SL-Class (R129) 1990-2002: SL 280, SL 300, SL 320, SL 500, SL 600, SL 60 AMG

SL/R129: R129 M113 Modifications

Old Oct 22, 2022 | 10:47 AM
  #26  
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Originally Posted by Ryanr317
For you guys that removed or gutted the secondary cats on a 99-02, was there a noticeable improvement in sound and performance? Maybe at least better throttle response?
For me the exhaust tone changed slightly. Very slightly. It did not seem to get really that much louder. Throttle response is about the same.
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Old Oct 23, 2022 | 03:10 AM
  #27  
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Originally Posted by Ryanr317
For you guys that removed or gutted the secondary cats on a 99-02, was there a noticeable improvement in sound and performance? Maybe at least better throttle response?
My 2ndaries are gutted.
No improvement on performance, but the sound was slightly raspier.
A couple of my videos ( undercarriage of my car and exhaust sound )


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Old Oct 23, 2022 | 11:32 PM
  #28  
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Originally Posted by Ryanr317
For you guys that removed or gutted the secondary cats on a 99-02, was there a noticeable improvement in sound and performance? Maybe at least better throttle response?

Slight sound, they usually make 10whp on a 156 car. I am sure it makes some power.
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Old Oct 27, 2022 | 02:16 AM
  #29  
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Well I hit the race track tonight, only got 3 runs in but I managed a 14.159 @ 101.26mph for the 1/4 mile.

I honestly believe I could have gotten into the 13s if I had some more runs to dial in my launch technique. I was spinning way too much off the line especially after the tires got cold.

All stock ‘99 except for the M113k intake and muffler delete. Not bad for a 20 year old luxo barge with 111k miles.

EDIT: Run was with the Hardtop off, 1/3 tank of gas, everything else all stock.

Last edited by SLGuy408; Oct 27, 2022 at 02:46 AM. Reason: More info
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Old Oct 27, 2022 | 06:32 AM
  #30  
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Originally Posted by SLGuy408
Well I hit the race track tonight, only got 3 runs in but I managed a 14.159 @ 101.26mph for the 1/4 mile.

I honestly believe I could have gotten into the 13s if I had some more runs to dial in my launch technique. I was spinning way too much off the line especially after the tires got cold.

All stock ‘99 except for the M113k intake and muffler delete. Not bad for a 20 year old luxo barge with 111k miles.

EDIT: Run was with the Hardtop off, 1/3 tank of gas, everything else all stock.

oh hell yea, that’s solid. Yea your 60ft was horrible. It would be well into the 13s.

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Old Oct 27, 2022 | 06:36 AM
  #31  
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Originally Posted by SLGuy408
Well I hit the race track tonight, only got 3 runs in but I managed a 14.159 @ 101.26mph for the 1/4 mile.

I honestly believe I could have gotten into the 13s if I had some more runs to dial in my launch technique. I was spinning way too much off the line especially after the tires got cold.

All stock ‘99 except for the M113k intake and muffler delete. Not bad for a 20 year old luxo barge with 111k miles.

EDIT: Run was with the Hardtop off, 1/3 tank of gas, everything else all stock.

I have a heat shield for it now also. When I get some free time, I will dyno this, and then throw a 113k intake on it and see what the difference is.
My car feels really strong, and the same setup on my 210 E55 made 20whp and 20tq, through the whole rpm range.
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Old Oct 27, 2022 | 01:19 PM
  #32  
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Originally Posted by eurochargedw210
oh hell yea, that’s solid. Yea your 60ft was horrible. It would be well into the 13s.
Yea exactly, 60ft was garbage, reaction time was garbage too lol, wasn't exactly paying attention on that run. I think if I feather the throttle a little bit I'll be able to hook and go.

Originally Posted by eurochargedw210
I have a heat shield for it now also. When I get some free time, I will dyno this, and then throw a 113k intake on it and see what the difference is.
My car feels really strong, and the same setup on my 210 E55 made 20whp and 20tq, through the whole rpm range.
Nice, I'd really love to see what #'s it puts down with the m113k intake. Definitely remove the radiator baffles, that mod alone significantly contributed to throttle response (Make sure to put the baffles back on if you do drive in the rain as I believe that is what they're for).

