74mm TB shaft grinded to 5mm complement of Exotic_Metal55
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2003 W211 E55, 2003 W220 S600
74mm TB shaft grinded to 5mm complement of Exotic_Metal55
Exotic_metal55 was kind enough to grind the stock 9mm shaft in my 74mm TB to 5mm.
Here are the calculation courtesy of Exotic_metal55
74 mm = 2.9314 dia. = 6.749 sq. in. 9 mm (.3543 dia) shaft x 2.931" long = 1.0385 sq. in. 5mm (.1969 dia) x 2.931 = .577 So 6.749 - the difference in a 9 mm and 5 mm shaft is .4615 sq. in. Equivalent flow area = 6.2875 sq. in = 2.8294 dia. = 71.866 mm.
78 mm = 3.0709 dia = 7.4065 sq. in. - 9 mm (.3543 dia) x 78 mm (3.0709) long = 1.088 sq. in. = 6.3185 sq. in. = 72.044 mm equivalent.
Math can't lie.
Considering this is a relatively cheap/free mod, the benefits were incredible.
Right of the bat the throttle is much more responsive in terms of power the car feels a lot stronger at WOT. In a few weeks i will dyno the car and let you all know the outcome. My butt dyno definitely tells me i have gain a few hp (for free).
Once again thank you Exotic_metal55. It is because of member like him the automotive enthusiast community / forums are an interesting place.
Here are the calculation courtesy of Exotic_metal55
74 mm = 2.9314 dia. = 6.749 sq. in. 9 mm (.3543 dia) shaft x 2.931" long = 1.0385 sq. in. 5mm (.1969 dia) x 2.931 = .577 So 6.749 - the difference in a 9 mm and 5 mm shaft is .4615 sq. in. Equivalent flow area = 6.2875 sq. in = 2.8294 dia. = 71.866 mm.
78 mm = 3.0709 dia = 7.4065 sq. in. - 9 mm (.3543 dia) x 78 mm (3.0709) long = 1.088 sq. in. = 6.3185 sq. in. = 72.044 mm equivalent.
Math can't lie.
Considering this is a relatively cheap/free mod, the benefits were incredible.
Right of the bat the throttle is much more responsive in terms of power the car feels a lot stronger at WOT. In a few weeks i will dyno the car and let you all know the outcome. My butt dyno definitely tells me i have gain a few hp (for free).
Once again thank you Exotic_metal55. It is because of member like him the automotive enthusiast community / forums are an interesting place.
#2
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Thats so cool! I'm totaly love finding diy mods that work! Supercharged cars are very picky when it comes to inlet restriction. Time to apply this to my 82mm TB
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As you can see from the math, the potential flow area can equal an 80mm TB for pennies on the dollar.. Even with area being near equal, it is still possible for the 74mm to still out flow an 80mm but only a true flow test will verify this..
how come there is no throttle anything on the v12's? I have to assume there is some room for improvement
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E63 Biturbo, UPD Cold Air induction kit, UPD performance crank pulley and UPD adjustable rear suspension with ride height adjustment.
CL55 UPD Cold Air Boost kit, UPD 3000 stall converter, UPD 77mm SC clutched pulley and beltwrap kit, Custom long tubes, UPD crank pulley , UPD suspension kit, UPD SC pulley, Aux. HE, Trunk tank w/rule 2000 pump, Mezeire pump, UPD 5pc idler set, Aluminum rotor hats.
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2005 SL600, 2016 ES300h, 2012 Hayabusa
how hard is it to take apart the throttle body? I have a friend looking at getting some parts designed and fabbed up and could make some form of diy kit that would flow better
#13
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The TB shaft blocks close to 20% of the flow, so that is all that is ground and polished.. It is the easisest way to get the flow of the 80mm or more.. Nothing comes apart, just need a good air grinder, burring bit and 3/4 dia. sand wheel bit.
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E63 Biturbo, UPD Cold Air induction kit, UPD performance crank pulley and UPD adjustable rear suspension with ride height adjustment.
