Is there a huge difference in air being moved by the motor out the exhaust at WOT between say 1,2,3 gear compared to 4th & 5th?

I assume the difference is significant enough that if there was a restriction of some sort that the car would behave fine in the lower gears at WOT but when at hwy speeds rolling into would be when you encounter the issue, is this correct?

 

Can you be a little more clear on what the issue is you are seeing?

 

Airflow is dependent on RPM, not car speed. You could be heat soaking your intercooler though by staying in it longer and seeing the loss in power there.

 

^^ as stated rpm dependent-- if you were NA it would be where your cams kick in and then stop pulling--if you have built the car correctly, your turbo will operate in the same rpm range and make this simple---thats not to say that the higher the rpm the more VE either--watch your torque curve.

 

I'll look on the drive home while in the gears I mentioned and see where the issues arises. But I suppose one ask is the volume of air flow different in third gear say @ 5000 rpm's versus 5th gear @ 5000?

 

No its exactly the same---think about it, nothing changed in the motor. Gears outside the motor changed but they have nothing to do with VE.

 

^^^ This

If you're having a problem it would be best/easier to just explain your symptoms rather then ask for information.

 

Volumetric efficiency(VE) on a normally aspirated engine is 100% or less. Volumetric efficiency on a forced induction motor is 100% or more. VE varies dependant on barometric pressure/altitude, temperature, and humidity.

 

Are you seeing the same boost in third as you are in fifth?

 

Look at the big picture. At a given RPM, a higher gear will have you traveling faster and the frontal air pressure at higher speed should help with cooling, evacuate heated air from the engine bay though the body vents, allow for reduced intake air temperature, and increased intercooler effectiveness.