Alfa Romeo Owners Club of Australia Forum

Technical => 160 Series (90, 75, 164 Sedans) => Topic started by: Gusto on July 26, 2016, 06:32:28 PM

Title: Motronic tuning
Post by: Gusto on July 26, 2016, 06:32:28 PM
Hi all, can anyone tell me if the motronic injection is tuneable for bigger cams? I'm getting left for dead on the straights!
Cheers


Sent from my iPhone using Tapatalk
Title: Re: Motronic tuning
Post by: Duk on July 26, 2016, 06:43:10 PM
Yes.
What car/engine is it?
I'd still suggest going for a decent programmable if you're using the 75 or early 164 Motronic ECUs. The air flow meter on the V6 is too small (and will be hurting power).
Title: Re: Motronic tuning
Post by: ARQ164 Shane on July 26, 2016, 09:21:51 PM
HI all
I have a big afm from a 3lt 164 I've had it running in my car .
hope that helps
Title: Re: Motronic tuning
Post by: Gusto on August 01, 2016, 11:29:05 AM
Thanks guys, it's a twinspark 75. Is the 75 3L L-Jettronic AFM interchangeable with the twinspark? Or do I need to find a motronic 3L AFM?


Sent from my iPhone using Tapatalk
Title: Re: Motronic tuning
Post by: LukeC on August 01, 2016, 02:38:19 PM
The difference between the ECU set in 91 and 97 octane mode is around 10 kW at the rear wheels. This was measured on my own car a few years ago with a healthy, standard TS engine on a Dyno Dynamics dyno on 98 octane fuel (remembering that there is no difference calorific value in different octane petrols).

Aussie cars were set up for 91 octane because that was all that was available in the day.

Not that there are many T-S cars left out there on the roads, but I recently stuck one still running the 91 trim.

http://www.users.on.net/~craigf/fuelquality.htm (http://www.users.on.net/~craigf/fuelquality.htm)

Title: Re: Motronic tuning
Post by: Gusto on August 01, 2016, 05:58:44 PM
Thanks Luke! My car is a UK private import and doesn't run an oxygen sensor or catalytic converter. I'll check when I'm back home.


Sent from my iPhone using Tapatalk
Title: Re: Motronic tuning
Post by: Duk on August 01, 2016, 06:28:58 PM
Quote from: Gusto on August 01, 2016, 11:29:05 AM
Thanks guys, it's a twinspark 75. Is the 75 3L L-Jettronic AFM interchangeable with the twinspark? Or do I need to find a motronic 3L AFM?

I wouldn't be surprised if they weren't the same size already.
If they are different sizes you will probably be able to remove the circuit board and inlet air temperature sensor from the small AFM housing and put it in the larger housing. That worked for me years ago on my MR2 where I got the AFM housing from a 2.2 litre Mazda MX6 Turbo and swapped the boards.
But there's some bad news for you, there will be a calibration curve somewhere in the EPROM code to set the way the ECU reads the AFM signal. And all of the load measurements the ECU does will be based largely off that curve.
Including acceleration enrichment (no linear TPS).
If you knew where in the code that curve was and you knew how to adjust it so that the ECU functioned basically correctly, then you could re-jig the curve to suit.
Or you could get an interceptor tuner that will allow you to change the AFM signal to replicate the signal the original smaller meter would dish out for the same driving conditions, but how much time and money do you want to put into fudging an old system (no linear TPS, all injectors fired simultaneously and old school vane air flow meter).

If want to get more into playing with the Motronic and you haven't seen the AlfaBB thread http://www.alfabb.com/bb/forums/engine-management/190352-what-stock-75-ts-motronic-can-cannot-do.html I'd suggest get stuck into reading Festy's contributions to what he learned.
Title: Re: Motronic tuning
Post by: Gusto on August 01, 2016, 07:22:02 PM
I found on a photo of my plug it is red. I'll remove it and see if that helps. Thanks


Sent from my iPhone using Tapatalk
Title: Re: Motronic tuning
Post by: Gusto on August 01, 2016, 07:26:53 PM
Quote from: Duk on August 01, 2016, 06:28:58 PM
Quote from: Gusto on August 01, 2016, 11:29:05 AM
Thanks guys, it's a twinspark 75. Is the 75 3L L-Jettronic AFM interchangeable with the twinspark? Or do I need to find a motronic 3L AFM?

I wouldn't be surprised if they weren't the same size already.
If they are different sizes you will probably be able to remove the circuit board and inlet air temperature sensor from the small AFM housing and put it in the larger housing. That worked for me years ago on my MR2 where I got the AFM housing from a 2.2 litre Mazda MX6 Turbo and swapped the boards.
But there's some bad news for you, there will be a calibration curve somewhere in the EPROM code to set the way the ECU reads the AFM signal. And all of the load measurements the ECU does will be based largely off that curve.
Including acceleration enrichment (no linear TPS).
If you knew where in the code that curve was and you knew how to adjust it so that the ECU functioned basically correctly, then you could re-jig the curve to suit.
Or you could get an interceptor tuner that will allow you to change the AFM signal to replicate the signal the original smaller meter would dish out for the same driving conditions, but how much time and money do you want to put into fudging an old system (no linear TPS, all injectors fired simultaneously and old school vane air flow meter).

If want to get more into playing with the Motronic and you haven't seen the AlfaBB thread http://www.alfabb.com/bb/forums/engine-management/190352-what-stock-75-ts-motronic-can-cannot-do.html I'd suggest get stuck into reading Festy's contributions to what he learned.
Thanks Duk. I'll have a read


Sent from my iPhone using Tapatalk