm not sure about so am only being guided by the tuning shop who will be supplying the Wolf and tuning the car but apparently they have done it before.
OLDCOROLLAS - What is the reference to the waste spark systems not supplying equal spark. I have not heard anyone mention this from the various ECU suppliers/tuning shops as an issue and I have discussed whether to be running 4 single coils or 2 doubles. Why is this so. Why can't multiple coils deliver reliable spark when a single coil has to do it more often.
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Location:
Montrose, VIC
Registered:
May 2002
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Re: Dizzy Vs. DLI
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Thu, 27 January 2005 13:35
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What OC meant was that some double ended coils can be a bit questionable, obviously individual coils will deliver fairly even spark. As for the trigger issue, obviously without some kind of reference attached to the camshaft, how does the ECU know which revolution the engine is on? (Remember, it takes TWO full revolutions for a 4 stroke engine to do everything)
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Location:
Kita-Ku, Sapporo, Japan
Registered:
January 2003
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Re: Dizzy Vs. DLI
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Thu, 27 January 2005 13:49
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zactly... with a double ended coil, the spark energy travels from head, to spark plug to coil then back to 2nd spark plug and back to head... like a push-pull arrangement.. only that one of the sparks is not as strong...
i've always wondered.. why can't you use the ignitor trigger to trigger two ignitors with individual coils, rather than a single ignitor and a double ended coil.. or could you mix and match ignitors to get the right impedance/resistance?
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Location:
Gympie Qld
Registered:
December 2004
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Location:
Rocky Mountains, Canada
Registered:
May 2002
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Location:
Arthurs Creek, Victoria
Registered:
May 2002
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Re: Dizzy Vs. DLI
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Thu, 27 January 2005 23:31
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Just a note, irrespective of the issues with crank pickups, if you have a properly setup hall effect switch on your dizzy it will be fine, BUT if you have a standard toyota one, it will FUCK UP continually. They are a shit thing to use, infact they practically don't work with anything except standard management. Do yourself a favour and DON'T touch it.
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Location:
Kita-Ku, Sapporo, Japan
Registered:
January 2003
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Re: Dizzy Vs. DLI
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Thu, 27 January 2005 23:37
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| M.W.P. wrote on Fri, 28 January 2005 03:14 |
IIRC the cyl to be fired (the one with fuel) actually gets the stronger spark anyway due to the lower resistance of the air+fuel in that cyl.
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ahhh, i forgot about the different ionisation properties of the gases  , thanks 
as for full sequential and coil on plug using only a crankshaft signal? thats crap.
as Mr Shin said | Quote: |
how does the ECU know which revolution the engine is on? (Remember, it takes TWO full revolutions for a 4 stroke engine to do everything)
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Wolf may often speak of a crank sensor that is located ON THE CAMSHAFT... technically speaking, if it is on the cam, then it is actually a better "crankshaft position sensor" because it will know which valves are opening and so which cylinder is firing. if the sensor is ONLY on the CRANKSHAFT, you can only run wasted spark and 2 cyl batch injection (well you cna run sequential, but it means nothing.. and anyway, there is not much to be gained at WOT from true sequential, but that's another argument)
back to coils  i know of someone running the hyundai coils and had one (intermittently) fail during tuning (it was a Wolf), causing all sorts of starting headaches.. a new set of coils fixed the problem.
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But i've some big numbers of dizzied engines and i haven't seen much info at all on engines with DLI.
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that's because there are more motors with dizzies, and it's kinda expensive to go to DLI if you don't need to.
look at yello rollas 3TGTE.. he has DLI and getting around 185rwkw
and fwiw, i'm either going to a single coil with dizzy or twin coil with wasted spark as my next step.. the wasted spark would be controlled by a Ford EDIS4 module, and that uses a crankshaft signal (36-1 toothed wheel) to tell it which pair of cylinders is at TDC.
Cya, Stewart
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Location:
Kita-Ku, Sapporo, Japan
Registered:
January 2003
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Re: Dizzy Vs. DLI
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Thu, 27 January 2005 23:55
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| stradlater wrote on Fri, 28 January 2005 10:31 |
Just a note, irrespective of the issues with crank pickups, if you have a properly setup hall effect switch on your dizzy it will be fine, BUT if you have a standard toyota one, it will FUCK UP continually. They are a shit thing to use, infact they practically don't work with anything except standard management. Do yourself a favour and DON'T touch it.
