Up sizing throttle body - Re tune?

[jeffreyk]

Hi,

I hope the more technical people in the forum can help me out... I think I know the answer but I need to confirm...

So I have an APR Ultracharger and dual pulleys installed on my car with the appropriate APR II+ tune.

The throttle body is giving me grief and I need to replace it. See my other thread. https://www.audizine.com/forum/showthread.php/848513-Can-you-identify-the-APR-Ultracharger-Throttle-Body

If I swap my 80mm APR throttle body for a 'ported' or 'bored' 85mm throttled body, which flows more air per same amount of throttle position, would it required a re-tune?

I think the answer is yes.

My thinking is: The ECU should base the fuelling and timing and based on the throttle position right, manifold air pressure and temp? We don't have a MAF to tell the ECU air going in right?

OR..... can the computer sort this out based on the O2 sensors? or other sensors?

Who does custom tunes for things like this?


Thanks

Jeff

[BlueSteW8]

If I were in your position, I would try to get the car running right before trying a larger TB.
That being said, I believe you shouldn't need a retune on the APR UC file.
Is there an APR dealer close by?
Maybe start there.

[jeffreyk]

If I were in your position, I would try to get the car running right before trying a larger TB.
That being said, I believe you shouldn't need a retune on the APR UC file.
Is there an APR dealer close by?
Maybe start there.

Yes... probably wise words. I will make it run first.

It’s always so tempting to ‘upgrade’ if at all possible. Lol.

I contact APR and they asked me to double check the wiring harness. I will do that tonight.

Jeff

[englishbay]

Does anyone know what's expected if you do swap the APR Ultracharger throttle body to a larger one? There are lots of threads on doing this but little on what the impact is with just this change alone will do.