What don’t we know about the cautionary side of tuning the M113k engines cars?

[DSK]

Whilst the M113k engine is a legend (and my favourite MB power plant, possibly forever and always) and the dated but, granite like 5spd box are well known to be tuneable etc, I’d like to learn more before enquiring about an MSL tuned car for sale.

My understanding is that the a remap, 77m pulley, uprated pump and plm heat exchanger gives around 600bhp plus the insanity of torque that goes with it. I have read these engines struggle to keep cool as standard, so to ensure consistency and usability of the increased performance, associated cooling is a must.

(How idiots seem to spend money on more power but don’t get a ****** quaife LSD to utilise even the standard power is beyond me but, that’s a moan for another day.)

What I don’t see or hear about is any real cautionary or negative aspects of this, if there are any, so I’ll appreciate experiences and comments;

- are colder spark plugs required?
- can the standard injectors really handle this?
- can the fuel pump take this in its stride?
- how resistant to fade are the original powerful brakes?
- does a different oil spec need to be used?
- how much torque can the 5spd box easily take with out caution?
- can the supercharger itself reliably handle this?
- I’ve seen some cars with an uprated gearbox map? Basically to quicken shift times, is this safe/reliable for the design of the gearbox.
- what are the tell tale signs of potential damage if the power has been increased without the supporting modifications?
- comparably for the McLaren SLR to be running such power figures of 600-720bhp or so, did MB/McLaren change any engine internals?


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[Wighty]

I would guess that @alexanderfoti might know some of these answers . It’s all beyond me

 

[alexanderfoti]

1 are colder spark plugs required?
2 can the standard injectors really handle this?
3 can the fuel pump take this in its stride?
4 how resistant to fade are the original powerful brakes?
5 does a different oil spec need to be used?
6 how much torque can the 5spd box easily take with out caution?
7 can the supercharger itself reliably handle this?
8 I’ve seen some cars with an uprated gearbox map? Basically to quicken shift times, is this safe/reliable for the design of the gearbox.
9 what are the tell tale signs of potential damage if the power has been increased without the supporting modifications?
10 comparably for the McLaren SLR to be running such power figures of 600-720bhp or so, did MB/McLaren change any engine internals?

1. Not until you reach +150BHP more than standard
2. No, above 600bhp it needs bigger injects as duty goes past 90-95% in some cases and they risk "going static"
3. Different 55k platforms have different fuel pumps (W211 fuel pumps are in tank, W220/215/230 etc are external.) 211 pumps need upgrading, external pumped systems are usually fine, but fuel filters must be in good condition etc.
4. They are big brakes, but the cars are huge and are not designed to be tracked, so will fade relatively quickly compared to a much lighter car.
5. I ONLY use fully Ester Group 5 base stock oils in heavily tuned engines, whilst its not a requirement, it gives additional protection when pushing power levels. The bottom end is very strong on these engines, the hypereutectic pistons and rings are the weak points when pushing power.
6. Most 55k engined cars use the 722.643 box, which is rated for 580nm of continuous input torque, but its all down to the tuning etc as to how long they last. Autoboxes only wear when "slipping" or when changing gear. They can be beefed up relatively easily, but are not usually an issue.
7. This is arguable, with a 77mm pulley, its turned into a big heater. It is being pushed out of its comfort range, but a good unit will stay reliable. Big power really needs a different supercharger that can flow more air.
8. Faster shifts, less torque managment, more wear.
9. They burn slightly more oil until they blow up, unfortunately, not easily identified. Must check how much they are breathing via the filler cap etc, but as a lot of people A) Don't have mechanical sympathy b) Don't monitor intake temperatures and c) drive them without thinking about these things, the damage often happens from detonation due to intake temperatures and over aggressive tuning.
10. Yes, its had so much changed it gets a different engine number (M155) The SLR engine has changes such as a looped fuel rail. Different supercharger (engine oil fed for lubrication) and completely different charge cooler system. It has a lower compression ratio and a closed deck block design. Dry sumped etc. Steve@Avantgarde https://forums.mercedesclub.org.uk/index.php?members/steve-avantgarde.39053/ can answer more details about the SLR specific engine

What are you planning?

