Any ideas what a completly stock 2003 4.8 would produce at the wheels in an extended cab Z71? TQ and HP if you have a good guess.

 

i'd guess about 210.

 

do you really think it would be that much lose?
i was thinking about 235 or so but i am still learning on all of this stuff and that is why i asked.

 

At 35 - 40 HP below rated HP at the crank. I'd guess 230 - 235.

 

if the 4.8 is rated at 275 hp 275 x 0.8=220 rwhp, this is using 20% drivetrain loss.
I think that the 4l60e usually loses about 20-23%, the manual trans. are about 15-18%.

The 5.7L Vortecs dyno around 200rwhp, the new 4.8's sure do put out the power, the torque is a bit lower though.

peace
Hog

 

how come on the 60e 4x4 there is people losing only about 14-15% at least thats what 310-15%=263 to wich some people acctually put out with the 5.3 ho.

 

If that 263 is an actual dyno number, the 5.3 L33 is actually outputting around 315 hp at the crank. GM has been under rating its engine for a while now.
The LS1 camaros dyno from 290-310 rwhp which is 348-372 hp at teh crank, they were rated at 305-310 net hp from 98-02.

The new LS7 427 7.0 LS7 dynos at 454 rwhp which is really around 544 at the crank, its rated at 505sae hp at 6300 rpm.
the cadillac STS withthe 4.4 L supercharged engine was rated at 435hp withthe OLD sae spec(just like the XLR) but using the new SAE spec, its now rated at 469hp, for teh same engine. No more can manufactures round off their hp numbers, and they must use ratings for that engine for whatever application it is going in. It cant use a hp rating that was found in a Van, for a truck for instance.


NEVER take GM's rating for gospel, I would think that they should be getting more true due to the new SAEspec for rating the 2005 and newer engines. the LS7 was the 1st engine to adopt this new rating system.

When talking about hp, there is crank hp, SAE net crank hp, rearwheel hp. The hp you see from an engine dyno is ususally about 5% higher than that engine would dyno for SAE net numbers.

The 1992 LT1 Vette had 300 hp net, which is about 380 gross, or about 315 engine dyno or magazine hp.

Its really confusing, we cant even compare chassis dynos becuase they all differ, a mustang is different than a dynojet, then there is correction fro altitude.

peace
Hog

 

I have seen Stock Dyno number in the 220's.

 

Look at this dyno it is 267 hp from a l33 it had an drop in so im assuming 1-3hp from tha drop in just to be safe

 

Do you guys think i could hit 300 rwhp without opening the engine?

What i have now plus:
I was thinking a reprogram, GRAN MAF Sensor, GRAN ignition wires, and a decent set of headers.
How close do you think i will be doing this?

I was also thinking of the lingenfelter LPE LS1 Camshafts 350-383 205/212 .540/.540 w 1.7 rocker 116.5 CL setup if needed.

I am trying to stay cheap and keep good drivability at the same time.