Dear M157 owners,

all of you, who have at least ECU Tune + Downpipes, please post the amount of mileage you have covered with your mods + list of mods + at least a wild guess of WOT pulls you have done. All I was doing during last couple of days was watching Tasos videos, like this one here: Of course, I am now terrified to drive my car hard (which I often did before) and I am confused as what to do now - drive it more carefully, don't push it or just keep driving it until I bend connecting rods and have cylinder scoring. I had a couple of missfires one year ago, but changed the OEM spark plugs to 1-step colder from Weistec and never had any issues after that, so I assume at least for now, my engine is healthy.

Here are my mods (S63 Coupe M157, 52k miles):
- RENNtech Stage 2 ECU Tune
- Weistec TCU Tune
- HMS Tuning Turbo-Backs
- Downpipes
- Full 3" Exhaust
- Racing Cats
- Weistec 1-Step Colder Plugs
- My best 1/4 mile run with Dragy: 11.3 sec / 127 mph

I was on dyno and I am close to 750-760BHP and about 1200-1250NM, 1.25 - 1.4 bar of boost.

 

I’ve also wondered about long term tuned cars that frequently press the pedal to the floor. I know I’ve WOT untold times. Every drive, all the time, I’m WOT in this car. As soon as it’s at operating temp I floor it. It gives me joy.

I have passed 171,000 kms or 106,000 miles. Only the last 11,000 kms tuned. I still drive it hard. Very hard.

ECC Slav 93 Stage 2 tune
Catless Downpipes
ECC TCU stage 1
Stock plugs stock gap

 

Mods
Eurocharged s2 ecu tune and tcu tune
Blackboost intakes and catless dp
Plx side mount IC upgrade and pump rewire
NGK 1 step colder plugs, Renntech bov

I have been tuned for about 8k miles now without any issues. So did all my mods at 18k, currently have 26k on car. No passing 3k rpm until car is fully warmed up oil and coolant temp, no exceptions!! As far as full throttle runs, it's typically 60mph and up.. Sometimes well into the triple digits

 

Mods:
AMS 93 tune - dyno tune
AMS 100 tune - dyno tune
EC E40 tune
EDOK TCU tune
black boost intakes
sprintbooster
IC always on mod
OEM plugs with STOCK gap

Car purchased new in 2014
Tuned at 36,000 miles until now at 46,000
coils, plugs, and routine maintenance
NO MAJOR ISSUES (outside of needed coils and occasional misfires due to coils)- my entire tuning experience is well documented in the sticky:
https://mbworld.org/forums/w212-amg/...-w212-amg.html

lots of WOT, many 1/4 mile sanctioned and dragy runs, 1/2 mile events etc

its a wonderful daily but babied for sure

 

I have covered about 29k miles from 52k with 700+ bhp and 1100+ nm. I really wonder, how many cars have statistically bent connecting rods vs healthy cars with same mods. If it’s something like 1:10 or 2:10 ratio, then it’s not much to worry about. But then again, Tasos warns that just an ecu tune is enough and just a matter of time before inevitable happens. Let’s wait for other members to post up.

 

Must not forget, cars from his neck of the woods, ambient temps are extremely high.
The M157 runs hot even in decent ambient temps, and our IC system on tuned cars cannot keep up which shoots IAT's to the sky. Add in a restrictive turbo exhaust manifold and housing that creates massive amount of backpressure and high EGT's, things can go south very quick and very random.
To add, the fuel quality I remember reading reports is very low in UAE.

I cant say we can see the same amount of bent rods and bore scoring here in the USA, or at least from what I have seen here out east, along with my buddies have seen as techs, and we have a bunch of guys making some serious power here with 80k+ miles.

 

I think bending rods is more common then people think. All the tuned mileage posted so far is very very low.

If you are tuned have a plan B! If you never need to execute the plan, cool. Don't tune if you can't afford a Plan B or afford to cut your losses and walk away.

Tuning is not a set and forget. Constantly log and check for shadow DTC codes, change plugs often, monitor health all the time, only run good gas. As soon as anything is off stop WOT and have it addressed immediately.

M157 is not bullet proof. It's just got turbos that are easily turned up with a push of a button. Until I hear of a really high mileage tuned car that gets beat on like mine, I'm prepared and expecting the inevitable. In the meantime, life is short. Pedal to the metal!