CL55 UPD Cold Air Boost kit, UPD 3000 stall converter, UPD 77mm SC clutched pulley and beltwrap kit, Custom long tubes, UPD crank pulley , UPD suspension kit, UPD SC pulley, Aux. HE, Trunk tank w/rule 2000 pump, Mezeire pump, UPD 5pc idler set, Aluminum rotor hats.
www.ultimatepd.com
instagram @ultimate_pd
facebook.com/ultimatepd
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E63 Biturbo, UPD Cold Air induction kit, UPD performance crank pulley and UPD adjustable rear suspension with ride height adjustment.
CL55 UPD Cold Air Boost kit, UPD 3000 stall converter, UPD 77mm SC clutched pulley and beltwrap kit, Custom long tubes, UPD crank pulley , UPD suspension kit, UPD SC pulley, Aux. HE, Trunk tank w/rule 2000 pump, Mezeire pump, UPD 5pc idler set, Aluminum rotor hats.
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instagram @ultimate_pd
facebook.com/ultimatepd
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SL55 AMG
Only some of the 03 TB`s could be taken apart and all the rest are epoxied together.. Trying to port the ID of these fly by wire TB`s is very tricky and fail rate high.. Idle issues are a big problem with the ID port.. Stick to the shaft reduction and you will get easy safe flow gains..
The TB shaft blocks close to 20% of the flow, so that is all that is ground and polished.. It is the easisest way to get the flow of the 80mm or more.. Nothing comes apart, just need a good air grinder, burring bit and 3/4 dia. sand wheel bit.
The TB shaft blocks close to 20% of the flow, so that is all that is ground and polished.. It is the easisest way to get the flow of the 80mm or more.. Nothing comes apart, just need a good air grinder, burring bit and 3/4 dia. sand wheel bit.
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E63 Biturbo, UPD Cold Air induction kit, UPD performance crank pulley and UPD adjustable rear suspension with ride height adjustment.
CL55 UPD Cold Air Boost kit, UPD 3000 stall converter, UPD 77mm SC clutched pulley and beltwrap kit, Custom long tubes, UPD crank pulley , UPD suspension kit, UPD SC pulley, Aux. HE, Trunk tank w/rule 2000 pump, Mezeire pump, UPD 5pc idler set, Aluminum rotor hats.
www.ultimatepd.com
instagram @ultimate_pd
facebook.com/ultimatepd
![](https://mbworld.org/forums/signaturepics/sigpic87171_15.gif)
E63 Biturbo, UPD Cold Air induction kit, UPD performance crank pulley and UPD adjustable rear suspension with ride height adjustment.
CL55 UPD Cold Air Boost kit, UPD 3000 stall converter, UPD 77mm SC clutched pulley and beltwrap kit, Custom long tubes, UPD crank pulley , UPD suspension kit, UPD SC pulley, Aux. HE, Trunk tank w/rule 2000 pump, Mezeire pump, UPD 5pc idler set, Aluminum rotor hats.
www.ultimatepd.com
instagram @ultimate_pd
facebook.com/ultimatepd
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SL55 AMG
bro we may have to figure out how to do this...maybe talk to your guys that did the adapter plate/inlet job on the TB kits...I'd like to get a precision job done, do it once and do it right,,,that way when it's in you can forget about it!
#19
Very interested in this, especially since Im looking at spending over $2k for an 82mm throttle body, and if this is pretty close, I would love to know if there is anyone in my area that would do this type of mod.
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2003 porsche 996 turbo
if your talking about enlarging the body of the t/b maxbore does this. they can bore the 74 body to 77 mm and install a new butterfly and gasket match for 125$ shipped. if your talking about grinding the butterfly to a knife edge many on the srt-6 forum do this to the leading edge to improve airflow.
remember grinding the shaft down may weaken the mounting points. allowing it to crack and break. dont go to far!!
remember grinding the shaft down may weaken the mounting points. allowing it to crack and break. dont go to far!!
Last edited by 320 dreamer; 01-31-2010 at 09:25 AM.
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2003 W211 E55, 2003 W220 S600
After doing this mod and switching to a 180mm for a 175 I put the car on the dyno I gained 18rwhp and 38 rwtq. The tq gains were in the 3000 rpm range