if i am posting this in the wrong section please steer my into the right one. i just bought a innovative motorsports lm-2 wideband tester with a data logger. i bought it to use on my F/I motorcycles.

while i have the engine out on my 914 i thought about welding in some o2 sensor bungs in the exhaust while i have my engine out. the lm-2 might help me tune my carbs. i am running duel weber 40's.

my question is, should i weld one bung for each pipe? or just one in the silencer?
the way my exhaust configured i cant run one sensor per bank of carbs. i will have to do 4 individuals or one at the end where they all come together.

are there any tuners out there?

If you are serious about tuning, install 5 bungs. 1 at each cylinder and 1 at the collector. You would be OK with just 1 at the collector unless it's a full race engine. Make sure the bung is above 3 & 9 O'clock on the collector to keep moisture out of the sensor.

@ 'kg6dxn', i agree either one at collector or one per each cylinder.

but why 1 + 4? Can you please explain?

thanks
d

cool. i will put 5 in no problem. im guessing i want to install them behind the heat exchangers. correct? i dont want them real close to the head. i wish i could remember if there is room between the body and the exhaust back there. im going to have to take some measurements and go with my best guess.

IMHO unless you suspect a problem with a single cylinder you only need the one in the collector or tailpipe.

1 at each cylinder and 1 at the collector =5 or 1+4. The 4 cylinder bungs are for individual cylinder tuning. 1 at the collector for rough tuning and while driving to keep an eye on things, especially under load.

i could use the one at the collector for a gauge right?

Yes.

I WAS going to say that you should just install the one at the collector, then I saw you were running webbers. running one per cyl is a good idea as you can tune each barrel perfectly. Granted they should all be the same, but that fine tuning will do good for a weber.

that was my thinking.

i got the 4 bungs welded in today but i came up short for the collector. the one in the collector i will use for the guage. im on the fence about installing a gauge. if i do install one im afraid i will be looking at it all the time and not be able to enjoy the car. thats what this whole exercize is about. enjoying the ultimate driving experiance.

golly my eyes is going bad, i thought that said lambd windsheld sensor


i may want to get one, i have used one borrowed to tune a truimph engine with a side draft piston type Zenith Stromburg carb. funky carbs but the lamba sendor worked nice in tuning,pass smog!!!!

Whoa 5 heated wideband o2 sensors is a chunk of change but probably will be worth it in educational value.

is this for a highly competitive championship race car?

no. just one. i will move it around and then plug them.

does it matter?

Good luck, but the final tune would be at the collector....when you are satisfied.
Not just for the gauge....but for the tuning.

For contant tuning, EGR probes at each port are smaller, cheaper and produce the same level of data...
Then one O2 at the collector will confirm the overall tune.

RIch

How do the EGR and O2 sensors differ (other than cost)? Do both deliver the same data?

Bingo.

Do the majority of your tuning with the collector, Then run a test run that is going to be re ran. for example, 1 min @ idle, cruise for 5 sec in second gear at 1500, 2k, 2.5k, 3k, 3.5k, 4k ect til redline, then cruise @ 40 for 20 sec, then a full throttle for 2 gears (2nd and third, or the highest your most with)

Then run the same test @ each cylinder. When done, compare notes and note this is the baseline. Tune as noted..

With this method you could probably fine tune the car in ~ 5 days. However note that a winter tune is different than a summer tune.

OK, maybe i am missing something, but with 5 sensors and one gauge, wouldn't you need a 5 pole switch to get a reading of each sensor individually?

You are missing something. The OP intends to weld in 5 O2 Bungs but ultimately will only be putting a permanent sensor in one. He will use the other 4 to check individual cylinder tune.

exactly