 

80k tuned?

 

It makes sense, indeed. Out of my curiosity, how often do you or your buddies see bent rods? Let’s say is it 1 out of 10 cars or more often than that?

 

There a bunch of FBO tuned M157 cars in NYC with 100K miles running healthy..
Heck @Cifdig had 115K+ miles and his cylinders walls looked beautiful and he was tuned for 70K+ miles and he beat on his car as he could attest. he broke a few records in his stock turbo car and has 100's of dragy 1/4 runs.
He can also attest to a few buddies off ours in the AMG NYC group chat we have helped dial in the cars also with good miles 70K+ and healthy M157's.

But absolutely like you mentioned, health checks, healthy practices go a very long way, and M157 is def NOT bullet proof, esp with guys running aggressive timing/boost on E85/race gas with aggressive wastegate duty cycles. There is a physical limit to our engines and on top of that high miles only wears and degrades strength of these engines consistently running that much power and tq.
To tell someone we can run a race gas or E85 tune consistently at 100K miles and not worry would be a lie and I think we all know that at this point in time with the knowledge we have on the M157 engine.

Not to say there has not been any failures, there has been a few, one of our friends cars just jumped timing at 90K and bent his rods. Abused M157 driven very hard, tuned for 50K or so. There has been a few valve guide failures in our area cyl 5, which seem to be more common believe it or not.

Not many, maybe 2 out of 10 maybe. At this point, the failed valve guides, and exhaust valve in cyl 5 scare me more then bent rods lol.

Tasos is right, an aggressive tune, low quality octane, high ambient temps being pushed, can cause irreversible damage. Knock sensors are good, but they arent 100% spot on and quick enough all the time, and it takes that split second to cause the damage that is needed.

 

Great write-up, thanks! One question - you mentioned running aggressive boost. What boost is actually considered to be aggressive for the M157? I am between 1.25 - 1.4 bar with all the mods.

 

"tune + mods + stock internals - Oh boy bent rods " - Tasos

im at 91K original owner . the car was tuned by factory. I drive it like a *****... and proud

 

So of course there will be opinions on this, and this is just my view, I am not here to bash any tuner or anyones choices, and this is why this forum is great, we have conversations our beloved cars and speak ideas.

1.4 bar is nothing to worry about. Most cars and tunes currently are running 2.2+ bar peak, and at least 2 bar sustained to redline. Being understanding of your environment, conditions, fuel, driving style, maintenance, age, etc helps understand things alot more.
A car driven on the Nürburgring with these high boost tunes, wouldn't have a long life compared to the guy doing occasional highway pulls on high boost for short period of bursts. So there is always different perspectives from owners around the world.

So one issue is the turbos when it comes to boost for the M157, and its a big can of worms. Our turbos are tiny, are made to produce peak tq and quick spool. They run out of talent pretty quick in the rev range, and being as the m157 isnt much of a 'revver', works well with these turbos lol.

The issue comes when trying to sustain that high boost to redline, with a turbo that cant produce the pressure efficiently in that range.
Most tunes I have seen being ran, are pushing the turbos well outside of their efficiency range at high RPM. This creates alot of heat and of course can slowly degrade turbo longevity, that is usually the outcome when running turbos outside of their efficiency range (every turbo setup has a compressor map or a efficiency map showing where it is happiest at).

BUT, I can say for certain we have some very strong turbos! Garrett did a great job, as these things are tanks! I have opened a few turbos and 1 recently with 100k+ miles with high boost and there is 0 shaft play, 0 oil seal issues, no WG rattle, etc. Not to say some may fail from aggressive boost and WG duty cycles, always possible. But we don't hear of many failed turbos on the M157, just cracked exhaust housings, which is still a failure of course and prob the most common failure for our turbos.

Heat being the other issue of the coin, when a turbo is outside of its efficiency range, it may or may not create the boost your forcing it to make, but it is doing it with great heat.
This is why in some logs if you look closely and do enough of them, you will see massive IAT swings as the out of range turbos producing the boost, are creating massive heat. What happens here is a tune is trying to target, for example, 19psi at high rpm's, it wont produce anymore power than a tune tapering boost off at 14-15 psi at high rpm because of the extra heat being generated and pushed at 19psi. Its a game of diminishing returns. Not saying this is always the case but in theory and at times.

