Originally Posted by Jahangeer
Along with the other members I also welcome you aboard, and it is great to have a knowledgeable person such as yourself writing here. I have a question...one that has been asked many times..
What could you safely/reliably extract from the 3,8 block on the E34 M5, as a daily driver?
I have the Schrick cams and a UNICHIP and 100 cell catalysts. I suppose extensive headwork?
Regret to admit I have no answer for that one. The 3.8l was very late in BMWs development path, and only presented limited appeal for tuners, therefore nothing serious made it into the marketplace.
As with most M engines, someone has already done the fettling work to quite a high standard, so gains are relatively poor for quite a lot of effort (=cash). Best way forward would be to convert the engine management to alpha-n, using MoTec. Expensive, but you are guaranteed to get better performance in absolutely any engine configuration you may arrive at in the future. If they or their dealers have done a configuration like this before, then you will be able to tap into existing knowledge. Would be nasty if you had to fund your own development costs though.
Otherwise, a really careful set-up and remap of the existing engine management would be the only other route to get the best out of what you have. I would guess that you would only see maybe another 20hp from really slick headwork.