Air Intake Options
Not true at all. There is a drain and it is the other side of the firewall. See pic.

The seal makes a difference for noise mainly that we have found. QIKC63 and RDO have been running like this for a fair while now in all conditions I believe.
The rest of the air goes under the car and out as has been said here by @BMS straight past the pod filters.
As far as water ingress - after carefully looking at the seal, design of the plastic covers in the area, drain locations, and how far back the rear of the hood extends backwards over the opening from removing the seal… it seems highly unlikely that any significant amount of water would enter the engine Bay that way, even in a heavy rain.
Last edited by LessIsMore; Oct 11, 2019 at 01:59 AM.





"It’s an interesting debate and there is definitely a lot of misinformation out there.
For a start - running a turbo with just a screen doesn’t give the highest possible flow rate. Since it’s just a hole you get delamination of the airflow around the entry of the hole. So in effect the opening for flow is smaller than the actual diameter of the hole. Adding a funnel with a radius to the turbo inlet gives a greater flow rate potential than just an open hole.
The open cone vs sealed debate is all about how you intend to use your car. Also depends on the design of the system for pressure drops.
With an open cone in the C63S - you will start off with an incredibly high intake air temperature so the initial boost pressure ramp rate will be slower as the turbo tries to spool up with less dense air. Higher air temperatures entering the cooling system also means a higher air temperature exiting the cooling system to the engine. The coolers don’t reduce temperature to an absolute number. They cool the air by an efficiency percentage. So higher temp in means higher temp out. When this reaches the engine the ECU will see it and reduce timing accordingly.
Once on the move and under full acceleration, the engine bay does not miraculously get cold since the turbos are now generating intense heat and will start to glow red - that heat will radiate out to all components in the engine bay including the intake. The air around the turbos and manifold will also heat up and the open cones will be drawing this heated air in. Simple heat shields will not stop hot air entering the cones.
Open cones can work if the area they are pulling air from is away from the turbos and manifolds. Like for example within a wheel arch or behind the nose grills. On the C63S the cones are literally next to the hottest components on the engine and to make matter worse they are facing away from the cold air entry for the airbox system.
Turbo charged cars are very sensitive to high IATs. During development on other platforms like the Audi RS6 which has a similar problem with turbos on top of the engine, we tested our Venturi pods which are semi-open and we lost 10hp vs the stock airbox. So even though the airbox had a lower maximum flow rate vs our filter pods, the IATs resulted in a loss of power. Then we designed a full airbox for the RS6 instead and gained power.
On the C63S, the stock and other hybrid turbos do not exceed the flow demand that our sealed airboxes can handle. In fact people are running in excess of 800hp with the stock airboxes!
The other consideration is the design of the open cone systems. Often these are designed with metal tubes which are mandrel bent like and exhaust pipe. For a start - metal tubes will conduct heat very fast and they will then transmit that heat to the intake air passing through them. The coefficient of thermal conductivity for carbon (through plane) is a fraction of the value for metal. Secondly this type of tubing cannot change in diameter so you find that it remains at around the same diameter as the turbo inlets all the way to the filter. Compare our design which opens up after the turbos and increases in volume all the way to the filters vs the metal tubes which stay at the same diameter as the turbo inlets. It’s like sucking through a straw vs sucking through a funnel. The pressure drop is higher. So even if in ideal conditions on a drag strip with a cold engine bay to do one pass - the advantage of an open cone to de-restrict the intake is still compromised by constant diameter tube has a higher pressure drop than a flow path which increases in size.
We will be doing a final round of flow bench testing on Tuesday with the stock airbox and our system. Perhaps I will also do a flow test on some tubing with a open filter purely for academic purposes.
From our experience on working with turbo charged cars, IATs are very important. High air temperatures increase the turbo wastegate duty cycle as the turbo tries harder to achieve target boost with less dense air. Furthermore higher IAT causes the ECU to retard timing to protect the engine. On a performance road car - you are not going to be able to avoid increasing IAT as the engine bay heat soaks. Hence why we spent the best part of a year developing our sealed system.
Hope that helps."
. But I’m sure you know more than Helmut and worked at AMG.
Last edited by ezatnova; Oct 12, 2019 at 05:59 PM.
The Lion - "I do believe in open air flow, I do believe in open air flow, I do, I do, I do." The Witch - "You'll belive in more than that when I'm finished with you, just send me your money and you'll believe."
The Best of Mercedes & AMG
We all know we don’t have to upgrade our intakes to make big power but some of us are interested in our options.
As you say, Renntech make 725hp with standard intakes, what does yours make, my car makes 860hp on a DynaPack hub dyno with standard intakes.
Will any of these intakes add to our current power levels, make or cars sound more aggressive, lower intake air temps, allow our turbos to breath better, well time will tell.
What I do know is that it will make my engine bay look a little nicer.
If you would like to start your own thread on the advantages of the standard intake boxes I’d be happy to follow along.




