HD Rumble in the Rockies - Chevy wins

[91Terminator]

every motor will have issues. but the 6.4 didnt have the problems the 6.0 did, is all im saying.

Keep in mind that the Dmax is basically maxxed out in its numbers, chevy cant do much else to bump up the power. Ford is not even close to maxxing out that motor.
but this just means chevy will have to come out with somethin new in 2012

its a competition we all benefit from

well i dont know about the power thing but i do know the 6.4's are in the shop quite often for head gaskets like the 6.0 and the egr cooler like the 6.0 and hpop like the 6.0

[turbonine]

every motor will have issues. but the 6.4 didnt have the problems the 6.0 did, is all im saying.

Keep in mind that the Dmax is basically maxxed out in its numbers, chevy cant do much else to bump up the power. Ford is not even close to maxxing out that motor.
but this just means chevy will have to come out with somethin new in 2012

its a competition we all benefit from

Very true that the 6.6 Dmax is maxed out and that the 6.7 has plenty of room to grow.

For now, I love my 7.3.

[Tanner]

Oh now now fellas. I wouldn't exactly say the Max is maxed out on HP. Don't be spreading rumors that were started from Ford guys that supposedly heard it from a GM rep.

All GM has to do is attack the fuel delivery system and a dependable ~500 HP is easily attainable. The rods and pistons will hold up into the low 600 range on the newer trucks. Actually a few of us have improved the piston designs on the LMM and newer trucks by simply modifying the stock pistons from the LB7.

I recently tore down 2 Max's (LBZ, and a LMM) with different set-ups to see how the pistons were holding up (Fire Ring Pattern).

The LBZ has PPE dual CP3's and a PPE LVL 7 tune, and drops 540hp to the ground. the truck has 108K miles and the fuelers and tuner went on at 10K.... pistons look almost brand new. Which was surprising considering the build and tune. I really expected a dark fire ring that was burned in. Nope! Not totally unusual. Yes there were signs of a tuner, but nothing alarming. Actually the fire ring wiped clean w/ rag believe it or not.

The LMM has 86K miles, twins since 5K miles, cut LB7 pistons since 25K, forged rods at 25K, switched between a PPE LVL 6 tune and a few custom tunes. The motor shows no premature wear, as the motor was torn down at 50K as well for inspection, there's been no noticeable change since. So that's over 80K miles running over 600HP w/ no noticeable wear, using LB7 pistons w/ minor machining.

Point is, the Max has alot to play w/ and still be reliable. GM may play w/ the pistons, but I suspect the fuel delivery system is what will be attacked, as it's the cheapest and also the weakest link in getting any power. But like I said, the pistons are fine, as are the rods, although the lip'd LB7 pistons are better overall. Don't count the Max out in it's current form just yet. It may be reincarnated like has been done since it's conception, but it won't be replaced just yet.

[dom w. forte]

Is there anywhere in the test where they discuss fuel economy for the run, I couldnt find it or how much rpm were both trucks turning at any particular point.
Also would be interesting to try different rear gear ratios to see if both engines perform the same with different power band per rpm.

[Timmy!]

How do you guys figure the duramax is maxed out on power? 60% of it is new for 2011 and they also added 22lbs of steel to the block alone to hold more power.

[G-MONEY]

Chevy Chevy Chevy.....

[jbort]

Maybe we need to start a truck forum - since its a hot topic and fun. I have a 95 Ford F-350 dually w 7.4 diesel & 92K miles. Just dumped the antifreeze out via drip-drip-drip in the front. not good. taking to the dealer in a few days.

[Timmy!]

We definitely need a tow rig forum.

[91Terminator]

Fueling the fire

And you guys thought i was done ha ha ha..........

Pleas tell me what your thoughts are on this little bit of info.....

One noticeable difference between the trucks is transmission gearing. To me, that's the ONLY reason the Chebby got the Ford in this loaded "acceleration" test because basically HP/TQ is not the factor here as they are nearly identical. Both trucks can do the test, but Chevy had the "speed" advantage in this case.

Final drives of both GM/Ford in each gear...... (Trans Gear x Rear Gear). Both trucks are on a 32" tall tire, and same rear end obviously.
1. 11.56/14.81 > meaning the Ford engine has to spin 3.35 more RPM to move the same distance
2. 6.75/8.65 > meaning the Ford engine has to spin 1.9 more RPM to move the same distance
3. 5.26/5.67 > meaning the Ford engine has to spin .41 more RPM to move the same distance
4. 1.00/1.15 > meaning the Ford engine has to spin .56 more RPM to move the same distance
5. .71/.86 > meaning the Ford engine has to spin .15 more RPM to move the same distance
6. .61/.67 > meaning the Ford engine has to spin .06 more RPM to move the same distance

Allllright, now, that may not sound like much, BUT let's look at speed at PEAK POWER. 1600RPM/3000RPM (tq/hp peaks) with 32" tall tires.

1. GM=13/25mph
Ford=11/19mph

2. GM=24/43mph
Ford=18/34mph

3. GM=30/55mph
Ford=27/50mph

4. GM=41/75mph
Ford=35/65mph

5. GM=59/100+mph
Ford=50/90mph

6. Doesn't Matter


Chevy clearly had its peak power at higher speeds due to transmission gearing, thus, this is why Ford got beat and it doesn't prove by any means that Ford is junk or Chevy is better. In first through fourth gear the Chevy had a 7.5 mph average advantage speed at peak power, and in the power gear (4th gear) the chevy had a 10 mph advantage. The trucks were not exactly equal when looked at more closely, a more "comparible" truck to the GM would be a Ford with 3.31 gears due to transmission gearing or the Chevy with 4.10's, IMO.

and the battle continues......

[jwanck11]

I am just happy to see some fresh meat on the fire.

[91Terminator]

Waiting.....................................

[islander033]

"The Ford clicked off the quarter-mile in 31.25 seconds at 45.13 mph, and the Chevy ran the same distance in 28.93 seconds at 50.3 mph. But the Chevy was already coming on like a freight train at that point. It took the Silverado 28.56 seconds to go from zero to 50 mph, while it took the Ford 42.02 seconds."
Since the Ford has lower over all gearing (according to the specs in the article and 91Terminator's info), why didn't it have greater acceleration to 50mph? Both trucks would have hit 50mph in 3rd gear....

[Timmy!]

For what? A rematch? The Ford makes its torque sooner, carries it longer and flatter and makes more than the Chevy on the dyno chart. Great job on the engine by Ford! They really did their homework on it!

Looks like Ford has done enough that GM is back to the drawing board:
http://news.pickuptrucks.com/2010/11...auto-show.html

[91Terminator]

For what? A rematch? The Ford makes its torque sooner, carries it longer and flatter and makes more than the Chevy on the dyno chart. Great job on the engine by Ford! They really did their homework on it!

Looks like Ford has done enough that GM is back to the drawing board:
http://news.pickuptrucks.com/2010/11...auto-show.html

For your answer to how the rumble in the rockies was fair???

[Timmy!]

Well, they got the truck with 3.73's because the Ford guys all cried foul in their HD shootout on the hill climb portion and said that the Ford would do better if it had 3.73's instead of the 3.31's or 3.55's. It wasn't fair to the Chevy according to your chart. The Ford should have been accelerating much quicker according to your chart and the dyno chart facts.