I just spoke to me dealer yesterday and he had a couple of interesting things to say on the subject of performance mods:

With regard to the ECU, he said that part of its job was to try and achieve an air:gas misture ratio of 14.7:1. The ECU is a work-in-progress and at present it is capable of achieving this up to about 4000 RPM. Above that it pretty much gives up and just injects fuel at a predetermined rate that is designed to be a rich mixture. This was to prevent engine "detonation" (his word). The upshot is that going to a reputable ECU tuner would not violate the warranty but adding something like a new intake would make the ECU's job harder. Any thoughts?

He went on to speculate that the right combination of mods could bring the Mini engine up to 300hp (I think he was exaggerating) BUT, when you get to a point where you are generating more than 140hp per litre, you can pretty much guarantee that you'll blow the rings at about 80,000 miles. Any comments on this?

Thus he speculated that the John Cooper Works kit would come in around 200-210 hp and would include a new supercharger, new head, new exhaust and would be quality piece of work. He guessed that it would be available toward the middle of this year but would not comment on the price.

Cheers,

Chuck

 

Correct, one of the ECU's jobs is to keep A/F at close to 14.7:1 during normal operation (steady state). The O2 sensor before the cat monitors this mixture and the ECU tweaks injector pulse widths correspondingly. WOT is a completely different matter. As I have measured with a wideband A/F meter, the mixture is very rich, even stock, and even at low RPM. At 4,000 RPM the A/F is about 12.5:1 and it keeps getting richer from there. The ECU needs to do its job, regardless of the presence of intakes, exhausts, etc. Electronic systems like this don't wear out from doing too much work.

 

1.BillyT is a legend in the MKIV forum.

 

Wow you weren't kidding! 362 hp out of a 1.8 L engine is very impressive. But at over 200 hp pr litre what would that do the longevity of the engine? One thing I forgot to mention was that the dealer had said that the designers were being purposfully conservative in order to get 200,000 miles out of the engine.

Chuck

 

it all depends on proper tuning and some internal work. with the right tuning and beefed up internals you will be safer with more power. we've got one guy on our site (www.focaljet.com) running this:



with stock internals and AWESOME tuning. the red run is just the turbo the blue is with a 75hp shot of n2o. it's totally street legal and 100% reliable. in fact the car has well over 50k on it, is drag raced weekly, and is running like new.

it's all about the tuning.

Nate

 

oh btw that is with a 2.0 Ford Zetec motor.

 

Here's Billy's car with:

blue: no nitrous
red: 40-shot
green: 65-shot

:smile: