Hey all, just thought you'd all like this 8.1L build up article in car craft:

GM Vortec 8100: The 454's Forgotten Big Brother

 

That sounds like a lot of money for only 330hp and 410lbs of torque.

 

The 8.1 is a very cool motor and that article was a great read, but I'll echo the above posters feelings as well. 330 hp is very underwhelming from a 547 even accounting for the platform.

 

The thing that no one remembers is that you're losing a ton of power from the flexplate back - typically quite a bit more than the smallblocks (not to mention the small block crowd only quotes crank figures).

Stock output is 320hp / 455ft-lbs at the crank, 202rwhp / 303rwft-lbs.

202rwhp x 1.58 = 320hp crank / 303rwft-lbs x 1.5 = 455ft-lbs crank.

Assuming the same rate of loss:

Modified crank output of that 547 stage 1 (towing oriented) package 521hp / 627ft-lbs with headers attached to completely stock exhaust.

 

And all the haters have probably never even drove a stock one

 

What I'd really like is some real world towing experienes with the Raylar stuff. Ive been searching for months and can't really find anything. I'm completely "underwhelmed" by the stock towing performance of the 8.1 and 4L80E. The HP/TQ numbers aren't all that important. I want towing reviews. Mountain passes, speed, RPM, trailer weight etc.

 

Car Craft Magazine Article "An Avalanche Of Torque" In PDF Format

We just got the 540cid shop Suburban back from a trip to McCall, Idaho and back to southern California with a 25ft Rinker behind it. Average fuel consumption for the trip was 10mpg, though the best part was the ease of accelerating uphill.

 

Damn you probably drove right through salt lake and didn't even stop to let me test drive it

 

The 8.1/4L80E/4.10 Express van I have driven had plenty of power.