Emerald K6 Mapping

[Gourlay83]

Fitted a PLX Wideband O2 Sensor to the Caterham, so I can now map the car. New to Emeralds, so a bit of a learning curve. A few questions for our experienced Emerald users.

Engine
VHPD
Jenvey TB's
Cam Timing adjusted using Verniers
3.0 bar fuel pressure
4-2-1 SLR Exhaust

After warming the car up I set the TB's up for 1000 rpm idle on a 14.7 AFR, but engine doesn't seem to like it. If I set the idle richer (around 13.5 AFR) it runs smooth with a good pick up, but see no reason to run the car so rich on idle. Is it common to run these engines a little richer ?

Engine doesn't start well from cold (not fantastic hot either). I tried a few settings on the injector advance for coolant/air temp which did help but bit of a minefield. Anyone recommend values for these tables.

That'll do for now, cars not actually road worthy yet so just trying to get a good base point.

Alan

P.S Emeralds are complete balls, table after table after table .....

[kerryxeg]

I initially had problems with cold starting, but Ricky mapped mine and I've not had problems since. Maybe worth giving him a call if you don't get a solution.

[robin]

Are you able to check the air balance between the intakes? It's possible that you need it to run rich to compensate for one lean cylinder (lean because it's pulling more air than the rest). The other problem you get is fuel drop out. With such high lift cams, big intake tracts, ports and valves the air speed is low and the fuel vapour condenses back to droplets before the compression/ignition phases. The droplets don't burn particularly well (I've read that a lot of the droplet fuel will just stick to the cylinder walls).

I would first balance the intakes with the fuelling and/or idle RPM set high enough to keep the engine smooth. It also pays to use a pointy thermometer to measure the temperatures of each exhaust primary - I've heard of engines where one pipe is white hot at idle - don't know how true that is, but best check!

Once the intakes are balanced I would then set the idle speed to be whatever it needs to be so that the engine can idle at 14.7 AFR (otherwise you'll struggle with the MOT).

I would ignore getting a good cold start and warm up until you get hot starting and idle working.

You must get hot idle and hot running mapped with zero input from the correction tables - at low temperature you can have whatever makes it workable in the correction tables at this point.

Once you've got the hot idle and starting working you should then be able to simply increase the idle RPM at low temperature (feel free to aim for 1600 RPM for the first 40C - nobody cares and it makes your life easier ) and use the stock coolant-fuel correction table. Note that if your idle speed is high you'll have two of the fuel and ignition cells active during idle, so you need to make sure they are both sane - in fact you probably need to make sure the first three cells are correct as there is some interpolation going on.

Then you get logging sorted out so that you can log idle speed, AFR and coolant temperature, run the car up from cold and just let it warm up without any throttle input. Review the log and look for problems in the AFR. Then adjust the coolant-fuel correction table to try to smooth out the AFR.

At idle you should let the Emerald control ignition advance to stabilize idle speed, though you'll need to get the advance mapped sensibly to give it a starting point that will work. You should also give it a wide range of ignition advance to play with - if it starts to pop and bang on idle then you may need to review that choice - but otherwise you might as well give it maximum scope for keeping the car idling.


You may also need to use logging to see what's happening during cranking. Chances are you need a huge amount of extra fuel during cranking, but if you then fail to start the engine you may find there is so much fuel in the bores that the engine doesn't want to start for a good while. I think the emerald has a initial cranking correction that tails off as cranking continues. That's good to prevent flooding, but you do still need to compensate for the increased fuel drop out. A well charged battery is going to be a significant advantage as the engine cranking speed directly affects how much fuel drop out you get - the faster it cranks the less drop out.

I have a megasquirt lying around here which is yours for the asking if you want to give something different a go ....

Cheers,
Robin

[Gourlay83]

Thanks,

Kerry - It's going to Ricky's for a MOT, so worst case I can let him map it then but believe it's just because i'm new to the software and need to spend some time going through everything.

Robin - Thanks for the information, the TB's were balanced when i fitted them but don't have a gauge in the garage to re check. I'll see if I can get a hold of one locally, before going any further.

"Once you've got the hot idle and starting working you should then be able to simply increase the idle RPM at low temperature (feel free to aim for 1600 RPM for the first 40C - nobody cares and it makes your life easier"

How do you set the idle for low temperatures ? i thought it was basically fixed throughout range ?

The Emerald is fine, i just want to map the important bits and go out driving in the sun

Alan

[robin]

"Once you've got the hot idle and starting working you should then be able to simply increase the idle RPM at low temperature (feel free to aim for 1600 RPM for the first 40C - nobody cares and it makes your life easier"

How do you set the idle for low temperatures ? i thought it was basically fixed throughout range ?

