I BENT MY RODS THREAD - My Experience (M157)
#227
MBWorld Fanatic!
OP....
Few notes..... I understand your frustration in the project you took on when your Bent Eight blew up.
Were it my project....
It would get crank steered rods; longer then stock if possible. Dimensions inside the engine don’t have to be as standard. Stroke stays the same, but a smaller diameter wrist pin that is wider, and shoved up as far into the piston as possible can allow for a longer rod which does good things. We are already giving it custom pistons, rods and liners and you have paid handsomely for them. We can specify what we want built and piston manufacturers will gladly produce them. I have used CP in the past. Most of the time they start with an off the shelf piston and make a few changes. Same with rods. Pick an American V8 rod that is similar dimensionally and a few machine steps has a custom that is just so.
I guessed turbos would get attention. Just a little more effort has bigger turbos that are well within the efficiency map for bigger power.
I hope that when you finally get the car back she runs great and you fall in love all over again.
I tip my hat to you sir... Your thread has much that is valuable for others to read in the future.
Best wishes.
Few notes..... I understand your frustration in the project you took on when your Bent Eight blew up.
Were it my project....
It would get crank steered rods; longer then stock if possible. Dimensions inside the engine don’t have to be as standard. Stroke stays the same, but a smaller diameter wrist pin that is wider, and shoved up as far into the piston as possible can allow for a longer rod which does good things. We are already giving it custom pistons, rods and liners and you have paid handsomely for them. We can specify what we want built and piston manufacturers will gladly produce them. I have used CP in the past. Most of the time they start with an off the shelf piston and make a few changes. Same with rods. Pick an American V8 rod that is similar dimensionally and a few machine steps has a custom that is just so.
I guessed turbos would get attention. Just a little more effort has bigger turbos that are well within the efficiency map for bigger power.
I hope that when you finally get the car back she runs great and you fall in love all over again.
I tip my hat to you sir... Your thread has much that is valuable for others to read in the future.
Best wishes.
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I.T. Guy (02-18-2024)
#231
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2014 E63S; AMS 100 octane ecu tune; edok tcu tune; BB intakes; dyno tuned
Good luck and let us know how it's going as you have faithfully done so thus far. Thank you for your contributions
#232
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Thread Starter
First 200 miles are done. First 50 miles with Xentry MB diagnostics. Showed one missfire (faulty counter) on cylinder 5. Additional 150 miles done - no issues. Decided to change oil after 200 miles. There is a VERY strong smell of gasoline in the engine oil + filter. Otherwise oil is very clean, temperature is good, no issues. But there is this smell. Mechanic says to try and deactivate renntech ecu and see if the smell is still there on a new oil. What do you guys think of this smell? I am worried about it. Otherwise oil consumption literally none, no smell or smoke from the exhaust.
#233
MBWorld Fanatic!
First 200 miles are done. First 50 miles with Xentry MB diagnostics. Showed one missfire (faulty counter) on cylinder 5. Additional 150 miles done - no issues. Decided to change oil after 200 miles. There is a VERY strong smell of gasoline in the engine oil + filter. Otherwise oil is very clean, temperature is good, no issues. But there is this smell. Mechanic says to try and deactivate renntech ecu and see if the smell is still there on a new oil. What do you guys think of this smell? I am worried about it. Otherwise oil consumption literally none, no smell or smoke from the exhaust.
#234
Super Member
Thread Starter
#235
Super Member
First 200 miles are done. First 50 miles with Xentry MB diagnostics. Showed one missfire (faulty counter) on cylinder 5. Additional 150 miles done - no issues. Decided to change oil after 200 miles. There is a VERY strong smell of gasoline in the engine oil + filter. Otherwise oil is very clean, temperature is good, no issues. But there is this smell. Mechanic says to try and deactivate renntech ecu and see if the smell is still there on a new oil. What do you guys think of this smell? I am worried about it. Otherwise oil consumption literally none, no smell or smoke from the exhaust.
