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Lambda sensor for a V6
DIY Si - 10/12/08 at 05:33 PM

Evening all, just having a sit and a think about my next project. I'm planning on using a Go-Tech ecu to run the 24V 2.5 V6 from a alfa 156. Now, for the lambda senors, the 156 has one in each manifold collector. Would this be needed to run the engine with the after market ECU, or could one heated sensor be used further down the exhuast where the two banks will (probably) come together?

mr henderson - 10/12/08 at 06:37 PM

I'll be interested in the answer to this one as well

It would seem that one signal would be enough, as long as there wasn't any significant variation between each bank, but maybe that isn't the case?

John

clairetoo - 10/12/08 at 07:28 PM

I'm running a single sensor on one side as my exhausts are completely separate - I just keep an eye on balance between the two banks of throttle bodies , and I'm having no problems

DIY Si - 10/12/08 at 07:31 PM

Claire, if you had the choice though, which option would you go for? One for each bank seems as if it should be better, but is it worth the extra cost and wiring?

piddy - 10/12/08 at 07:46 PM

The sensor should be mounted as close to the head as possible, but reading all cyclinders. You would therefore be better to mount one sensor where the three pipes join and check balance as clairetoo has done. Or fit two sensors if your ECU allows.

britishtrident - 10/12/08 at 07:51 PM

A primary Lambda sensor needs to be as close as possible to the exhaust valves.

Running one Lambda sensor on one bank a vee engine is better than putting it in a cooler part of the exhaust futher away from the cylinders.

As already mentioned just watch the throttle balance and other factors that could cause each bank of the Vee to experience different operating conditions.

clairetoo - 10/12/08 at 07:53 PM

quote:
Originally posted by DIY Si
Claire, if you had the choice though, which option would you go for? One for each bank seems as if it should be better, but is it worth the extra cost and wiring?

Two sensors would be the best way to go - but horribly expensive . It allso leaves you with a small problem - how to adjust the fueling on each side , independently ? My megasquirt wont do it......
Theres allso the question of `information overload` - you could easily end up with `data` that you cant do anything with

Chippy - 10/12/08 at 11:01 PM

I run my V6 Cossie with just one Lambda, on a twin pipe system, as the engine is batch fire the fueling "should" be the same on both banks. The easiest way to check that this is the case is to get your local "friendly" MOT man to check both pipes for emissions. When I first set mine up I did this and found one bank was running lean, (18.6 instead of 14.6), this was "eventualy" traced to a dry joint on the adaptor board, now every thing is fine with 14.6 on both banks. HTH Ray