Bigger throttle body - 986 Forum - The Community for Porsche Boxster & Cayman Owners

blinkwatt · 09-18-2007, 03:50 PM

I was thinking about putting the non e-gas 3.4L throttle body on my 2.5L.
Does anyone know the specs of how big the butterfly is on the 2.5L compared to the 3.4L body? I was told that the intermediate shaft(plastic piece between the intakes,connected to the throttle body) is the same from 986-996,so that means it will mount up on one side.

Are there any adverse affects to a larger throttle body?

Does anyone have pics of the two compared side-by-side?

I'm guessing since the throttle body opening will be bigger I will have change out my intake tube to a silicone hose or something else,I just can't use what I have now?

tholyoak · 09-18-2007, 05:02 PM

The OD of the throttle body is the same on both. The 2.5L one tapers down and uses a smaller butterfly.

I really doubt that you would see much gain with a larger TB, but everyone thinks bolting different stuff on makes improvements, so to each their own.

Todd

09-18-2007, 05:37 PM

Your right, just updating the throttle body wouldnt do much good, unless it was the source of restriction. So unless youve got headers, air intake, exhaust, supercharger, ect... and you cant get anymore air into the engine, then this would help. But other than maybe losing power (decreased air velocity) it may help with throttle response (mainly because youd be putting in a completely clean unit).

blinkwatt · 09-18-2007, 06:37 PM

Thanks Todd,I appreciate the pics.

Tool Pants · 09-19-2007, 08:14 AM

Todd, what throttle bodies are in the picture. Both look like cable operated.

chaudanova · 09-19-2007, 10:33 AM

Quote:

Originally Posted by Tool Pants

Todd, what throttle bodies are in the picture. Both look like cable operated.

TP, looks like the top one is from a 2.5 97-99 boxster, and the bottom one is from a 99 3.4L 996. Hopefully Todd can chime in...

tholyoak · 09-19-2007, 03:26 PM

Tool Pants,

Bottom one is a '98 Boxster, top is a '99 C2 996 (only 996 with a cable TB).
Bottom one tapers down to a smaller butterfly, 996 one doesn't taper, sort of hard to see in the pic but the 996 butterfly is a fair bit larger, I guess I could measure them if someone really wanted to know.

Todd

szentej · 09-19-2007, 04:30 PM

If the specs of those Throttle bodies are different, wouldn't they have different part numbers?
John

tholyoak · 09-19-2007, 04:35 PM

They do
996 110 025 08 (boxster)
996 110 065 53 (996)

The cross plenum they mount to is the same part.

Todd

Tool Pants · 09-19-2007, 05:10 PM

The only Porsche part numbers I see in the picture is 996 606 160 01 on the sticker on the idle speed adjuster valve. Same part number on both because it is not the throttle body part number. Per PET that same valve is used on the 986 and 996 cable throttle body.

But PET may be a bit screwed up.