Also, for anyone that does the M113K intake & baffle mod, you're going to have to change your air filters every oil change. I usually change air filters once a year, I happened to check mine after like 3-4 months and they were filthy.

Last edited by SLGuy408; Oct 27, 2022 at 08:24 PM.
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Old Oct 27, 2022 | 07:20 PM
  #33  
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The baffles are air dams that pool low(er) temperature air creating a slightly higher ambient air pressure before being sucked into the twin air intakes. The V12 cars have an extra headlight to radiator core support block-off to further increase the outside air pressure.


V12 intake helper.


Cutting out the dual fresh cool(er) factory intake system for a single under the hood intake system is a step backward; otherwise the real tuners (RENNtech, Carlssen, AMG, Brabus, Kleeman, etc.) would have done so.

Fresh, cooler air (in abundance), a resonator delete and attention to the throttle body are the time honored paths to increased performance.

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Old Oct 27, 2022 | 07:45 PM
  #34  
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Originally Posted by mahunt
The baffles are air dams that pool low(er) temperature air creating a slightly higher ambient air pressure before being sucked into the twin air intakes. The V12 cars have an extra headlight to radiator core support block-off to further increase the outside air pressure.
I think there is some confusion, the baffles that I am talking about are the ones that go in front of the stock air intake tubes, not the piece that the stock intake tubes connect to. And they are baffles as they block the stock intake tubes from having a direct ram air from the grille. Their function is 1. Sound resonator to prevent obnoxious intake noises 2. Prevent water ingress during heavy rain 3. Prevent larger pieces of debris making it through (probably why my air filters get dirty so quickly).

From your picture it appears that your intake baffles have been removed from your car as well (those two holes in your rad support in front of the hood latch is where the baffle clips on to).

I agree with everything else you said though which is why I went for this factory parts bin cold/ram air setup. I'm running the m113k air intake as described in this picture.


Last edited by SLGuy408; Oct 27, 2022 at 08:56 PM.
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Old Oct 27, 2022 | 09:21 PM
  #35  
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Nope, those are them.

I also got some RENNtech larger airbox intakes to help with airflow.


Extra air damming plus baffle. Pure SL600 MB and AMG.


Larger RENNtech airbox intakes.

Resonator delete increases exhaust flow and adds a little (very little) more bass.

Stainless resonator eliminator pipe and genuine AMG muffler. The AMG and V12 mufflers have a larger inlet than the V8 or 6 cylinder cars.

If anyone is interested, I have a resonator delete for a V8 car (90-98 cars) and a AMG muffler. Not inexpensive, but a noticeable improvement in sound and performance.
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Old Oct 27, 2022 | 10:34 PM
  #36  
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I understand the use of the headlight to radiator core support block off piece as it is funneling the air into the air intake tubes.

I disagree with your interpretation for the purpose of the baffle. With the baffle in place it blocks the air dam from getting air directly from the grille, it does not pool the air or create "high pressure", if anything it creates a low pressure point. Without it, the air from the grill funnels directly into the air intake tubes and into the engine.

Put it this way, if you stand behind a wall on a windy day, how much of the air wraps around the wall and hits you, almost none. So why would a wall in front of the air intake tube not be different?

Ram air = HP.

Last edited by SLGuy408; Oct 27, 2022 at 10:43 PM.
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Old Oct 27, 2022 | 11:09 PM
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The air dams up in front of and on either side of the radiator core support.
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Old Oct 27, 2022 | 11:25 PM
  #38  
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Originally Posted by mahunt
The air dams up in front of and on either side of the radiator core support.
Is this a complete sentence or thought? Am I missing something?

The air intake (dam) on either side of the car, behind the headlight, inside the core support which connects to the air intake tubes which then connect to the airbox is all still in place on my car. And it gets ram air from the grill with the baffle removed.

The baffle, circled in red, 3x4 inch piece of plastic placed directly next to the headlights does nothing but obstruct the airflow from the grille to the air intake. It does not create a high pressure point or "pool" the air.

