coozer
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| posted on 11/10/08 at 09:45 PM |
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Turbo on LPG
Nice article in PPC has given the boost (amounst jeeps and scooters) to go for a turbo conversion running LPG.
Sounds like a great way to cheaper, extra power!
I'm wondering about the practicality of running lpg full time.. there is a Total garage close that sells the stuff, but how do you reckon I
would fair on track day?
Any one running LPG??? with a turbo??
Any restrictions running an LPG system in a 7? I'm not that familiar (yet) with LPG.
Steve
1972 V8 Jago
1980 Z750
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big_wasa
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| posted on 11/10/08 at 09:50 PM |
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Funy, Having read that I am now reading up on it.. The idea of tubo-ing the zetec with out compresion mods sounded awsome.
Its a Liquid lpg injection system..
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zilspeed
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| posted on 11/10/08 at 10:22 PM |
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I run an LPG system on my Golf. That's not a Turbo though.
Modern injection systems will easily run on a turbo engine because the fuel requirements are mapped just like petrol injection.
If, as stated above, the car in question has liquid phase injection, then that's a whole different can of worms.
There really are few people who will touch a liquid phase system.
Sequential gas injection is the proverbial piece of pi,,,, though.
Mine is completely closed loop and so consantly tunes itself for stochiometric.
You can still get in about it and alter the map though if you want to.
Easy Peasy.
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MikeRJ
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| posted on 11/10/08 at 10:29 PM |
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You really need a liquid phase injection system for any serious amount of power on the turbocharged application because a vapour phase system a)
doesn't deliver enough gas for high specific outputs, and b) doesn't provide enough cooling.
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mark chandler
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| posted on 11/10/08 at 10:32 PM |
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I have run cars for a few years on LPG, p38 range rover on venturi system 100k miles, system backfired occasionally and restricted performance.
P38 range rover on full time sequential LPG system, again 100k miles but a bit of valve ressesion, no discernable loss of performance.
Now an XK8 on sequential system that allows you to bleed in fuel by mapping, 10k miles so far, this is very good, £36 to travel 300 miles, 100% petrol
when you floor the throttle so no lose of performance.
Gas is good!
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Ninehigh
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| posted on 12/10/08 at 12:43 AM |
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To start with you'll need to consider a second fuel tank, and all the plumbing/wiring too. Iirc lpg gives 70% of the economy and a small
reduction in power, although surely it can be adjusted (maybe adjusted to give more power?)
As for racing it I dunno, you got all that extra weight would it be worth it for cheaper fuel?
As an aside it doesn't run full time, it can't start on lpg and needs 5 mins to warm up. I don't know if this is any
different now I got all this info a few years ago when it was all pretty new
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hobbsy
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| posted on 12/10/08 at 04:34 AM |
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You can run solely on LPG with some setups.
Also the tanks are VERY heavy, think it would blunt your performance a bit and you'd have to think about where you were going to put it weight
distribution wise.
Also refuelling at a track day could be a PITA, its not like you can fit extra gas in Jerry cans.
(although you could do something with a calor gas bottle and a hand pump but thats a totally different kettle of fish).
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Volvorsport
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| posted on 12/10/08 at 08:51 AM |
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while LPG is probably cheaper , it doesnt mae sense to use it if you could get your hands on E85 , which has a much higher octane rating , therefore
lots more boost .
if only this country would catch on !
there a 16v turbo in sweden (2.3 redblock) which makes 900 hp at 2.7kg boost on E85 , hes about 200 hp shy with normal unleaded .
www.dbsmotorsport.co.uk
getting dirty under a bus
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MikeRJ
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| posted on 12/10/08 at 09:31 AM |
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IIRC LPG has a higher octane rating (~110) than E85.
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zilspeed
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| posted on 12/10/08 at 09:36 AM |
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quote:
Originally posted by Ninehigh
As an aside it doesn't run full time, it can't start on lpg and needs 5 mins to warm up. I don't know if this is any
different now I got all this info a few years ago when it was all pretty new
Things have moved on a bit, you can start the car on LPG nowadays. On mine I just tick a box in the software setup and that's it done.
Having said that, I run it on petrol until there is a bit of heat in the engine. In my case and depending on the ambient temperature, that will vary
from around 20 seconds to 70-90 seconds on a bitterly cold morning. It switches over on a trailing throttle above 2000rpm, so you have to look at the
LED indicator to see that it has switched. Otherwise that's it.
Regarding power. There is less calorific value in LPG compared to petrol, so to make the same power, you just stick a bit more gas in. That's
where the higher consumption comes from.
I get 29 mpg versus 40 on petrol, so that's 72.5 %.
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coozer
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| posted on 12/10/08 at 10:01 AM |
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Hmm, sorry but whats the difference between gas injection and liquid injection? Different tanks and availability perchance??
PPC article says lpg is perfectly suited to turbo engines as the octane is higher @ 110.
My whole idea was to build a zetec turbo wholly for lpg with one tank.. no petrol system at all.
1972 V8 Jago
1980 Z750
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mad4x4
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| posted on 12/10/08 at 01:18 PM |
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quote:
Originally posted by mark chandler
I have run cars for a few years on LPG, p38 range rover on venturi system 100k miles, system backfired occasionally and restricted performance.
