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I'd like to take a swipe at this. Let's use some axioms and some deductive inferences, maybe we can be on a similar track or continue to see it in different ways.
First I'd like to put some facts out there and if there is disagreement we (or anyone) can bring those up and we can work through them, but I'll assume this is all acceptable until I hear differently:
1. The intake system starts at the grill > intake (including pipes, filter, more pipes) > Turbos > more pipes > intercooler > more pipes > throttle body > intake manifold > cyl head > intake valves > HOME where the power is made.
2. I've highlighted the place, (the component above) that is topic of this whole discussion, but important to define the entire path of airflow.
3. There are a couple different formulas out there that calculate the relationship between HP and Airflow needed to support that HP. The one I like is:
Airflow (in CFM) = (HP x 0.625) x 1.1104. This becomes distorted on an FI platform which becomes more complicated, but for simplicity....
4. For the discussion that follows, I'd like to use the early AMG GTS which produces about 503 HP (according to factory). I picked this one BC it is approximately at the low middle of the GTx family and we know the same intake is used on the entire family from the GT at about 459HP, to the GTR at about 550HP to the BS FP crank engine at about 720HP. Then, of course, we have at least one example above somewhere in this thread where we see the factory intake used on a big build of 1100HP (BTW, I don't want to wander, but actually I've heard of tuners doing big builds that have used the factory sys on 1300HP where it does finally seem to start hitting a wall).
5. The highlighted intake component in #1 DOES NOT GENERATE AIRFLOW (This is very important). This component is like a corridor or passageway. It can only ALLOW airflow to pass (or restrict it).
Again, any disagreements on any of the above, let's talk through them in future posts. This is especially true for #5.
Let's take the early AMG GTS now - 503 HP. If I apply the formula in #3. it takes 349.08 CFM of air volume to flow through the entire intake system as described in #1, to produce 503HP. Just for simplicity's sake, I'll add all the other family members in CFM
GT = 318.55 CFM
GTR = 381.7 CFM
GT BS = 499.68 CFM
1100hp + 763.4 CFM
1300hp = 902.2 CFM
To continue, I have a question to ask. When engineers contemplate an engine design they ponder this same question. Here is the entire air intake system again:
grill > intake (including pipes, filter, more pipes) > Turbos > more pipes > intercooler > more pipes > throttle body > intake manifold > cyl head > intake valves > HOME where the power is made.
Thinking of AIRFLOW and what it takes to produce a given HP - where is the GATE in this intake? In other words, what component poses the biggest risk or challenge to accomplishing the target HP? In this case 503. When engineers design a platform, they actually ID the GATE (beside the obvious one), then redesign it, then find the next gate, redesign, then on and on until they're satisfied.
For those who have made decisions to discard the factory front intake, starting past the grille and up to the turbos, (where an aftermarket like the Eventuri would replace) have already decided that the highlighted component IS the gate. Is it?
If you decided that the factory intake is the restriction, the gate, then how can you explain (or argue) that same system (unchanged), can support enough airflow to produce - 550HP; 720HP; 1100HP? That's a spread of 350CFM to 763CFM; or, in another way, the stock intake on the GTs is only being used at 70% of the capacity needed on the BS; or only 45% of the 1100 HP build.
So back to this part of the above quote - "the stock intake can handle 1000hp" doesn't mean "the aftermarket intake won't do any better." I'll take the double negative to mean you think the aftermarket intake CAN produce maybe some more HP than 503. How would it do that, BC if you agree with #5, this system cannot generate airflow, it can only pass air through to the turbo which is the source of the ariflow demand to produce 503HP. I can make an additional 5 to 10 to 15 to 50 more HP by commanding the turbos to demand more CFM which we already know the intake has no problem handling. So the argument that at 503HP the intake causes unintended resistance to flow, but doesn't at 1100HP is a false argument.
One last comment and I'll restate - When engineers design a platform, they actually ID the GATE, then redesign it, then find the next gate, redesign, then on and on until they're satisfied.
The reason I am so skeptical of these aftermarket systems, it presumes the "factory engineering team" went ***** out on this engine, created a great product, then just crapped the bed on the intake part. Then I have to believe it was some genius mechanic in some garage somewhere that "discovered" the mistake and corrected it with an aftermarket intake system. And stranger yet, practically EVERY performance car, regardless of the brand name, those engineers made the same mistakes on their designs too. They somehow just gave up on the intake and every one of those cars have "aftermarket" solutions to find HP/TQ the engineering teams missed. There is one intake system for the GT platform being sold on these forums and the guy who designed it was a bicycle mechanic before he tried his hand at solving intake airflow problems that factory engineering teams missed.
