LPG Chimaera (Follow My Conversion)

[phazed]

Just done 3 tanks of LPG in my newly acquired 4.0 RV8 Disco.

Mixed heavy footing, 10-11 mpg, (who would ever buy these new?).

Adjusted , (non TVR style) driving, 16MPG !

That on approximately half price gas, I'm happy

[ChimpOnGas]

phazed said:

Just done 3 tanks of LPG in my newly acquired 4.0 RV8 Disco.

Mixed heavy footing, 10-11 mpg, (who would ever buy these new?).

Adjusted , (non TVR style) driving, 16MPG !

That on approximately half price gas, I'm happy

Nice

There's a lot of debate amongst the Rangie/Disco crowd over diesel vs LPG converted petrol.

For me it's no contest, a smooth powerful petrol V8 Rangie/Disco on LPG beats a rattly old agricultural slow as fook diesel all day long.

Time & time again on literally thousands of converted Rangie/Discos the venerable old Rover V8 proves itself to be the perfect engine to consume cheap as chips LPG.

Most get converted at the 80-100,000 mile mark and from there on go to over 200,000 miles only ever sniffing gas.

Lets just say you had a thirsty sports car with an enormous boot and that same Rover V8 engine, wouldn't it make perfect sense to put it on gas?

I thought so

[ChimpOnGas]

The Chimpongas way to fill his TVR with over 300 miles of fuel.

• Sainsburys, London Colney

• LPG per Lt = £0.679

• 95 Ron Petrol per Lt = £1.279

• £1.279 divided by £0.679 = 1.8836 (cost equivalent multiplier)

• 45.08 Litres divided by 4.546 = 14.31 Imperial gallons

• 304 miles divided by 14.31 = 21.24 Mpg

• 21.24 x 1.8836 = 40.007 Mpg (cost equivalent to 95 Ron Petrol)

And before you ask, no this was not driving Miss Daisy.

Only last week I pulled an easy LPG powered 153 Mph on the M40, I mean my private track

"Ferrari fast, Ford Fiesta economical"..

[A900ss]

ChimpOnGas said:

Only last week I pulled an easy LPG powered 153 Mph

Great numbers Dave and I love to see all this. I reckon I'm going to be doing close to 7k miles this year so these posts are really informative.

You must have bigger balls than me because my bonnet starts to shake at about 100 and I don't think I've done more than about 120 in the car. Private test track of course. 150+ in a Chim doesn't sound much fun to me (exciting I can imagine though!). However it's also fair to say that 140 in my BMW can feel like 70 does in most cars!

[SILICONEKID345HP]

ChimpOnGas said:

The Chimpongas way to fill his TVR with over 300 miles of fuel.

• Sainsburys, London Colney

• LPG per Lt = £0.679

• 95 Ron Petrol per Lt = £1.279

• £1.279 divided by £0.679 = 1.8836 (cost equivalent multiplier)

• 45.08 Litres divided by 4.546 = 14.31 Imperial gallons

• 304 miles divided by 14.31 = 21.24 Mpg

• 21.24 x 1.8836 = 40.007 Mpg (cost equivalent to 95 Ron Petrol)

And before you ask, no this was not driving Miss Daisy.

Only last week I pulled an easy LPG powered 153 Mph on the M40, I mean my private track

"Ferrari fast, Ford Fiesta economical"..

Yes but you get far less mpg from LPG ! Is it about a third less

]"Ferrari fast, Ford Fiesta economical"[/b]..

How can a a donkey of a 4 litre be Ferrari fast

[ChimpOnGas]

SILICONEKID345HP said:

Yes but you get far less mpg from LPG

The figures are there Daz, and clear as day

• 304 miles traveled & divided by the 14.31 gallon fill = 21.24 Mpg

21.24 Mpg is true LPG Mpg, not petrol Mpg you Muppet.

It only becomes the cost equivalent of 40 Mpg when you compare the price of LPG with petrol, but of course that's what's important

Try reading the post properly and engaging your brain before engaging your mouth.

For comparison, here's my wife's 1.4 Litre 4 cylinder Nissan Micra that is only 2.6 Mpg better than my LPG powered 4.0 Litre 8 cylinder Chimaera.



And she only gets 42.6Mpg by driving like a granny, if she'd covered the same 300 miles at the same speed as the TVR did she'd be seeing under 40 Mpg.

This makes my TVR cheaper to fuel than my wife's Micra.

I'd call that a result

Edited by ChimpOnGas on Saturday 21st June 18:57

[Prizam]

SILICONEKID345HP said:

ChimpOnGas said:

The Chimpongas way to fill his TVR with over 300 miles of fuel.

