Hello everyone

Is it possible/likely for a fullyengine upgraded car (short of engine rebuild, but everything else, with 65mm vtg's, etc) to produce greater hp/tq by just going from a 82mm plenum to a 74mm?

What am i missing?

 

74mm TB ( stock 997tt TB ) is fine for 1100-1200whp engine setup

 

Really???

 

Yup! To make power you need to get in more air, which is a simple concept, however, air acts very funny at high speeds and the path for the air has to be designed and tuned very specifically for certain flow rates. Because of that, in certain situations the tune is better with a smaller diameter where you get the accelerate the air (the velocity stack concept).

To that end, take a look at the stock air filter housing, which is designed to work as an accelerator and a velocity stack working in conjunction with the throttle body. The stock airbox is designed for about 1,000 hp.

Cheers.

 

I was considering going from 74mm to 82mm haha. You are doing the opposite?!?!?

 

Yep. Both stock plenum and TB should be fine.
Stay away from 82mm TB..No real gain

What is your current mods?

 

Well, i just went from 82mm to 74mm and FEEL a very significant gain, I'd say 50ft, 30hp if not greater!
My configuration is fully upgraded including 65mm vtg's, airbox is stock and internals unchanged.
I could not believe what I was experiencing.
Thank you all.

I learn something new everyday!