[HugoB]

I recently installed the Madness CAI/Cowl mod and plan on installing a Borla "street" or Milltech exhaust. I may consider a 15% pulley in the future as well. I have seen posts from people who dyno'd some of these mods and found little or no improvement. I thought I read somewhere however, that it may take the MCS ECU up to 800 Kms to adapt fully to a lower restriction intake, or reduced exhaust pressure. This would tend to invalidate before/after dyno results from people who are bolting stuff on and immediately re-testing their car. Can anyone verify the learning capabilities of the MCS ECU?

[Root Ginger]

This is a myth. The ECU has no learning capabilities as such. Any improvment should happen instantly with a new part. It's more the owners getting used to it themselves.

The ECU makes thousands of calculations a second so why should it take any sort of mileage to realise it could be utilising extra air. It simply doesn't work like that.

The car is constantly adapting it's settings to cope with the conditions at the time. Whether the ECU can adjust enough to cope with new parts is another matter entirely.

[HugoB]

Perhaps "learn" was the wrong word. Some further google searches revealed that the ECU's have a number of algorithms that react to different engine conditions, such as knocking, pinging, etc. Each starts off with a baseline that advances or regresses over time. I found one entry from Vishnu Tuning (re. Impreza WRX) with instructions on how to make the ECU switch from baseline settings to a more aggressive algorithm by manipulating the throttle. Vishnu Tuning mentioned settings 1 to 16, with a baseline of 8. (These guys are well regarded Evo tuners) If the Mini ECU functions the same way, it may indeed take time for the ECU to switch to more aggressive algorithms as it reacts to more airflow, no pinging, etc. Some write ups from JCW also refer to this type of process. Anyone try to make mod., dyno it, drive for a while and dyno it again??

[DaFlake]

The two mods that you mentioned are not going to give you huge increase in perfomance alone. Once you do the 15% pulley, you will notice an increase. However, I recommend that you get the car tuned to take advantge of the mods that you have. I run MTH (my preference) but there are a few others out there as well.

[roland2003]

The bulk of the trimming change for items such as intercoolers (lower intake temp) or pulleys (more boost) are instant. The 'T' map sensor is mapped to the ecu already and just access's the relevant part of the existing map. Fuelling to maintain 14.7-1 AF ratio at idle & part throttle will correct accordingly as soon as the sensors are warm enough & it goes into closed loop. The long term just re -zeros that nominal point. Therefore even if you change injectors or fuel pressure (within its adaptation range )you will still get 14.7-1 AF ratio at idle & part throttle. Multi applicative adaptation also corrects to AFAIK also incorporating 'target lambdas ' outside closed loop. Its very clever,and I dont claim to have sussed it all. Im still sussing (ie trying things out) as we speak.
Knock tends to retard the ignition ,but if you then potter around for a day or so,then suddenly 'floor it' the timing which will have progressivly re-advanced back to nominal will often cause it to pink again. In other words dont rely on knock sensors to give the timing you want ! Advance curve needs to be right , idealy only a hint of pinking (and therefore retarding) occuring under extreme situations.
An ecu reset sets everything back to nominal.If the adaptation is slight its usually all corrected in a very short time. Where big corrections are required Ive found upto about 3 days is a max. There is only a certain amount (percentage) of correction the ecu will allow, but it appears to be quite a lot.
Best Regards Roland GTT

[Robboc]

I wish i was as clever as Roland

I have just had a remap and 15% pulley installed on my MCS and can definately say it has made a HUGE difference to my machine. I would definately recommend it.

[HugoB]

Thanks Roland, for an obviously well informed reply. With all the people running dyno tests out there, I found a lot of conflicting information on the effects of say, intake changes. Once I narrowed down my research to reputable tuners such as Dinan and independent magazine tests only, I found some consensus that a low restriction intake makes a bigger difference than a low restriction exhaust. A pulley change, of course, makes the biggest difference because of the increased boost pressure. (also kills the balance of my warrantee however) But back to remaps... I found one magazine test where a remap from a reputable source caused the engine to run too rich once over 4000 RPM, which actually decreased power. Once the pulley, intake and exhaust are installed, what type of further increase might a good remap provide?

[DaFlake]

The idea of the remap is not to think of it in BHP but rather a way to fully exploit your mods. The biggest issue I have with the remap ads is that they leverage on BHP rather than what they are really designed for. Yes, you will see some BHP increase but the biggest thing you will see is the driveability of the car. So, a remap will take all those mods that you did and allow the car to make the most of them. Bottom line is that it is a way to tell the car computer what you have done to it to get the most out of it.

[roland2003]

...Ive tried running our car as rich as 9.3:1 A/F ratio (0.63 Lambda) which is ridiculously rich yet power (butt dyno) still gives pretty reasonable power. Any richer and it does eventually misfire. Mind you goes to show how good the 40KV coil pack + Livewire Leads + NGK Iridium plugs are.Best Regards Roland GTT