• Sainsburys, London Colney

• LPG per Lt = £0.679

• 95 Ron Petrol per Lt = £1.279

• £1.279 divided by £0.679 = 1.8836 (cost equivalent multiplier)

• 45.08 Litres divided by 4.546 = 14.31 Imperial gallons

• 304 miles divided by 14.31 = 21.24 Mpg

• 21.24 x 1.8836 = 40.007 Mpg (cost equivalent to 95 Ron Petrol)

And before you ask, no this was not driving Miss Daisy.

Only last week I pulled an easy LPG powered 153 Mph on the M40, I mean my private track

"Ferrari fast, Ford Fiesta economical"..

Yes but you get far less mpg from LPG ! Is it about a third less

]"Ferrari fast, Ford Fiesta economical"[/b]..

How can a a donkey of a 4 litre be Ferrari fast

Filled mine to the brim and then went driving. Some fast, some not. Start and stop traffic for a lot and 2 nights in a hotel.

308 miles later i filled her up again for £56.65

So... a tenna ish difference.

How much is the conversion?

[SILICONEKID345HP]

ChimpOnGas said:

The figures are there Daz, and clear as day

• 304 miles traveled & divided by the 14.31 gallon fill = 21.24 Mpg

21.24 Mpg is true LPG Mpg, not petrol Mpg you Muppet.

It only becomes the cost equivalent of 40 Mpg when you compare the price of LPG with petrol, but of course that's what's important

Try reading the post properly and engaging your brain before engaging your mouth.

For comparison, here's my wife's 1.4 Litre 4 cylinder Nissan Micra that is only 2.6 Mpg better than my LPG powered 4.0 Litre 8 cylinder Chimaera.



And she only gets 42.6Mpg by driving like a granny, if she'd covered the same 300 miles at the same speed as the TVR did she'd be seeing under 40 Mpg.

This makes my TVR cheaper to fuel than my wife's Micra.

I'd call that a result

Edited by ChimpOnGas on Saturday 21st June 18:57

I only said it because you bite every time It`s a brilliant conversion and worth every penny ,Are you happy now ?

Edited by SILICONEKID345HP on Monday 23 June 18:16

[Tyre Tread]

Prizam said:

Filled mine to the brim and then went driving. Some fast, some not. Start and stop traffic for a lot and 2 nights in a hotel.

308 miles later i filled her up again for £56.65

So... a tenna ish difference.

How much is the conversion?

32mpg? Hmmmm

[Prizam]

Tyre Tread said:

Prizam said:

Filled mine to the brim and then went driving. Some fast, some not. Start and stop traffic for a lot and 2 nights in a hotel.

308 miles later i filled her up again for £56.65

So... a tenna ish difference.

How much is the conversion?

32mpg? Hmmmm

Sounds about right and is fairly consistent with what i usually get.

My Calculations using the receipt show 30mpg tho.

[Tyre Tread]

Prizam said:

Tyre Tread said:

Prizam said:

Filled mine to the brim and then went driving. Some fast, some not. Start and stop traffic for a lot and 2 nights in a hotel.

308 miles later i filled her up again for £56.65

So... a tenna ish difference.

How much is the conversion?

32mpg? Hmmmm

Sounds about right and is fairly consistent with what i usually get.





My Calculations using the receipt show 30mpg tho.

Depends upon the price of the fuel used


£56.65/(assumed)£1.30 per litre (less fuel if super u/l) = 43.577 litres/4.546= 9.58 gallons
308/9.58 = 32.15MPG

at £1.40/L that increases to 34.6MPG

On a gentle run up the A1 to Scotland I was pleased to get 25MPg , the best I have ever got and my average is regularly 19-20mpg.

I thought that was a mpore realistic expectation.

Maybe my car needs some fettling somewhere but I'm not falling into the plumber's trap.

[Quinny]

Over in France, my 6 ltr LS seemed to be returning 25 mpg........until I decided to use the sat nav recorded mileage instead of the speedo trip....

It then went up to 29 mpg

Comparing speedo with satnav.......satnav says 100 miles, speedo records 86..... And yet the speedo itself is pretty accurate..... TVR's gotta love em

[phazed]

So what you're saying is my average 15 mpg could be better, (or worse).

With 265/35/18s on the rear the speedo is spot on!

I must check and compare distance with a sat nav though

[ChimpOnGas]

Tyre Tread said:

32mpg? Hmmmm

32mpg from a Rover V8 petrol Chimaera.

[SILICONEKID345HP]

phazed said:

So what you're saying is my average 15 mpg could be better, (or worse).

With 265/35/18s on the rear the speedo is spot on!

I must check and compare distance with a sat nav though

That triple plenum likes to suck a`lot of air in not like the tiny 4l throttle size .

