Thinking out loud: M103 + LPG + Turbo - Page 2 - PeachParts Mercedes-Benz Forum

auspumpen · #16 06-03-2009, 08:07 AM

If fuel economy is one of your priorities in addition to power, then I think a cost/benefit assessment would steer you toward shipping your IP off to Myna and simply installing a slightly larger turbo and IC setup. Myna's pumps are externally adjustable, so you could tailor the power output to suit the needs of the boost available as well as your interest in economy. Messing with gassers, would probably end up costing more ($/time) in the long run, since you already have the entire OM602 installed and ready for mods. I'd ditch your LPG setup once the IP is modded.

Deni · #17 06-03-2009, 09:51 AM

Quote:

Originally Posted by auspumpen

If fuel economy is one of your priorities in addition to power, then I think a cost/benefit assessment would steer you toward shipping your IP off to Myna and simply installing a slightly larger turbo and IC setup. Myna's pumps are externally adjustable, so you could tailor the power output to suit the needs of the boost available as well as your interest in economy. Messing with gassers, would probably end up costing more ($/time) in the long run, since you already have the entire OM602 installed and ready for mods. I'd ditch your LPG setup once the IP is modded.

Hmm, lets see:

Cost to ship to Finland and back + the cost of the mod is about $1300.

Cost of a larger turbo and intercooler ~ $800.

Total cost for a ~250hp diesel engine ~$2100.

Diesel fuel price is: ~100 ALL/ liter (~$1.18/liter)

Cost of the m103 + multi point lpg injection ~$1300.

Cost of om603 exh. manifold + turbo ~$300, so I can use the stock air filter box.

A used om602 goes for about $1300 here. I can sell the om602 for about $1000 or even $800.

LPG fuel price is: ~49 ALL/liter (~58 cent $/liter).

So even if I don't sell my current engine the m103 is about $500 cheaper.

c280nz · #18 06-03-2009, 04:34 PM

im not sure the turbo you talk of will be suitable for a petrol engine?
often diesel turbos are to small and designed for boost at alot lower revs/airflows

auspumpen · #19 06-03-2009, 11:10 PM

Quote:

Originally Posted by Deni

Hmm, lets see:

Cost to ship to Finland and back + the cost of the mod is about $1300.

Cost of a larger turbo and intercooler ~ $800.

Total cost for a ~250hp diesel engine ~$2100.

Diesel fuel price is: ~100 ALL/ liter (~$1.18/liter)

Cost of the m103 + multi point lpg injection ~$1300.

Cost of om603 exh. manifold + turbo ~$300, so I can use the stock air filter box.

A used om602 goes for about $1300 here. I can sell the om602 for about $1000 or even $800.

LPG fuel price is: ~49 ALL/liter (~58 cent $/liter).

So even if I don't sell my current engine the m103 is about $500 cheaper.

I have no way of assessing prices in Albania, but the time involved in what you've described sounds rather excessive. Personally, I think it'd be easier to convert a gas rig over to diesel power, rather than the other way around. Easier still, would be to purchase a factory M103 powered car in the first place. It's all about priorities. Good luck

Deni · #20 06-04-2009, 02:53 AM

Quote:

Originally Posted by auspumpen

I have no way of assessing prices in Albania, but the time involved in what you've described sounds rather excessive.

Do you mean money? Because time doesn't make any sense.

Quote:

Originally Posted by auspumpen

Personally, I think it'd be easier to convert a gas rig over to diesel power, rather than the other way around. Easier still, would be to purchase a factory M103 powered car in the first place. It's all about priorities. Good luck

I agree with you, it's much easier to convert a petrol to diesel than vice verse and that a factory petrol car would be the best, but over here we have a lot of Benzes so I can't sell my car for any decent money. It is also impossible to find 6 cyl petrol cars here because of economy, or lack of.

Even the ones that exist are imports and custom tariffs and duties are too high.

So there are very limited options.

The brother of my fiancee is a mechanic and I can count on him on the swap, maintenance and modding.

Quote:

im not sure the turbo you talk of will be suitable for a petrol engine?
often diesel turbos are to small and designed for boost at alot lower revs/airflows

We are talking here about a 3.5 liter engine's turbo. The diesel engines need much more air to create power than petrol ones. That turbo should be able to support over 15psi of boost.

I'm looking for about 220-250hp at the crank, that would be in the 6 psi range. What I'm worried instead is turbo lag.

How difficult is it to fit a TPS to the m103 but without messing with the cis-e?

auspumpen · #21 06-04-2009, 08:53 AM

The time refers to the amount of it you'd need in order to wire/plumb the fuel system, engine management system, etc. Over here, we believe time = money.

Deni · #22 06-04-2009, 09:30 AM

Quote:

Originally Posted by auspumpen

The time refers to the amount of it you'd need in order to wire/plumb the fuel system, engine management system, etc. Over here, we believe time = money.

Is cis-e that complicated?

auspumpen · #23 06-04-2009, 10:28 AM

No, but it still requires mounting the pump/accumulator and engine management items, and re-locating washer pump and lots of other big and small stuff that takes time to sort out--Maybe I'm just too lazy to bother with such things. The only way I'd undergo that swap, would be to buy the whole donor car, then just initiate a straight side-by-side swap. Over here, I don't think anyone would even contemplate such a project unless they had car with a dead engine and tons of spare time on their hands.

For the record, I had a FMIC custom made for $200, and a T3/T4 hybrid can be picked up for ~$150 (Chinese copy).

