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Discussion Starter #1
Throttle body on the SLK55 seems small vs other NA motors iand I didn't see a direct bolt on replace(might have missed it) so I had a M113 TB sitting at my house that I had ordered for another car. Decided to port it and skinny down the throttle shafts.

End results is right 76MM leaving a "no go" zone where I didn't port to allow the TB To seal.



Rainy morning in Chicago so I thought why not
 

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Discussion Starter #3
Took the car out, no issues, no idle changes, would like to go with a bigger TB... Intake opening may be a restriction, would be curious if anyone has gone bigger
 

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Registered 05 SLK55 & 06 Kleemann 55K S8
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For performance mods I end up looking at what the C55 and E55 guys are doing. They seem to be the most power hungry. I have seen TB upgrades that they do, I think up to a 85mm, but don't quote me on that.
 

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Discussion Starter #5
I think the intake manifold is 74mm or so.... car definitely needs an bigger TB I was reading MAP KPA readings in the mid 90s so a significant restriction there....
 

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Registered 2005 SLK55 AMG
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Don't want to be a party pooper but it seems to me that on the 171 55's it's the extraction that is holding things up. No matter what we do to the induction, the headers will let us down!

Maya ~ Tapatalk
 

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Registered 05 SLK55 & 06 Kleemann 55K S8
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I looked last night and the E55 guys making big power are only getting 25whp from a 82mm TB, so a NA car is not going to see much at all, maybe 5.
 

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It's no secret that Merc knew what they had with the SKL55. 0-60 was already .2 quicker than the supercharged SL55. So it wouldn't surprise me if they purposely decided to tone it back to avoid eclipsing the SL. IMHO that's why we never saw a SLK63.

Back when I was toying with the idea of going with a Kleeman s/c they told me that if I didn't choose the s/c route, instead of upgrading the intake side, the best gains for the $$ was not just headers, but a full exhaust replacement. As for me, I got to the headers (and also thermotech wrapped them) but am still running the rest OE.

They also said with the s/c, just installing headers and leaving the stock exhaust would super restrict results. I cant imagine how big JB's smile would be with a new exhaust system then...

Throttle body on the SLK55 seems small vs other NA motors iand I didn't see a direct bolt on replace(might have missed it) so I had a M113 TB sitting at my house that I had ordered for another car. Decided to port it and skinny down the throttle shafts.
Since you'd also be changing the MAF sensor to match the new throttle body diameter, would you be using someone's dyno to recurve the ECU's A/F ratio's after installing?
 

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Registered 05 SLK55 & 06 Kleemann 55K S8
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They also said with the s/c, just installing headers and leaving the stock exhaust would super restrict results. I cant imagine how big JB's smile would be with a new exhaust system then...
His smile would probably be as big as mine :D

Yes, the biggest restriction on the 55 is the exhaust side. Without upgrading that first your intake side gains will be minimal.
 

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Discussion Starter #11
I took the TB out last weekend and actually knife edged the front/back of the plate so that there is no thick surface when its open at full throttle...... TB plate still seals it just no longer has a flat edge.
 

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Registered 05 SLK55 & 06 Kleemann 55K S8
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The E55 guys have now figured out that a stock Hellcat TB fits with minimal modifications, it is a 90mm.
 

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Discussion Starter #13
Our intake opening is pretty small, you could buy an 80MM adapter and port the intake, the benefit of reducing the blade and shaft is that you can make this TB flow like a larger one
 
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