LPG Discussion Forum

Hi,

I have an 06 BMW M6 V10 - after running the e39 m5 with a bigas kit pretty much flawlessly for thee years I went the bigas route again, performance is second to none brilliant... however when in sport mode and you give the car some welly the headup display sound and screen cut out for a second - these are all on the can line but cant work out why and whats up? advice?

pyro225 wrote:however when in sport mode and you give the car some welly the headup display sound and screen cut out for a second - these are all on the can line

Is this when it's on LPG only or petrol as well?

If its just on gas. Cut the wires to the diagnostic socket. See if it changes anything. Also do you have the flap shut or open. There are some jumpers in the lid. When you shut it the lpg ecu looses the fuel trims. That could also be affecting it. I presume when you welly it it's going open loop anyway. Is it switching back to petrol ?

Hi, thanks for the quick replies..this is ONLY on LPG this happens

Also do you have the flap shut or open. There are some jumpers in the lid. When you shut it the lpg ecu looses the fuel trims

Which flap are you referring to? and lid? The injectors hold on right till the end with no addition (I think its because the v8 ones are rated to 400bhp and they are the same with two extra cylinders...)
What would cutting the wire to odb do? I know that it reads the rpm signal off the can I think.. its annoying as its only the 10cyl ecu that read it that way...

The lid on the diagnostic socket that you actually open to get to the socket. And I'm only offering some advice mate it's not something I have ever heard of or seen personally. It would be where I would start if I was trying to track down the problem. Infact thinking about it maybe I would just turn the OBD link off in the software first. If that didn't work I would snip the wires. If that didn't work I would move onto something else. It's obviously something directly influencing the can line that wasn't there before.
Not having fitted bigas for a good while. Does the software have the option to use the injectors for an rpm signal instead of connecting up to the coil wire ?

Thanks tubbs, no it doesnt which i think is part of the problem, it did have that option on the v8 ecu not the v10 one though, and i think thats can linked too... will look at disconnecting that wire

I may be wrong. But i always believed that you had to run two 5 cylinder systems on the v10 of this age ? A 10 cylinder kit wouldn't do. I can't tell you why I know that or what the problems are. Helpful I know !

is this because its too new for a v10 kit or too old? thanks

I think it's too new. But I'm not sure. It's just something another installer who I trust said to me about some issues he was having with one.

Hmm. Ive run a 2006 V10 Dodge ram on a Bigas 10cylinder kit with no problems. Maybe not quite as advanced as a M6 but even so. It works just the same as a 8cyl kit but with two extra channels. The main differance is there is no OBD connection available on a AEB 10cyl ecu, so OBD wires cant be upsetting anything.

If it has no OBD connectivity then it can't be upsetting much !

@dualtech

You don't get the option to get the rpm signal from the injectors either hence why I think this is causing problem? do you have any ideas... weird thing is if you switch one bank on petrol the other on gas it runs faultlessly and the same if you reverse the banks...

Switch it how? I'd guess it's throwing a wobbly because the gas pressure droops under demand and causes compensated injector times >100%

I know nothing about converting high power cars so sorry for gatecrashing this one.
Does'nt the M6 produce 500+ hp. I thought the Bigas kit's twin reducer were rated up to 380hp in theory? Or have you used 2 of these?

@ billynoband - that's correct hence why I went with EMER rails and reducer as it can go up to 500bhp...

Don't care what bits your hybrid is made up of, though it would be interesting to see what the reducer is rated for. What happens to the gas pressure as you approach your problem load area? What happens to gas injector times?

pyro225 wrote:after running the e39 m5 with a bigas kit pretty much flawlessly for thee years I went the bigas route again

pyro225 wrote:I went with EMER rails and reducer as it can go up to 500bhp

So what bits have you actually got?

The EMER vapourisers are rated at 227hp, It would also need injectors that are rated to give 62.5 hp per cylinder, and although they may seem to work correctly under normal load conditions they may struggle under heavy load conditions.

Can't imagine this running on LPG under full throttle on the system being used.

As ross has already said. I think abit more info regarding injector timings and stuff is in order really.
And tommo, ive run 260bhp on a 4 cylinder with the emer palladio without any pressure or supply issues.
Even a single reducer on a v8 range doesnt drop more than half a bar at full throttle. But its obviously more about the petrol injector duration that the gas system is following. But there are a few ways round that too.
I asked at the beginning wether it was switching back to petrol. Or is it hitting the duty cycle ?