skunk vs type r intake manifold.

[shiroitenshi]

isn't different size of throttle body or runner will effect the flow velocity?

Yes, siputmagic, in the carburetor days, it does affect flow velocity, due to the venturi effect in the carb intake opening, but with new intake manifold designs, it seems that the venturi effect is determined by the runners leading down to the combustion chamber.

I'm not sure if any book/technical paper discusses this topic specifically, but if I remember right, venturi effects work best in a straight path, which isn't the case with these intake design.

So, in my thinking, the runners play a bigger part than the TB in this case, and using bigger TB usually means you'll hit peak flow at lesser throttle angle, like if the stock one gets peak flow at around 80% throttle with the 70mm, then with a 90mm, it'll be earlier, possibly at 60% throttle. Since ultimately limited by runner size, running bigger TB simply means it will only consume as much air as the engine can suck, unlike boosting, where air is forced in, hence any bottlenecks is a restriction.

 

[rossi46]

so finaly whic the best...?
if for B18-R engine whic batter? Skunk 2 or ori ITR?

Bump: so finaly whic the best...?
if for B18-R engine whic batter? Skunk 2 or ori ITR?

 

[kelflee]

For a stock ITR, will changing only TB (S2 70mm) makes any difference? :hmmmm:

 

[AD_EG]

For a stock ITR, will changing only TB (S2 70mm) makes any difference? :hmmmm:

it will not be a good idea.

if your intake opening is not port matched to the bigger TB, most likely is to cause loss of power and not gains.due to the step effect.

if you plan to port match the ITR intake...it only can be maxed out at 68mm. if you install a 70mm TB on 68mm intake, it will also cause step effect...the air that flows through the 70mm TB hits the remaining 2mm intake which is obstructing the path for the air to go.

in short, changing your TB to 70mm on your stock intake will cause loss of power and not gain.

 

[super fei lo]

bravo bravo

it will not be a good idea.

if your intake opening is the same installing a bigger TB with the same opening most likely is to cause loss of power and not gains.due to the step effect.

if you plan to port match the ITR intake...it only can be maxed out at 68mm. if you install a 70mm TB on 68mm intake, it will also cause step effect...the air that flows through the 70mm TB hits the remaining 2mm intake which is obstructing the path for the air to go.

in short, changing your TB to 70mm on your stock intake will cause loss of power and not gain.