Wastegate duty cycle tells another story for anyone who datalogs. Higher the wastegate duty cycle, the more the wastegate is closing, which means the more exhaust that is being diverted to try to spin the turbo up further to produce more boost that is being targeted.
As many of us turbo guys know, higher wastegate usually points to restriction or the turbo running out of breathe. Seeing as we are sometimes producing 2x the amount of stock boost and most guys are catless with intakes and are still running 80%+ WG dutycycle and sometimes MAX wastegate DC at higher RPM, we know this is purely from running the turbos to their max, and of course, outside their efficiency range and outside the reliability zone.
At this point, just like any other turbo setup, you know its time for a bigger turbo so you can be more efficient for that amount of boost your targeting, or to tame things down a tad on the tune.
In some logs I have seen a MAX wastegate DC target, and the boost rises as it should and then actually begins to taper off/ drop because it cannot produce anything further, which is a 100% sure sign, the turbo is outside of its operational zone. This is just turbo systems 101, not saying that if you run high WGDC, your turbo will fail or engine lol. As we have seen this isnt really the case, as there is plenty of fellow M157's running around with aggressive boost and high miles.


Another issue or topic with big boost for our cars specifically is the exhaust manifold and exhaust turbine housing. The backpressure created here is immense because of the design. all 4 cylinders running in a single row into a turbo exhaust housing that is pretty small to begin with.
There are a few companies that have tested backpressure at the exhaust manifold turbo housing, PRE turbo, for the M157, and found it to be over 4 bar on a stock turbo without heavy boost. That is alot of backpressure, and of course as you could imagine, adding aggressive boost and a closed wastegate to this equation, will only create more backpressure. We would need to tap into the exhaust turbo housing to read backpressure and most anyone, its not a worthwhile event, as the engine needs to be dropped to access the turbos.
High Pressure + high heat, is never a good thing. As that is why like Tasos, i have seen alot of turbo exhaust housing's with cracks in them. We have to mindful of the stock turbo exhaust side setup and how restrictive it is PRE turbo. High RPM, high boost, a near complete closed wastegate, will create a bad outcome sooner or later for sustained period of times.
Too much backpressure can lead to a host of issues and random invisible engine killers, super high EGT's, knock, denotation, higher cyl temps, A/F corruption, etc.
With all the tech and safety measures in our ECU's from the factory, it does a good job trying to control these things and keep things safe, but these safety measure usual react to danger, and sometimes can just be a bit late to respond and control, and that is where we can see random engine failures, bent rods, scoring, dento, etc.


Sorry for the speaking out loud tech write up.
I may have gone off topic, and also I didn't talk about timing here which of course adds to the equation, as the M157 LOVESSS timing lol. I guess that is another time

In summary, a ' aggressive boost tune' would be something in my opinion that the turbos arent very happy making, high RPMs, 5K+ RPM, moving 17psi to 19 psi up top is what i would consider aggressive depending on the ambient conditions. These little turbos are in the most happy place above 5K rpm trying to move so much boost and more wastegate is needed to create and keep that boost in that RPM region.
For the safety of the trans/clutches, and rods, keeping boost or TQ low in the low rev range, 3000RPM to 35000RPM and below, will save them. That is why most tuners dont target big boost down low, even when our engine and turbos can shoot for some big boost even at 2500RPM, it is for the safety of the engine and drivetrain.

Have we seen turbo failures from aggressive boost, not really, exhaust housing cracking, yes.
Engine failures from just high boost, heat and backpressure, not really either, as logic would expect, but im sure there is many examples running around without even knowing there on their way to failure.
Most pump gas map guys on high boost, I haven't seen many common failures here in the east coast, possible, of course, and im sure there is some running around with slight bent rods and bore scoing.
Any failures usually are coming from the Racegas/E85 high timing+ aggressive boost crowd.
Again this all ties into conditions, ownership, and driving style as X factors.

Below are some pics i had from my phone from recent or some older to give some ideas.

Here i outlined in RED the specific issue we have with our exhaust manifold for the M157,the path of exhaust and where it the back pressure builds up by the outlet of cyl 5.





