Originally Posted By: Mean buzzen half dozen A.K.A. Hank
efi-diy,
these figures are just on an engine dyno correct?

Definetly sounds like the TB is too small for NA mode. Got some pics of your custom intake maifold?

BTW,what size is the stock TB ?

I thought you had some figures w/the turbo also???

Keep it going!!

MBHD


75mm >>> TB

Engine >> correct so this is at the flywheel.

Testing was done with the stock intake, exhaust manifolds and TB size.

Once the turbo is added the TB is fine.

51 GMC 4.2 turbo
Can't solved today's problems using the same technology/thinking that created them