After spending a lot of time with my celica off the road, the components for the engine that me and a mate are building are ready for assembly. The efi setup to be used came off a 2tgeu, however the computer to run my setup was always going to be aftermarket. Originally, I was going to get a fuel only (Microtech LT4 was the preference) and run with the electronic ignition and current ignition curve. After talking to a mate briefly, he suggested I get an ecu with ignition timing and a dizzy setup to suit.
-What is involved in converting to ignition control? Crank angle sensor? Do I need to install something before the engine goes back together?
-Cost wise? How much extra do you think?
-Performance? Are the benefits going to be significant?
-Can't the fuel delivery be mapped to existing curve with good results?
Thanks Guys. Let me know if you require more information. I'll need to do a bit more research yet, but perhaps you could point me in the right direction.
Cannot supply answers to all your efi questions mainly because I am a carby man but,
Something to remember, if going to a crank angle sensor, which I recommend doing if the engine is going to run constantly and hard at high revs:
For the 2T/3T/2T-G motors the distributor cannot simply be dispensed with as it engages the oil pump to drive it.
I believe I have seen a set up around, which uses a toothed gear as the rotor on the distributor as the trigger for an ignition computer.
The solution, I would have applied if still running my 2T race motor in competition was to ditch the distributor and the oil pump, run a dry sump set up and crank angle sensor.
You should be able to make something to cap the dizzy off, just keep the shaft and the gear, machine the dizzy off and make up a cap to hold the shaft.
Alot of the time your choice of trigger will largely depend on your choice of computer, as some require specific signals.
There are plenty of ways to trigger the computer though, a crank toothed wheel, etc. If you have an electronic dizzy, you should be able to trigger off that, keep the dizzy (ie: single coil) but still have full control of ignition.
As for the first question. You generally can assemble the motor as all triggers are generally external ie: in the dizzy, or on the crank.
Second question, If you get a computer that can trigger off a VR sensor, and has an ignition driver that will trigger a coil. It wont cost any more. But if you want to go silly with COP and ignitors to suit, it then adds up. and you WILL need a custom trigger setup
Performance will be significant if your ignition curve is considerably better than the last. If the mech/valc setup was fine it wont make much more power. Mech/vac setups can wear and wont keep the same curve etc. Add to that full ignition control means forced induction will be easy in the future if you so desire as you can easily implement boost retard
As far as ignition control is concerned, what is your purpose for this engine? Is it a daily driver or do you intend on wringing it's neck for h.p.?
Really, electronic ignition will run the car reliably with no problems. The only reason to upgrade is to chase more power by running a more aggressive, non-linear advance curve. Also remember that you can get your dizzy remapped. But if you did decide to control fuel and ignition with the computer, your best bet would be to adapt an optical/VR sensor to the distributor (This is basically a cam angle sensor. This is the signal most ECU's need for spark). Really, it is incredibly easy to do. You'll probably get a sensor with the ECU and instructions for the required signal. Then you can get a toothed-wheel milled up to mount to the dizzy shaft, and then all you have to do is program it!
Cost wise, you can do it cheaply if you are handy at making brackets and are good friends with a machinist.
Sounds like a plan. I'll look into the "next up" microtech computer with ignition control, do some more research and see what I come up with. Thanks for your advice though guys. Much appreciated.
2t/3t efi ecu/ignition q's
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