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Discussion Starter · #1 ·
Hello all, just thought ide say that these forums are great (+ the people) couldnt be more helpfull.

Ok
my 1990 9000i 2.0L non-turbo has a Gas conversion and is running great.... when its on gas.

I think its the injectors that are giving it trouble on petrol though, just wondering if anyone has had the same trouble, and i was wondering what modifications i could do to the motor to try and get better than standard performance out of the petrol (when its fixed) which wouldnt effect too much the way it runs on LPG. Would the modds be co-operative with both fuel systems?

e.g. i want a race car on petrol & econo-saab on gas ,

is this possible, and has anyone done similar that thay could offer some advice.
& (not to ask too much) would turbo parts fit a non-turbo motor and if so what would be the side-effects?

or am i juggling with milk & orangejuice
 

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'fraid so..
If it was a turbo car however because lpg has a higher octane rating you can do lots to the boost before detonation will rein things back
but on a N/A car there is little you can do on one side that will not effect the other and they will be expensive
Stuff like increasing the c/r ratio, porting the heads ,higher lift cams etc all will cost and all will have the same effect on gas and petrol running
sorry ...
The best thing is ..buy a turbo !!
 

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Discussion Starter · #3 ·
Ohh thanks

so is it possible to throw a turbo on my motor or is it a complete motor change thats required, and if i can just bolt on, without changing all the internals?.
Or
If i was to work the motor am i right in saying that anything that can handle petrol could handle gas?

as it stands it seems to run realy well on gas, and im worried i might blow something unless i tame down a bit,
would it be worth getting better components when/if i do a rebuild, whats the jazz on running gas on saab motors, (if anyone has the patients to explain this one)

ide still like to get it running awsome but if a turbo is too hard/expencive (like insurance 4 me) ill have to find another way
 

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sorry what I meant was buy a turbo car ...
putting a turbo motor into a n/a car ..
possible but difficult you need to take the ecu/wiring loom and adapt it
putting a turbo on a n/a engine..really not worth it ..there is a lot of detail differences
also you would have to re-programm the gas ecu

I would enjoy what you have ..the saab ecu is probably making the most of the octane rating of the gas and giving you the good performance
 

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Discussion Starter · #5 ·
Hmm....


ok thanks again.

ill have to price up some standard mods and see what i can do with this motor,
maybe.... nah
what about...... dont think so

ill keep thinking and stop past a few performance places

im sure(I hope) ill find something, to give me extra Bhp,
if not ill have to wait till i get a new(er) car . *kicks saab* "why cant you be a 2.3L"

be ok if i was back in Australia i know where to go (and who to see) there to get cheap mods, im just out of my league here .

thanks for your assistance
 

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Hi PTK
Try a JR airfilter and a free flowing exhaust...that should add some bhp. As far as your injectors are concerned, try running some injection cleaner through (Wynn's is good). Check the condition of your rotar arm and distrib cap...I've just changed mine and the difference in pull is quite noticeable even though the car has only done 49k miles.

Hope this helps
Al
 

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I'd be careful about going for a "free flowing" exhaust. Engines need some backpressure to help develop torque. If you lower the back pressure, you will get high rev bhp gains, but often this can be at the expense of low end torque, which is not always desirable.

Make sure everything else is in good order though as Al suggests and you may find you get a little from that.
 

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Yes, I'll do a U turn on the free flow exhaust suggestion The 2.0 n/a stuggles for low down torque as it is..well mine does anyhow!
 

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PTK

There's no better 'mod' than making sure all your bits are working correctly! - new rotar arm made the biggest difference for my low mileage 900 especially curing the sluggishness from 1 to 3k rpm.

Cheers
Al
 

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I'm not sure why there's the big desire to get the petrol system working.

I try as hard as possible to run our Volvo on LPG, petrol is that nasty (expensive) stuff used to start the car when the engine is cold.

LPG @ 30p per litre is nice.

David.
 

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Discussion Starter · #12 ·
this is true i know and to get 350 miles to 20 pounds is fine for me
but im not sure if it can get as good performance out of it, it seems that all the people with LPG (like you & me) seem to love it and wouldnt like to go without it. (or i wouldnt anyways, unless i have too)

So has anyone got a Gas performance vehicle??
if so please tell the Specs & milage you get, and what you had to get/sacrafice to do it.

im curiouse to find out
 

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I take it you've taken it to an LPG tuner?

My Volvo has a Bigas multipoint sequential injection system and when we first had it done, it wouldn't produce power above 4000rpm. At the first service, the chap put the laptop on it to remap the gas ECU and all of a sudden, end of problem.

However, i've just had it's second service done and took it elsewhere due to job relocation and that chap discovered that the injectors were wired up out of sequence so that for certain injectors, they were firing gas and then the mixture was being pulled back round the manifold to the desired cylinder - not best practice!

Now I don't want to suggest that this is the issue but certainly I don't have any performance problems out of a mere 2.0i 5 cylinder Volvo lump, which I concede isn't going to set any records for performance but for similar sized cars with 2.0i engines, I'd have thought you could have got it running ok.

Do you know what sort of gas system you have? There's a moderately active newsgroup uk.rec.cars.fuel.lpg

David.
 
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