M20B20 engine AFR

Hi!

I'm reading lots os post's and topics in this forum but i have so many doughts

In my BMW E21(only to drift), i have a stock engine with turbo, Speeduino ecu, external westgate, Dump Valve....

What is the best AFR to tune this engine??? And...by your experience... with stock internals maximum turbo pressure???

We are using in M50 and M30 engines 1 Bar without problems.

Sugestions??

best regards

There isn't a single 'best' AFR that we can apply to every engine and expect perfect results. This really comes down to testing as discussed in this course to find how your engine responds best. For example it would be quite typical on pump gas to tune a turbo engine at 1 bar boost to an AFR between perhaps 11.5:1 and 12.0:1. The fact that your engine is a N/A and hence will have a CR that's not ideal for boost may mean that you will benefit from a richer mixture which will allow more timing without knock. You'll need to actually find this out though.

I don't have any personal experience with your engine unfortunately so I can't recommend a safe power level. I'd research what others have found on some BMW enthusiast forums and see if you can find what the weakness is with these engines. Also remember that boost is not particularly relevant. It's power and cylinder pressure that really matter. What I mean is that 15 psi boost on a T28 is a very different amount of power and airflow compared to 15 psi on a GT4202!

Hi!!

Many thanks André.

What is the best knock sensor and best way to analyze(software or headphones)? Can you recommend?

Thanks.