megajolt lpg map

[tel]

hi does anyone have a good lpg map for a 3.5 v8 running on a closed loop lpg system? just fitted the megajolt now need to tweak it

[V8 EFI]

hi does anyone have a good lpg map for a 3.5 v8 running on a closed loop lpg system? just fitted the megajolt now need to tweak it

Hi there,

Did you find what you were looking for ?. Out of curiosity, as i'm running the same engine, what kind of mapping do you use know ?.

[Hybrid_From_Hell]

To add to this

Many people with LPG just "Back Off" The tinming on say a dizzy set up

by "X" Degrees to allow the softer spark, and this then affects the spark

for the entire rev range.

One of the huge advanatges of MS / MJ is the ability to have differing maps within the MSQ

along with switcable tables to maybe start on pertol and then switch to gas etc

and to then have the map for spark for gas to be what the engine needs and not just a

"X"% lowe than petrol on every position of the dizzy.

I haven't don't much work on LPG, but as a start its more about close to petrol at lower RPMs

and much less at higher rpms and a mix of both at WOT, this would be a good time for

those who have experience and knowhow to add to this thread.

The only way you can get a "Proper" Spark MAP in either MS or MJ is via a Knock sensor

but there may well be knowledge here to narrow the gap more than the basic info I have posted above

Bring it on eh > Gawd when the 5.2V8 goes in the 90 I may even have to consider gassing it

Nige

Edited February 7, 2011 by Hybrid_From_Hell
Don't stop reading at this point - the above information is corrupted due to a fine Merlot - read below for sensible answers :O)

[nicksmelly]

You want more advance (Not less) with LPG as it burns slower.

[bobtail84]

Here you go, this is my LPG map.

Use this at your own discretion as it works for me but it might not be the best for you.

Nige, we at SXMS have a proto squirted LPG engine running in an off roader with the road going version in the next few weeks. That is injected LPG but not liquid... yet...

Jeff

[TobyMellin]

Jeff,

is that for a 3.5 or 3.9? would you say it's a safe starting point for a mark adams 3.9 with megajolt?

cheers.

[ThreeSheds]

It is (in the main) more advance that you want with LPG but not all the time, which is why MJ and MS are so great with their map-switching. There is a nice graphical representation here showing where you do (and don't) need the extra advance. Basically its the same at tickover, then more advance through the normal working zone, then flatten off to give less advance at higher rpm. Don't take that graph too literally - some engines will need the curve to flatten sooner and some later, some will need lass advance and some more etc. etc.

CAVEAT: MY MAPS ARE NOT OPTIMISED IN ANY WAY AND MAY BE DANGEROUS TO YOUR ENGINE, but they are below, in MJ format so you an just plug them straight in if you want to try them as a start point. Just paste the blue text into notepad and save them with an .mjlj extension and load them direct.

For reference, mine is a '96 3.9 (serp) with single point LPG injection and is open loop on both petrol and gas.

Please don't ask questions about the logic behind these maps - there isn't any! I don't know why they are like that, I just kept trying things until it seemed to work. Actually the gas map works better than the petrol one which is not so good at pickup off idle, but since I hardly ever use petrol I'm not too worried about that.

LPG:

cylinders=8

mapBins=10,20,30,40,50,60,70,80,90,100

rpmBins=7,9,12,14,16,18,23,40,50,60

advance0=6,18,24,28,31,35,38,38,38,10

advance1=12,18,24,28,31,35,38,38,38,10

advance2=12,17,23,27,30,34,37,37,37,10

advance3=12,16,22,26,29,33,36,36,36,10

advance4=12,16,21,25,28,32,35,35,35,10

advance5=9,15,20,24,27,31,34,34,34,10

advance6=8,14,19,23,26,30,33,33,33,10

advance7=8,14,18,22,25,29,32,32,32,10

advance8=7,13,17,21,24,28,31,31,31,10

advance9=7,13,17,21,24,28,31,31,31,10

userOutType0=1

userOutMode0=0

userOutValue0=5

userOutType1=1

userOutMode1=1

userOutValue1=5

userOutType2=1

userOutMode2=1

userOutValue2=5

userOutType3=1

userOutMode3=1

userOutValue3=5

shiftLight=63

revLimit=60

PETROL:

