Mercedes A-Class Forum banner
1 - 20 of 318 Posts

677 Posts
I wouldn't dream of commenting on the commercial aspects of the different tuning approaches and specifically not from the other side of the world.
However, as a 50 years of experience turbo application Engineer, I can tell you that the absolute possible peak power output is set by compressor mass flow, intercooler efficiency, fuel octane/ ignition timing and finally ambient conditions.
Tuners can claim any power numbers they like, achieved by any method they like; however they cannot change basic physics.
I have owned all three iterations of the A45, Original, FL W176 and current W177 45S and in one area they all have one thing in common..

AMG apparently prefers to only provide somewhere just over 10% in turbo compressor headroom.
(Which I must admit, is in stark contrast to the RS Division of Audi, who seem to usually supply at least 30% of compressor headroom).

So, bottom line?
Any tuner who claims they can increase the peak power output of the current 421 HP A45S, by more than around the 45HP mark, all variables being equal, needs to be treated with a high degree of scepticism.
Mid range Torque??
Now that is quite different and so long as the drivetrain can handle it, big gains are certainly possible there.
I would suggest that THIS is where the difference in tuning approaches may become most apparent technically, if not commercially.
I strongly doubt a "Tuning Box", no matter how good, could compete with a professional recalibration of the ECU's controlling both Engine and Gearbox,

677 Posts
Dyno tune complete at evotech Sydney (International Autohaus).

My car was 318kw stock now 360kw at the flywheel (300atw) and 492nm up to 562nm. I am really pleased with it!

Launch now doing consistent 3.7 flat, high 3.6s and making some great sounds.

Allen the tuner was slightly disappointed with the NM gain, as he was looking for around 585, and he said a contributing factor was that mine has new software, being a ‘21 and may take another look when I have it in again.

Great guys and a great operation!

The tune is software only with the charts before and after further up the thread.

Considering now just servicing with Allen and Con @ International Autohaus and doing some hardware mods.

What should I do next?
I looked at your previously posted sheets from the only Maha dyno I know of in Australia, with interest.
40 KW improvement or 55HP
I know how Maha claims to derive engine HP from the number measured at the wheels and I shall not get into a discussion here on the subject, as it is potentially a VERY long one and somewhat off topic.
The important thing is, you are happy with it and fundamentally, that is all that matters.

I shall stick to my previous comment though.
The best Tuner in the world cannot change the laws of Physics.
Your current Tuner MAY be able to improve mid range torque further if you give him more time.
I just hope he has the transmission control software as well, as he will probably need it.

The one thing I can say for sure though is, if you are looking for more power, (as opposed to more torque), you will need a larger compressor.
I don't believe TTE have their product out yet; however GotTuned out of Poland have something on the market.
No direct personal knowledge of it; however looking at the Specs, should be good for around 550 HP or 410 KW

677 Posts
Good numbers. What also interested me is that the stock number is 435.1 bhp. I wonder is that is more typical to countries where there are not the same exhaust restrictions as Europe.
This is precisely the reason it is best NOT to treat so called "engine" power numbers from ANY brand of chassis, ( "rolling road") dyno, as an absolute figure.
If we are going to start discussing this subject, I would respectfully suggest a new thread.

The incremental increase of any power mod? Sure, that can be measured as shown; however it it best left stated as what in fact was measured.. An increase at the wheels.

Ultimately, of course, what matters is that the customer is happy with the vehicle, not any numbers.
On the subject of which, have any of you tried Posaidon in Germany?

677 Posts
I would suggest someone from the Forum contact Herr Hummes at Posaidon. [email protected]
(Excellent written English)
They have both Tuning Box and ECU recalibration options.
Not cheap; however show me a quality German tuner who is!! :)

They also have some extremely interesting engineering data on the W177 A45S, although not sure how much of that they will be prepared to share in a public forum.

