Notices
Drivetrain Gearbox, Diffs & Driveshafts etc

LPG a way to get cheap power?

Thread Tools
 
Search this Thread
 
Old 12 February 2002, 05:28 PM
  #1  
brickboy
Scooby Regular
Thread Starter
 
brickboy's Avatar
 
Join Date: Jun 2000
Posts: 2,965
Likes: 0
Received 0 Likes on 0 Posts
Question

It has been done to a couple of private Volvos (both older T5s) on the Volvo Club forum. Both are still fairly recent, so the long-term prognosis isn't known.

However, Volvo's own 'factory' bi-fuel cars are normally aspirated, which is interesting when you think that pretty much every car they make in the 60 / 70 / 80 range apart from the 2.4 is turbocharged.

Edited to say that DNB's right -- as soon as there's a decent number of people using LPG, the tax will jump up to stupid levels ... basically, unless you drive 20,000+ miles per year and can get the coversion costs back on savings at the pump, it probably ain't worth it.

[Edited by brickboy - 12/2/2002 5:31:26 PM]
Old 01 December 2002, 11:32 PM
  #2  
Echo
Scooby Regular
 
Echo's Avatar
 
Join Date: Oct 2002
Posts: 1,333
Likes: 0
Received 0 Likes on 0 Posts
Question

I have been told that LPG is close to zero emission? If so, that would mean that all the cat's could be taken off which would give quite a power boost and half the running costs. I must be missing something as I've not seen any mention of this before!

Has anyone managed a conversion and what were the results?

Cheers!

:-)

Mike
Old 02 December 2002, 02:11 PM
  #3  
Gez
Scooby Regular
 
Gez's Avatar
 
Join Date: Mar 2002
Posts: 809
Likes: 0
Received 0 Likes on 0 Posts
Post

I thought that scoobs didnt react too well with LPG conversions.

Gez
Old 02 December 2002, 02:21 PM
  #4  
dnb
Scooby Regular
 
dnb's Avatar
 
Join Date: Feb 2002
Location: oustide the asylum?
Posts: 3,306
Likes: 0
Received 0 Likes on 0 Posts
Post

I've asked this before, and was told "It will happen sometime..." and "research is being done"

Apparently the Subaru flat 4 doesn't take well to LPG (due to low compression ratio apparently) And turbos just add to the problem.

I like the thought of no cats, cheaper fuel (until 2004 when the govt will wind up tax to the point of stupidity ) and passing emissions tests...

Also, the octane rating of LPG is greater than petrol (108 springs to mind, but I don't know for sure) so better det protection maybe? The calorific value of the fuel is lower, so you won't get as much power or mpg. (All AFAIK)

Anyone up for doing a DIY LPG conversion?
Old 02 December 2002, 02:26 PM
  #5  
nom
Scooby Senior
 
nom's Avatar
 
Join Date: Oct 2001
Posts: 2,602
Likes: 0
Received 0 Likes on 0 Posts
Post

Zero emissions?
Ha - nope - but politically it is, which seems to be the important thing these days
I imagine it's a case with LPG that, as usual, turbos raise the risk of problems hugely & no LPG conversion company wants to be known as the company that blows cars up.
Old 02 December 2002, 05:07 PM
  #6  
grant620
Scooby Regular
 
grant620's Avatar
 
Join Date: Jul 2002
Posts: 40
Likes: 0
Received 0 Likes on 0 Posts
Post

Has anybody fitted LPG to a turbo car yet?
Old 02 December 2002, 05:32 PM
  #7  
globbits
Scooby Regular
 
globbits's Avatar
 
Join Date: Jan 2002
Posts: 275
Likes: 0
Received 0 Likes on 0 Posts
Post

Hi all

The problem with LPG on Scooby's is the same as with all turbos - that of the massive difference in fuel-delivery levels. When off-boost, a turbo'd car needs "normal" amounts of fuel, and so a small gas-vaporiser. Trouble is, when the turbo spools up, they need an awful lot more and the vaporiser just isn't man enough for the job.