There is deffo a target idle speed RPM vs. coolant temperature table. It's in one of the buried extra bits ... I'll look at the s/w at home tonight and find the relevant page for you.

Cheers,
Robin

[kerryxeg]

I had an issue with the standard ecu once the remote thermostat was fitted, the temp / idle table with the emerald was used to sort that out. One of the few things I learned.

[hiscot]

have a look at craig's map on his 340 , it may be a good starting point ?

[steviej]

This might help ? k80rum.co.uk/emerald_maps.aspx

[2F45T4U]

how are you currently adjusting the idle speed?

[Gourlay83]

how are you currently adjusting the idle speed?

Mapping on hold for the moment, i'm finishing off the rest of the car so I can take it out (so I can map the main tables and then concentrate on cold starting etc later)

Adjusting the idle using the idle adjust screw on the Throttle Bodies, after engine is warm, correctly balanced and at 14.7 AFR.

Robin - I found all the tables for coolant temp vs rpm, seems straight forward enough.

Alan

[2F45T4U]

how are you currently adjusting the idle speed?

Adjusting the idle using the idle adjust screw on the Throttle Bodies, after engine is warm, correctly balanced and at 14.7 AFR.

Alan

With the cams and verniers, the cylinder filling is probably poor on cranking. Once its running, set the idle on the TBs higher to about 15-1800RPM then retard the timing to give the idle speed you want. It makes a much stronger. Stick a sharp advance on the speed sites under the idle speed and a sharper retard after to stop it hunting or running away with its self. i've found this gives a strong idle expecially on turbo cars which have to draw through I/Cs or contorted pipework etc.

the AFR is probably not 100% accurate. Again, it you have a lot of overlap then unburnt air will be coming in to the cylinder and passing straight through the exhaust. it ends up with a situation a bit like tuning with a hole in the exhaust upstream of the lambda, giving an artificially lean mixture. The mixture will appear to change as you adjust the timing. You will really need a 4-gas to check if its MOT compliant, at least a CO and HC meter.

Remember that using the air bypass (or butterfly bypass) screws/ports to control idle will not alter the pot position and therefor not change the fueling. You can be chasing your tail unless your adjusting the map as you tweak them.

As suggested, use the cranking fueling enrichment and the cold start tables.


edit:
Sorry, just noticed you dont actually have non std cams so that may not be entirely applicable, but maybe if there is a lot of overlap.

[Gourlay83]

Cars now on the road (turns out still had MOT ),and spent the afternoon mapping the car.

One of the problems was that the injection map was a fair bit out. I've been concentrating on idle AFR (basically one table), not noticing that the tables either side were about 15% away from that figure. Quickly changed all the idle/light throttle tables inline with the corrections I made to idle table and now idles perfectly (1000 RPM @14.7).

This allowed me to take it out on the road, again a fair bit out. Light throttle was fine but ran very lean on high load, a few changes to get 12.5 AFR. I've still got loads to sort out but I now have a good base to work from. I plan on sorting most of the map then get Ricky to finish it off on his dyno. Car is heading up his way for a MOT anyway.

Still having issues starting, it now starts from cold and hot but takes a few engine turns to do so. I can worry about that later, when map is complete.

Cheers
Alan

P.S anyone used a 64bit machine for the Emerald software ?

[Gourlay83]

All I had to do was add initial injector prime, now starts first time.

BOOM

[Gourlay83]

Thought I would update this. I was a bit hasty writing the emerald off, spent the last few weeks mapping the car and getting to know the emerald. A great piece of kit for the money, just takes a while to get around all the tables.

Car is now seriously fast, picks up instantly and still producing power at 7500 rpm. I spent a few hours on the light throttle as well, and set-up closed loop for cruising speeds. So the lambda sensor trims my fuelling at cruising speeds and idle, basically getting a perfect 14.7:1. Giving the car (believe it or not) around 35-40 mpg when cruising, and POWER when I want it.

Alan

[kerryxeg]

I have been stunned at the improvement in MPG with the Emerald. This was a big issue with the VHPD on the west coast - as those who have been to Durness with me in the past will recall.

I've not really worked it out, but a tank is now doing over 250+ miles vs a more traditional 200 and I have seen it as low as 150. Driving style etc has some effect obviously but the 250+ over about 600miles on the Arisaig trip was generally on little roads pax plus all the luggage I could carry which wouldn't exactly be considered an economy run. So a great side benefit.

This makes the exige the most economical car in my fleet by a long way!