LPG kits - Which one?

[alienb4ndit]

Hi
I'm new to this forumas I've just bought a Saab 9-5 estate 2.3t. Lovely car but a bit thirsty, I'm used to diesels but needed this Saab to tow a large caravan.

I have lots of questions but I won't bombard this thread with them, I'll ask one at a time
First one being: I'm looking to buy a kit and fit it myself.. What type of kit will I need for my car and should I steer clear of the cheaper kits

Cheers,

[sijones]

Welcome, first of all do some research on here, there are plenty of threads about kits http://lpgforum.co.uk/viewtopic.php?f=33&t=11814 being the latest.

Have a read and then come back with any questions.

[alienb4ndit]

Thanks for the link, plenty of info which was very useful. My question was slightly misunderstood, I was asking whether I need multipoint, sequential, etc. Also, if I was to buy a used kit, how would I know it would be suitable? I don't intend to buy a used kit, I'm only asking so that I can understand the differences between kits and cars.

Thanks in advance

[Gilbertd]

A multipoint will be capable of sequential operation (unless you buy some geriatric old tat like a Tartarini Etagas) and, while you could fit a single point to your car, it isn't recommended. If you were to buy a used kit then you don't know if it is still good or about to reach it's sell by date and you won't know if it is up to the job of supplying sufficient gas for your car. A lot of the used kit that is advertised seems to be BRC and Prins, both good systems but both approved installer only. For a first install go for a new kit from somewhere like Tinley Tech or FES Autogas (Gas-it) at least then you'll get support when you get stuck.

[alienb4ndit]

Righto.

Are you saying, then, that most if not all of the kits on the market are of the sequential type and will be suitable for my car?

[Gilbertd]

All current ones, yes. You need to make sure that the kit you get is up to the job. What is the power output of your car? I have a feeling the 2.3T is quite powerful for a 4 cylinder car.

[alienb4ndit]

Up to the job in what sense? Reliability or able to supply the required gas? I'm not sure of the output of my engine, I do need to find out. It's got loads of low down torque.

[Gilbertd]

Reliability shouldn't be an issue with a new kit provided you install it properly, it is whether the kit can supply sufficient gas to cope with your engine. The reducer will be specced with the maximum bhp it can supply so you need one that is specced for something higher than your car produces (to give a bit of overhead to allow for any inefficiency as the reducer ages) and injectors are made up to a certain bhp per cylinder figure. This is why you will see mention of things like brown injectors, orange injectors, etc, the colour coding signifies the power output they can handle.

[Tubbs]

If you are going down the tinley tech route the bigas system is very good. And more than capable of coping with your car. You have another consideration to look into and that may be a valve saver system on top. Depending what age it is. The older actual saab engine has valves and valve seats made out of very stern stuff indeed, the later gm ecotec does not.
On a car like that its probably best not to go cheap. Good injectors, good reducer etc is a must. The most demanding cars are the turbo 4 cylinders. You can get away with a bit on a v8 or 6. But on a 4 you will have nowhere to hide if the injectors or reducer aren't up to the job, other than blending or reverting back to petrol. And if you want to blend you need an OBD kit in order to access that function.
Both are a cheat in my eyes.

[alienb4ndit]

Thanks.

Sorry for the anal questions but in order for me to make an informed choice I need to understand fully what I'm doing.

If I was to get injectors etc more than capable of coping with my engines output would that have an adverse effect on fuel economy?

[Gilbertd]

No, the amount of gas injected is controlled so it won't give more than you need. The only time you would have a problem is if they are so over specced they can't open and close fast enough at idle. I think the 2.3T is the old, proper Saab engine (B234) and not one of these dodgy GM lumps. The Saab engine loves LPG and will go on for 300,000 miles easily as long as you give it regular oil changes and doesn't need Flashlube.

I may be telling you something you know already but an explanation of how the gas system works might help. When running on petrol the petrol ECU takes inputs from various sensors on the engine and sets the fuelling (by adjusting the length of time the petrol injectors open for). It can check that all is well by looking at the output from the lambda sensor which will show that the mixture (air/fuel ratio) is correct. When you fit a gas system you interrupt the pulses from the petrol ECU and use these to fire the gas injectors instead. The LPG ECU adds a fiddle factor to the pulse length as the gas injectors need to be open for slightly longer (between 120 and 150% of the petrol pulse length). The petrol ECU doesn't know that the car isn't still running on petrol so will still adjust the injector pulse duration to keep the mixture correct. If the fiddle factor is incorrectly programmed and the petrol ECU has to make large adjustments, it will flag a fault and bring the MIL on.

[alienb4ndit]

Ok, I now understand a fair bit more about lpg systems than I did before posting on this forum.

Are the front end kits on ebay any good? They seem quite cheap at around £200.

[Gilbertd]

At that price, I doubt it. Link to one and we can all condemn it.......

[alienb4ndit]

Ok

This is possibly the cheapest on eBay

http://www.ebay.co.uk/itm/200828517922? ... 1438.l2649

and this one is a little more

http://www.ebay.co.uk/itm/190753597740? ... 1438.l2649

Your condemning responses please!

[Tubbs]

Now if you notice the reducer (tomasetto alaska ? ) is the same in both kits. And they arnet very stable, pressure over shoot during gear changes. Not good on a turbo car.
The injector rail (valtek 30's) are very cheap, and tbh surprisingly good in the right application, a 1600cc car for example. No problems, or a 6 cylinder so the overall horsepower is lower per cylinder. But on a 4 pot turbo ? Not much hope really....

[alienb4ndit]

Ok.

Thanks for that... only experience can give that kind of advice.

Is it worth me continuing to look on ebay?

If not, where can I get e decent kit at lowest price as I'm on a budget.

Thanks again

[Tubbs]

Play a bit of mix and match if you want anything decent im afraid. For example 4 cyl king ecu obd, zavoli zeta and valtek 34's. Im an italian system fitter though through and through im afraid. So my opinion is a bit biased.
The other game you could play is hope its up to the job, kme gold, magic jets and a stag ? Sure it is, just dont have much experience of them myself so cant really pass comment.

[Gilbertd]

and, if you look at the first ad, the tomasetto alaska reducer is only good for engines up to 136 bhp. It would just about manage a 2.0 litre non-turbocharged Saab on a good day , but a 2.3 Turbo produces considerably more than that. Not sure how much but I know the 2.0 litre high pressure turbo version is at 180 bhp so would expect the 2.3 to be over 200.

[Tubbs]

The 2.3 9-5 hot aero is 260bhp. They range from 210-260 dependent on wether its a manual LPT or HPT. The autos are higher output, bar the last of the 9000's there are a few, very rare manual 250bhp 9000's.
Then you have mine, the v6 HPT, the last pre vauxhall engine, sadly i am unable to find a Di cassette for it, and am probarbly going to have to scrap it soon.....

[demonicwillow]

The 2.3 9-5 hot aero is 260bhp. They range from 210-260 dependent on wether its a manual LPT or HPT. The autos are higher output, bar the last of the 9000's there are a few, very rare manual 250bhp 9000's.
Then you have mine, the v6 HPT, the last pre vauxhall engine, sadly i am unable to find a Di cassette for it, and am probarbly going to have to scrap it soon.....

https://sites.google.com/site/pierecksa ... airing-dic