cylinders=8

mapBins=10,20,30,40,50,60,70,80,90,100

rpmBins=7,10,15,20,25,30,35,40,50,60

advance0=6,18,24,28,31,35,38,42,42,10

advance1=12,18,24,28,31,35,38,42,42,10

advance2=11,17,23,27,30,34,37,41,41,10

advance3=10,16,22,26,29,33,36,40,40,10

advance4=10,16,21,25,28,32,35,39,39,10

advance5=9,15,20,24,27,31,34,38,38,10

advance6=8,14,19,23,26,30,33,37,37,10

advance7=8,14,18,22,25,29,32,36,36,10

advance8=7,13,17,21,24,28,31,35,35,10

advance9=7,13,17,21,24,28,31,35,35,10

userOutType0=1

userOutMode0=0

userOutValue0=5

userOutType1=1

userOutMode1=1

userOutValue1=5

userOutType2=1

userOutMode2=1

userOutValue2=5

userOutType3=1

userOutMode3=1

userOutValue3=5

shiftLight=63

revLimit=60

[Hybrid_From_Hell]

Ooops

Yes, ta for the corrections, meant mainly more low and less more high - but it came out all wrong

I blame the merlot meself

Nige

[Quagmire]

I don't have any maps here with me at work (since my machine was nuked and win7 installed), but I think my idle advance is somewhere around 17 degrees on gas... This is ticking over at around 800 RPM with a MAP of around 30kPa.

I simply sat there with the laptop and kept increasing advance around the idle area until revs stopped rising, then went back a few degrees.

One guy on the MJ forums hooked a variable resistor to the input and used it to add advance with a knob on the dash, that way he could simply twiddle the knob, drive and then compare to what he had before in terms of performance to what he was seeing before:

Megajolt forum

I have yet to do this...

[Quagmire]

Heres mine:

cylinders=8

mapBins=10,20,30,40,50,60,70,80,90,100

rpmBins=7,9,12,14,16,18,23,40,50,60

advance0=6,18,24,28,31,35,38,38,38,10

advance1=12,18,24,28,31,35,38,38,38,10

advance2=12,17,23,27,30,34,37,37,37,10

advance3=12,16,22,26,29,33,36,36,36,10

advance4=12,16,21,25,28,32,35,35,35,10

advance5=9,15,20,24,27,31,34,34,34,10

advance6=8,14,19,23,26,30,33,33,33,10

advance7=8,14,18,22,25,29,32,32,32,10

advance8=7,13,17,21,24,28,31,31,31,10

advance9=7,13,17,21,24,28,31,31,31,10

userOutType0=1

userOutMode0=0

userOutValue0=5

userOutType1=1

userOutMode1=1

userOutValue1=5

userOutType2=1

userOutMode2=1

userOutValue2=5

userOutType3=1

userOutMode3=1

userOutValue3=5

shiftLight=63

revLimit=60

USUAL WARNINGS APPLY- this has run my 3.5 fine on LPG for the last 17000 miles, but could blow yours up! I take no responsibility, your house may be repossessed if you do not keep up repayments on you mortgage...

Engine is a 9.35:1 compression 3.5 running a 3.5 EFI cam, 10 bolt heads and SU carbs.

Gas setup is single point, closed loop LPG

[TobyMellin]

I've got myself a wideband gauge with sensor. could anybody tell me where i can find info on what afr's i'm wanting?

thanks.

[ThreeSheds]

Heres mine:

cylinders=8

mapBins=10,20,30,40,50,60,70,80,90,100

rpmBins=7,9,12,14,16,18,23,40,50,60

advance0=6,18,24,28,31,35,38,38,38,10

advance1=12,18,24,28,31,35,38,38,38,10

advance2=12,17,23,27,30,34,37,37,37,10

advance3=12,16,22,26,29,33,36,36,36,10

advance4=12,16,21,25,28,32,35,35,35,10

advance5=9,15,20,24,27,31,34,34,34,10

advance6=8,14,19,23,26,30,33,33,33,10

advance7=8,14,18,22,25,29,32,32,32,10

advance8=7,13,17,21,24,28,31,31,31,10

advance9=7,13,17,21,24,28,31,31,31,10

userOutType0=1

userOutMode0=0

userOutValue0=5

userOutType1=1

userOutMode1=1

userOutValue1=5

userOutType2=1

userOutMode2=1

userOutValue2=5

userOutType3=1

userOutMode3=1

userOutValue3=5

shiftLight=63

revLimit=60

USUAL WARNINGS APPLY- this has run my 3.5 fine on LPG for the last 17000 miles, but could blow yours up! I take no responsibility, your house may be repossessed if you do not keep up repayments on you mortgage...