I used to get 35mpg at 70mph in the 190bhp 4l Rover MGRV8 with the standard 14cux ,it had the Rover gear box so higher geared .

[Clem64]

Late 2013 I had my Skyline GTST R33 converted to LPG, with the exception of a slight case of gas contamination this year I am the happiest man on the road right now, my daily 80 mile round trip just makes me smile, knowing it costs me around half what it would on petrol without any loss in power.

[SILICONEKIDOBHP]

Question 1 Can LPG cars be used for track days and Santa Pod ?If not can the tank be removed ?

Question 2 On an Emerald what wires need to be connected to the new piggy back ECU ,allowing for the three switchable maps I have or would you have to choose one map ?


Question 3 How different are the AFR`s, cruise ,full power etc . I know the piggy back copies the map you put in to it then quickly converts the fueling and advance to suit lpg .

Question 4 Can the piggyback ECU cope with full power or is it down to injector size ?


Question 5 Why do some LPG systems automatically switch on the petrol on high loads/rpm ?

Question 6 Does the inlet manifold need to be removed to drill fr injectors ?



I would be happy with a tank like this ,this is a smaller griff boot with a 65 litre tank ,filler behind the rear number plate

Edited by SILICONEKIDOBHP on Tuesday 8th July 20:12

Edited by SILICONEKIDOBHP on Tuesday 8th July 20:14

[ChimpOnGas]

SILICONEKIDOBHP said:

Question 1 Can LPG cars be used for track days and Santa Pod ?If no9t can the tank be removed ?

I don't see why they would not allow it, they allow Nitrous Oxide after all and thats compressed in a bottle. LPG tanks are way safer than petrol tanks...fact!

SILICONEKIDOBHP said:

Question 2 On an Emerald what wires need to be connected to the new piggy back ECU ,allowing for the three switchable maps I have or would you have to choose one map ?

You could do it a number of ways, but best would be to build an Emerald LPG map that means the piggyback has less to do.

SILICONEKIDOBHP said:

Question 3 How different are the AFR`s, cruise ,full power etc . I know the piggy back copies the map you put in to it then quickly convert the fueling and advance to suit lpg .

On the ignition side you need a lot more advance early on it then slowly starts to return more towards the petrol curve meeting at max RPM, its a lot more complex than this when you factor in load & temps but that's the basic rule.On the fueling the stoichiometric ratio for burning LPG in air is between 15.6:1 and 15.8:1 against 14.7:1 for petrol.

SILICONEKIDOBHP said:

Question 4 Can the piggyback ECU cope with full power or is it down to injector size ?

Of course it can, however... your LPG injectors and the vaporisor must be specified with the engine power & number of cylinders in mind.

SILICONEKIDOBHP said:

Question 5 Why do some LPG systems automatically switch on the petrol on high loads/rpm ?

Because they have failed to make the system work properly

[SILICONEKIDOBHP]

So the piggy back ECU does not work that well straight off the petrol map ,it will need to convert to petrol lpg on spark and fuel .

Who would be able to get a closer map ,would that need to be done after the install on the rollers . Most people are happy just to run off the petrol map .


What afr`s are full load ?

Do you have a picture of your engine bay ? and where is the lpg hose routed ?

How many litres are in your tanks ?

[ChimpOnGas]

SILICONEKIDOBHP said:

So the piggy back ECU does not work that well straight off the petrol map ,it will need to convert to petrol lpg on spark and fuel .

Who would be able to get a closer map ,would that need to be done after the install on the rollers . Most people are happy just to run off the petrol map .


What afr`s are full load ?

Do you have a picture of your engine bay ? and where is the lpg hose routed ?

How many litres are in your tanks ?

Come on Daz, read through this post fully and you'll find all the answers to your next list of questions.

A piggyback is always trying to twist the petrol map to suit LPG but they can work well, it just stands to reason the less manipulation the piggyback has to do the more accurate your fueling will be.

One thing you need to know about LPG is it's volume increases & decreases dramatically over quite a small temperature range, that means your AFR changes too so can create some frustrating challenges if you're running open loop.

Closed loop & or a fuel temperature ECU input is the answer, you absolutely must have the means to compensate for fuel volume/AFR fluctuations on the fly or you'll be chasing your tail for ever.

Get it all right and you'll never know your running on gas until you fill up at the pumps & pay for your fuel.

I'm just back from Le Mans and my passenger was absolutely amazed how cheap our fills were

We also pulled a genuine sat nav confirmed 142 on gas spanking yet another Porsche 911, he arrived at the next fuel station 10 minutes after us with the boys in blue on tow.

The fekin Porker weasel started pointing at us gassing up with LPG, I think he was saying "that TVR was going much faster than me".

Bet he also couldn't get his head around the whole TVR filling with gas thing, I get a lot of that