Air/fuel ratio meter installation

Pete · Post by **Pete** » Thu Sep 13, 12 9:13 am

Thanks guys, very useful!

Adrian Worman · Post by **Adrian Worman** » Thu Sep 13, 12 9:14 am

I can see a slight difference after adjusting the vac can for slightly more advance, the AFR's did get a little higher at part at idle and very light cruise and over run, indicating a leaner condition, maybe went 0.5% up.
When I go to the track tomorrow I'm gonna take me dial back gun and a box of jets and rods and have a little session

Be interesting to see the changes making a real difference as well as indicating them on a gauge

Dave999 · Post by **Dave999** » Thu Sep 13, 12 9:24 am

in theory it must...

you can see that even when carb tuning at idle, gotta get the advnce right first

however to spot it you need to be logging the gauge output to a lap top i'd guess cos the gauges move fast
you'd end up doing the same routine about 10 times
put it all in excel and average the ten

even the cheap ones have a signal and ground pin for serial coms....
and a 0-5 volt varying output to drive your igntion or FI controler for exactly this reason

i.e at 3500 rpm your advance might be 32* but back on the peddle the mixture will richen up and you might need more advance. using the 0-5 volt analouge output you could tune your igntion controler to advance say a few degrees to pull it back into ranage..

you'd be looking at an ignition conroler with the usual TPS or MAP and RPM input AND a customisable user input...

like a Megajolt Lite Jnr that has an input specifically for situations where you want to trim your igntion map based on any input you like
lambda
cylinder head temp
intake temp
etc

or say in a nitrous situation switch off the igntion if it sees anything like lean

http://www.autosportlabs.com/megajolte-p-41.html

I guess the more expensive MSDs and digital controlers will have same facilities

just the one above is mega bang for only 161 Bucks

Dave

db · Post by db » Mon Sep 17, 12 2:31 pm

Mine works!!

I managed to persuade Igor at the ebag store to send me a replacement gauge (direct from Latvia...). It's all calibrated, wired in and awaiting a running engine to try it on!

Pete · Post by **Pete** » Sat Sep 29, 12 7:35 am

Got mine on with no issues.
VERY handy.

My only observation is that the gauge could do with some "damping" as the readings change every second - either that or the engine needs more fettling in the carb department; but it is hard to do that if the gauge is bouncing around all the time.........

Adrian Worman · Post by **Adrian Worman** » Sat Sep 29, 12 10:19 am

Digital readout or analogue Pete? My innovate digital one is very stable, shifts no more than a couple of tenths either way at a steady load or idle, very quick response tho

Pete · Post by **Pete** » Sat Sep 29, 12 10:54 am

Just referring to the display at this time, Ade - I have not connected it to a readout.........

Pete · Post by **Pete** » Wed Apr 17, 13 8:49 am

Resurrecting this thread again.

I am going to move the AFR from the Barracuda, where it did not work as the headers are open and results in innacurate readings.

Ade has provided me with a bung for the aperture thanks!!

Therefore, I turn to how to install the sensor in the Coronet.

The car has a complete TTI system that is ceramic coated, so I am not massively happy about taking a drill and a welder to it to install the sensor mount.

Then one has to factor in that I am lazy....
The Headers are out of the car and so it would be easier to put the sensor fitting in the header (as indeed did Hausers for the Hemi).

I am not sure that placing it there would give the best heading for a road car, but as hte system is quite big (3") there is not a lot of room under the car to mount the sensor at either 2 o'clock or 10 o'clock.....getting a drill in will not be that easy either.

Any views or tips please?

Thanks.

Pete

Dave-R · Post by **Dave-R** » Wed Apr 17, 13 9:09 am

You want it in the exhaust pipe - not the header.

If it is a self heated sensor you can just about put it anywhere along the exhaust pipe as long as it is not too close to the tailpipe.

Pete · Post by **Pete** » Wed Apr 17, 13 9:11 am

Dave wrote:You want it in the exhaust pipe - not the header.

Poo

Thought so, thanks, Dave

Dave-R · Post by **Dave-R** » Wed Apr 17, 13 10:01 am

Pete wrote: The car has a complete TTI system that is ceramic coated, so I am not massively happy about taking a drill and a welder to it to install the sensor mount.

The headers are ceramic coated but the pipes are just coated with a thin aluminium paint I think? That's how mine looked anyway.

Pete · Post by **Pete** » Wed Apr 17, 13 10:09 am

Not sure if Vince had the whole system coated.

Mind you, Roydon has one of those 90 degree drills!!

Dave999 · Post by **Dave999** » Wed Apr 17, 13 4:48 pm

mines in a tube i had made up by this mob on ebay

http://www.ebay.co.uk/itm/220783509427? ... 079wt_1178

i measured the secondary and the main pipe to the silencer

got them to make up a 6 inch slip fit bit with bung

cut off appropriate length of the main exahust shoved it back on its mounts an slipped the new bit in

lambda needs to be just above the horizontal to stop unburnt fuel and condenstaion running into the heater

just bolt in the lambda and twist the slip fit bit to appropriate position to achive that and keep its wires off the rest of the system

quick and cost about a tenner

their clmps were rubbish so i used 3/4 inch wide motor cylcle tail can clamps in a 2.5 to 3.5 inch diameter...they were very good

yes they can do a double ended Y with a bung in the single pipe bit in the middle if you have a full dual system

Dave

Pete · Post by **Pete** » Wed Apr 17, 13 4:54 pm

Good posting, Dave; thanks!

I actually understood that one

Bang on!

Dave999 · Post by **Dave999** » Wed Apr 17, 13 5:15 pm

no probs

stainless so won't rust and....

they will work from a biro drawing scanned in and sent provided you can get approx mesuremnts/angles on there only a little pursuasion with the big hammer is necessary

do it today and you might have it by the weekend.

everything on ebay is just an example they do each job kinda bespoke

dave