AFR tuning query

Alan L · Alan L's Garage

We take WB O2 sensors for granted now.
But wondering how did they tune the early 930/935s?
A WUR setting and send it out the door from the factory may work for street use - run on the rich side and trust it doesn't blow up. But once you push them to the edge on the track that won't really do. So what technology did they have?
EGTs? CO/CO2 analysers? I am thinking late 70s and early 80s.
Just wondering how they achieved the same results without O2 sensors.
Alan

stownsen914 · 01-07-2022, 03:38 PM

EGTs was certainly common on NA cars back then for tuning. I may have heard they were used on turbos too with a higher target temp?

RarlyL8 · RarlyL8's Garage

In the absence of exhaust gas analyzers or the like you tuned by ear and read the spark plugs.

David · David's Garage

Mark Donahue's book The Unfair Advantage has some unflattering words on Porsche's tuning around that period. My favorite book and I learn something I missed every time I read it.

Alan L · Alan L's Garage

Hmm, wondered how they could do it smartly, with the lack of instrumentation we have access to now.
Sounds like it was fairly hit and miss.
A good engine tuner would be in high demand, given the stakes on these boosted engines - especially at the track.
Alan