677 Posts
Point of clarification, I was NOT saying Maha is unreliable.
I was saying that it is almost, (stress, almost) impossible to accurately infer (as that is what it is, an inference) accurate engine HP from numbers measured at the tyres.
This is true of any chassis dynamometer I have ever seen, anywhere in the world, over 50 years in the Industry.
However, as I said in the beginning, if we are going to discuss this, best to start a new thread.

There is little or no relationship between 400M ET and HP.
In order to get to the bottom of this situation, I would need his trap speed and in the quick look I just made at his data, i could not see it.
If you can get me stock trap speed and his, I can certainly tell you what that represents by way of incremental HP.

Yes, as you quite rightly suspected, I do have full tech on the M139 Turbo.
Not prepared to post yet; however shall do so in the fullness of time, as I outline what I have in mind to do with my vehicle,

677 Posts

You are correct, so I hope you are happy!!. An incremental 55 flywheel HP, presuming ALL variables, such as fuel octane, ambient conditions, are IDENTICAL etc etc.
In a real Engineering exercise, one would do the comparison on the same day same car, of course.
IE, does the guy in particular just happen to have a really nice stock spec car that was 10HP over standard rating as delivered?
Certainly not out of consideration.
One thing I can say with certainty.
His tuner is SERIOUSLY leaning on the stock turbo and he is 5% past the 60% compressor flow line.

677 Posts
I see the moderators have moved us to what amounts to our own Thread!!! :)
I also see someone has posted DYNOJET numbers on the original thread.
Given that "Dyno" is at the the diametrically opposed end of Chassis Dyno Tech to a Maha, I am surprised you have not commented!!! :)

In any event, to keep on topic.
Yes the example vehicle is probably somewhere around 13% over stock, as opposed to my originally stated maximum.
However, this has been achieved by exceeding the design limits of the Turbo.
Does anyone care?
Well the two reputable German Tuners I mentioned certainly do, as they will not exceed 465 HP on the stock turbo.

However, obviously not the Tuner who did the example vehicle, that is for sure.
That said, don't you think owners should know what is being done to their relatively expensive stock turbo?
THAT was the real point of my original post.( I'll bet the tuners doing this will not tell the customer, even if they know)

IE if any of us want greater than a10% increase over our stock wW77 A45S Power outputs (Not Torque), we need to be considering a Turbo swap.

Australian Spec is UK Spec without the Filter.
However. ALL our A45S's come with the AMG performance exhaust as stock. Not sure if that is the case in the UK; however I am sure you will know!! :)

In the interests of International co-operation :)
Stock A45S Turbo
Compressor Inducer 50 mm
Exducer 63 mm
Turbine Inducer 57 mm
Exducer 50 mm

However, please don't' get too hung up on these numbers. Technology can play merry **** with the resultant flow numbers, at both ends of the turbo.

Just to give you an idea, from both ends of my personal career, so fifty years apart.
When I entered the industry, 350 HP from a 50 MM inducer would have been considered state of the art. Today if one was not achieving 500 HP, it is just average.
(Yes, the comp wheel in our stock A45S turbo is just average)

677 Posts
I'm not just happy, you just made my day. I'm kidding :)

Mate, I know about incremental hp, I know how the result comes out, just wanted to see how you think as I found your statement a little weird, that tiny 10% of headroom I mean. And I'm sure it's not just me. But remember what I said, I don't question your knowledge, I said I'm willing to accept that 10%. It's my first MB car anyway, I'm new here, so I wouldn't know.

I'm no engineer, probably have a fraction of your knowledge, but I've had several discussions on the subject (dynos, hp and all that) with people with several years of expertise, in 5 different forums, in 15 years. I've built hybrid turbo setups, with water methanol or not, which is why I asked if you have our turbo specs - I always want turbo specs in all the years of owning turbocharged cars. I also know about that Polish company that makes hybrid turbos, unfortunately they haven't announced detailed specs. I once thought of emailing them, pretending to be interested in their product and somehow extracting that info (our stock turbo specs) but then I thought that some human being would be spending minutes of his working time to answer my questions and just didn't seem right. Or maybe I'm too nice in a sh!tty world.

