Summary of Aftermarket ECUs / Controllers

[Whisky_Tango]

Dear all

The topic on ECU remapping or tuning for more engine power has been discussed so many times in this forum such that those useful information are scattered about.

I took the initiative to gather these info together as well as recent discussion on Apexi AFC Select and put them down here so that anyone at anytime can access it for information.

Attached Word document explains the differences of ECUs and its effects on tuning, etc... (PLEASE NOTE THAT THE UPDATED DOCUMENT IS IN PAGE 3 OF THIS THREAD)
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Hope everyone finds this useful and enriching.

If you spotted any mistakes or would like to contribute information, you are most welcome to do so.

I kindly request this thread to be free from off topic so that objective discussions can come to a point for updating.

Yours truly,
Eric Neo

[Nuke]

thanks dude

[ryan]

Sticky'd this thread.

[Geoff Ang]

wow bro... thanks man... very informative!!!

[Whisky_Tango]

Nuke and Geoff

Dun mention, I hope the write out is easy to understand. I have tried my best to make it as simple as possible especially for non-techie.

I also gain some knowledge by doing this and believe me this is only a grain worth of info. There's heaps more which Im still struggling to comprehend.

So I duno if this is a good way to consolidate the info and updating it as time fly by.

Cheers!

[Crufty Dusty]

Eric,

Good effort, maybe make some minor amendments:

Originally Posted by Whisky_Tango

As a general rule of thumb, it happens at about 20% to 30% and higher of throttle position, which corresponds to about 1.0V from the throttle position sensor (TPS). I have not seen any evidence to show that the ECU looks at any other parameter in determining when to operate at open-loop conditions. If someone knows of any other method, you are most welcome to share the info here.

The ECU also goes into open loop mode when it detects a sensor has become faulty, when the engine is cold etc.

Originally Posted by Whisky_Tango

Firstly, for petrol to burn it needs oxygen. For a complete combustion, a ratio of 14.7 parts of air to 1 part fuel should be attained. This air to fuel ratio (AFR) is called stoichiometric or Lambda = 1. This is just a ratio between air and fuel. 14.7:1 AFR is normally considered the best trade off between emissions, fuel economy and power production.

14.7 is lambda 1 for petrol engines only. Other fuels will have different stoichioimetric ratio.

[MRacer77]

Isn't the ratio of 14.7:1 a little misleading cause in actuality, the ratio for a NA car is more to be in the 12s and for FI cars in the high 11s?

[Crufty Dusty]

Originally Posted by MRacer77

Isn't the ratio of 14.7:1 a little misleading cause in actuality, the ratio for a NA car is more to be in the 12s and for FI cars in the high 11s?

No.

Stoichiometric just means that the ratio of air-fuel is chemically ideal, i.e. complete burning of reactants. In this case, for gasoline engines, it is 14.7 parts of air to 1 part of fuel. The stoich point for diesel and alcohol engines are different (can't remember the numbers off-hand).

What you're referring to are some reference points to making best torque, which are not written in stone and may vary greatly depending on load, chamber design (pent roof, wedge etc), NA or FI, compression ratio etc.

[MRacer77]

I see. Thanks!

[axl]

Wah both Erik and Eric so clever!! I'm so proud to be driving the same car as them!!

Kekek.