Deni · #24 06-04-2009, 10:51 AM

Quote:

Originally Posted by auspumpen

No, but it still requires mounting the pump/accumulator and engine management items, and re-locating washer pump and lots of other big and small stuff that takes time to sort out--Maybe I'm just too lazy to bother with such things. The only way I'd undergo that swap, would be to buy the whole donor car, then just initiate a straight side-by-side swap. Over here, I don't think anyone would even contemplate such a project unless they had car with a dead engine and tons of spare time on their hands.

I can't say anything about this one until I try it

.

Quote:

Originally Posted by auspumpen

For the record, I had a FMIC custom made for $200, and a T3/T4 hybrid can be picked up for ~$150 (Chinese copy).

Here in Albania car tuning doesn't exist so I can't make an intercooler here. I have to import it or use one from the scrap yard. 6 psi is not a lot so I guess a small-ish one might do. Plus the extra octane of the LPG might help to suppress detonation.

As for Chinese copy turbos ... I find them too risky.

400Eric · #25 06-09-2009, 04:54 AM

I'm following this thread with great interest. I haven't contributed anything like I usually do because I am still learning about this stuff myself. But I too am determined to do a LPG turbo car or two. The much higher octane rating of the LPG makes it a perfect match for boost.
Deni, could you please post links to the sites where you were reading about LPG injection systems?
Regards, Eric

RBYCC · #26 06-09-2009, 08:46 AM

The only problem I see with a LPG fueled Turbo engine is that the tuning is counter intuitive.

If you run a rich AFR with LPG you end up with detonation as there is no cooling capacity in the LPG vapor /air mixture versus a Gasoline liquid/air mixture.

You are better off with LPG running closer to stoichmetric and getting power by increasing boost.

But increasing boost adds to engine component stress such as pistons, rings and rods.

The LPG will need more intercooling due to the heat properties of the vapor/air mixture.

I'm still a believer in a gasoline engine making more power at less cost and more safety then LPG.

I wasn't a believer in using additional injectors for gasoline AFR enrichment as I was concerned about equal fuel distribution to all cylinders.

Now I would not do a turbo on an older style engine any other way...the additional injectors mounted in line with the throttle body not only enrich the AFR, but act much like a water/alchohol injection as the gasoline mist acts like a cooling charge to the incoming boosted air !!!

Just some thoughts on the subject...comments always appreciated as this is a great learning experience !!!

Deni · #27 06-10-2009, 03:34 PM

Quote:

Originally Posted by 400Eric

I'm following this thread with great interest. I haven't contributed anything like I usually do because I am still learning about this stuff myself. But I too am determined to do a LPG turbo car or two. The much higher octane rating of the LPG makes it a perfect match for boost.
Deni, could you please post links to the sites where you were reading about LPG injection systems?
Regards, Eric

Eric, I don't know where you're located but here in Europe, and as far as I know in Australia as well, LPG is widely used for economical issues, LPG being much cheaper than petrol. In many countries LPG is also being subventioned by governments (both kits and fuel) for being a cleaner burning fuel.

Here you can read something more about different LPG conversions: http://www.go-lpg.co.uk/which_conversion.html

I still didn't get a clear answer if these outputs can be found (or easily added) on the cis-e setup:

Oxygen (Lambda) sensor signal(s) (I think this is already there)

Throttle Position Sensor (TPS) signal (does the cis-e have this output or can I add it somehow?)

RPM (tach) signal (I guess this is already available)

Manifold ambient pressure (MAP) (this looks easy)

I'm leaning more on the m104 3.0 liter engine than a "little bit more complicated" turbo m103.

RBYCC · #28 06-10-2009, 11:03 PM

Quote:

Originally Posted by Deni

Eric, I don't know where you're located but here in Europe, and as far as I know in Australia as well, LPG is widely used for economical issues, LPG being much cheaper than petrol. In many countries LPG is also being subventioned by governments (both kits and fuel) for being a cleaner burning fuel.

Here you can read something more about different LPG conversions: http://www.go-lpg.co.uk/which_conversion.html

I still didn't get a clear answer if these outputs can be found (or easily added) on the cis-e setup:

Oxygen (Lambda) sensor signal(s) (I think this is already there)

Throttle Position Sensor (TPS) signal (does the cis-e have this output or can I add it somehow?)

RPM (tach) signal (I guess this is already available)

Manifold ambient pressure (MAP) (this looks easy)

I'm leaning more on the m104 3.0 liter engine than a "little bit more complicated" turbo m103.

The CIS-E doesn't have a true throttle position sensor....O2, Speed/tach and MAP are available.
The throttle is mechanical so there is no need for a sensor that gives you a linear output.
You could possibly pull the throttle signal from the 3.2L M104 with HFM, not the 3.0L M104 with KE.

Deni · #29 06-11-2009, 02:42 AM

Quote:

Originally Posted by RBYCC

You could possibly pull the throttle signal from the 3.2L M104 with HFM, not the 3.0L M104 with KE.

IS it possible to explain online how can I do this

?

RBYCC · #30 06-11-2009, 08:43 AM

Quote:

Originally Posted by Deni

IS it possible to explain online how can I do this

?

The M104-24V with HFM has an electronic throttle actuator.

I am not that familiar wiith it, but there is a signal level sent from the pedal to the engine bay actuator.

I'm not sure of the level or type of signal output, but I would assume it is linear...