So, at present, you either have to go for a car that runs stupid-rich off boost, or dangerously-lean on boost - both of which are dangerous.

The new injector-based systems are still in their infancy and, because of the flat-4 arrangement of the Subaru's, they aren't being focussed on as much as for the in-line engines. My LPG Legacy (normally-aspirated) is being converted from vaporiser to single-injector in the new year. This _might_ be a simple (read that as basic) solution for turbo'd cars, but you wouldn't want to play the game with tweaked Scoobs at all yet.

Sorry - I promise I will keep you guys posted
Old 02 December 2002, 11:12 PM
  #8  
easyrider
Scooby Regular
 
easyrider's Avatar
 
Join Date: Sep 2002
Posts: 950
Likes: 0
Received 1 Like on 1 Post
Post

There is roughly a 10% decrease in power on LPG-dont ask me why though-but if it was possible to fit it to a turbo scoob and decatting it ,the decat would outweigh the losses,also, i dont think that the range is as good on LPG(about 150 miles on a converted N/A car)which is why most conversions are dual fuel.-----so we'll be lucky to get 1.5 miles out of a scoob then!!
Old 02 December 2002, 11:36 PM
  #9  
globbits
Scooby Regular
 
globbits's Avatar
 
Join Date: Jan 2002
Posts: 275
Likes: 0
Received 0 Likes on 0 Posts
Post

It's better and worse than that. The power output is about the same (although I've lost quite a lot of torque) but the mpg is seriously hit. I got 29mpg on petrol and now get 21mpg on gas!

Fortunately, part of the reason for that is the vaporiser, so it should improve with the single-injector system next year. But, if you assume you won't be able to boot it quite as hard, it's a reasonable assumption
Old 03 December 2002, 11:26 PM
  #10  
Echo
Scooby Regular
 
Echo's Avatar
 
Join Date: Oct 2002
Posts: 1,333
Likes: 0
Received 0 Likes on 0 Posts
Post

Ah well, if it was such a good idea it would be available by now I guess. As I do big miles I thought that this could be the solution but looks like I'd better start driving the missis Sport to keep the costs down :-(

:-)

Mike
Old 04 December 2002, 12:55 AM
  #11  
Paul_M
Scooby Regular
 
Paul_M's Avatar
 
Join Date: Jun 2002
Location: Scotland
Posts: 1,664
Likes: 0
Received 0 Likes on 0 Posts
Post

Lower calorific value explains the some of the loss of power and MPG, but due to higher octane you can remap to get back most of that power. Only if the car will be run on LPG all the time though.

Still not convinced it's a good idea on a turbo, too many variables to control to keep charge temps down and prevent det etc. How many NA cars do you hear of being turboed and blowing up because the ECU couldn't get the fuelling right under all conditions? I think the same risks apply to running LPG on a turbo car, cos the factory ECU no longer controls the fuelling when using the LPG.

TBH I'm not an authority on this subject but just my opinions going on what I've read. LPG can cause valve seat erosion on some cars so is not yet 100% problem free even on NA cars.
Old 04 December 2002, 03:38 PM
  #12  
DeanF
Scooby Regular
iTrader: (1)
 
DeanF's Avatar
 
Join Date: Apr 2002
Posts: 2,808
Likes: 0
Received 0 Likes on 0 Posts
Talking

My mates been running on LPG now for 2 years on his Nissan S14 the only problems he has experienced is under high load/boost the Lpg cannot keep up with the Turbo. If you inrease revs gradually in high gears it's fine Floor it & it just runs out os Steam.

Dean
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
JimBowen
ICE
5
02 July 2023 01:54 PM
KAS35RSTI
Subaru
27
04 November 2021 07:12 PM
FuZzBoM
Wheels, Tyres & Brakes
16
04 October 2015 09:49 PM
Davalar
General Technical
19
30 September 2015 08:54 PM
Ozne
General Technical
2
27 September 2015 03:06 PM



Quick Reply: LPG a way to get cheap power?



All times are GMT +1. The time now is 02:37 PM.