wide band O2 and EGT sensor fitting

[Jesus-Ninja]

Where have folk fitted these on VR4s?

I'm thinking of swapping out my stock lamda sensor for my wide band, as the harness has a narrow band output too that can be used. Is there just the one O2 sensor on the VR4, or one for each bank?

The EGT sensor typically goes into one of the pipes on the manifold. I was thinking about putting it after a turbo, but as the turbo relies on temperature differences across the vanes, I assume the temps will be lower post-turbo.

[Anderz]

There is just one O2 sensor, right before the cat

[Turbo_Steve]

As above: single O2 sensor.

EGTs are a really cool thing to monitor, butneed to be measured in the manifolds, or they're pretty meaningless.
So EGTs need to be measured in both manifolds, I'm afraid: just measuring one bank does give you some information if you're mapping, but it's not enough to warrant the cost of the gauge IMO.

Unless you're planning to change ECUs / fit a piggyback / go mad with an SAFC, EGTs probably aren't as useful as oil temps.

If you're going to go to all the hassle of tapping manifolds (and it will need to be the rear one, as this bank is likely to run hotter) to fit an EGT, and you're going to be mapping aggressively (or tuning heavily) then you might as well fit one to each bank, as well as a wideband in each bank. This will give you a lot of valuable information, and allow you to push things that little bit closer to the limit.

[Jesus-Ninja]

Ah, bugger, I thought that might be the case.

[goes off to order another.....]

[Gowf]

As above: single O2 sensor.

If you're going to go to all the hassle of tapping manifolds (and it will need to be the rear one, as this bank is likely to run hotter) to fit an EGT, and you're going to be mapping aggressively (or tuning heavily) then you might as well fit one to each bank, as well as a wideband in each bank. This will give you a lot of valuable information, and allow you to push things that little bit closer to the limit.

In each bank is essential, but just to be pedantic, would the rear be hotter?
You are measuring the temps pre turbo and yes the rear turbo more enclosed than the front and obviously subject to less convection from incoming air, but as the rear bank is fed fuel first, you are likely to have less fuel on the front bank and so potentialy hotter exhaust gas. All that being said, how much difference i dont know. I know that my rear is slightly hotter than the front, but then im running two slightly different manifolds so it doesnt really matter all that much.

What i will say regarding using the egt's, is be very aware when routing your k-type theromcouples that they do not short out on things, and also watch out for kinks within it. Mine have on occasion produced totally random temps whcih are clearly not right, but a quick wiggle sorts them out. I need to reroute mine properly, but that will be happening soon.

[Jesus-Ninja]

Second gauge ordered. Got some fitting to do when I get back! :smash:

[Turbo_Steve]

In each bank is essential, but just to be pedantic, would the rear be hotter?
You are measuring the temps pre turbo and yes the rear turbo more enclosed than the front and obviously subject to less convection from incoming air, but as the rear bank is fed fuel first, you are likely to have less fuel on the front bank and so potentialy hotter exhaust gas. All that being said, how much difference i dont know. I know that my rear is slightly hotter than the front, but then im running two slightly different manifolds so it doesnt really matter all that much


Interesting...thought the fuelling went the other way (have to confess I hadn't checked).

Airflow seems to make a massive difference to EGTs....never ceases to surpise me.