This is a picture of looking into the exhaust port on the turbo manifold for cyl 5. Left is from incoming port of exhaust coming from cyl/ 6-7-8, next to it on the left is the wastegate port, and to the right is the port to the turbine.




Here you can see the massive crack in the exhaust turbine housing.



This is a motor with over 110K+ miles, that did eventually end up failing from the cyl wall actually chipping away and coolant rushing in, just a product of physically limits and fatigue. For a high mile motor that was pushed very hard on a very aggressive tune, the cyl walls looked absolutely amazing.




Recent buddy with jumped timing, more than likely bent rods and scoring. also around 90K miles, race gas maps regularly and pushed hard.

 

@5soko great info. And yes I can attest to what your saying being that the engine in the pictures have a personal relationship with me 😂. I'd like to point out the fact that this motor did not blow. This motor failed from hardware limitations. And for people not to be afraid it's gonna blow and not drive. Follow the steps of those that went through the struggle. I took every step possible and knowledge acquired though out the years to build a strong consistent motor, from running thicker weights @ 5w-50 to running methanol and removing as much back pressure from the exhaust as possible and using race gas only, every time I added my race gas tune. Keeping heat down to a minimum running more consistent. Making sure intake temps at peak would stay under 125 degrees at redline. Unfortunately there's nothing I could do when hardware limits are met .like a bent rod from to much tq. This is not chalked up to blown a motor . That relates to someone pushing a tune to unsafe territory having misfires, and timing being pulled from poor octane and having high cylinder pressure. Maxing out injectors or pushing and e85 tune to where it breaks up while doing 130mph plus and runs lean. Now that's blowing a motor. That motor ran consistent, clean, ran hundreds of passes on the street data logging and testing, did over 15 back to back runs @ atco race track and drove home .Unfortunately we now know that 750-800 awd hp using a 17% drivetrain loss which when corrected equates to 950-1000 crank horsepower and over 1000- 1100 ft lbs tq is standing with the physical limits of this motor even if ran with clean. It's a matter of time before a limitation is met wether it's rod or cylinder wall. While some are actually driving around with a slightly bent rod and not even knowing. It's a bit to late for you. I guess my point is we know this engine has Cyl 5 rod issues and with the amount of tq the m157 we also know that an open deck has its cons under high boost and tons of back pressure. Knowing this do what you can to address these issues and you will be able to enjoy your car for years. Avoid maxing out boost and having to much back pressure, do what you can to free up back pressure in your exhaust giving the manifold back pressure some chance to escape a little more, free up intake flow. It's proven how much better intakes free up hp, and even with some of the best intakes I find it's still restricted, bends cause pressure drop for every bend your turbo has to over come the harder it's gonna work, the harder it has to work to reach a set boost pressure then that means more back pressure in your exhaust. Another over looked bolt on. Blow off. Get a blow off. This extra spike in boost during shifts need to go somewhere . It goes through your exhaust during a wasted spark design, which means if your tuned pushing 33 psi of absolute manifold pressure that's 35-36 psi spikes needing to go somewhere, this adds to your back pressure even more, stressing out turbos on an already stressful state. So blow off will absolutely help. Everything adds up to something. I can say although not as much as overseas but lately seems like more rods have been failing, and some of these tuners are not even using high boost, they are using timing. And seeing the rods bend still shows me that if it's not back pressure and poor setup failure, it's just from so much power and the limit of what the rod can take was met. These are guys doing 6.5 -7.0 60-130 , 10.4-10.6 quarter miles. That's some serious hp out of a stock turbo m157. Upgrade your turbos fellas while
you still have a good engine, remove that back pressure and get the same
power levels with less boost from a more efficient turbo

 

@5soko @Cifdig
Gentlemen, I can't express how thankful I am for your posts. This is why I love these forums - it's so informative, so much experience is centralized here - it's absolutely amazing. My list of mods is written in the beginning of this thread, but I didn't consider a blow-off ventil, as of yet (mostly due to the sound it makes, which I never liked for the S-Class Coupe). As for the intakes - I have Blackboost M157 intakes, probably the very best product on the market today.

