Threshold for Pain: How much can your diesel take?

[ShinerBock]

Recently Diesel World Mag made a few articles about how much each diesel can handle, but never ended up posting the Cummins numbers. Drivingline, an autoblog owned by Nitto, just finished up a similar series of how much each diesel has been known to handle and what their weak link is. This time, they posted all of the diesels.

***Please note: These power numbers are for engine only assuming all supporting mods(i.e. driveline, trans, fuel delivery) are capable of handling these power numbers. So yes, a stock trans will blow long before you hit these numbers.

What is also interesting, and contrary to what many here believe, is how well a diesel engine will hold up to high power numbers with proper tuning. With the advent of common rail and electronically controlled injectors, many novice tuners added too much fuel and timing down low causing too high of cylinder pressures which is very hard on engine internals. This caused many horror stories and many internet myths. Cutting back on fuel and timing at low rpms and increasing it as the rpms rise is much better for your engines internals as the articles state. And of course these are all rear wheel numbers which are generally about 15% less than crank numbers.

THRESHOLD FOR PAIN: POWER STROKE EDITION

7.3L Forged Rods (94.5-00)
Threshold for Pain: 600 HP (1,100-1,200 LB-FT)
Weak point: Rods

7.3L Powdered Metal Rods (01-03)
Threshold for Pain: 450 HP (850-900 LB-FT)
Weak Point: Rods

6.0L (03-07)
Threshold for Pain: 800 HP (1,300-1,400 LB-FT)
Weak Point: Rods

6.4L (07-10)
Threshold for Pain: 900+ HP (1,500-1,700 LB-FT)
Weak Point: Pistons

6.7L (11-Present)
Threshold for Pain: 700 HP (1,300-1,500 LB-FT)
Weak Point: Rods


THRESHOLD FOR PAIN: DURAMAX EDITION

LB7 (01-04)
Threshold for Pain: 550 to 600 HP (1,100-1,200 LB-FT)
Weak Point: Rods

LLY (04.5-05.5)
Threshold for Pain: 550 to 600 HP (1,100-1,200 LB-FT)
Weak Point: Rods

LBZ (06-07)
Threshold for Pain: 650 HP (1,200-1,300 LB-FT)
Weak Point: Pistons

LMM (07.5-10)
Threshold for Pain: 650 HP (1,200-1,300 LB-FT)
Weak Point: Pistons

LML (11-16)
Threshold for Pain: 700 HP (1,200-1,300 LB-FT)
Weak Point: Rods

L5P (17-Present)
Threshold for Pain: Not yet known since no one has been able to crack the ECU yet


THRESHOLD FOR PAIN: CUMMINS EDITION

5.9L Mechanical (89-02)
Threshold for Pain: 800 HP (1,400 to 1,600 lb-ft)
Weak Point: Rod Bolts
Threshold for Pain (Race Applications): 1,400 to 1,500 hp due to running at higher rpm's

5.9L Common Rail-6.7L (03-Present)
Threshold for Pain: 900 HP (1,800 lb-ft)
Weak Point: Rods

[ShinerBock]

Double post

[ShinerBock]

4x4ord wrote:
Nothing for the 6.7 cummins?

Yes, at the very bottom.

5.9L Common Rail-6.7L (03-Present)
Threshold for Pain: 900 HP (1,800 lb-ft)
Weak Point: Rods

The rods for the Common Rail 5.9L and 6.7L are the same fractured rods. In fact, they are the same dimensions as the mechanical 5.9L, but the mechanical 5.9L rods can handle more power due to how they are made. This is one of the main reason the mechanical 5.9L is no popular in the diesel higher echelons of the diesel pull and drag world.

[4x4ord]

Nothing for the 6.7 cummins?

[ShinerBock]

TakingThe5th wrote:
I'm pleasantly surprised that the Ford 6.0 did so well. I've been told that it's one of the strongest Ford blocks once all the quirks are worked out. So far I've been very pleased with my bulletproofed 6.0.

While the 6.0L did have some issues, some of these issues in the aftermarket world should have been attributed to bad tuning rather than the 6.0L itself. Being one of the first Powerstoke engines that could be tuned electronically, novice tuners would crank up the timing and fuel delivery at lower rpms causing very high cylinder pressures. This would cause head bolts to stretch and gaskets to blow. The same thing happened when the Cummins 6.7L first came out blowing head gaskets left and right.

As tuning software became more sophisticated and tuners became more knowledgeable, these problems became a thing of the past. However, many on the internet don't know this and still contribute these old issues to anything tuned even though they don't even relate. Heck, even the software mapping the OE's used back then has advanced giving them better and more smoother fuel mapping. The fuel mapping on the old ECM's used for the 6.7L Cummins when it first came out are much different with less parameters available than the ECM's used on the current engines. More parameters means smoother fuel mapping and greater ability to control low rpm cylinder pressures.

[TakingThe5th]

I'm pleasantly surprised that the Ford 6.0 did so well. I've been told that it's one of the strongest Ford blocks once all the quirks are worked out. So far I've been very pleased with my bulletproofed 6.0.

[SidecarFlip]

Typically rods because that is where all the 'bang' goes...

[ib516]

Interesting. Thanks for posting.