Aftermarket intake systems are low hanging fruit. Easy to snap something together that looks cool. Put enough Kool-Aid in the marketing writeup and they come running with cash in hand. I don't deny them the right to earn a living!
I'll look forward to any follow on discussions..no issues with disagreeing with anything I put up here.
All the Best,
Acta
Thank you for the highly informative, well structured post. This appears to be what I was missing! Am I summing it up correctly as "the stock intake is nowhere near hitting its limits and is not restricting airflow for any level requiring below its maximum capacity (e.g. stock GTS)" which would also mean, assuming one existed, "adding an intake which could support more airflow than the stock one would also yield no gains for applications below its maximum capacity?"
Trying to wrap my head around this with applying it to another part of the equation mentioned above: dirty filters. Would this mean that, for a dirty filter to reduce power on a stock GT, the filter would have to be dirty enough to cut the capacity to support airflow from ~900 CFM to below ~318?
Thank you for the highly informative, well structured post. This appears to be what I was missing! Am I summing it up correctly as "the stock intake is nowhere near hitting its limits and is not restricting airflow for any level requiring below its maximum capacity (e.g. stock GTS)" which would also mean, assuming one existed, "adding an intake which could support more airflow than the stock one would also yield no gains for applications below its maximum capacity?"
Trying to wrap my head around this with applying it to another part of the equation mentioned above: dirty filters. Would this mean that, for a dirty filter to reduce power on a stock GT, the filter would have to be dirty enough to cut the capacity to support airflow from ~900 CFM to below ~318?
YES…You are thinking clearly about the factory intake now.
About air filtration there is one more brilliant part of the factory design the aftermarkets do NOT have, especially those using cone filters that either fill the entire passage (as the Eventuri does) or others where the cone fills the majority of the airbox.
With the factory design, notice the size and shape of the filter box. See the cubic space allotted to and the dirty air intake is BELOW the filter which is suspended above the intake air. Heavy particles under hi airflow hit the back of the box (below the filter) and fall to the bottom of the box and never make it into the filter. If you want evidence of that just take off the filter top remove the filter see the debris at the bottom of the box when getting ready to change a filter. Also because the filter is suspended with the dirty side down gravity causes some of the dirt to fall out of the filter when the engine is shut down.
The aftermarkets, on the other hand, catch all of the debris, especially the Eventuri. So they will reduce airflow at a much faster rate as the mileage builds up comparing them to the same mileage with the factory intake.
In all of this we haven’t even discussed COLD AIR features of the factory design compared to the aftermarkets but here too there is more brilliance in the factory design.
Last edited by Acta_Non_Verba; Oct 25, 2022 at 07:53 AM.
The points I made above about the factory design that help keep the filter from contamination and perform much better over time than the aftermarkets do was important enough to do a simple demonstration for you. I spent five mins pulling the left side filter on my car and the pics below should be proof points for anyone.
I JUST changed my air filters in July, so there are only 3 months of street use. In the first pic you can see where/how the factory air filter fits into the air box. The topside of the air box is clean, the bottom side of the air box is dirty. The dirty side of the filter faces DOWNWARD.
In the last pic I want you to see the debris, including some large pieces that are inevitably going to get sucked into any car in most any environment. The debris you see here is NOT clogging the factory air filter or reducing air flow. Think about where this debris would be right now in an aftermarket setup, pick any of them, look at their pics on their sites, follow the air flow and debris. Is it in the filter blocking airflow? Imagine what the third pic will look like after 24 months.
One last point about filtration - filtration surface area. The accordion folds you see in paper elements (and in the wet filters), if opened up and laid out on a table would represent the sq.area of filtration available to allow for airflow, and to retain dirt particles which we know will eventually reduce or inhibit airflow. Simply, the larger the area of filtration, the greater the airflow, and the longer the filter will perform. Here too, look at the aftermarket filters being used and compare to the filtration area of the factory one. Visual is enough here without actually having to cut up filters and lay out the filtration paper or media.
Hope this is helpful,
Acta
Last edited by Acta_Non_Verba; Oct 25, 2022 at 03:03 PM.
Great pics. Is this a function of gravity or by design??
Also what filters do you use.
BTW Has anyone seen the intake of the GT3 AMG GTC? They look a bit like the Eventuri. Lol
Hi Mike,
It's the function of gravity that the designers took advantage of. I use OEM filters that are paper. Using an aftermarket oiled filter in place of the factory paper defeats this function as any dirt particles will stick to the oil then turn into a micro sludge that sticks to the filter element. The factory has it all figured out on the intake we just need to appreciate the brilliance in the design.
I was considering changing out to the eventuri intake as well but ended up using BMC drop-in filters as the factory intake system is sufficient enough for my needs. I have catless downpipes with a capristo exhaust paired with an evolve technik tune.