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you mean the VR (variable reluctor) pickups? what if they interface to an ignitor to condition the signal to a 12V square wave for the ECU first? that's what im planning (since i have a brand new dizzy...)
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Location:
Arthurs Creek, Victoria
Registered:
May 2002
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Re: Dizzy Vs. DLI
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Fri, 28 January 2005 00:01
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THey dont' interface to the ignitor, they interface to a thing call a reluctor adapter.. Which I used to have. Actually, I still have it you want to buy it. BUT. I had no end of trouble with the dizzy never putting out enough power and then the reluctor adapter couldn't pick it up properly and the signal all went to shit. I wouldnt' recommend it to anyone, they're a prick of a thing.
Do yourself a favour and get it converted to a hall effect switch. It'll cost you a little bit more than the reluctor adapter, but it'll cost you shit loads less in heart ache and fucking around in the long run when you wind up the power of something like that.
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Location:
Kita-Ku, Sapporo, Japan
Registered:
January 2003
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Re: Dizzy Vs. DLI
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Fri, 28 January 2005 00:10
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ahh, thats why i was going to use an ignitor.. because the 'reluctor adaptors' suck. since the ignitors HAVE to work to make the car go, in standard form, surely they will be fine when used as a trigger for the ECU? since the ignitor usually either interfaces with the stock ECU, or directly fires the coil, you will have either a 5V or 12V square wave.. or possibly a switching earth that you can use with a pull-up resistor to turn it into a 5V squre wave...
fingers crossed.
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Location:
Arthurs Creek, Victoria
Registered:
May 2002
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Re: Dizzy Vs. DLI
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Fri, 28 January 2005 00:51
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I don't like your thinking, not at all.. Using a device that's supposed to be used one way and putting to backwards isn't what I'd class as sound. Never the less, that's just my 2c, I wouldn't do it. But best of luck all the same.
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Location:
Kita-Ku, Sapporo, Japan
Registered:
January 2003
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Re: Dizzy Vs. DLI
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Fri, 28 January 2005 01:18
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heh heh thanks ... problem is.. i have a brand new VR dizzy from toyota, and i have a Megasquirt.. and the two need to talk... oh wait, i might be able to use the VR signal conditioning circuit from the new V3 PCB MS..
http://www.bgsoflex.com/v3/megasquirt_ShemV3.00.pd f
page 3 of the schematics shows signal conditioning for coil/hall (which are both basically 5 or 12V square waves (since coil has a 'pull-up' resistor in the form of a coil)), and for VR
yayy
oh and on topic...
it's whatever floats your boat. with DLI you may be able to (depending on ECU) alter the timing for each cylinder, whereas dizzy cannot.
dizzies have been around for many years and only suffer from mechanical wear and slop. the coil output is most likely high enough that it will not preclude it's use in a performance car..
DLI is pretty, less wearing parts/slop (tho it's arguable that waste spark has even less parts and less slop, ie crank vs cam), and you cna use pretty coils.. but costs more, and needs ECU to manage it.
Cya, Stewart
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Location:
Arthurs Creek, Victoria
Registered:
May 2002
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Re: Dizzy Vs. DLI
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Fri, 28 January 2005 01:45
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Just another tip.
With waste spark you get a nominal amount of spark energy going to the cylinder that isn't being fired.. Obvious? yes..
But
If you are running LPG (and I'm sure probably carbi fed petrol) then a certain amount of gas is going to be in the cylinder that isn't supposed to be fired, yet it is getting spark...
BOOOM Backfire..
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Location:
Canberra
Registered:
April 2003
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Re: Dizzy Vs. DLI
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Fri, 28 January 2005 02:39
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Geez,
I'm in a bit over my head i think. I'll think i'll talk to the person who is gonna tune it and see what they think. Personally, i prefer a dizzy. I know where i stand with a dizzy, after playing with the old aussie V8's. Maybe its time i embraced new technology... gonna have ta find out about these new fangled "eeseeyous"
I like the idea of DLI though, as you get more dwell time on a high revving engine. And 4 coils would sure look purdy.
