924Board.org

[Rick MacLaren]

I have a 1980 924 with a straight pipe, no cat. However, the oxygen sensor is welded into the straight pipe so it does sense the level of oxygen. I recently reconnected it. What differences can I expect in performance? Does the oxygen sensor have anything to do with fuel-air mixture?

[eturbo924]

I do not know what kind of performance gain you will get but a properly functioning O2 system regulates the air fuel ratio. It keeps sending a signal to the proper quiptment to ajust the fuel mixture to optimum condition for engine output. I have the same set up as you, straight pipe but with O2 placed into header. I have no pictures of it yet, but I plan to post some shortly. I know that you should get better gas mileage with the O2 in.

Eric
http://www.geocities.com/eturbo924

[Rick MacLaren]

That's cool Thanks. I wonder why the guy removed the O2 sensor?

[larso]

if you remove it it keeps your air fuel mixture constant....I think that helps a little bit because the system was made for emmisions...it's always better to have a little bit of a richer system than the emmisions friendly setup that porsche was forced to put on the car..ie the euro 924s do not have an OX system at all on the 125HP stock 924 euro engine.

[numbers]

Not a good idea to run a richer mixture. As I said in a previous post, you cannot beat the perfect 14.7 to 1 mixture that you get with the Lamda system. If you run it richer, your cylinder temperatures will be a little less because the extra gas acts a a coolant. But you will not get anymore power. The extra hydrocarbons will just go out the tailpipe.