I dunno, he'd have to tell us what he dynoed stock, if he has even dynoed his car. It just seems that nobody has dynoed higher than spec, except @Gunn but could it be that gpf-less cars make slightly more power? I wouldn't know. I don't even know the full detail of Australian spec, like is cat the same? Only thing I know is you guys don't have that piece of crap gpf.

677 Posts
Can @Turbo_Ed explain the Brabus stage 1 software only tunes which way exceed 10%? e.g.

Brabus B40-600 for C63S, GLC63 etc - 600 PS v 510 PS stock, an 18% gain

Brabus B40-700 for G63 - 700PS v 585 PS stock, a 20% gain

My comment was purely in the context of the W177 A45S, which is what i thought this thread cornered.

I don't have the compressor flow maps for the vehicles you have mentioned.

677 Posts
Guess I was lucky as my tuner was able to make more than 10% gains?
Possibly; however more likely the Tuner, knowingly or unknowingly, simply over sped your compressor.
Depending upon many variables, you will get away with this for a while.

Still not desirable though. You would do far better with the correct size turbo.

677 Posts
Yeah but see it can't work this way man. You are essentially calling pretty much the majority of tuners unreliable in terms of turbo longevity (yes the majority, as most tunes make anywhere from 475 to 490ps - I would say 480 could be an approx. avg) without providing any relevant data to back that up. So people will just have to take your word for it.

First of all thanks for revealing your secret. That was quick, I wonder what changed your mind. Nevermind, I'm happy that you did. That's what forums is all about btw, sharing knowledge and experience. And yes, sharing our excitement too.

Average by what standard? I would say for 2 liter engines such as Audi S3's it could be a nice big turbo upgrade. I wouldn't say it's average. But anyway, let's not argue about that too, wanna call it average, average it is.

Now, on the 10% safe maximum.

You're saying the two reputable German tuners won't exceed 465hp because they know better. Which is not the case with MSL (the example vehicle). And that "owners should know what is being done to their relatively expensive stock turbo", again, implying, actually more than implying, that they're operating beyond the design limits of the turbo, overspeeding the turbo in other words. First of all let me tell you, that's not necessarily catastrophic, I've done that before except what you need to do is run thorough logs and closely monitor several things such as cf's. In many cases you need to run water methanol which can be the only way to lower temps caused by overspeeding. We used to do that with K04-064 turbo (S3 8p, MK6 Golf R, Edition 30 GTI, Scirocco R, Leon 2 Cupra etc) whose map ends at about 370ps, beyond which, you have to upgrade wastegate and use a harder spring and if you get boost way up, you got temps and then you got cf's that can only be dealt with water methanol injection, then you can up timing as well and make more power. That way the K04-064 can even make 420ps and we're talking about a fully bolted stage 2+. And that's an extreme example, there's no way M139 turbo would be anywhere near that at stage 1.

Yes, the more boost you run beyond map, the less your turbo is going to last. Much like every other part that you're asking to do more than it was designed for. But you're making it seem like @Gunn's turbo will grenade any time. You know how everyone drives? If you're a little careful and don't do 100 runs on your way to work and back, chances are you can enjoy your turbo for years to come. I've never had a single failure. Brabus only makes 450ps for one reason, just one reason alone; they provide huge warranty, meaning you can keep driving your car exactly as you did when it was stock. But see, that's marketing right there, driven by risk assessment. Brabus thinks they likely won't be able to cover potential failures with a stronger tune, because likelihood would exceed their safety %. That means that for every X cars they tune, a small % will fail and that costs them money. So what they do is make as much power as their model suggests. The rest is up to the customer, you want warranty stick with 450, you wanna take a small risk go more. But no way does running 490ps mean you're killing your turbo. Assuming the tuner knows what he's doing. You need to run several logs you don't just click a few buttons and off you go. Certainly doesn't make the majority of tuners unreliable and don't tell me you didn't call them unreliable because come on, you did, I mean "don't you think owners should know what is being done to their relatively expensive stock turbo" ??