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Location:
Kita-Ku, Sapporo, Japan
Registered:
January 2003
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Re: Dizzy Vs. DLI
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Fri, 28 January 2005 02:43
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true you get more dwell time, but you can run a Jaycar HEI box which will increase dwell quite a lot (ie whenever the coil is not firing), which is a vast improvement over points... maybe a slight improvement over normal elec ignition...
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Location:
Brisbane
Registered:
February 2003
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Re: Dizzy Vs. DLI
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Fri, 28 January 2005 03:27
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the 'wasted' spark in a DLI system will only fire in a chamber that's post combustion with no intake valves open - unless your spark timing for that cyl is very delayed (e.g. near TDC) and you have enourmous overlap on the intake (e.g. opening before TDC) which is also unlikely as you'd get a pressure wave coming back up the intake manifold (e.g. not good at all)
stu: i've decided to try DLI on both the 18R and 1gte first - it saves having to attach the 36 teeth EDIS wheel to the crank pulley ... this is all predicated on getting suitable igniters tho  
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Location:
Arthurs Creek, Victoria
Registered:
May 2002
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Re: Dizzy Vs. DLI
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Fri, 28 January 2005 03:43
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It's gas.. Something goes wrong, it can go very wrong. Just a warning.
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Location:
Montrose, VIC
Registered:
May 2002
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Re: Dizzy Vs. DLI
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Fri, 28 January 2005 06:46
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People love blaming LPG for everything don't they The actual problem is the LPG systems, not the fuel itself...
And yes, my mother's commodores tendency to sneeze quite regularly is what inspired me to do something about it!
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Location:
Victoria
Registered:
May 2002
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Re: Dizzy Vs. DLI
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Fri, 28 January 2005 08:14
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Ive done a little bit of research on this topic because im thinking of doing it the same way, im pretty sure itll work
There are a few guys running the MS on MR2's with spark controlling the stock dizzy/ignitor
On the early 4a's from what i can see its just a 4 tooth wheel that triggers the ignitor, the ignitor shapes it and sends a square wave to the ecu, the ecu does time based advance and sends the signal back after its been delayed for the advance. The ignitor then fires the coil
In short, i think it will work, and several people have it working on the MR2 forums on 4AGE's
You are not turning the original ignitor setup backwards, just using it as intended and replacing the ECU with a megasquirt
| oldcorollas wrote on Fri, 28 January 2005 11:10 |
ahh, thats why i was going to use an ignitor.. because the 'reluctor adaptors' suck. since the ignitors HAVE to work to make the car go, in standard form, surely they will be fine when used as a trigger for the ECU? since the ignitor usually either interfaces with the stock ECU, or directly fires the coil, you will have either a 5V or 12V square wave.. or possibly a switching earth that you can use with a pull-up resistor to turn it into a 5V squre wave...
fingers crossed.
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Location:
Kita-Ku, Sapporo, Japan
Registered:
January 2003
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Re: Dizzy Vs. DLI
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Fri, 28 January 2005 08:17
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ahhhh, so the 5 wire 4AG ignitors work like the 7 pin GM HEI units?
that might be easier
i think i'll try the zero crossing detector circuit first.. is a little more tolerant of VR signals than an ignitor (ie it will detect from less than 20mV AC to over 400V AC)
then i'll try the 4AG ignitor when i get one
Cya, Stewart
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Location:
Victoria
Registered:
May 2002
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Re: Dizzy Vs. DLI
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Fri, 28 January 2005 08:31
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| oldcorollas wrote on Fri, 28 January 2005 19:17 |
ahhhh, so the 5 wire 4AG ignitors work like the 7 pin GM HEI units?
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Bingo!
I must stress that i only found this out by reading the ignitor document on autoshop101.com and other various docos (inc the MS2 ignition page ;P ) If i could get hold of a 2TG dizzy i was gonna try it out on a cro. The only difference i found with the base timming is the toyota ignitor defaults to 10degress when there is no return signal from the ECU and the GM one has a wire that when powered will return to base timing
My plan is to use the toyota bigport ignitor and coil with a MS2 on my 2TG 
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Location:
Kita-Ku, Sapporo, Japan
Registered:
January 2003
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Re: Dizzy Vs. DLI
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Fri, 28 January 2005 08:43
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i had read that doco a few times a while back, but i was unsure of the signals that come out of it, go into it, and wether the ignitor or the ECU controlled dwell..
hmm, so i need a VAST igntior, connect reluctor straight to it, send the Ne signal to MS, then MS sends the IGt signal back to the ignitor, and basically just ignore the IGf signal?
hmm, 22RE, 2SE, 4YE, 4AGE.. kinda limits the choices
it does simplify things a fair bit tho.