Engine is a 9.35:1 compression 3.5 running a 3.5 EFI cam, 10 bolt heads and SU carbs.

Gas setup is single point, closed loop LPG

We appear to have ended up with exactly the same LPG map!

[Quagmire]

Whoops- i did copy and paste yours to take a peek compared to mine in Megajolt, I think I may have pasted yours back in here by mistake!

[Quagmire]

Heres mine :

mapBins=10,20,30,40,50,55,70,80,90,100

rpmBins=5,6,10,12,15,20,25,30,40,50

advance0=17,18,20,23,26,32,38,38,38,38

advance1=17,18,20,23,26,32,38,38,38,38

advance2=16,17,19,22,25,31,37,37,37,37

advance3=15,17,18,21,24,30,36,36,36,35

advance4=14,16,17,20,23,29,35,35,35,34

advance5=13,15,16,19,22,28,34,34,34,33

advance6=12,12,15,18,21,27,33,33,33,32

advance7=11,11,14,17,20,26,32,32,32,31

advance8=9,9,13,16,19,25,31,31,30,30

advance9=9,7,12,15,18,24,30,30,30,30

correctionBins=0,0,0,0,0,0,0,0,0,0

correctionValues=0,0,0,0,0,0,0,0,0,0

correctionPeakHold=0

userOutType0=2

userOutMode0=0

userOutValue0=88

userOutType1=0

userOutMode1=0

userOutValue1=45

userOutType2=1

userOutMode2=0

userOutValue2=10

userOutType3=1

userOutMode3=0

userOutValue3=10

shiftLight=45

revLimit=45

Usual disclaimer applies!

[bobtail84]

Jeff,

is that for a 3.5 or 3.9? would you say it's a safe starting point for a mark adams 3.9 with megajolt?

cheers.

This is a 3.9 and you could back it off a bit but it works fine for me. (Theusualtermsandconditionsapplyuseatyourowndiscretion)

Jeff

[Hybrid_From_Hell]

in simple terms the 3.5 can take / have more spark than a 3.9

[ThreeSheds]

Heres mine :

mapBins=10,20,30,40,50,55,70,80,90,100

rpmBins=5,6,10,12,15,20,25,30,40,50

advance0=17,18,20,23,26,32,38,38,38,38

<.....>

shiftLight=45

revLimit=45

Usual disclaimer applies!

Hope you don't mind a couple of comments/questions?

Your rev limit appears to be 4500, but mine really hitches up it's skirt at 4500, I wonder why you have set it so low?

The top left box (17 above) is the 'cranking advance' (unless that has changed in later models?) and so in my case I set it low (6deg) with the idea of reducing the chances of blowback and giving the starter an easier time. To me, 17 degrees appears to be rather a lot of advance for an engine that is probably turning at only a couple of hundred rpm. I wonder if you have established that that value is best? My gas starting is pretty good but I am always looking for improvement

Roger

[Quagmire]

Roger,

Questions and comments welcome thats what we're here for!

Hopefully we can somehow comeup with some kind of semi-definitive 3.5/3.9/whatever maps based on our collective experiences.

I'm using a MJLJ v 4.0 if that makes any difference...

The cranking advance on mine is set in the "global controller options" where you also set the number of cylinders etc, and overrides the value of 17 degrees you see there, I think mine is set to 8 or maybe 10 degrees. I will check for you when I get home tonight.

One thing I will say is that whatever it is currently set to used to work very well when it was running rich. I recently installed a wideband lambda sensor and could then see that I was getting AFR's of around 11:1 ! I

I have since reigned this back in a bit so that it gets around 13.5:1 on tickover. However, this has affected my cold starting a little as it turns over a bit more now before catching. I will try taking some advance out and report back.