You got a Renntech airbox, you seem to like HP, take 2 minutes and remove the baffles and drive your car around for a while, I guarantee your throttle response will improve.

Last edited by SLGuy408; Oct 27, 2022 at 11:31 PM.
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Old Oct 28, 2022 | 08:47 AM
  #39  
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Never mind.
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Old Oct 28, 2022 | 01:30 PM
  #40  
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Is too little air a bottleneck in the supply of the M113? The airflow changes direction six times, often by 90 degrees. Do you think a seventh change will have a serious impact?
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Old Oct 28, 2022 | 02:10 PM
  #41  
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Is it a bottleneck? Depends....if you're happy with the car as it is then no....if you're seeking more HP then yes I believe so. The more air you can get into the engine the more HP you'll get, especially cooler air. So if you can remove as many restrictions, bottlenecks, or bends then the more power you can potentially make. Manufacturers know this but they also have to contend with making a car quiet, reliable, etcetera. It is why aftermarket air intakes is a billion dollar industry, for the car enthusiasts that want the noise and the power.

Now, If you look at the w220 S500 it has its air inlets without baffles so that it gets ram air from the grille. As does the CLK55 and pretty much every Merc designed after 1996. However, the airbox on top of the engine is also the resonator to keep the noise down. As far as the ram air from the grill, I'm not doing anything Merc engineers aren't already doing but I'm also adding a smooth 1 way airflow for the air directly into the intake manifold with the m113k air boxes.

EDIT: This picture is also a primary example of why it might not be a good idea to remove the baffles if you don't meticulously maintain your vehicles.



Last edited by SLGuy408; Oct 28, 2022 at 02:46 PM.
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Old Oct 29, 2022 | 05:29 AM
  #42  
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Originally Posted by SLGuy408
Is it a bottleneck? Depends....if you're happy with the car as it is then no....if you're seeking more HP then yes I believe so. The more air you can get into the engine the more HP you'll get, especially cooler air.
Mayby a picture will help. The airflow changes direction six times, often by 90 degrees. Do you think a seventh change will have a serious impact?


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Old Oct 29, 2022 | 12:28 PM
  #43  
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Originally Posted by mahunt
The baffles are air dams that pool low(er) temperature air creating a slightly higher ambient air pressure before being sucked into the twin air intakes. The V12 cars have an extra headlight to radiator core support block-off to further increase the outside air pressure.


V12 intake helper.


Cutting out the dual fresh cool(er) factory intake system for a single under the hood intake system is a step backward; otherwise the real tuners (RENNtech, Carlssen, AMG, Brabus, Kleeman, etc.) would have done so.

Fresh, cooler air (in abundance), a resonator delete and attention to the throttle body are the time honored paths to increased performance.
Well I guess we will see. Like I said before it made 20whp, on my 210 E55 over the stock airbox. Next week I will install another tube to collect fresh air from the bumper area directly onto the intake. They also didn’t go with a single intake, because they wanted to keep it traditional I am sure. The air filter sits directly onto the fresh air scoop. It’s getting plenty of air. I will dyno it today made at work maybe.
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Old Oct 29, 2022 | 01:32 PM
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Originally Posted by AndreasHannover
Mayby a picture will help. The airflow changes direction six times, often by 90 degrees. Do you think a seventh change will have a serious impact?
Yes I do. As I said before, if you can remove as many restrictions, bottlenecks, or bends then the more power you can potentially make. There is an entire industry dedicated to doing just that.

Moreover, number 7 (which actually should be #1 as that is the beginning of the path) is a rather big offender in my opinion. It acts as a wall preventing the air from going into the intake, so the engine has to suck the air in through all those bends. When that wall is removed the air is forced into the intake, rammed if you will.

This is backed up by the fact that my SL ran a 14.1 in the 1/4 mile with nothing other than this intake mod and a muffler delete. If I had some traction I would have been into the 13's. Factory stock the SL runs a 14.5 as noted by multiple automotive magazines at the time.

No one is saying you have to do this mod to your car, BUT why not remove the baffles and give it a try for a few days instead of bashing me for doing something new.

