12.7 Detroit need a new turbo (upgrade?), hauling light and best mpg?

true that. i am 100% positive that about 95% of trucks wont properly use a 171702 turbo. they are better off witg a turbo size of the k31. of course there are better turbos out there like the variablr geometrys but you cant veat price and complexity . as owner operators we need less to make more. the amount of money needed to have or replace a variable geometry turbo is the same as 4 k31s. performance wise its barely noticeable. those o/o pushing 600+ the 171702 woulds be a lovely add but if you arr not a speed/power junkie is just a waste of turbo , money, performance and flexibility because you cant do stop and go aplications

 

hi ! just a quick follow up after pulling flatbed for some weeks:
Running stock 500 /171702 1.45 ar/full tilt manifold.
truck runs like a detroit, slow to pick up speed, decent power when 1.500 rpm+, pyro rarely touches 900F, max boost around 27 PSI
It really needs a tune to be ok/drivable .
i have 2 friends that went to CT and got a " progressive" tuning 580/1900tq from leon, along with the turbo(1.32) and manifold he sells.Their trucks can cross PA with 45k on the trailer with almost no shifts at all and good mileage but, as you noted, they must be always on higher rpms 's.I will drive one of these trucks this weekend to see how this tuning performs. Maybe after a tuning i will change my mind but , so far, i hate the guts (or the lack of it) of this engine .

 

I finally sent out my ecm to Fernando at DCS and will be testing his 550hp tune with k31 turbo when it comes back

 

He is changing the ecm battery now and cleaning it up. There was some oil inside, I blame it on the diamond seal leak. Gotta get to that sometime soon

 

swap your turbo to a k31 and you wont have to tune it

 

What would be wrong with the Borg warner 171701 1.32AR in this case ?

 

i think the 171701 is the same size as the k31 but withiut the wastegate. maybe a tiny bit bigger

 

171701 has no wastegate. It's a 71mm version of the 171702.

 

If your only making 27 psi boost you don't need a 1.45 housing.

Get a good tune and put a 1.32 housing on your 171702. You will be happy.

The only time you need to step up to a 1.45 when you have enough fuel to push 45 psi boost. Then and only then you might want to go to a bigger housing to slow the shaft speed down and lessen the restriction.

The 171702 is efficient up to about 44 psi.
Put a tune in it that has enough fuel to give you 40-45 psi boost and you'll be happy.

I've never had or tried a K31 but sounds like a great option also according to some educated people on this board.

 

the k31 is great. im doing around 7.4 mpg dry van at 68 mph weight between 20 to 35k