As for the rev limit being set to 4500, I never really rev it that high anyway, I think I have only hit the limiter two or three times. My Dad (3.5 in a 110) however found that he needed it set higher as he was hitting it all the time! My 90 is pretty light, being an early one (no soundproofing etc) and a softtop so I wonder if that would account for the different use of the rev range?

Cheers

Jamie

[ThreeSheds]

Hopefully we can somehow comeup with some kind of semi-definitive 3.5/3.9/whatever maps based on our collective experiences.

Now that would be nice...

I'm using a MJLJ v 4.0 if that makes any difference...

Yes - I realised that when your map wouldn't load in my configurator

I have since reigned this back in a bit so that it gets around 13.5:1 on tickover. However, this has affected my cold starting a little as it turns over a bit more now before catching. I will try taking some advance out and report back.

On my system when you turn on the ignition with the switch set to gas, it bleeds a small amount of gas through (about three seconds) thereby priming the inlet manifold and speeding starting, but you have to turn it on and then give it some time to get "up the pipe". The manifold full of gas/air mix is another reason for my ultra conservative cranking advance...

As for the rev limit being set to 4500, I never really rev it that high anyway, I think I have only hit the limiter two or three times. My Dad (3.5 in a 110) however found that he needed it set higher as he was hitting it all the time! My 90 is pretty light, being an early one (no soundproofing etc) and a softtop so I wonder if that would account for the different use of the rev range?

Just try it Jamie, up the limit to 6000, find a straight bit of road, get in third, and PLANT IT!

You will be amazed!

Roger

p.s. What system are you using? Mine is an old single-point setup with a knackered vapouriser which won't adjust properly...

[Quagmire]

Roger,

My LPG switch does the same- the solenoids will open for 3 seconds only if the engine is not seen to be running. I usually turn the key, get the "ping!" as the tank valve opens, pause and then start.

Even doing this hasn't helped much since I leaned it off. Don't get me wrong though, it still starts every time- these are EDIS sized sparks we have here! It may just crank over 2 or 3 times first.

Still havent had a chance to check what my cranking advance is because I am rubbish! Will try to do it this evening.

Might also try upping the rev limit a bit too Third is my favourite gear

As for what system I have, its a kit from Tinley Tech consisting of:

BiGas M84 Vapouriser (probably needs a rebuild as it has done about 50,000 miles, and I cannot get it to go rich enough on WOT no matter what I do)

Mixer ring/plate on each SU

Closed loop control powered by a VIP 100 box from Tinley.

[ThreeSheds]

It may just crank over 2 or 3 times first.

Hmm - that's the same as mine - which I thought was quite good!...

Third is my favourite gear

Mine too - on a country lane it will take you from a jogging pace to over 60mph with ease, and always with power in hand.

Interesting what you said about the vapouriser and not getting it to go rich on WOT - mine is like that too...

[ian_s]

i was under the impression that the VIP100 box would control the AFR for you, so no matter what you do with the vapouriser it will never go too rich, as the VIP100 will tell the stepper motor to restrict the flow of LPG.

[TobyMellin]

i was under the impression that the VIP100 box would control the AFR for you, so no matter what you do with the vapouriser it will never go too rich, as the VIP100 will tell the stepper motor to restrict the flow of LPG.

It does control the AFR yes.

These chaps are having problems of being lean though, due to the vap not allowing high enough flow on wot.

I'm running an omvl r90e vap, open loop thumb screw valve, wideband lambda & gauge, but am yet to install my megajolt system.

[ThreeSheds]

I'm running an omvl r90e vap, open loop thumb screw valve, wideband lambda & gauge, but am yet to install my megajolt system.

What do you think of the R90E - I am thinking of getting one for mine..

[TobyMellin]

Only hiccup I've had with it is that it got blocked with a small plastic threaded part which stopped coolant circulation through it. No idea where this came from and as far as I, and an LPG specialist can see, nothing to do with the vap itself.

Apart from that its been great, rebuild kits are easy to get, I think they're still made and many say good things about them.

Mines are 10 years old I think.