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Location:
Victoria
Registered:
May 2002
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Re: Dizzy Vs. DLI
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Fri, 28 January 2005 08:55
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Yeah im unsure on if the ecu controls dwell or not, but one of the MR2 guys seems to think its ECU controled, hes using the MSnS experimental dwell control on his 4AGE
Heres a link to the doco he wrote, has some information on what hes doing for ignition: http://members.cox.net/jdlaugh/index_files/Megasqu irt%20configuration.doc
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Location:
Brisbane
Registered:
February 2003
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Location:
Gympie Qld
Registered:
December 2004
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Re: Dizzy Vs. DLI
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Fri, 28 January 2005 12:52
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| oldcorollas wrote on Thu, 27 January 2005 23:49 |
i've always wondered.. why can't you use the ignitor trigger to trigger two ignitors with individual coils, rather than a single ignitor and a double ended coil.. or could you mix and match ignitors to get the right impedance/resistance?
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I'm confused here. IF you are running 4 coils don't you need a special igniter that can trigger 2 coils or you run 4 igniters. Whereas the more common Bosch one people talk about is supposed to be only able to fire one coil which can also be a twin coil.
When pricing these up whilst the individual Bosch coils are reasonably priced as are the standard igniters I was told the igniter tahn can trigger 2 seperate coils was like over $200 as it is made for a Porsche. Of course you would then need 2 of them.
This is why the second hand Hyundai twin coils and 2 new Bosch igniters appealed to me. Not much over $200 whereas if you go teh way they suggest for the 4 coils & 4 igniters it doubles.
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I supported Toymods
Location:
melbourne
Registered:
June 2002
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Re: Dizzy Vs. DLI
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Fri, 28 January 2005 13:22
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why would you need 4 igniters?
my direct fire plan involves using a custom chopper disc running off the dizzy, coupled with 4 optical sensors which run to 4 transistors, so the one ignitor runs the 4 coils, im not oversimplifying things am i?
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Location:
Kita-Ku, Sapporo, Japan
Registered:
January 2003
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Re: Dizzy Vs. DLI
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Fri, 28 January 2005 14:04
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each coil sucks about 5 amps (tho not sure about the smaller DLI coils?), and the transistors in each ignitor (except special ones) can chew thru about 5 amps.
as for your intended setup, have you considered, advance, spark time and dwell time? you will need a single transistor for each coil, and an ignitor is just a glorified transistor (with dwell and spark time inside).. basically the jaycar HEI is an ignitor, and it controls spark time, with the remaining time being dwell... it doesn't control advance....
unless you are talkign abotu a routing circuit using the optical sensors, to swich the ignitor between the coils? even then, you have to be wary of dwell and spark time.. if you are not charging the coil, it fires.. so you need to keep up the current/voltage to each coil, which makes the switching difficult.. unless you are switching the off time..
aaaanyway...
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Location:
sydney
Registered:
March 2003
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Re: Dizzy Vs. DLI
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Fri, 28 January 2005 20:50
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i would just go with what is easier to hook up
in the end i doubt u will feel any difference if u tried both setups
the run dli u need 2 pulses on the crank every revolution
and also 1 pulses on the cam every cam revolution
this is so the engine knows what stroke its on
look at the big hp v8's that still run dizzys
if anyhting just get an msd
i used to run a dizzy signle coil and an msd on my fj and i had not probs at 30 psi boost
both systems will work fine
to buy bosch ignitors new is not cheap about 200 to 250 each
you might aswell go buy an msd dis4
or even an autronic cdi which does 4 coils
these retail at 1100 bucks and have enough grunt to make yr heart miss afew beats if u do get zapped by the leads heheh
but i pressume for the hp of the 4a you wont need anything over the top most basic setups can handle 200kws
its just the crank and cam triggers that will be a pain in the arse
easiest way to fix that is to run a 4agze crank sensor instead of a dizzy unless u have a 20v
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