I found out MINIs are stupid.
The R53 supercharged engine I have has suffered a terminal failure. The stock R53 is 8.5:1cr.
It does, however have a LOT of serviceable parts.
I also have a R50 natural aspirated engine in another car. The stock R50 is 11:1cr.
Those who have assembled Lego that shouldn't have been assembled please chime in on what I am about to ask:
If I run a larger injector, say 800cc vs 420cc, a new timing set, a SFI approved balancer, a larger 340lph fuel pump and run E85 fuel would I REALLY need a tune in the OE supercharged ECU?
I know it SHOULD have one, even stock setups can be improved by tuning. But what is the probability of failure?
The basic math of a nearly double flow rate injector and e85 instead of gas should be fairly close to correct. It may be on the edge of what the factory ecu can adjust to, but not far off. That all assumes the injector specs are close (resistance, dead time, etc).
The fuel injector calculator I see is pretty basic, but it is recommending about 650cc injectors if you are doing JUST the injector swap and going to E85 from pure gas. Not sure how the other mods you are planning will affect it. Someone more knowledgable then me can chime in, I have my 0.02c
So, you're changing the compression ratio, injector size, and fuel chemistry.... It might run without changing the tune, but it's going to take a performance and drivability hit in the best case. I would have this tuned properly.
Challenge car? How about a double stack of head gaskets on the R50 engine to drop compression?
