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Tuning over sized throttle body

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So i made the mistake of oversizing my throttle body it is 75mm on a turbo vr6 short running intake stock was 68 or less. I,m not sure yet if the only down side of it is barely cracking the throttle for cruse but that's what i notice most so far. the question i have is can having the wrong size affect what would be consider a normal load verse rpm flow on the ve table... it seem like i cant quit find the right transition into cruse with my resolution.... I hope i'm explaining this clearly maybe i need to just do some left foot tuning but it just seems weird

Thank you in advance!

I think that you might have to alter your accel enrichment settings, as the airflow on low throttle openings will differ a lot compared to your old TB.

If you're mapping the fuel/ignition with MAP as the load axis then the larger throttle body should have no real impact on what load point you're accessing at cruise for example. What you will find (and it sounds like you've figured this out already) is that you're going to need less throttle opening to get there. This can make the throttle response feel touchy and make the car harder to drive smoothly. For your application I wouldn't call a 75 mm TB overly large though so I doubt you're likely to have any real trouble. It may just take a little time to get used to the feel of driving with this throttle body.

If it was a dbw throttle body then you can correct this effect by adjusting the throttle plate vs throttle pedal target table but with a manual throttle body this is much harder.

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