kiki5

What are the maximum rpm generated with street large port?

RGHTBrainDesign

Until the power falls off, then add boost. 8500 RPM is a good spot.

kiki5

Thank you so much for everything.

rx72c

iTrader: (8)

Why would you add boost when an engine is no longer efficient?

RGHTBrainDesign

To carry the powerband when the engine builder chose the wrong turbo for the customer's goals or doesn't understand tuning properly.

TwinCharged RX7

iTrader: (14)

Yes. If power falls off before redline, if at safe boost levels, increase boost to hold power flat or keep it increasing. That's better than shifting prematurely if in a racing environment.

If a dyno queen then it doesn't matter as all you would care about is peak power, regardless of whether it falls off before redline.

BLUE TII

iTrader: (9)

I actually found power goes up when you decrease boost toward redline (Decreases backpressure and so exhaust dillution).

But then maybe you werent assuming maxing out the boost the turbo can provide in the midrange .

WANKfactor

iTrader: (1)

7800-8200 is probably a good place to have your rev-cut for longevity's sake.

TwinCharged RX7

iTrader: (14)

Good point. Based on what I see in most dyno charts, my thinking was most people don't max out the turbo (e.g. they have boost at 15psi but could tune it to 20). Of course, this is assuming the turbo is big enough to not run out of breath at 15-20 psi.

RGHTBrainDesign

x3. Damn right, Gents! For the masses however, they'll be detonation restricted by fuel quality, not maxing a turbo. Hehehe

Shainiac

iTrader: (7)

My Pineapple Racing "Large" template TII engine made peak TQ at 6500, peak HP at 7500 and I shifted it at 8500. With an EFR 9180, it was basically never out of the power band.