Wideband o2 sensor placement

14500rpm · Post by **14500rpm** » Mon Feb 18, 2008 12:00 pm

Hola chaps, I'm looking at places to fit my Innovative LC-1 WBo2 sensor and the only practical place I've been able to find is towards the back of the exhaust about level with the rear wheel (but before the only silencer). Is this an OK place to put it or will it not get hot enough?

Andy

chodjinn · Post by **chodjinn** » Mon Feb 18, 2008 12:54 pm

I'm planning on fitting mine on one of the downpipes from the turbos. Can't you fit it any closer to the front of the engine - like the y-pipe or collector?

14500rpm · Post by **14500rpm** » Mon Feb 18, 2008 1:52 pm

Not really, the manifolds are very tight and exit through the wheel arches and then run down the sills as four seperate pipes and only meet finally at the back where they go into the silencer. The problem is that the part of the exhaust that I fit the sensor into will need to be removed from the car in order to have the bung welded in and I'm not crazy about removing one of the manifolds.

I am planning cylinder head changes at some point in the (far) future so can put the bung in a better place then.

ChrisJC · Post by **ChrisJC** » Mon Feb 18, 2008 3:27 pm

It's self-heating, so it can go in free-air if you like! It might be however that at the rear of the exhaust the gasses have cooled enough to be able to overcome the heater and force it to operate out of spec.

Chris.

P.S. Why is the exhaust like that?

bill shurvinton · Post by **bill shurvinton** » Mon Feb 18, 2008 7:53 pm

Most rolling roads use a tail pipe probe which only goes 10" at most into the exhaust, so where you suggest is fine.

For a turbo engine the danger is over heating so you need to get as far from the turbo as is sensible or heatsink the sensor. If you get over 750C then the sensor cannot work properly.

Bill

14500rpm · Post by **14500rpm** » Tue Feb 19, 2008 10:25 am

Thanks for your replies gentlemen!

Chris, the exhaust is like that because theres not much room to do anything else. The blue subframe type thing in the middle is the gearbox mount and helps locate the rear diff which means theres no room to bring the exhaust down the transmission tunnel, and two thinner pipes per side were considered to be a better idea than one fat one per side when it comes to ground clearance. I bought the car like this and whilst it would be nice to have the exhaust up out of the way with a nice X-pipe it'll have to stay as is for now, especially as it cost the guy who built it a hell of a lot of money to have made!

kiwicar · Post by **kiwicar** » Tue Feb 19, 2008 12:51 pm

Hi
I've had a hunt around for clues, but what car is this a picture of the underside of? it is 4 wheel drive (if that is a front diff) and I suspect has a rover in it but the rest?
Mike

Eliot · Post by **Eliot** » Tue Feb 19, 2008 1:02 pm

kiwicar wrote:Hi
I've had a hunt around for clues, but what car is this a picture of the underside of? it is 4 wheel drive (if that is a front diff) and I suspect has a rover in it but the rest?
Mike

thats the view from the rear of the car. Thats a ford diff in the back.

14500rpm · Post by **14500rpm** » Tue Feb 19, 2008 6:50 pm

'Tis a MX-5

I can't claim responsibility though, it was like that when I found it. The chap who did build it (on his driveway

) kept a build diary which is HERE.

kiwicar · Post by **kiwicar** » Wed Feb 20, 2008 3:15 pm

minorv8 · Post by **minorv8** » Mon Feb 25, 2008 7:37 am

One thing that you need to consider when placing the sensor in the back: leaks in the system prior to the sensor will play havoc with the sensor readings.

stevieturbo · Post by **stevieturbo** » Mon Feb 25, 2008 6:29 pm

Then dont have leaks

14500rpm · Post by **14500rpm** » Tue Feb 26, 2008 12:19 pm

Good point though, I will have to go through it and make sure there's no leaks up stream.