turbo boost pressures

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Oct 24, 2017 | 10:24 AM

6point7

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turbo boost pressures

have a 2011 350 4X4, at 65 in 5th gear runs 2000 rpm, when going up grades or fighting crazy Kansas wind with 15000 lb 18ft cargo trailer, boost guage stays on 30 psi, shouldn't it downshift to 4th to put less stress non crank and rod bearings?

Oct 24, 2017 | 10:57 AM

Braggs

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Nope. Torque is flat between 1800 and 2600 RPMs. It wouldn't have anything to gain by shifting down as torque is what you need for force to the ground. Now if you're in a gasser, it's a different story as torque continues to increase with RPMs. I suppose you could argue the lower gear could help the engine to increase speed better (and it would if you applied more pedal), but just to hold speed, nah. Here's a couple images from another forum:

http://www.powerstrokehub.com/img/fi...-hp-torque.jpg
http://www.powerstrokehub.com/img/fi...utput-2015.jpg

Oct 24, 2017 | 11:31 PM

GregWork

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Are you running a tune?

Factory maxes out at about 20 PSI

30 PSI will likely ruin your ceramic bearings

Oct 25, 2017 | 09:14 AM

rob17

More Turbo

Joined: Feb 2005

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From: Graham, WA

Quote:

Originally Posted by GregWork

Are you running a tune?

Factory maxes out at about 20 PSI

I was wondering the same thing. The max I've seen is just touching 20 PSI.

Rob

Oct 29, 2017 | 08:13 AM

BCooke

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If you are between 1600 and 2800 you are good. Torque is flat and the HP is linear. 1600 and 2800 are basically the roll-off points, both high and low.
I like to keep it between 2000 and 2600. That gives me some time for manual override if I want. We generally travel the same roads and knowing the locations the engine loads up I can force a downshift early to keep the power level up.

Oct 30, 2017 | 10:13 AM

6point7

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high boost, low rpm loads

I have plenty of boost to tow, my concern is rod bearing loading and side force of piston on cylinder walls. Would it be better on engine to go 2500-2600 rpm 22lbs boost or 2000rpm at 30 psi? Truck has 102k, egr,dpf and cat delete with "stock" tune on HR XRT Pro tuner.

Oct 30, 2017 | 06:23 PM

RedRage

Tuned

Joined: Apr 2004

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From: Calhan, CO

Pulses

I think your talking about the torque produced divided by the number of power pulses. In that sense you are correct. By upshifting, the engine would spin faster and each power pulse would be less if the total amount of power being produced remained constant.