I bet Mr. Herr Hummes at Posaidon that you just happened to suggest in your first 4-5 posts, knows better. I'm sorry, couldn't help that either.
Sorry; however I couldn't follow all your points, although the gist of seems to be that it is OK to overspeed a turbo and handle the resultant excessive compressor discharge temperature by installation of water / meth injection? Is that a fair summary?

Also, basically that the reward in increased performance out ways some increased risk? Would that also be fair?

With regard to Posaidon, I believe I had already admitted / stated that they were not happy going beyond 465 HP Flywheel. (Nothing to do with warranty, though)

Finally, could you please repost or link the Maha post to which you refer?
You have already noted the "high" stock Flywheel power figure on the only Maha of which I am aware in Australia and there is at least one other element of the posted numbers from that machine which seem odd.
What would be excellent if you know of them, would be a before / after set of numbers of a W177 A45S in the UK from the same vehicle on same Maha dyno

677 Posts
I was asking myself exactly the same question. Also the 30% for the VW group.

On the thread being split. I think there will be overlap so it's not a pure technical/general compartmentalisation. For instance a discussion around Brabus only offering a 29PS power uplift is not a technical discussion.
I have the compressor maps for the current RS3, RS4 and RS6.

Someone made a comment somewhere in the responses, regarding Audi S models.
Just as i don't have the map for the A35, I don't have Audi's S model turbos either, sorry.
I shall not comment on a turbo match without the maps.

677 Posts
My comment was purely in the context of the W177 A45S, which is what i thought this thread cornered.

I don't have the compressor flow maps for the vehicles you have mentioned.
Apologies, on further investigation, I do have the compressor maps for both the 375 KW and 450KW (which are different to the 375KW turbos) versions of the V8 hot twin install.

Brabus's 20% increase of the 375 KW variant, probably to no one's particular surprise, is right on the professional limit of those turbos.
Hence the 450KW turbos being different in their stock configuration.
In other words, Borg Warner/ KKK will not run their product right on the limit, even though it is technically possible.

677 Posts
You speak as though all tuners will just increase the boost and spin the turbo out of its efficiency area whenever they tune. There are other factors such as ignition timing, AFR ratio that comes into play as well.

Anyhow, nothing wrong a very general academic angle of approach of viewing things, this is after all a forum for sharing.
Apologies if that is how I came across, definitely not my intention.
After being around turbocharged engine development for over 50 years, I have a reasonably good understanding of the variables involved.
While you are generally speaking correct, mass flow is mass flow and if you exceed the 60% efficiency line of the compressor, (not to mention, max recommended RPM) all sorts of interesting things happen, none of them particularly good.
Can they be partially addressed by "band aids", such as the water/ Meth suggested by Theo? Absolutely.

However, if you go back to my original post. all I was saying is that if you want to incrementally increase the power output of the W177 A45S by more than 10% (since amended to 13% at Theo's suggestion :) ) you should seriously consider a larger compressor output turbo.
That's it.
If people chose to not modify their personal vehicle in an Engineeringly correct manner, this is entirely their own choice.
There is no force implied here, just advice.
Yes, based on one or two year's experience.
Chose to take it or not.
It will not affect how I go about the same exercise on my own vehicle.

If no one on this Forum is interested in hearing about how to undertake this sort of work in a professional manner, just continue in the current vein and I shall not bother.
Plenty else to do.