 

[DSK]

Amazing info!! Just what I wanted.

Not planning anything just looking to buy something nice. I made offers on some of the most expensive standard CLS55’s in recent months within 10% of asking prices but dealers are firm on the asking price, even though they remain unsold for 5 months. 2 MSL tuned cars remain unsold for several months and the grey for a year. I’m just doing my homework on tuned cars rather than assume just because it’s tuned by MSL that is good enough. I don’t really believe all the ‘yeh just bolt this and that on, map it and jobs a good un’, because actually there is more to it as you have stated! I never see people talking about injector duty cycles, flow rates, intake temps etc which matter.


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[alexanderfoti]

IMO, I'd wait a few more months. Prices are starting to move after being high for the past 24+ months.

 

[Wighty]

Amazing info!! Just what I wanted.

Not planning anything just looking to buy something nice. I made offers on some of the most expensive standard CLS55’s in recent months within 10% of asking prices but dealers are firm on the asking price, even though they remain unsold for 5 months. 2 MSL tuned cars remain unsold for several months and the grey for a year. I’m just doing my homework on tuned cars rather than assume just because it’s tuned by MSL that is good enough. I don’t really believe all the ‘yeh just bolt this and that on, map it and jobs a good un’, because actually there is more to it as you have stated! I never see people talking about injector duty cycles, flow rates, intake temps etc which matter.


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Normally if I don’t know the answer @alexanderfoti does

 

[DSK]

Lol I can be very patient, searched for 6 years until I got the Supra and 4 years for the S70R. I don’t need anything but a CLS55 would be a nice addition to the nice ‘proper’ car collection.


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[mioba]

1. Not until you reach +150BHP more than standard
2. No, above 600bhp it needs bigger injects as duty goes past 90-95% in some cases and they risk "going static"
3. Different 55k platforms have different fuel pumps (W211 fuel pumps are in tank, W220/215/230 etc are external.) 211 pumps need upgrading, external pumped systems are usually fine, but fuel filters must be in good condition etc.
4. They are big brakes, but the cars are huge and are not designed to be tracked, so will fade relatively quickly compared to a much lighter car.
5. I ONLY use fully Ester Group 5 base stock oils in heavily tuned engines, whilst its not a requirement, it gives additional protection when pushing power levels. The bottom end is very strong on these engines, the hypereutectic pistons and rings are the weak points when pushing power.
6. Most 55k engined cars use the 722.643 box, which is rated for 580nm of continuous input torque, but its all down to the tuning etc as to how long they last. Autoboxes only wear when "slipping" or when changing gear. They can be beefed up relatively easily, but are not usually an issue.
7. This is arguable, with a 77mm pulley, its turned into a big heater. It is being pushed out of its comfort range, but a good unit will stay reliable. Big power really needs a different supercharger that can flow more air.
8. Faster shifts, less torque managment, more wear.
9. They burn slightly more oil until they blow up, unfortunately, not easily identified. Must check how much they are breathing via the filler cap etc, but as a lot of people A) Don't have mechanical sympathy b) Don't monitor intake temperatures and c) drive them without thinking about these things, the damage often happens from detonation due to intake temperatures and over aggressive tuning.
10. Yes, its had so much changed it gets a different engine number (M155) The SLR engine has changes such as a looped fuel rail. Different supercharger (engine oil fed for lubrication) and completely different charge cooler system. It has a lower compression ratio and a closed deck block design. Dry sumped etc. Steve@Avantgarde https://forums.mercedesclub.org.uk/index.php?members/steve-avantgarde.39053/ can answer more details about the SLR specific engine

What are you planning?

This guys an encyclopaedia.

No no not you @Wighty