4AGE NA ECU used for turbo

[CHB]

"
This setup is good to run a turbo 4AGE with stock ECU up to a boost cut of around 14psi. It may or course need adjustment of the fuel pressure to do so safely, but that's best done on a dyno, or with a wideband O2 sensor. I've been in contact with a dude from Turborolla website, who is running the same setup as I'm going use, even the same turbo. He's using the 4EFTE sensor and the 4AGZE injectors.

Use a Toyota MAP Sensor, as the plugs are the same three pin plug. Use either the 4EFTE one or an early model 3SGTE one, as they are both 2 BAR sensors (fuel cut will occur at around 14psi

The 182cc injectors use the stock MAP sensor from max vacuum up to 0 vacuum, (no turbo, so no boost). That will go full scale of the MAP sensor voltage 0-5v.

With the 4EFTE MAP sensor, it will run from max vacuum to 0 vacuum in a scale that's 0-2.5v, then boost to 1 BAR (~14psi) 2.5v to 5v.
"
The voltage range might go the other way (0v for max load on the N/A sensor), but the theory is still sound...

So, now as you can see you have half the voltage scale in the vacuum range, so thus the reason for using injectors that are twice the size of stock (182cc vs 365cc).
This works because the basic trend for fuelling of an engine is linear (take away compensation of water temp, air temp.... and stuff like that). I've been looking at fuel maps on my mates Hondata S300 and a stock 4AGE MAP someone had posted on the intenet.

It all works out quite nicely, except when boosting high, where you might need to use a rising rate fuel pressure reg, as the differential pressure in the plenum will lower the effective fuel pressure. Eg 10psi boost and 50psi fuel pressure, will effectively be like 40psi fuel pressure due to the pressure differential. Well that's my theory anyway. I'll be testing this with and without a RRFPR on my car. "

i've read this from club4ag.com and all my friend running similar setup about this. the car response great. I've done A/F ratio logging and i found out that it idling at 10:1! it only goes leaner when i left off my left foot off the pedal.

i'm trying to figure out how the ignition timing will be. as the ECU are for NA, that means it won't retard the timing when boost comes in. then we are talking about 30+degree of ignition timing with boost around 14psi! that is quite unexplainable.
any one can clear out this thing?

[CHB]

sorry double post..

[celicapain]

hmm, sounds like a clever way of doing it(though a bit dodgy, your always going to need to run it pretty fat a a safety margin).Have you had a look at one of the jaycar programmable ignition kits?
Thats probally the cheapest way to get some control over the ignition, though from memory they arn't boost referenced so youd have to run a fairly retarded ignition map as well. If you add up all the work and time your spending on doing this youd probally be better going full aftermarket, and be able to tune the engine properly, probally make more power and definatly have a more reliable package(thats my sensible side though, and most sensible people dont modify cars).
Best of luck anyway