Regarding the boost - I have a RENNtech Stage 2 ECU Tune, so I contacted RENNtech HQ with my question regarding the max. allowed boost that is set in the ECU and this was their answer: Due to the hand built nature of these engines, there is no way to know the exact power output of your engine without running it on a dynamometer. I can say that the car should make similar power and torque at the wheels as the dyno shown on the website. It should make somewhere around 1.25-1.4 bar of boost. There are many safety limits still in place in the ECU with regard to boost, calculated torque, ignition, and temperature. However, these engines are known to bend rods even without aftermarket tuning on stock power. So I can’t tell you that these engines are good up to a certain boost level, or a certain torque and anyone who does is being misleading.

Austin Woodward, Engineering Associate

Back in a summer I did a dyno run, it was before I have installed my last three mods (but I already had a renntech stage 2 ecu, full 3" exhaust, racing cats, downpipes, turbo-backs):
1. Blackboost M157 Cold Air Intake
2. Weistec TCU
3. 1-Step Colder Weistec Spark Plugs (ordered from Weistec website)

And it was the hottest day over here in the Czech Republic - 100F (38C) and literally the worst day to make a dyno run, but I did it anyways and here was the result (the blue and red line underneath the elevated ones was my second dyno run with switched off ECU tune just to compare stock vs tuned):


The technician told me that I can expect about 10% more BHP and NM in colder weather with temperatures around 35 - 45 F, which then means that during winter I probably have ~ 761 BHP and ~ 1223 NM of torque. And that is even without freshly installed blackboost intakes that probably produce even more power & torque. On that hot day I also tried my 100-200 run and it was almost 1 full second slower than the same 100-200 run that I did recently in 35 F temperature - both measured with Dragy, same fuel/location/elevation, etc. This really means that now my power figures are significantly greater than during the summer when temperatures were close to 100 F. Does that make sense to you guys? I am kinda concerned mostly with torque, because I know that anything above 1200 NM is probably too much = higher risk of bending rods.

I have also written to Weistec about my TCU tune and asked them what is the maximum torque limit set by their TCU tune and this was 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. Best Regards, Staff


And so, coming to an end, this is the issue that I have, RENNtech confims that I should be running boost of 1.25 - 1.4 bar of boost, Weistec confirms that maximum torque limit is set at 1200 NM, yet my power output is probably too high with expected 761 BHP / 1223 NM or maybe even more today. On a side note - I am absolutely babying the car - changing the oil (5W-40 AMG oem oil) every 6k miles, changing the spark plugs every 12k miles (1-Step Colder from Weistec), not pushing it until it's fully warmed up, but mostly using all the available power on autobahns, meaning long pulls from about 100 km/h (60mph) up to a top speed - relatively frequently. I remember Tasos said that pulls 2500 - 3500 rpm are the worst, even worse then full throttle from a standstill. So far, I have this car for more than 3 years and had a total of about 5 missfires during the whole time of ownership (all were after the ECU tune, mostly it was cylinder 5 + had a couple of times P0108 Manifold Absolute Pressure/Barometric Pressure Circuit High). After I've changed the spark plugs to Weistec ones these missfires stopped completely. Not that were often before, but now they are non-existent. Previously when missfires happened, it wasn't even on full throttle, but rather 3/4 throttle when merging on the highway.

Anyways @5soko @Cifdig - looking at my graph at 100F temperature + all the information that I have written above - is there any reason you would be concerned out of your experience? Car drives completely normal, no issues at all. I became worried after watching Tasos videos. I am going to do one more dyno run now in January to confirm the output in a cold weather, but I am pretty sure it's definitely 10% more than the graph above.

 

anything above 1200 NM is probably too much = higher risk of bending rods.

I have also written to Weistec about my TCU tune and asked them what is the maximum torque limit set by their TCU tune and this was 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. Best Regards, Staff



This information seems off and I wouldn't go by this . @5soko is the best person to ask about the tcu and what limits at set to . Seems like everything they said makes no sense and like the are not settting real tq limits per gear. There much more then setting it at 1200nm no way they have done this in first gear . I'm srry that's hogwash they are feeding you

 