The car runs great now!
Interesting. I was specifically referring to the portion of system that comes out of the nose of the car. Not same as but reminds me at least of the Eventuri.
If you’re going bigger past this point you have to consider turbos.
Just a caution, you have to be careful about the lower end of the GTS. It’s different than the shortblock configuration on the GTR. You’re going to run out of range maybe even with bigger turbos BC the compression is too high on the GT/GTS.
Thanks Acta!
what about sending the turbos into weistec and getting them machined?
would I need to change/upgrade anything else with doing that?
Thanks Acta!
what about sending the turbos into weistec and getting them machined?
would I need to change/upgrade anything else with doing that?
Hi AMG,
It's getting tough to advise you. Online, anything is only theory. Performance mods reach a point where they cease to be cumulative, so asking online, if I do this and this and this, what will it buy in performance? becomes an impossible question to draw any good conclusion.
If you're wanting to build this motor past 50/60 additional HP you want to start working with a builder/tuner because the "canned" marketplace with piecemeal tunes, intakes, exhausts, turbo upgrades, etc. start to need expert coordination. Otherwise, these add on commercial upgrades start to work against each other, when you're thinking they're additive.
A couple of examples of mistakes:
Canned tunes (stage I, stage II) are a kick in HP but are terrible tunes. These mostly are producing HP simply by increasing boost. The companies selling them set up a tune on a mule, can it, then sell to use on other cars like yours (and no two cars are the same). Whether they are adjusting the VVE to match the extra boost, or just letting fuel trims and lean fueling in PE take over is a question (a big one in my mind). Same thing with timing. Increasing cylinder air mass by boost and maybe not adjusting timing and just letting knock tables constantly do the adjusting is NOT a good tune, nor is it good for a healthy motor. Although I don't know what exactly is in any company's "secret sauce" I've done enough tuning that I can use an educated guess.
The easiest/cheapest product to create/sell is a canned Stage I tune. Increase boost, call it a day, package it, sell it in a hand held or an ECU (upgrade). Remember the stock AMG GT and stock AMG GTS have the exact same motor, the difference, that produces 50 ish more HP is a 0.1 BAR increase in boost...that's it.
Now combine that canned tune with other aftermarket products - intake, exhaust, etc. Does the intake help, or hurt? What is the impact by changing exhaust flow (eliminating back pressure)? Positive or negative? I know we've beaten the intake stuff to death here. I promised you I wouldn't trash the Eventuri you've purchased and installed, but ask yourself, what is its limit? Can it handle more airflow if you impact boost? That's what turbos (and turbo upgrades) do.
Then you have to take all of these mods, or the next level of performance mods and constantly be asking yourself, - Do I have a bottom end that can handle the extra power? How much extra power? How much extra cylinder pressure? How much extra heat? How much extra strain on the rotating assembly? Do I have a transaxle that can handle more torque? What about the rest of the drive train...like the CF driveshaft?
So, with all of that, once you get past all of the kiddie stuff - (canned tunes, intakes, exhausts) and you want to start seriously building HP/TQ, you need to get to a TUNER/BUILDER. They'll build and custom tune your engine to get to a real HP limit and based on HOW you intend to use the car. This is something that amazes me every time someone mentions tunes, mods. How are they using it? Street racing? Track? Each one of these takes a different tune...or at least the way I did it.
Hope this helps, although I wasn't able to actually answer your Q directly,
Acta
Last edited by Acta_Non_Verba; Nov 6, 2022 at 01:33 PM.
you gotta be high or something man lol
you think the stock intake is better then the eventuri!?
Just by looking at the parts in front of me I can tell it’s gonna have better airflow then the stock
just by looking at the design and feeling the weight I kno it’s gonna be better then the stock.
I dunno how people are saying an eventuri intake would not be better then the stock air intake 🤦♂️
even just the filter itself is better.Mercedes restricts a lot of things with these engines. And if you thinks about it changing the stock air filter gives better airflow.
BUT how much more horsepower is the question. They say 12-18hp. Even a 5hp gain would mean it’s better then stock… even the little bit of weight u save with the carbon fibre would make a difference
might not be a huge gain but in the end it’s still better then stock
And seeing as how I can actually hold the system in my hands and look at it probably gives me a better opinion then someone who just looks at pictures on the internet ….
I do love the Eventuri intake for the GT, looks amazing however I’m not sure it’s actually better than the factory intake in terms of performance… 1 thing that actually concerns me a little is the fact that it’s now closer to the engine.
surely you’d want the intake away from the engine as much as possible to avoid heat soak.
I think run after run the factory intake will probably provide better performance.
