PappyDan

iTrader: (4)

it just does not look right does it.
a 6.0 needing so much work to make just 400 hp,
and a LS6 5.7 with 243 heads and the 02 camshaft
with a factory tune will put out 405 hp @ the crank.
take it to a tuner and he may squeeze out another 35 hp
and bring it up around 440 hp

InchUp

iTrader: (2)

It sucks for us truck-going fellas. Looking for low end horsepower and fat torque curves basically limits us to longer crankshafts, bigger bores or blowers. All the cars have to do is rev higher. Bastards!

As for Kerr and his Suburban, you'd be impressed what a 408 can do for you. 4.030" bore, 4" crank, stock 317 heads and 1-3/4" long tubes. The camshaft would be something like a 212/218 0.522/0.529 114 LSA and it would make in the neighborhood of 500lb-ft of torque at 2000 rpms. Peak torque of 545lb-ft at 3600rpms, and 480hp at 5500rpms. Honestly what more could you want and still see 15-17mpg or so? If this is your tow rig, slap on a set of 285/75R16's with 4.10 gears front and rear, 2200 rpms at 70mph through a 4L80E. If you need more torque than that, look for the next available Duramax diesel and go to town.

Kerr

Yea i know what you mean, Mom and dad both have 6.2L denalies and they run very good stock. I have 6.0L crew cab truck ( compay truck) that i the boss lets me tow with, It doese good, just doesent leave any room. it has 4:10 gears and stock tires.
The wife has a armada and it does real good as well, but all the power is in the upper rpms... sorta like "vtech" in a honda.

Brad (the guy that lives a few houses down) has a 8.1L with 373 gears and 285-75 tires. His truck move the load better from a stop and up hills. just sort falls off in the upper rpms. Or main problem is we live in the mountains.


Rayler said the intake manifold only added more hp and that in the upper rpms. They said it was developed for the race boats and will work on the trucks. He said there wasnt a reason to get it unless you where wanting to go for all hp goal...
I also think Rayler is the only company that makes parts for the 8.1L.. I know i saw comp cams, has few cams but no one makes heads.

I think the stock hp on the 6.0 and 8.1L are the same at 320hp. But the 8.1L has 450 lbta at like 1600 rpms.


The milage is not a big deal. Stock the 8.1L seem to get 11-12 mpg. The 6.0L gets 10-11 mpg, and the 6.2 Denali sucks the fuel at 9.1 mpg, all those are unloaded...

So it seems if i did a 8.1L then there head and cam package and a whipple later on i could make more than 1000 lbt in theory. I think whippled496 on here is making like 650lbq to the wheels with the whipple alone threw a allison trans.

InchUp

iTrader: (2)

Diesel. 550hp, 900lb-ft torque. 3.73's, 265/75R16 load range E tires through the Allison and 17mpg is within reach without tuning. I have driven trucks at work with the Duramax/Allison, flipped through the HUD on the dash to find the average economy to be 17mpg or greater. Fuel efficiency may not be a concern of yours, but if you can have your cake and eat it too why not, especially with the torque! If you don't have to rev high, don't. Mountains only require high revs because the vehicles you're driving don't have the low end torque to maintain 3rd and 4th gear. They lack the mechanical advantage to conquer the terrain so the tranny downshifts to get you into the optimal power band and more gear multiplication.

Plus if you make your own fuel it's 77 cents/gallon. I'm not old enough to remember 77 cents to the gallon for gasoline. But damn would it be nice right now.

Kerr

true but D max dont get any better mileage here than trucks, and they dont make a D max suburban. to be honet with you im good friends with guys that own diesel performace shop. You can make retarded amounts of power, and they do... The trucks just are not that fast even with parts. Quick yes, fast not really. Main problem ive seen is the gears are so short, you put all the parts on to make the high hp and tq but you only in each gear for a few split second then you in od.

Also you have no warranty at the local dealers if your truck has parts. Hard to spend that much on a diesel to void the warranty.

Norcalz71

so if the 500hp-600ft lbs goal isnt so reasonable in the 6.0....what numbers would be? 400hp-500ftlbs?

im in a similar boat for my hopeful 6.0 swap in my 94 z71 this summer. i run 38s and tow occasionally so I am definitely looking for that low end, the 8.1 just doesnt seem to have the aftermarket that the 6.0 does plus a good 6.0 is pretty readily available. id love to just swap in a d-max/allison, but that might be a bit more complicated.....

DubDuece

so most of you are saying that even going with a 6.7L 408 setup would be difficult to achieve those kind of numbers or am i mistaken?

I was wanting to get the same kinda numbers out of my truck... using a forged 408 with afr 205 heads, 220/224 112 lsa cam and full bolt ons besides using a fast 90 setup and just using my existing truck manifold.. I may hold off now and spend the 4 grand i have to play with on bagging it.. looks like it would be a waste of money if i'm wanting to reach 500hp at the crank and spend all that money and not hit that spot..be a big dissapointment in my eyes..

nightrunner

iTrader: (4)

500hp to the crank? i dont see why not. 500hp to the wheels? doubtful, especially with that cam and intake. probably about 420-450hp rwhp

trever1t

iTrader: (14)

Jeez guys, what's in a number anyway?
I'd rather build a 408/AFR engine (bigger cam!) and have performance over a show ride anyday...but that's why I'm on this froum I guess.

DubDuece

the way i see it..once a minitrucker always a minitrucker and to each there own.. Personally, I'd rather have the best of both worlds..