https://shieldoils.com/engine-oil-sm...oms-and-fixes/
#236
Super Member
First 200 miles are done. First 50 miles with Xentry MB diagnostics. Showed one missfire (faulty counter) on cylinder 5. Additional 150 miles done - no issues. Decided to change oil after 200 miles. There is a VERY strong smell of gasoline in the engine oil + filter. Otherwise oil is very clean, temperature is good, no issues. But there is this smell. Mechanic says to try and deactivate renntech ecu and see if the smell is still there on a new oil. What do you guys think of this smell? I am worried about it. Otherwise oil consumption literally none, no smell or smoke from the exhaust.
these are new injectors? Or your original
#237
Super Member
Thread Starter
Update:
- smell of gasoline faded away after another 100 miles
- engine oil now smells just fine
- new injectors, pumps, everything
- turbos were “refurbished”
- we have now much greater problem - gearbox
Engine is perfect, very strong, with all new parts like injectors, pumps etc - the power and torque probably went a little bit up. I can feel it, car is insane. Previously there was 740bhp on the dyno, now probably would push more.
Unfortunately gearbox can’t handle it, if you give 3/4 gas on 1, 2 or 3 gear, it is slipping like crazy. And even sometimes it disengages gear to preserve itself. Diagnostics show a fault within TCU that says something along the lines of TORQUE VALUE TOO HIGH.
Mind you, I have a TCU tune from Weistec. I will change the oil in the gearbox today, but I think the problem will stay. The torque is probably getting above 1200NM and that causes such behavior.
So I got the car with a perfect engine and now gearbox is giving up.
- smell of gasoline faded away after another 100 miles
- engine oil now smells just fine
- new injectors, pumps, everything
- turbos were “refurbished”
- we have now much greater problem - gearbox
Engine is perfect, very strong, with all new parts like injectors, pumps etc - the power and torque probably went a little bit up. I can feel it, car is insane. Previously there was 740bhp on the dyno, now probably would push more.
Unfortunately gearbox can’t handle it, if you give 3/4 gas on 1, 2 or 3 gear, it is slipping like crazy. And even sometimes it disengages gear to preserve itself. Diagnostics show a fault within TCU that says something along the lines of TORQUE VALUE TOO HIGH.
Mind you, I have a TCU tune from Weistec. I will change the oil in the gearbox today, but I think the problem will stay. The torque is probably getting above 1200NM and that causes such behavior.
So I got the car with a perfect engine and now gearbox is giving up.
Last edited by GMBALL; 02-20-2024 at 02:48 AM.
#238
Super Member
Update:
- smell of gasoline faded away after another 100 miles
- engine oil now smells just fine
- new injectors, pumps, everything
- turbos were “refurbished”
- we have now much greater problem - gearbox
Engine is perfect, very strong, with all new parts like injectors, pumps etc - the power and torque probably went a little bit up. I can feel it, car is insane. Previously there was 740bhp on the dyno, now probably would push more.
Unfortunately gearbox can’t handle it, if you give 3/4 gas on 1, 2 or 3 gear, it is slipping like crazy. And even sometimes it disengages gear to preserve itself. Diagnostics show a fault within TCU that says something along the lines of TORQUE VALUE TOO HIGH.
Mind you, I have a TCU tune from Weistec. I will change the oil in the gearbox today, but I think the problem will stay. The torque is probably getting above 1200NM and that causes such behavior.
So I got the car with a perfect engine and now gearbox is giving up.
- smell of gasoline faded away after another 100 miles
- engine oil now smells just fine
- new injectors, pumps, everything
- turbos were “refurbished”
- we have now much greater problem - gearbox
Engine is perfect, very strong, with all new parts like injectors, pumps etc - the power and torque probably went a little bit up. I can feel it, car is insane. Previously there was 740bhp on the dyno, now probably would push more.
Unfortunately gearbox can’t handle it, if you give 3/4 gas on 1, 2 or 3 gear, it is slipping like crazy. And even sometimes it disengages gear to preserve itself. Diagnostics show a fault within TCU that says something along the lines of TORQUE VALUE TOO HIGH.
Mind you, I have a TCU tune from Weistec. I will change the oil in the gearbox today, but I think the problem will stay. The torque is probably getting above 1200NM and that causes such behavior.