One thing I shall not do though is reveal Engineering data provided to me in confidence by long term Industry contacts.
Sorry, but that is how it is,

677 Posts
Well yes, it's a highly effective solution. Helps keep the intake valves clean too, particularly if you aren't running port injection (our engines do, so we should be ok). Of course turbo upgrade is the "better" way, but won't come cheap either. Though it still boggles my mind how you can ever run out of map at just a stage 1. Never seen that before. Like I said, in my experience it'd take at least a stage 2 and even that might not be enough.

"... the reward in increased performance out ways some increased risk? Would that also be fair?"
Absolutely. Just not with this car, which is why I'm leaning towards Brabus and for the first time in 15 years into tuning, I'm all for safety.

Question, do you happen to know what's the most we can get out of stock internals? I have detailed specs which I've collected over several months of searching, but haven't found an approximate number.

This is the post about Maha, I've also put a link to it in post #23 of this thread.

Dave (Administrator) @ - October 05, 2013

And everyone will keep trusting their reputable tuner and life will go on.
I want you to bother, it's good to have you here. But you should consider posting some data, otherwise why would anyone trust Turbo Ed? That's all.
Theo, thanks for the link.

Do you by any chance have any UK Maha data, with the same W177 A45S vehicle stock and tuned, on the same UK Maha?

I am afraid that the only data I have currently are compressor and turbine flow maps and there is no way that I could post those without the source being obvious to people within the Industry.
So, much as it appears to frustrate you, that is not going to happen.
As for people trusting Turbo Ed, I was not aware that I was requesting that.
I am not here trying to sell anything, so why is trust required?
I could ask the same question of anyone else here, unless some are proxies for Tuning shops.
I am simply expressing my opinion.
One that happens to be based 50 years of experience.
I think that experience will become obvious over time.
Certainly when I get around to outlining my objectives for my vehicle and how I intend to go about it.

However, as usual, you have brought up a couple of interesting points.

A) This term "stage". What does it mean, precisely?
To me, as an Engineer, it means nothing.
However, it obviously means something to you and the Tuning industry generally.
I can tell you, it means nothing to Turbocharger design Engineers.
If you would like to start a thread on how a turbocharger is matched to an engine for a given application, we could do that.
Although I suspect the obligatory proprietary data gaps might frustrate you ! :)
The current W177 A45S turbo has 10% "excess" mass flow, (over stock rated power) to the 60% flow line at a 3.1:1 Pressure ratio. It is just under the Turbo's design RPM redline at that point.
However, like most professionally designed mechanical components , there is some overload allowance.
How much?
Honestly, I don't know; however i am sure the Tuning industry is going to find out eventually!! :)
Not going to be me though, that's for sure.
I shall chose the correct Turbo for what I want to achieve and thus be certain that is one component about which I don't need to worry.

Which leads nicely into your second interesting point.

B) What is the max safe power limit of the stock W177 Engine?
No, I don't know.
However, i intend to find out and no, not by breaking the engine currently installed in my car!! :)
I have seen the engines being physically built, in person, during an AMG factory visit.
Let me tell you, the On Line videos do not even begin to do the facility and process justice.

My best GUESS, currently, based purely on physical component observation, (yes, they actually allow you to handle the components during the visit) and experience?
I would not like to put more than 550 REAL Flywheel HP at 7,200 RPM, through the connecting rods as used stock.
When I have some hard data, which is likely to be towards the end of this year, given I shall have obtained it personally, (as opposed to being given it in confidence by someone else), I shall be happy to post it.

677 Posts
Exactly, this a forum for information sharing and everyone is definitely entitled to their opinions. Whether it is making sense or not, it is up to the individuals here reading to decide for themselves.

For example, without increasing the boost, just by using better grade fuel such as RON 100, dialling in the ignition timing, air fuel, cams etc once could still achieve reasonable power gains.

There are many ways to skin a cat, you seem to advocate only one way and trying to come across as "Well I can't force you to be right" with the "Sorry, but that is how it is".

