Limits on the stock ECU

[V8hntr]

Please dont bash on me I am new to tuning. I wanted to tune my car with SAFC or MAFTPro but wanted to know the limits on the stock ECU. I know from the factory toyota ran the car rich to cool the combustion chamber .

1) What if I remove fuel at a certain RPM and load to make more power. Would the ECU compensate by advancing the timing ?
2) What if I run 25 psi on a capable turbo with large injectors without fuel cutoff. How would the Toyota ECU react to this extrordinary charge?

 

[Kai]

Cant say anything regarding your first question - but the ECU would pull spark if the boost pressure was raised past the 'danger' point. You'd need a piggyback to stop it doing that.

 

[Mr. Y]

Please dont bash on me I am new to tuning. I wanted to tune my car with SAFC or MAFTPro but wanted to know the limits on the stock ECU. I know from the factory toyota ran the car rich to cool the combustion chamber .

1) What if I remove fuel at a certain RPM and load to make more power. Would the ECU compensate by advancing the timing ?

+++ ECU will advance timing if you remove fuel... Actually you don't remove fuel, you say to ECU "engine consumes less air".

2) What if I run 25 psi on a capable turbo with large injectors without fuel cutoff. How would the Toyota ECU react to this extrordinary charge?

+++ Something may blow, bc ECU will see low AFM signal and advance timing too much (like it runs off boost e.g.)...
So, on the one hand running stock ECU with too much piggy-backs is not good idea. On another hand - some people (see 7Mpower.com) make great power on stock ECU.
I wish we can datalog stock timing without any corrections to AFM signal, and same - after some corrections to clarify things... Isn't MAFT-pro timing monitor working yet?

 

[dbsupra90]

highly debated. some say 500+ go stand alone.

from my experience, the ecu is completely capable to support up to 680cc injectors w/ an afc, mafpro, etc. an adjustable fuel pressure regulator helps dial it in as well.

anything bigger than 680cc it had a little trouble dealing with.

with a standalone you would have complete control over everything, and most likely be able to make more power. but a standalone isnt for everyone, and not required for most setups.

 

[V8hntr]

With piggy back systems such as SAFC II or Maft pro timing cannot be monitored or manipulated Can it? I have to save my pennys for Motech or AEM systems

 

[dbsupra90]

w/ the maft pro you can monitor, and manipulate timing (altho the harness to be able to change timing hasnt be released yet). not w/ the afc tho.

 

[V8hntr]

+++ ECU will advance timing if you remove fuel... Actually you don't remove fuel, you say to ECU "engine consumes less air".


+++ Something may blow, bc ECU will see low AFM signal and advance timing too much (like it runs off boost e.g.)...
So, on the one hand running stock ECU with too much piggy-backs is not good idea. On another hand - some people (see 7Mpower.com) make great power on stock ECU.
I wish we can datalog stock timing without any corrections to AFM signal, and same - after some corrections to clarify things... Isn't MAFT-pro timing monitor working yet?

Andy you tell the ECU engine consumes less air basically by pegging the MAF sensor's output?

 

[bowsercake]

You can adjust timing with the GReddy Emanage unit. You need the GReddy harness and a custom signal adjuster built from 1 or 2 small electronics. There is a schematic on mkiiitech i believe. It's also on the emanage message board.

I'm not sure if anyone got the Emanage Ultimate to run on the 7M but that would also eliminate the AFM and more.

 

[V8hntr]

John Lundsford runs stock ECU and makes 435whp but he's using 9.1:1 CR I think.

 

[bigaaron]

I don't think there is a specific power level the stock ecu is good up to. The question is, how much horsepower are you willing to try to make on a questionable tune? Above 400whp, it starts to become critical that the fuel delivery and timing is right on the money.

 

[mkIIIman089]

Like JBL shows, you can easily make good power on a stock ECU. He uses JE's BTW.

Would he have made more power on a well set up stand alone and all the same hard parts? Probably.

I have found that 90% of people will tell you nothing that really holds water as far as tuning with the stock ECU in these cars. Just so you know. Experimenting with a wideband, monitoring Vf and slowly working you way up yourself is best.

 

[V8hntr]

Like JBL shows, you can easily make good power on a stock ECU. He uses JE's BTW.

Would he have made more power on a well set up stand alone and all the same hard parts? Probably.

I have found that 90% of people will tell you nothing that really holds water as far as tuning with the stock ECU in these cars. Just so you know. Experimenting with a wideband, monitoring Vf and slowly working you way up yourself is best.

Thanks Colin, And great writeup on the Error codes.:icon_bigg