Yep. They actually have a thread in our C63 subsection announcing it: https://mbworld.org/forums/c63-c63s-...ke-system.html
Yep. They actually have a thread in our C63 subsection announcing it: https://mbworld.org/forums/c63-c63s-...ke-system.html
Australian dollars is extremely weak atm,

"It’s an interesting debate and there is definitely a lot of misinformation out there.
For a start - running a turbo with just a screen doesn’t give the highest possible flow rate. Since it’s just a hole you get delamination of the airflow around the entry of the hole. So in effect the opening for flow is smaller than the actual diameter of the hole. Adding a funnel with a radius to the turbo inlet gives a greater flow rate potential than just an open hole.
The open cone vs sealed debate is all about how you intend to use your car. Also depends on the design of the system for pressure drops.
With an open cone in the C63S - you will start off with an incredibly high intake air temperature so the initial boost pressure ramp rate will be slower as the turbo tries to spool up with less dense air. Higher air temperatures entering the cooling system also means a higher air temperature exiting the cooling system to the engine. The coolers don’t reduce temperature to an absolute number. They cool the air by an efficiency percentage. So higher temp in means higher temp out. When this reaches the engine the ECU will see it and reduce timing accordingly.
Once on the move and under full acceleration, the engine bay does not miraculously get cold since the turbos are now generating intense heat and will start to glow red - that heat will radiate out to all components in the engine bay including the intake. The air around the turbos and manifold will also heat up and the open cones will be drawing this heated air in. Simple heat shields will not stop hot air entering the cones.
Open cones can work if the area they are pulling air from is away from the turbos and manifolds. Like for example within a wheel arch or behind the nose grills. On the C63S the cones are literally next to the hottest components on the engine and to make matter worse they are facing away from the cold air entry for the airbox system.
Turbo charged cars are very sensitive to high IATs. During development on other platforms like the Audi RS6 which has a similar problem with turbos on top of the engine, we tested our Venturi pods which are semi-open and we lost 10hp vs the stock airbox. So even though the airbox had a lower maximum flow rate vs our filter pods, the IATs resulted in a loss of power. Then we designed a full airbox for the RS6 instead and gained power.
On the C63S, the stock and other hybrid turbos do not exceed the flow demand that our sealed airboxes can handle. In fact people are running in excess of 800hp with the stock airboxes!
The other consideration is the design of the open cone systems. Often these are designed with metal tubes which are mandrel bent like and exhaust pipe. For a start - metal tubes will conduct heat very fast and they will then transmit that heat to the intake air passing through them. The coefficient of thermal conductivity for carbon (through plane) is a fraction of the value for metal. Secondly this type of tubing cannot change in diameter so you find that it remains at around the same diameter as the turbo inlets all the way to the filter. Compare our design which opens up after the turbos and increases in volume all the way to the filters vs the metal tubes which stay at the same diameter as the turbo inlets. It’s like sucking through a straw vs sucking through a funnel. The pressure drop is higher. So even if in ideal conditions on a drag strip with a cold engine bay to do one pass - the advantage of an open cone to de-restrict the intake is still compromised by constant diameter tube has a higher pressure drop than a flow path which increases in size.
We will be doing a final round of flow bench testing on Tuesday with the stock airbox and our system. Perhaps I will also do a flow test on some tubing with a open filter purely for academic purposes.
From our experience on working with turbo charged cars, IATs are very important. High air temperatures increase the turbo wastegate duty cycle as the turbo tries harder to achieve target boost with less dense air. Furthermore higher IAT causes the ECU to retard timing to protect the engine. On a performance road car - you are not going to be able to avoid increasing IAT as the engine bay heat soaks. Hence why we spent the best part of a year developing our sealed system.
Hope that helps."
The best way to test intakes is doing 1/2 mile runs or at least 1/4 mile runs and comparing trap speed which are a good indicator of average power throughout the run.




(Catback) exhausts aren't a big flow restriction either. Sure you can get a better flowing aftermarket exhaust, but it's all about the sound...that's what ppl are paying for.
If you want "bang for your buck" mods (without having to worry about blowing your motor with a "shot of nos" you're referring to), DP and a tune are the way to go. And if you want even more power, upgraded turbos. The rest is just cuz....
(Catback) exhausts aren't a big flow restriction either. Sure you can get a better flowing aftermarket exhaust, but it's all about the sound...that's what ppl are paying for.
If you want "bang for your buck" mods (without having to worry about blowing your motor with a "shot of nos" you're referring to), DP and a tune are the way to go. And if you want even more power, upgraded turbos. The rest is just cuz....
All these performance mods increase the driving experience us enthusiasts are striving for.
We all have the same car, some are happy to leave it stock but some of us like to play.
Honestly, I’m happy to pay a reasonable amount of money for an intake that will add some carbon to my engine bay, increase induction sound and hopefully increase the performance of my engine even if only 10-20 hp.
Going back through this this thread I’ve added a lot of pictures of different intakes, some are cheap, some are super expensive but they’re all options.



