duff0000

I know several of the guys on here have ported their intake manifold TB opening up to have it work better with a larger TB. What's the biggest you can port it to before you break into the coolant chambers in the manifold

TIA

Sideways

Beyond 66 mm or so and you need to weld it.

PeanutButter

TB opening does not have coolant passages, mine is opened up to 75MM as I have a 75MM TB

Asura

At 74mm there is a section where the metal gets very thin and it should be welded then hand finished.

PeanutButter

Exactly what was done to mine

HMFIC

SIDEWAYS.........dood....i was like 234 WHP at 16 PSI?!?! iwas like HUH?...then i read PER LITRE..........i was like.. hahahahaha damn are you built or anything? or is your engine stock?

duff0000

Anyways, Sideways says 66 and other people say 70+ I would like to port mine to 68-70. I would just be giving it to a machine shop and tell them to port it. I just dont want to tell them to port it to 68mm and have them go into the coolant chambers, or have it so thin that it breaks open over time.

Can I get some kind of conformation that 68mm is not going to go into the coolant chambers?

PeanutButter

What the hell coolant chambers are you talking about?

Sideways

The chamber is the idle bypass system.

duff0000

^ Thanks for clearing that up Phil.