I just picked up the car and it works flawlessly so far. I will get some photos and what not tomorrow to post here and I am intending to write an article on this in the near future based on my driving experience. It took a week which was a bit much but I told them to keep it till it was 100% and this was a new type conversion for them. Cost was around 6K do I will have to keep it at least 5 years but my first CNG fill up was $11.50. So far the driving experience is no different than on normal gas and the transition between natural gas and normal gas is as seamless as the transition from electric to gas as before. The system does take 20 seconds to switch to CNG after starting out but they are working on a 5 second transition module which will help in around town driving. more to follow and it will always be posted in this link so check for updates

 

Way cool. How are the Auto-Stops in and out? How about V8-V4 transitions?

 

so far for me you would not notice any difference! EVERYTHING is normal, the only loss so far is a bit of room in the rear...small sacrifice for me. I'm going to drive it extensively tomorrow and will report back with a few photos.

 

sorry no pics yet. went on a little 100 mile highway/city drive today. Still pretty seamless except :

it stumbles a bit when elec boost comes on at highway speeds. I think it has to do with throttle position maybe some software fine tuning.

it threw a cel when accelerating hard then the system scramed beeped and flashed a red light. It didn't miss a beat going right in to gas mode. I shut the system off then restarted it and it seems to work fine. they told me that the car needed to "learn" the new fuel and not drive aggressively !

the cel was due to the fact that the cat sensor thought the engine went lean due the clean output of the engine. This should sort itself out over time.

only complaint so far-it takes 20 seconds to switch from gas to cng and in the hybrid at stoplights the engine is off so every time you drive off it takes 20 seconds to switch to cng, 5 to 10 seconds would be ideal and they are looking in to this and hope to have a solution soon. you can get around it by shifting to manual before the engine shuts off but that sort of defeats the goal of having the engine off when stopped, it will stay running on cng so moving off and up to speed is on cng so some creative math might be needed to determine the pollution output at idle on cng vs moving off from a stopped engine and running on conventional gas for the first 20 seconds.
I promise some pics tomorrow........

 

the bad... tanks in the wayback under the cover I made..


the tanks exposed...




plumbing under the hood...

[img]http://i40.tinypic.com/10qgzur.jpg[/img]

I am going to cover the tank cover with carpet...the space lost is considerable but worth the tradeoff ... I think. with the three tanks in place i think based on preliminary calculations I have added 440 miles of range so far. time will tell

all the high pressure lines are stainless steel under the hood they go to pressure regulators that lower the pressure to flex hose pressures to the injectors. took the pics late as i thought it would show up better in the dark...WRONG! also found out that the underhood pressure regulators are cold sensitive so there was a stumble this morning when it switched to NG. the pressure regulators are connected to the heat system in the car.

 

Wow, pretty amazing stuff.

I'm also guessing you're not a smoker.

 

so far so good. It works just as it should except for a couple of minor issues. it stumbles when it switches to cng the first time as it needs to be a particular temp to start operating. the pressure regulators are connected to the heating system of the car and as I live in a cold climate area its a little fussy, if I was in calif (soon to be my permanent residence, time to move!) it would not be an issue.
it looks like I will be able to get 450 miles out of cng only, but this may change. it has to go in for a recalibration in 500 to 1000 miles. It doesn't like full throttle yet so there is some tweaking to do.
here are some better pics.

the tanks
http://i40.tinypic.com/x1f11i.jpg
underhood plumbing
http://i41.tinypic.com/28h07yq.jpg
pressure regulator (1 for each fuel rail)
http://i40.tinypic.com/neupzd.jpg
fuel injectors (8)
http://i43.tinypic.com/2hcqj2c.jpg
underhood view 2
http://i44.tinypic.com/723vok.jpg
tank cover I built for the system
http://i41.tinypic.com/169fh9d.jpg

oh and..... nope I don't smoke!

 

Jet,
That's a great job well done.
Keep us posted with more results
Guss

 

just did my first cng fill...pretty seamless just like gas. got 400 miles out of the first cng fill. It was not empty but the station was close. I filled up on gas at the same time I filled the cng tanks and I have more than 3/4 tank full of dino gas at 400 miles. I think the mpg is close to the same as fossil gas but its to early to tell it is 90% cleaner and 60% less expensive though!

problems so far:
cel is on I think this is a tune issue on the cng
it stumbles when it first switches to cng and its cold outside
it will not take full throttle on cng hopefully a tuning issue (this is the serious issue for me)

I have been playing with driving in manual mode to bypass the auto stop, which keeps it in cng mode all the time since the engine doesn't shut down at stops. so far the mileage isn't effected with this and the hybrid elec mode works the same as in normal drive. Advantages---stays in cng instead of running 20 seconds on gas then switching. in stop and go traffic the engine is on even if you are technically running on elec. the boost from elec is actually as good as with just gas electric and in manual mode it seems to get slightly better mileage than in the stop start mode..(??? ) according to the on board readouts.....more to come. I haven't taken it on a road trip...that's the next step

 

GM should cover all your expenses for that Expereiment Jet