Last edited by SLGuy408; Oct 29, 2022 at 01:48 PM.
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Old Oct 29, 2022 | 01:42 PM
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Originally Posted by SLGuy408
Yes I do. As I said before, if you can remove as many restrictions, bottlenecks, or bends then the more power you can potentially make. There is an entire industry dedicated to doing just that.

Moreover, number 7 (which actually should be #1 as that is the beginning of the path) is a rather big offender in my opinion. It acts as a wall preventing the air from going into the intake, so the engine has to suck the air in through all those bends. When that wall is removed the air being forced into the intake, rammed if you will.

This is backed up by the fact that my SL ran a 14.1 in the 1/4 mile with nothing other than this intake mod and a muffler delete. If I had some traction I would have been into the 13's. Factory stock the SL runs a 14.5 as noted by multiple automotive magazines at the time.

No one is saying you have to do this mod to your car, BUT why not give it a try for a few days instead of bashing me for doing something new.

He’s just hating. I’ve dynoed over 30 m113/114k cars. 113k air boxes are known to make power, so is my single intake set up. If brabus, or renntech doesn’t do it, then most Mercedes tan boys think it isn’t cool or doesn’t work. My e55 210 made 370whp. That’s 10 less than a stock 113k E55. Sooooo I might know a little about making power on an NA 113 engine. Just wish these cars had me 2.8 not 2.0
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Old Oct 29, 2022 | 02:00 PM
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Originally Posted by eurochargedw210
He’s just hating. I’ve dynoed over 30 m113/114k cars. 113k air boxes are known to make power, so is my single intake set up. If brabus, or renntech doesn’t do it, then most Mercedes tan boys think it isn’t cool or doesn’t work. My e55 210 made 370whp. That’s 10 less than a stock 113k E55. Sooooo I might know a little about making power on an NA 113 engine. Just wish these cars had me 2.8 not 2.0
Yea, even worse as an r129 most these guys hate anything that isn't 100% stock. Nice, yea I wish it was ME2.8 as well so that I could do a manual swap without having to have to keep the auto shifter in the car.

And actually, I shouldn't have said that I was doing something new. I copied the idea from TechTune and some other forum guys that modded these cars when they were new. That isn't even my car in those pictures lol, that's the forum guy who initially did this mod.
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Old Oct 29, 2022 | 02:10 PM
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Originally Posted by SLGuy408
Yea, even worse as an r129 most these guys hate anything that isn't 100% stock. Nice, yea I wish it was ME2.8 as well so that I could do a manual swap without having to have to keep the auto shifter in the car.

And actually, I shouldn't have said that I was doing something new. I copied the idea from TechTune and some other forum guys that modded these cars when they were new. That isn't even my car in those pictures lol, that's the forum guy who initially did this mod.

Talk to MBswapshop. He can convert your car easily to me2.8 with a harness and a me2.8 ecu
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Old Oct 29, 2022 | 02:21 PM
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Originally Posted by SLGuy408
Yea, even worse as an r129 most these guys hate anything that isn't 100% stock. Nice, yea I wish it was ME2.8 as well so that I could do a manual swap without having to have to keep the auto shifter in the car.

And actually, I shouldn't have said that I was doing something new. I copied the idea from TechTune and some other forum guys that modded these cars when they were new. That isn't even my car in those pictures lol, that's the forum guy who initially did this mod.
Oh yea a lot of them really hate that I modified my 171,000 mile silver arrow lol
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Old Oct 29, 2022 | 02:41 PM
  #49  
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Hate because of a question? Really? Isn't that a bit childish?
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Old Oct 29, 2022 | 02:57 PM
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Originally Posted by AndreasHannover
Hate because of a question? Really? Isn't that a bit childish?
That is true and I was actually just about to say, It is a good thing to have people question and challenge ideas, because if you cannot articulate a defense for your idea then you probably did not know what you were talking about to begin with. And it is how things are improved.

Although, we should also acknowledge that not all questions come from a place of general curiosity.

Not implying that you weren't being genuine in your question btw.

Last edited by SLGuy408; Oct 29, 2022 at 03:06 PM.
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