Got a 81 911sc, does this car have an O2 sensor?, I looked at the cat and notice no hole for the O2 sensor, I also checked a friends SC and notice no O2 plug or hole in the cat either.
Also any mods for more hp for this type of car?
get a K&N filter, carrera chain tensioner update, nology wires.

Thanks

 

oops forgot to mention, the car came with a Bursch single outlet muffler, and the cat was hollowed out.

thx

 

your ECU wants an OX sensor, my 80 has a single wire sensor in the cat

 

Assuming you have a US-spec 1981 911SC, it should have an O2 sensor. Since the CIS engine management relies on the O2 input, I would put it back in - your engine will, overall, run better. No horsepower to be gained running without it.

About the only way to gain HP on a CIS-based engine is to backdate the heat exchangers to pre-1974 configuration. Most people use SSI's, which are made of stainless steel. That conversion also requires a new muffler and takes the catalytic converter out. Figure about $1100 for new SSI's and two new oil lines, plus the cost of a muffler.

There's been recent discussion on K&N filters, scan the last two weeks for K&N. Your money is probably better spent on something else.

You've probably already read the 911SC FAQ on this site, if not, it may help answer some questions.

 

I have an 83SC Targa.I had an O2 sensor and unplugged it when I put a cat-bypass in.A good mechanic can use an 4 gas exhaust analizer to properly tune the car to run better without the O2.I also have the Bursch muffler and a K&N filter.I have the Dyno-Jet sheet to show the improvements gave me 20HP.
For under $450.00 I got 20HP and I get 425 miles on a tank of super.I also have 211,000 miles on my car with only the upper-end rebuild.Now I did not get the chance to run the Dyno without the K&N, I did 3 runs,so I can't really say what upgrade gave me the most gain but I am very happy with the results for the money.The SSI's were too expensive for me, although, I do wish I could have gone with them and maybe a better muffler.The tensioner update is a good thing but I'd rethink the Nology wires,do more research,stock wires are fine,maybe Magnacore (?)if you just can't go stock. Good luck !

 

That car should have an o2 sensor along with a control box under the passenger seat. On my 80, I disabled it since the interior got flooded while parked in a low spot during one of those South Florida "showers." I just chucked the box since it died by drowning. I don't feel it ran any better until I backdated the fuel distributor to a 79 unit that was designed to run without an o2 sensor. I have been happy with it but I am now about to pick up a euro fuel distributor #911 110 977 00 that came on the 9.8:1 compression 204hp euro sc's from 81-83. That one isn't designed to run with an oxygen sensor either.