Fellow MBWorld, members, I've been testing member speed43's custom airbox setup along with his Fast-Flow Elbow (FFE) on my CLK500. First, I have to say that dealing with him has been nothing but great. He has always answered my emails promptly and helped me with the installation process.

The removal of the airbox was simple. All you have to do is put your existing filters (or new ones for better results) in the new airbox and bolt them back up to the unit itslef.

The FFE was a little more tough. Since the throttle body is in a tight spot, it took me about 20 minutes to wiggle the elbow of the MAF housing. I gave the MAF a quick spray with CRC MAF cleaner and let it dry for about 30 minutes.

After driving it a few miles, I couldn't feel anything at first. I let speed43 know and he told me that the ECU is learning the extra airflow and a it'll adapt quickly. He was right. I could hear the extra air going into the airbox (it's an addicting noise I must admit) and could feel the stronger pull from 2K RPM all the way to redline. It sometimes throws me back in the seat (which never happens since I'm so used to the power of the car). I should be pushing right around 340 HP (I dyno'd at 330 crank without the intake a couple months ago) and it's a blast. The exhaust has more growl to it.

I would 100% recommend this product to anyone looking to get as much HP out of their cars. It is a steal at the price he's offering it. Great purchase and great customer service!

 

I'm sorry, but I still am calling BS on all of this. "Learning the extra airflow" Give me a break. There is zero verification of any of this. First, you have to assume that the engine is not already getting all the air it needs. If you strap a 4 inch piece of pvc pipe to my head, and put some baffles in it, and make me run a marathon, you can say that removing the baffles will increase airflow. Except that I cannot possibly suck in enough air that removing the baffles makes any difference. I could easily run the marathon with a 2 inch pipe. Second, why would Mercedes leave all that power on the table just by including baffles? Third, this whole theory ignores the fact that the air filters themselves are the biggest baffles of all. Any plastic fins sticking out are nothing compared to that. Finally, the idea that the claimed 10 hp increase would throw you back in your seat is nonsense. As I've said before, my car is down 60 hp because I live a mile high, but when I go to seal level, I really don't notice a difference. There have never been side by side dyno runs on the same day under the same conditions to verify any of this. I will stand by my $100 bet that if I sneak into your garage and switch back to your original air box, the next day you'd be like "man, this is awesome!"

 

I won't call BS, but I will suggest this: get a proper dyno test with and without the intake mods. Then you'll know for sure.

 

Thank you for the review KB24.
Yidney, no need to be sorry. Your opinion and others matter in forums like this. I had many people like yourself say the same thing about my modded C43 airbox. Even after customers posted that the results made a great difference. They kept saying dyno dyno. Finally one of my customers did a dyno and those guys moved on.

Mercedes puts the fins to stop air intake noise. The plastic elbow alone is very restrictive. Two huge fins in there to stop the air sucking noise which sounds great by the way.

And yes the ecu has to learn that more air is coming in. Than adds more fuel which in turns puts out more power. Don't believe it look it up it's a known fact.

I don't bet or gamble so you can keep your money. But contact me and let's work something out so you can test my airbox and elbow for 7 days. After 7 days report back what YOU think.

You will see that you do not need a dyno to notice the difference.

speed43mods@)gmail.com

​​​​​​

 

You should definitely feel a 60hp difference so I don't know where you're getting that from. Your average supercharger adds about 100hp and that's a dramatic difference that will push you back in your seat.

Intakes in general make proven power, mostly around 5-7 WHP. No, you're not gonna feel it but yes, it's been proven many times before. I am pretty sure these boxes/elbows will be dynoed eventually and the numbers will be up not down. Kudos to speed43 for making a product and putting it out there. What other options do we have for intakes? Renntech...aka makes power but it's 1500$ and the 55K airbox that sorta kinda fits and sorta kinda makes a couple of HP (2hp???).

What I would be worried about here is the reason for the baffles in the airbox and the elbow. Has anyone here done any flow simulations to actually see what removing the baffles does? I am pretty sure the engineers at Mercedes weren't designing the airbox and all of a sudden they decided to put in baffles to rob the car of some power or, as another theory goes, to silence the intake . They're probably there to either improve or distribute the air in a certain way. I, personally would not remove the baffle from the elbow.

And yes, the ECU has to learn fuel trim over some time and no, you won't feel a push you in the back of your seat difference from an intake, ECU adapted or not.

 

In addition to altitude, temp difference affects hp at about 1% for every 10 degrees. So in a 300 hp car, the difference between a 30 degree and 80 degree day will be at least the 10 hp we are talking about here - probably more. But you never read posts from people talking about how they feel the power or are pressed into their seats on colder days. Track guys see the difference because they are timing on repeated runs down to a hundredth of a second, but as a general matter nobody mentions it. It's because they are not primed to feel something. So they don't. My point about the 60 hp is similar - it's not that I couldn't feel the difference if I was really trying to or timing it, but at 60 hp you'd think I'd notice a wow factor without trying, but I don't. So when the OP says it presses him into his seat, that's a placebo effect. I've seen some of the threads on this and other forums, but have still not seen before and after runs on same day on the same machine.

 

Sure, but you are currently making the assumption that Mercedes was making these for the most horsepower possible. Unfortunately, there are many other things they must consider.

First, noise! Yes, they actually try to make stuff quiet the *******s!! Haha. You will notice almost all cars have some sort of resonator tube, baffles, or other trickery to keep the intake noise down. Im sure removing the baffles do help to increase airflow a bit, and Im almost positive removing them increases the noise.

Second, you must consider the RPM range that Merc was targeting with the intake. They most likely designed it with an emphasis on low RPM torque for drive ability and gas mileage. Your assumption that the intake is not a restriction may be very well true at a "marathon" pace, but when you want to sprint, it wasnt designed for it.

There are probably tertiary reasons as well, like emissions or packaging.

Now, I am in agreement that 10hp is extremely hard to feel. I think most people *want* to feel it, but also, the extra noise gives it the feeling its making more power.

I've tested his boxes in the past on my CLK500, and although we never were able to get hard numbers (it was hit by a deer shortly after we tested), i would be comfortable saying it was making more than stock. I wasnt thrown back in my seat to the point my carefully calibrated butt dyno could detect the difference, but its seemed to help.

Here is something I'd like to see. You all ask for dyno numbers to see if there is extra power made. Can you not look at MAF flow numbers? Any one of us can hook up a bluetooth OBDII reader. The MAF I believe reads out in grams of air per second (g/s). Cant we use this number to tell if more air is flowing?

Last, but not least, I still have my stock airbox. Can you sneak into my garage and put on speed43s intake and see if i notice the difference? Haha.

 

I'm not going to debate this. I been there and done that with the c43 forums when I modified that air box. My customers there gave great reviews. And one of them took the time to dyno the box. And probably the same day hour and minute back to back, LOL! People that want dynos are the ones that either can't afford or don't even care to buy. That's just been my experience. I offer this guy that says BS to my work and he never takes me up on it. Just likes to be negative.

For those of you who would like your engine to breathe at its best and make your car feel much better. Just contact me, I will be making them one by one. For the rest of you guys just move on. Leave the ones who want a better running car to buy and try for themselves.

Cant believe you people actually think that whatever Mercedes or AMG does is the best for everyone. And that it must be the most power the engine can make. Wow.

 

What I mean by "throw in the back of the seat" is the way the power is delivered in the midrange. It's definitely different. It pulls stronger in the midrange.