But again, you could be right! Who am I to say what I said earlier is for sure, I don't have secretive data revealed to me by industry contacts. ;) And, I'm not even 40 years old, so definitely for someone claiming that they've been around turbocharged technology way before I was born, I am pretty sure you'd definitely have experience to share.

Though I would probably add that the turbochargers has too evolved much over the long years resulting in operating efficiencies that one wouldn't probably expect it to compared to the past. Again, who am I to say that I know for sure.

Don't be discouraged if you think no one on this forum is not interested to hear about your professional opinion, that may not necessarily be the case at all. It is too early to assume that.
What I think you are missing is the the compressor of a turbo is simply a pump.
Every pump, of every design, has a maximum flow capacity.
With the turbo, this is measured as mass flow
If you are below the choke flow of the "pump", certainly playing the tuning games you are suggesting alters engine power output.
However, once you EXCEED the choke flow of the pump, NOTHING you change makes any more power and depending upon how far the Tuner goes, seriously endangers certain mechanical parts and I don't mean just the turbocharger.
It is the classic RISK / BENEFIT analysis.
If anyone is prepared to go much over 10% more REAL engine HP on the stock W177 A45S turbo, then just be aware of the risk, that is ALL I am saying.
Knock yourselves out, at least for the moment, it is a relatively "free" tuning world. (Although Californian residents may object to that statement!! ))

677 Posts
Nope, I don't. Btw you don't need to mention your 50 years of experience all the time, I got it.

Yeah "stage" means so much to me you have no idea, lol. Only using it so I won't have to name every single mod individually. Stage 1 typically consists of just software, which in our case should also involve CPC and TCU, aside from the ECU. If you want it done right that is. Sometimes it includes an intake too. Stage 2 is software along with basic bolt ons such as an intake and a dp with a free flow cat/catless or a complete exhaust system. In some applications there are more things involved such as an upgraded hpfp, wg, ic, etc. Stage 3 usually involves either a hybrid turbo or a bt setup along with everything else, plus several other mods. Further stages would involve even bigger turbos and required mods.

So let me rephrase, overspeeding the turbo at just a tune, with no other mods? Never seen that before.
I'm not buying the 10% headroom. I'd trust my reputable tuner unless PROVEN otherwise. You're gonna say you're not here to convince anyone and you don't care and life will go on.
Please do me a favour and have another look at the numbers posted on the original thread from the Australian Maha.
Apart from the supposed "stock" number, on which you have commented previously, please just look at the other numbers and tell me if anything jumps out at you, particularly in light of the Maha operational thread which you so kindly reposted.

With the W177 A45S,. could a Tuner run beyond the turbo Choke Flow number and into overspeed, with no other mods?
You and I can debate whether this is going to occur at 465 HP, 475 HP 485 HP or 495HP. Maha HP, however, at some point it will happen.
What is the most likely reason for this NOT happening?
A good Tuner is going to get to some combination of variables where he cannot make any more power, (Choke Flow) and IF he really IS any good, back the variables off slightly.
Thus deliberately, or simply by dint of good Tuning practice, save the turbo.

As for where one goes beyond that point, that is where it gets REALLY interesting.
Now, remember our Australian cars have no filter and the AMG performance exhaust as standard.
Also, I would guess by your posts that you would have already had a really good look at the air intake system into the compressor?
Do you really believe this can be significantly improved, at least in the context of the stock Turbo's Choke Flow?
I certainly don't.

What i am really saying is, I don't see a "Stage 2". Perhaps there is in the UK, with an "export" exhaust system; however not for us, as we are effectively already there.
Have you seen what Akrapovic claims for their 200 CPI downpipe over stock? 6 HP at peak RPM!!! :), which is obviously somewhere between absurd and pointless.
All this on the stock Turbo, of course.

Which brings us right back to the beginning.
My original point being, if one is going to want to go beyond what you (and the Tuning Industry) describe as "Stage 1", it is going to take a larger compressor wheel turbo.
1 - 20 of 318 Posts