AE101 throttle body on an AE86 what ECU?

[megabob]

Hi all,
when using a AE101 throttle body on an AE86 what ECU is best to use. as at the mo my AE86 is running carbs and has no ECU

[Chrisso]

Any aftermarket ECU of your choice. While alot of people tune them on speed-density (map vs rpm), you may benefit from have a computer capable of alpha-n (tps vs rpm). I would guess that most, if not all, ecus should be able to do this.

The reason for alpha-n is that ITBs severly limit the resolution of your map signal. That is, most of your reading will be in the close to atmospheric range.

Some ecus will happily run a blend of SD and AN as well.

[megabob]

yeah in my previous car i installed a Megajolt system and it was setup using MAP which isn't the best method as it measures the vacuum which is constantly changing, i was advised to convert it to TPS as its a much more digital based signal and wouldn't fluctuate the advance curve so much.

cheers for the advice, i think im gonna try and work on my FCR cabs and see how it goes. if no luck then i may start saving up for ITB's

[Ivan141]

What I havent heard up till now is how the ITB'd guys using vacuum buffers are doing. Seems like a better solution than alpha-n, which is an algorythm that doesnt take engine load into consideration at all.

[robokill]

K to put em up for you.

Get the itb's and an adapter plate.

Get an programmable ECU.

- omex
- megasquirt
- Motec (very good but really expensive model 4 is about 3k)
- etc

Get all the needed parts. Think about all ways to measure and calculate the amount of air with fuel is needed for the best mixture.

so:

- Wide band O2 sensor
- crank sensor (or original one)
- Map sensor
- TPS (you can use original 20v one)

With these componements you can measure all needed info on the engine for the best tuning. Using a wideband o2 sensor makes it possible to tune it on the street.

[Chrisso]

Ivan - I've heard success stories with both speed density and alpha N on ITBs. This is across a range of vacuum solutions including accumulators and reading off a single runner. Also, I think MS2 Extra is compatible with an Air flow meter which may be the best solution for ITBs, but I'm not sure on the details of the calculations that incorporate it. I can't say that I've looked at AFMs much at all.

[Ivan141]

An AFM kind of ruins the whole charm of ITB's if you ask me. But it is an excellent way of measuring airflow.
A way to get the best of both worlds would be to pick an ECU that can run blended speed-density/alpha-n, where you use alpha-n for the range where the map sensor is lacking in resolution.
Problem is that it will probably be plenty more difficult to tune.

Anyway, this is just me chewing out some theoretical solutions. I have no experience with ECU tuning, hoping to start next year, but it'll be on a turbo engine so no problems using speed density there.
From what I've picked up alpha-n is a solution for extreme engines, preferably used in race applications where you will be at WOT most of the time anyway. For a streetable engine I think it's worth the extra effort to take an actual parameter for engine load into the equation (such as map/afm).