Intake tubing size

[4OfaKind]

How would you determine the size of intake tubing you would run from intercooler to intake manifold? Is it TB size? If so, how do you determine TB size? Or is it IC outlet size?

400ci LS motor running two 60-1 turbos on a carb manifold w/ intake elbow and LS2 Drive-By-Wire TB

Do I use a 70-ish mm TB , or 90-ish mm TB? How big is too big?
What size intake tube from 2" - 4" or more would be good?

Will drive mainly on the street with some weekend track time.

Thanks

Mal

[camcojb]

Originally Posted by 4OfaKind

How would you determine the size of intake tubing you would run from intercooler to intake manifold? Is it TB size? If so, how do you determine TB size? Or is it IC outlet size?

400ci LS motor running two 60-1 turbos on a carb manifold w/ intake elbow and LS2 Drive-By-Wire TB

Do I use a 70-ish mm TB , or 90-ish mm TB? How big is too big?
What size intake tube from 2" - 4" or more would be good?

Will drive mainly on the street with some weekend track time.

Thanks

Mal

throttle body size and tubing size on the pressure side is not as critical as the inlet tubing and filters to the turbos, or as critical as a naturally aspirated setup.

I am running a 75 mm throttle body on my twin turbo LS2 because I made well over 1000 hp with that size before on another car. I have a single 3.5" inlet planned because that's the od of the tb inlet and also the outlet size of the intercooler. The lines from the turbos to the intercooler are going to be the same as the turbo outlets.

Jody

[4OfaKind]

Thanks for the info Jody. I figured it might not be important but I was not sure. I needed to know so I could plan which tubing to order.

I used a measurement conversion website and they said 90 mm converted to 3.5". 78 mm converted to 3.0". What am I misunderstanding here?

Mal