Problem with S6 running on LPG

[doncecone]

Hi guys,

I have a S6 2,2 T with RS2 7200 on RS2 EM. I recently converted it to LPG.

I have a bottle with 2 x probes, 2 x Magic 3 LPG evaporators, 2 x 8mm log hoses and a 2.4 mm nozzles on 1,5 OM. Management is done by AGIS.

Problem comes on full throttle between 3000 and 4500 rpm. The car stalls and when i release the pedal if accelerates again. After 4500 it is ok until 5300 when it switches to petrol.

Readings show that the pressure drops to 0.8 after 4000 rpm in these conditions.

Interestingly boost is around 0,7-0,8 between 3000 and 3500.

Do you have any idea how to solve this problem?

Thanks in advance

Sorry if i got the description wrong.

Please move my thread if posted in the wrong section.

[ManiacuV6]

Ask PRj ! HE knows his stuff !

[doncecone]

10x. Will ping him.

[kotnelson]

Hi


You should

- main LPG hose from tank to reducer ID 8mm (5/16 inch)
- expand nozzle to 3mm - 3.5mm (my car is 4mm a little too large)
- Magic III reducer max pressure I think is 1.4 bars. You must adjust the pressure to the lowest at idle this mean you have to screw the bolt down
- LPG ECU you need to re-tune everything

If above is still stall at WOT, but half paddle the car run fine up to max RPM
You should change the reducer with up to 2 bars pressure.

Hope this help
Kot



PS
My car is stock UrS6 I run E85 and LPG on VEMS stand alone ecu, both fuel I can hit 295 kPa of boost (Boost up to 1.95 bars)
Reducer is Magic II (350HP) max pressure 1.4 bar, I may change to another brand with up to 2 bars pressure.

[kotnelson]

PS 2
You should Tune when it is 1/2 tank full, not at full tank or almost empty tank

[doncecone]

Hi Kot,

Thanks a lot.

I have 2 main hoses running from the tank to 2 reducers at 8 mm.

The bigger nozzles i put earlier it runns out of pressure. When i run it with smaller and on higher reducer pressure it is fine but less power.

Who did the tuning of the ECU?

Thanks

[kotnelson]

Update...


I use a single Magic III as well, (just take a close look install long ago could not remember well)
You have to tune yourself is best. If you could not do it, just dont make any change.


-Top HEX screw, I screw all the way down.




Brass bolt out to manifold, was 2.4mm so I drilled expand to 4mm





Under the hood.

[doncecone]

Really appreciated!!!

I can do it, just i didn't know which way to go:

- smaller nozzles and higher differential pressure
- bigger nozzles and lower differential pressure

Do you use the newer coils with the engine cover? Doesn't that make them hotter?

Regards,

Tsvetomir

[kotnelson]

Try both way.
Coil D585 are behind firewall in a cool place !! You may see 5 white cable, they are spark plug wire run from coil to plug.

[doncecone]

This is very good solution with the coils!!

In your LPG setup is there a moment when the car switches to petrol due to lack of LPG? Especially under full boost and the paddle all the way to the floor?



I went through your writing several times today and i couldn't understand well the following sentance.
"If above is still stall at WOT, but half paddle the car run fine up to max RPM"

Magic 3 mac pressure is 1.6 bar. I'm running 2 such evaporators with separate LPG hoses so there should be no problem with the pressure.

[kotnelson]

Nozzle size / PS

1.8mm = 20-25 PS
2.1mm = 25-35 PS
2.4mm = 35-40 PS

Yours with RS2 should have 325 PS / 5 cylinders = 65 PS per injector
You must expand the nozzle, size you must calculate by yourself
Large size - lower pressure
Small size - higher pressure