Making the OM605 Fuel Efficient
Making the OM605 Fuel Efficient
Is it possible to make an OM605 from a C250DT produce more power while keeping its mpg or bettering it (35-45mpg)?
Condition:
I am having a W114 installed with an electronically pumped OM605, manual gearbox. I intend to use this for daily 90 mile round trips, motorway, 70-80mph. I would be delighted with about 200-220bhp and a reliable car.
I have to install a new exhaust anyway - what diameter bore is recommended with the above target? Would I benefit from an larger intercooler at this stage?
I assume these engines have power sapping kit on them - is there an AC pump that could be thrown out without damaging the engine? Power steering pump?
![[Image: OS.jpg]](http://i257.photobucket.com/albums/hh232/ChasesDragons/W114/OS.jpg)
ChasesDragons
07-15-2012, 06:38 AM #1Hello all,
Is it possible to make an OM605 from a C250DT produce more power while keeping its mpg or bettering it (35-45mpg)?
Condition:
I am having a W114 installed with an electronically pumped OM605, manual gearbox. I intend to use this for daily 90 mile round trips, motorway, 70-80mph. I would be delighted with about 200-220bhp and a reliable car.
I have to install a new exhaust anyway - what diameter bore is recommended with the above target? Would I benefit from an larger intercooler at this stage?
I assume these engines have power sapping kit on them - is there an AC pump that could be thrown out without damaging the engine? Power steering pump?
(completely burnt) fuel is equivalent to power, basically.
From my experience it is possible to have 200 hp with the same mpg with just the pump elements changed.
Asking for just necessary power to drive the car then will reduce mpg.
Exhaust diameter: I'd say 3" is fine, intercooler: no.
During your round trip you won't see permanent high boost, so no need to intercool. Additional plumbing might even reduce efficiency.
For more efficiency a VTG turbo would help but also needs to be well controlled.
A/C compressor is not necessary but keep the steering power pump for comfort and safety. (on high speeds the A/C in summer is more fuel efficient than open windows).
Tom
Hi,
(completely burnt) fuel is equivalent to power, basically.
From my experience it is possible to have 200 hp with the same mpg with just the pump elements changed.
Asking for just necessary power to drive the car then will reduce mpg.
Exhaust diameter: I'd say 3" is fine, intercooler: no.
During your round trip you won't see permanent high boost, so no need to intercool. Additional plumbing might even reduce efficiency.
For more efficiency a VTG turbo would help but also needs to be well controlled.
A/C compressor is not necessary but keep the steering power pump for comfort and safety. (on high speeds the A/C in summer is more fuel efficient than open windows).
Tom
Considering it is the UK, there is little chance aircon is going to be used!!
That is surprising re the elements, I was thinking that bigger elements were to supply more fuel? Just as confusing as dirty filters causing worse fuel consumption. Never understood that either.
I will get my budget set for 3" exhausts and the bigger elements. I will need to find a good tuner to sort out the electronic injection to cope with the larger elements too.
Keep the ideas coming please.
ChasesDragons
07-15-2012, 05:29 PM #3Thanks Tom,
Considering it is the UK, there is little chance aircon is going to be used!!
That is surprising re the elements, I was thinking that bigger elements were to supply more fuel? Just as confusing as dirty filters causing worse fuel consumption. Never understood that either.
I will get my budget set for 3" exhausts and the bigger elements. I will need to find a good tuner to sort out the electronic injection to cope with the larger elements too.
Keep the ideas coming please.
(07-15-2012, 06:29 PM)aaa Shouldn't be that surprising, the extra fuel is only used when you ask for it. So yes, it's possible for mpg to go down, how you drive is a big part of whether it will go down.
that's the point. I am running the biggest elements for M-pumps with stock turbo and I limit the max. delivery to about 30% only to avoid smoke.
But I would never use an electronic pump unless having a poti or similar inside the cabin for max. delivery adjustment.
The external adjuster on the mechanical pump is fantastic and I use it very often after each change of injectors, delivery valves or timing (all for further testing) and also depending on weather.
Tom
(07-15-2012, 06:29 PM)aaa Shouldn't be that surprising, the extra fuel is only used when you ask for it. So yes, it's possible for mpg to go down, how you drive is a big part of whether it will go down.
that's the point. I am running the biggest elements for M-pumps with stock turbo and I limit the max. delivery to about 30% only to avoid smoke.
But I would never use an electronic pump unless having a poti or similar inside the cabin for max. delivery adjustment.
The external adjuster on the mechanical pump is fantastic and I use it very often after each change of injectors, delivery valves or timing (all for further testing) and also depending on weather.
Tom
" It is far easier to get forgiveness rather than permission"
Riverstick
07-16-2012, 02:57 AM #6Am I correct in saying you are having this installed?....Why don't you fit a mechanical pump?....also what rear end ratio are you using? I have converted older petrol cars to Merc diesel power in my younger days,and we always ended up changing the rear end to a higher(faster) ratio...otherwise your OM605 will be revving its tiits off and won't be great on fuel. It won't so much be top end power that you will require,but low end torque
" It is far easier to get forgiveness rather than permission"
I was in kinda in this situation a couple of weeks ago re using the electronic pump. The parts that you need to transfer over to get it to work just isn't practical. You even need the clocks or the ECU doesn't like it. I bought a mechanical pump, problem solved.
I have enquired about installing a mechanical pump, the engineer doesnt think it is an easy idea. So I need to read up on the how tos a bit.
The car is getting a different diff, I cannot recall what ratio - 2.8x?
A remap was my thinking, but considering the amount of promotion for a manual pump, I think I really do need to reasearch this. All the needed kit must be at hand, considering I am in the UK and Ebay allows access to German/Finnish sellers....
I will start getting some electronic-to-Manual pump conversion threads together. If anyone can start me off in the right direction, I would be most grateful!!!
Warmest Regards
ChasesDragons
07-21-2012, 06:14 PM #9My apologies, I seem to have meddled with the reply notification.....thingy, again!!
I have enquired about installing a mechanical pump, the engineer doesnt think it is an easy idea. So I need to read up on the how tos a bit.
The car is getting a different diff, I cannot recall what ratio - 2.8x?
A remap was my thinking, but considering the amount of promotion for a manual pump, I think I really do need to reasearch this. All the needed kit must be at hand, considering I am in the UK and Ebay allows access to German/Finnish sellers....
I will start getting some electronic-to-Manual pump conversion threads together. If anyone can start me off in the right direction, I would be most grateful!!!
Warmest Regards
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