My 2016 just rolled over 78k yesterday. Unbeknownst to me, I was actually tuned since buying the car CPO from an MB dealer at 46k miles, so its been tuned for at least 32k miles and surely more than that, although the first was a mild stage 1 I would say - it dyno'd at 570 AWHP and 602 AWTQ. I've been running a Eurocharged (Jerry) E30 tune since mid August...have about 4-5k miles on it at which time I also installed the BB intakes. Car made 668 AWHP and 830 AWTQ. I've only launched from a stop twice, once on my all seasons, once on my summer setup. As for WOT, I did a Tail of the Dragon rally back in October - 6 hour even, but likely only 2 hours of aggressive driving given the traffic. And I drive the car 70 miles round trip 4 days a week for work - and usually have at least 1-2 WOT bursts but for limited time as I move in/out/though traffic, or if I run into the unsuspecting Corvette/S4/GTR/ZL1/Renntech tuned S63 lol...so far the car hasn't disappointed but I do think I have room to dial it in more, which I'm looking into currently. My peak TQ hits at a low 3k rpm and dips from there...it's a ton of fun in manual/paddle shift mode in 2nd and 3rd gear, but I want to see if I can move the TQ up safely in the higher rpms. Peak HP was at 5k rpm. I should probably study some other folks dynos/experience to see what I can do with moving my power curves around...

As for maintenance - after the dragon rally, did all fluids (oil/diffs/coolant) and had just had all new plugs/coils installed before the E30 tune. Will likely swap those out every 7.5-10k miles and do oil changes at least every 5k miles. I'm also considering going catless DPs and possibly turbo swap, but honestly after driving the dragon rally, I think I want to focus on handling first, although sticking all over the *** end of Vette's, Porsche's and multiple Shelby GT500s, pushing a bit more power would be fun too...

 

I have also been watching his videos recently and have been on edge about tuning my stock car.

 

So do you know what's funny? I've bent my connecting rods. Highway WOT pull up to 120ish, white smoke from the exhaust, lot's of vibration, blinking check engine light, engine kept running for about 30 seconds, then just died. Diagnostics missfire cylinder 1, 2 and 3. Fault codes cleared, car started again, tons of white smoke, lots of vibration, car barely moved. So I got it towed. Very rought idle. The mechanic says i've bent my rods. When engine is started, there is no knocking noise, maybe I didn't scratch my cylinder walls, we will see. I will know more later, once it's fully dissasembled.

Well, I guess I knew this was going to happen. I am now thinking on what to do - either repair it with OEM parts, remove my ECU/TCU tunes and sell it, or go all-in and do the italianrp rods/pistons, darton mid sleeves + hybrids. But that would be about 25-30k in total costs for a 2015 car with 60k miles - not really sure it's worth doing it. I am leaning towards first option. What a shame, what a car that was.

 

sorry man, let us know when you have the actual diagnosis as it may change your plans

 

So your engine lasted less than 4 months since you originally made the post. How many total miles did you have on the car with the actually tune and mods installed?

 

Damn.
I bought the ECC E40 tune last year and I've been too chicken **** to use it. Recently I called to get the E sensor put in, flash the tune, and do some Dyno pulls.
Now I'm scared. I need to sell/trade in the car (new one coming) and don't need a paperweight :/
Also
I will regret for the rest of my life that I did not "finish" my project and run a 10.xx

Argh

Sorry to hear about your car. My plan was always go get the built BB M157 if mine blew up (again). But now with a 2023 on the way all that has changed and I kind of need my car to sell/trade soon.
Dang

Let us know what you decide to do. Swap in a stock Ebay motor? Get a built one from BB? Rebuild yours locally with the good stuff?

 

PS this other car also had a Renntech stage 2 tune, got it checked out by ECC and it was too aggressive, had it removed:

https://mbworld.org/forums/w212-amg/...ml#post8663277

 

damn bro . I'm srry this happened . How does he know it's a bent rod? They tore the engine down already and can see it? For me my cylinder wall cracked . That's how I failed . Srry this happened.

 

Yea when the tq spikes that fast it safe to say the rest of the run is all heat and back pressure. Just throwing boost at it definitely not the greatest of ideas. But same goes for timing . Throwing high timing and low boost has its issues as well. There's little to no room for a missfires to happen that can ruin your valves or pistons. My opinion is the only 2 tuners that I will say can tune an m157 to run as best they can at the engines hardware limitation is Jerry personally my preferred tuner. . Who you have to have him tune your car personally and not someone random at ec with a box tune. because he just has a enormous amount of clients. And or slav ecc which does great work . 2 different approaches but with similar results.