So I got the car with a perfect engine and now gearbox is giving up.
can weistec give you your tq limits? If not I advice getting a new tcu @5soko will explain everything. Your tq isn't reaching 1200 because the limits aren't set that high. What's happening if this is your issue, Your limits are probably close to stock and your hitting that threshold fairly fast . It takes much more boost and timing to achieve 1200 ft lbs. . And your tcu would have to be completely open to achieve those limits which won't happen unless your running big turbos 37 psi and 17 degrees plus with race gas or e85 and even that's questionable . Just food for thought . Congratulations on the build bro im sure your gonna enjoy her
#239
Super Member
Thread Starter
can weistec give you your tq limits? If not I advice getting a new tcu @5soko will explain everything. Your tq isn't reaching 1200 because the limits aren't set that high. What's happening if this is your issue, Your limits are probably close to stock and your hitting that threshold fairly fast . It takes much more boost and timing to achieve 1200 ft lbs. . And your tcu would have to be completely open to achieve those limits which won't happen unless your running big turbos 37 psi and 17 degrees plus with race gas or e85 and even that's questionable . Just food for thought . Congratulations on the build bro im sure your gonna enjoy her
I have a TCU tune from Weistec for M157 Mercedes S63 AMG Coupe. I have modified the car with ECU, downpipes, full racing exhaust, blackboost cold air intake, turbo-back bridge pipes between turbo and exhaust. Everything worked just fine with Weistec TCU.
I recently did a full engine rebuild with forged internals, new pumps, injectors, etc - and it now pushes even more power and torque ~ 760bhp and 1200-1250nm of torque, and I have a problem with gearbox.
Unfortunately gearbox can’t handle it, if you give 3/4 gas on 1, 2 or 3 gear, it is slipping like crazy. And even sometimes it disengages gear to preserve itself. Diagnostics show a fault within TCU that says something along the lines of TORQUE VALUE TOO HIGH.
I think your tune doesn’t allow torque of more than 1200nm for the gearbox. But in reality I have probably up to 50nm more.
Can we modify my TCU to increase the limit? Otherwise I can’t really use the power.
My VIN below.
Thanks in advance for your help!
Here is their answer:
We set the torque limits to 1200Nm but that really is just a number that does not always correlate with the actual torque that is being made.
What it will actually handle depends heavily on your driving style. People that launch their cars a lot are more likely to break output shafts. Aggressive ECU tuning with heavy torque manipulation will result in excessive clutch pack wear.
The two primary purposes of the TCU tune are to increase the TCU torque limits and increase system pressure which results in more clamping pressure and slightly faster shifts. The increased clamping pressure helps increase torque capacity of the transmission slightly.
What it does not do is fix issues where the transmission is not able to shift properly. What you are describing sounds like either an issue with the valvebody or the engine is over revving, causing the transmission to go into neutral to protect itself.
Over revving can be caused by worn clutches that slip and allow the engine to rev too high before the next gear can fully engage. Another possibility is when driving in M mode and the ECU tune sets the rev limiter too high.
As I explained previously, that is just a number that does not always correlate with the actual torque that is being made.
What you need to check is how much torque your ECU is reporting to the TCU. That is done via datalogging. If your ECU is greatly under reporting torque, that will cause slip. If your ECU was actually reporting 1250nm then the transmission would work appropriately and simply request the ECU limit power.
#240
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2014 E63S; AMS 100 octane ecu tune; edok tcu tune; BB intakes; dyno tuned
Can you go back to stock ecu and tcu settings just to make sure the hardware is ok?
you may have already done this and I may have missed that in the discussions above ☝🏽
you may have already done this and I may have missed that in the discussions above ☝🏽
Last edited by PeterUbers; 02-20-2024 at 01:30 PM.
#241
Super Member
Thread Starter
Yes, I did remove the ECU tune and transmission didn’t slip. With ECU tune the car feels insane, more violent than before, but transmission either slips or it completely disengages gear into neutral. I did change the transmission oil today (2 years old) maybe it will help. But I feel like some parts are probably worn out.
#242
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2014 E63S; AMS 100 octane ecu tune; edok tcu tune; BB intakes; dyno tuned
Yes, I did remove the ECU tune and transmission didn’t slip. With ECU tune the car feels insane, more violent than before, but transmission either slips or it completely disengages gear into neutral. I did change the transmission oil today (2 years old) maybe it will help. But I feel like some parts are probably worn out.
before this whole thing happened you said you enjoyed the tune and did you have any issues with slipping? Is this a more aggressive tune than before the engine work?
