Question for memcal tuners - exhaust related

[Bizmark]

Firstly, apologies if this is a dumb question.

On a mildly worked V6 (In my case a VR auto V6 with interference headers, 2.5" catback, removed bellmouth, MACE CAI and may see a 70mm TB and high ratio roller rockers in future) with a memcal tune with the exhaust size factored in what would be better out of a standard 2 1/4" pipe and a run of the mill 2.5" aftermarket catback.

A: For street application, high low down torque for increased fuel economy in everyday driving (with a light right foot)?

B: For the faster 0 - 100 time?

I'm thinking about orientating my car toward power and fuel economy rather than making noise.

 

[The1]

exhaust wont change much really, just give you breathing space for bigger mods to push more through, it does let the stock setup breath more but nothing really other than seat of the pants. Go with extractors and 2.5 cat back which is most common and is the cheapest best performing. Rockers will give more with extractors and exhaust, get a tune once you get all those done, all up then should make a noticeable gain, fuel economy is mainly dictated by right foot, even v8's can get good fuel when right foot is controlled.

 

[Bizmark]

The car already has extractors (interference) and a 2.5" catback. Going too large an exhaust will diminish exhaust gas velocity, which in turn will reduce power and torque. The idea is to have the exhaust small enough to get good exhaust gas velocity, but not so small that it becomes a major restriction. Some have stated that a 2.5" catback is generally too big for a mild commodore V6 but that was without a memcal tune. Would a memcal tune address this issue by increasing airflow enough so that it would outperform a 2.25" catback in every way

So is it 2.25" catback with stock rockers, 2.5" catback with high ratio rockers for best peformance?

 

[The1]

should be fine with what you have already, do ya mods and get a tune

 

[Not_An_Abba_Fan]

A tune won't make the engine get any better air flow.

The best exhaust for the stock displacement V6 is the standard 2 1/4" with straight through mufflers. 2 1/2" is too big, tuned or not.

 

[Bizmark]

A tune won't make the engine get any better air flow.

The best exhaust for the stock displacement V6 is the standard 2 1/4" with straight through mufflers. 2 1/2" is too big, tuned or not.

How about if high ratio rockers and a larger throttle body were installed? These would increase airflow into the engine somewhat i believe