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Hi Andre/Fellow Tuners,
My buddy owns a 1993 Suzuki Swift GTi, the ones that came with the G13B engine. Basically a 1300cc DOHC EFI 16 valve engine running a distributor.
He is in the process of fitting an AEM EMS4 to the car to run the engine in place of the factory ECU but he's making some radical changes to the engine that I'd like some insight into problems/considerations he should be aware of.
What he's wanting to do, is to run sequential injection as well as convert the engine to coil on plug ignition. He's planning on doing this by using some smart coils (not sure on the specifics of the coils) together with fitting the engine with reference trigger information from a hall sensor on the crank. From what he's telling me, the guys that are doing the install say they're gonna get synchronization trigger info by leaving the distributor on the engine and modifying same in order to get this info....the ECU will be driving the coil on plug ignition system to provide the engine with spark.
I'm here providing support based on what I've learnt through all the HPA courses/webinars. From what I know you need a sensor on the camshaft in order to get engine position data to run sequential injection.....can what these guys propose to do with the distributor work in replacement to this?
Lastly what are some further considerations that we should be aware of in terms of providing the ECU with correct triggering information?
The distributor turns at the same rate as the camshaft, so you can pick up the engine phase from a simple trigger in the distributor housing.
Verify that the trigger mode they are implementing is supported by the ECU. Usually I will try to configure the ECU triggering, and that will tell me what it can really support. For example, I learned in the Infinity 508, if you wanted to use the MZR (Miata MX-5) Variable Valve Timing, it would only work with the factory 36-1-1 crank trigger and the stock cam triggers. I had a 36-1 fitted and had to machine off another tooth.
Getting cam and crank single from a distributor isn't uncommon. For example, on V8 engines Holley offers an aftermarket distributor to do that: https://www.holley.com/products/ignition/distributors/parts/565-100
In the late 80s through mid 90s on a lot of cars had sequential injection with electronically controlled distributor. I agree that he should confirm with AEM that the signal he is generating will be accepted by his EMS. Basically, you need to work backwards. Figure out what signals the ECU can handle, and then figure out how you are going to generate it accurately.
There are two basic ways of coil on plug. Dumb coils would be in say an old Nissan RB engine. The coils just generate the spark, and then a separate ignition module has heavy duty transistors to trigger them. Smart coils are like what's in an LS1 engine, where each individual coil has its own transistor to trigger it inside the coil. That allows easy individual cylinder spark control as long as the ECU can handle it.
Those smart coils are typically variations on the GM style coils that came to market 20 years ago ("LS1 style coils"). http://www.aemelectronics.com/files/pr/071211_High_Output_Coils/High_Output_Coils_PR.html
Hi- So you are going to fit ? Or it already has a toothed wheel on the crank ? How many teeth?/ Gaps ? .. And With the distributor you just need one sync reference tooth . So if it currently has 4 teeth maybe 3 can be machined/ground off . In any case what you are proposing sounds doable .
Couldn't they convert to g15a electronics (waste spark), camshaft and crank trigger wheel?
I've attached a photo of the trigger wheel they're gonna use on the crank. Basically once the EMS4 can accept this then it's all good? What about the distributor, does another sensor need to be mounted there to pick up the rotation off the cam?
Ken, no they're adding this trigger wheel to the crank it wasn't there before. As for the distributor, when you remove the other teeth to make only one input per rotation, would they need to fit a hall/optical sensor to pick up the single input?
Shawn, I'm not sure why they didn't go that way with the g15 stuff. Maybe the wasted spark coils wouldn't fit properly on the g13?
Yes, you'll need the equivalent of a cam sensor mounted in the distributor. Again, could be hall effect or variable reluctance (magnetic) -- You should verify that the crank and cam sensors are of the type that the AEM EMS4 will accept.
The picture is of a 36-1 crank trigger wheel.
Understood. What about the effects of taking an input from the distributor, would that be susceptible to what Andre spoke about in the triggering webinar concerning belt stretch, valve train harmonics etc and the possibility of the sync tooth crossing over with two of the ref teeth?
I don't know the particulars of the Suzuki GTI distributor, but normally those mechanisms are designed to stay closely in sync with the crankshaft. Design of the trigger and it's relationship to the crank sensor is something to be aware of for exactly the reason you mentioned.