P38 range rover on full time sequential LPG system, again 100k miles but a bit of valve ressesion, no discernable loss of performance.
Now an XK8 on sequential system that allows you to bleed in fuel by mapping, 10k miles so far, this is very good, £36 to travel 300 miles, 100% petrol
when you floor the throttle so no lose of performance.
Gas is good!
I run a P3 with LPG direct inejection - runs a dream never backfires and if anything pulls better on GAs than petrol. 4.6l = 180miles of 69L of LPG
@49,9
Scot's do it better in Kilts.
MK INDY's Don't Self Centre Regardless of MK Setting !
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mad4x4
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| posted on 12/10/08 at 01:20 PM |
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quote:
(although you could do something with a calor gas bottle and a hand pump but thats a totally different kettle of fish).
Don't think the Track day folk would like that .....
BOOM!
Scot's do it better in Kilts.
MK INDY's Don't Self Centre Regardless of MK Setting !
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Ninehigh
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| posted on 12/10/08 at 05:07 PM |
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If they can make a pure lpg system then maybe I should do that, I'm quite used to my 2l tdci consumption lol.
I heard they can covert diesel engines but the only person I found that did it ran the maths for me and I'd have to do about 120,000 miles a
year for 9 years to be worth it... Unless anyone knows otherwise?
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MikeRJ
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| posted on 12/10/08 at 06:47 PM |
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quote:
Originally posted by zilspeed
Regarding power. There is less calorific value in LPG compared to petrol, so to make the same power, you just stick a bit more gas in. That's
where the higher consumption comes from.
I get 29 mpg versus 40 on petrol, so that's 72.5 %.
If it were only that simple you'd be able to increase the power of any engine by injecting more fuel, which of course you can't unless you
get more air in as well.
LPG has a higher stoichiometric air/fuel raito (i.e. requires more air to burn a given amount of fuel), and in vapour form takes up a large amount of
space, displacing air so you will always get less peak power and economy, but you pay quite a bit less as well. Things are quite a lot better with
liquid phase, the fuel takes up a similar volume to petrol.
[Edited on 12/10/08 by MikeRJ]
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Volvorsport
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| posted on 12/10/08 at 08:08 PM |
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yeah E85 is 104-105 octane , bit like race fuel , but you dont need another tank or anything like that .
www.dbsmotorsport.co.uk
getting dirty under a bus
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Ninehigh
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| posted on 12/10/08 at 08:13 PM |
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Oh is that the alcohol stuff? Seen that in the morissons near liverpool airport but after the biodiesel debacle I wouldn't risk ruining my
girlfriend's car for 91p petrol
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MikeRJ
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| posted on 12/10/08 at 08:20 PM |
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quote:
Originally posted by Ninehigh
Oh is that the alcohol stuff? Seen that in the morissons near liverpool airport but after the biodiesel debacle I wouldn't risk ruining my
girlfriend's car for 91p petrol
You can't just stick it in any car, the engine has to be mapped to run it.
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Ninehigh
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| posted on 12/10/08 at 08:26 PM |
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Thought as much, good job I didn't bother
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Volvorsport
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| posted on 12/10/08 at 09:08 PM |
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yeah , the stoich ratio is different , cant just stick it in , well thats what the missus said .
91p a litre ? still 15p a litre cheaper , and you can make more power .
here , have a read , bit off topic really , i dont know anything about LPG ! so cant really add anythin purposeful
http://forums.turbobricks.com/showthread.php?t=73061
[Edited on 12/10/08 by Volvorsport]
www.dbsmotorsport.co.uk
getting dirty under a bus
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Ninehigh
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| posted on 12/10/08 at 09:10 PM |
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How much is it to remap an engine? No doubt it can recover the price :-)
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paulf
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| posted on 12/10/08 at 09:37 PM |
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The problem with E85 is that you use roughly1.5 times as much so at present prices it is actually more expensive than petrol.
Paul
quote:
Originally posted by Volvorsport
yeah , the stoich ratio is different , cant just stick it in , well thats what the missus said .
91p a litre ? still 15p a litre cheaper , and you can make more power .
here , have a read , bit off topic really , i dont know anything about LPG ! so cant really add anythin purposeful
http://forums.turbobricks.com/showthread.php?t=73061
[Edited on 12/10/08 by Volvorsport]
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Ninehigh
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| posted on 12/10/08 at 09:58 PM |
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Bloody hell with 101 octane? Isn't normal unleaded 95?
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Volvorsport
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| posted on 12/10/08 at 10:30 PM |
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your making more power with it , its more efficient , you dont need to put your foot down so much !
www.dbsmotorsport.co.uk
getting dirty under a bus
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iti_uk
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| posted on 14/10/08 at 03:16 PM |
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Isn't the only reason it doesn't feel as powerful (in normal daily driving) because it can run with more advance on the timing, so if you
keep the timing in the sweet spot for unleaded, when you switch to LPG, the engine will run (effectively) retarded? So either you train the ECU to
advance the timing when switching over or you run purely LPG and have the engine set up properly for that...
In theory I'd like to try a pure LPG setup in my car, but the whole track-day thing and availability are problems. 
Chris
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