TBH, a 408 with a big single and a 16.5:1 CR I would expect more horsepower

Things gonna be a riot!

 

yeah, something to do with a 1000lb hunk of cast iron not appreciating high-speed rotation for some odd reason

 

I am no diesel expert, I bought a 6.0 PSD after all; but my understanding about the RPM thing isnt heavy internals or lack of valve control (lots of reasons Ive seen claimed in the past) Its really that the harmonics of high RPM diesel ignition can tear the motor apart. When you watch them spin to the moon on a runaway, you never see them float a valve or drop a valve; they spin and spin and spin and spin until a rod comes out the side of the block. A common rail can probably even keep up with the fueling requirement; but I could see a mechanical or HEUI falling short on the delivery if RPM was too high

Anyway, thats my take on it. My van redlines ~3500. Good enough for what I do with her. No room for twins either lol

 

the powerstrokes & duramaxes definitely don't leave much room under the hood with the valley turbo - the inline cummins, however, has space for days. just gotta bend an a/c line & relocate the coolant reservoir before parking the atmosphere right over top of the stocker.

 

reckon it woulda been nice if i threw up a picture.


tuning's been slow but steady since November for a daily economy file, tow file, and "max" effort file (dumping boost above 40psi to be safe on stock head bolts).
i ended up with a Valair quiet dual disk that's solidly held about 1350lb indicated torque (nice improvement considering stock gave up the ghost at 690+). gear roll-over's been a bit ridiculous.

also hit 75k mi the other day & decided to swap out a bunch of fluids while i was changing the fuel filters. ended up with some RedLine 75w-90 GL-5 in both diffs (and f*@# Fiat for being too cheap to install drain plugs in the pumpkins!), RedLine MT90 GL-4 in the trans (1qt over-fill through the shift tower) - which almost eliminated the gear roll-over racket, and finally, fresh ATF+4 in the t-case.

just gotta do a few confirmatory datalogs with the new tunes to be squared away. one gay thing about the MM3 controller, though, is that it only records one .csv file at a time & will save over the file if you try to do multiple logs in a row... meaning you have to take a laptop with you & transfer the file from the micro SD before recording another.

 

That looks nice! You gonna run it on a dyno or track? Does the clutch actually hold like it’s supposed to? Does it roll coal?

that’s pretty dumb about the MM3 only holding one file, someone should be slapped for that.

 

might dyno if Rapid Diesel has a day pop up, but ain't no reason to try & hotrod it down an 1/8th. it's a G56 - not a T56; big difference.
tune's real clean & i ain't noticed no smoke... but then again, all the WOT pulls i've made/logged have been at night (at least on the power tune).
as for the MM3 logs: the high-speed recorder creates sequentially-numbered .dlg files, but the regular mode that saves a .csv from the active gauge setup only writes one file name for some stupid reason.

 

Well does it blow the tires off in 4th on the highway?

 

Nice install, I bet it rips. Your right about the Duramax, we have zero room for twins. Have to relocate a lot to accomplish 2 turbos. Did you install a muffler or resonator to bring down the noise? I have had a bunch of modified diesels but they were all loud af. I can't live like that again, I've got to figure out how to keep my 16 quiet and sounding tame while still packing a punch.

 

the car does
this one will burn 3rd... with an 80lb-ea 35" wheel/tire setup

both vehicles have 3.42s

https://www.performancetrucks.net/fo...roblem-557678/
the 475 technically also muffles it a little, too... but then adds some whistly/wooshy noises

there were a couple compound kits i'd checked out years ago with the lemon LLY... but the truck didn't run long enough for me to try anything on. it was definitely tight in there & required moving the passenger battery to the frame rail.