#243
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Thread Starter
did you lose traction? After my tcu tune when I would launch hard I would lose traction and the engine/trans would disconnect prolly cuz my engine over revved....
before this whole thing happened you said you enjoyed the tune and did you have any issues with slipping? Is this a more aggressive tune than before the engine work?
before this whole thing happened you said you enjoyed the tune and did you have any issues with slipping? Is this a more aggressive tune than before the engine work?
The thing is that it slips in the middle of rev range, between 3-5k rpm, so it’s nowhere near the shifting point.
Before this whole thing happened I put about 40k miles on this tune. It’s the same tune - renntech stage 2 tune, they ship their piggybox to you from the US, you connect it to OBD port and it flashes their tune to your ECU. It works only on my VIN.
Maybe my clutch pack is worn out? But then again, before the incident, it didn’t slip. Meanwhile the transmission was stored, so nothing could go wrong. Maybe the oil was too old.
#245
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2014 E63S; AMS 100 octane ecu tune; edok tcu tune; BB intakes; dyno tuned
It might have lost some traction, but the traction control light didn’t come on + I didn’t even WOT. But this over rev hypothesis might sound plausible.
The thing is that it slips in the middle of rev range, between 3-5k rpm, so it’s nowhere near the shifting point.
Before this whole thing happened I put about 40k miles on this tune. It’s the same tune - renntech stage 2 tune, they ship their piggybox to you from the US, you connect it to OBD port and it flashes their tune to your ECU. It works only on my VIN.
Maybe my clutch pack is worn out? But then again, before the incident, it didn’t slip. Meanwhile the transmission was stored, so nothing could go wrong. Maybe the oil was too old.
The thing is that it slips in the middle of rev range, between 3-5k rpm, so it’s nowhere near the shifting point.
Before this whole thing happened I put about 40k miles on this tune. It’s the same tune - renntech stage 2 tune, they ship their piggybox to you from the US, you connect it to OBD port and it flashes their tune to your ECU. It works only on my VIN.
Maybe my clutch pack is worn out? But then again, before the incident, it didn’t slip. Meanwhile the transmission was stored, so nothing could go wrong. Maybe the oil was too old.
now you have a healthy engine and perhaps it's revealing your drivetrain weaknesses
something seems odd though, I don't know enough about re installing a trans and rebuilding engines to know if this could be an installation error simply
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I.T. Guy (02-21-2024)
#246
MBWorld Fanatic!
perhaps the old engine was pulling timing for all the poor health issues it suffered from until it died .. the trans and tcu was happy and you were none the wiser.
now you have a healthy engine and perhaps it's revealing your drivetrain weaknesses
something seems odd though, I don't know enough about re installing a trans and rebuilding engines to know if this could be an installation error simply
now you have a healthy engine and perhaps it's revealing your drivetrain weaknesses
something seems odd though, I don't know enough about re installing a trans and rebuilding engines to know if this could be an installation error simply
Does Renntech have a TCU tune that matches their stage 2? I think what Weistec is saying makes sense - The torque reporting needs to match between the two ways ECU and TCU are handling / working with additional power.
#247
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Thread Starter
My dealer “adapted” my trans a few tines over the course of my ownership and re-set the wet clutches. Could it perhaps be as simple as that?
Does Renntech have a TCU tune that matches their stage 2? I think what Weistec is saying makes sense - The torque reporting needs to match between the two ways ECU and TCU are handling / working with additional power.
Does Renntech have a TCU tune that matches their stage 2? I think what Weistec is saying makes sense - The torque reporting needs to match between the two ways ECU and TCU are handling / working with additional power.
I think there is no possibility of error regarding the installation, it is pretty much plug and play.
I do think that the engine is now healthier with about subjectively maybe +20 bhp and +50nm, feels more alive. Maybe drivertain is now a weak point.
#248
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Thread Starter
Update: after oil change in the transmission, and after tcu reflash from Weistec it seemed to stop slipping under same conditions. Really strange how much change a new oil can make….
#249
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#250
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No, I am not keeping it. I will sell it this year, already put the ad online. I am thinking of replacing it with a 2-gen low mileage Bentley GT.
Last edited by GMBALL; 02-22-2024 at 04:05 AM.