Competition What happens when you make more power than your drivetrain can tollerate.

[firemanmarc]

... ..... and was run off... ... ...

 

[Mcarcerano]

The only 2 times we have had yoke failures is when Keating "cranked it up a notch" well that should tell you something. it may or may not be bad or not strong enough parts, chassis fatigue not set up right or what ever all I can say is to solve the suspension mystery you have to get a data acquisition system on the truck and monitor all the loads and angels,tp,rpm tire slip and it goes on and on that are present at time of launch and down track. hope this helps in some way

 

[Straight6Jeff]

Shock load question

Ok, it has been stated that horsepower is horsepower, torque is torque, and that the parts don't care weather it is from gas or diesel. Does a six cylinder engine making 1500 lb/ft impart more of a shock load on each power event (each cylinder) to the driveline than an 8 cyl making the same torque?



Or do I need more coffee?

 

[ob1kobi]

along those same lines, I would be curious of yalls thought on whether a 5500 lb truck making 1500 lb/ft of torque, affects the driveline the same as say a 3000lb truck or car, making more torque. When I talked to an engineer at Strange, and Jason at Mark Williams, they both said it was the weight combined with the power that would kill the rears, not the power itself. Strange said they wouldn't sel me a rear, if then knew that it was going to used in this application. Jason, at Mark Williams, said they would sell it but there was no warranty since there was no way for them to know if it would work or not. Jason mentioned both Greg and the Keating Machine trucks, but also noted there reduced weights. Keeping those tow answers in mind, I would think that the reduced weight of a truck like Greg's, wouldn't impact the driveline like a heavier truck making less power would.

 

[Straight6Jeff]

What Ted said.

 

[JLackman]

The thing is if diesel torque broke parts you didn't make the pass right?



And what good is diesel torque, or your understanding of it, if you don't make the pass?



Do pullers ever run up over the peak torque RPM?

 

[Sled Puller]

Right.

No good at all.

Yes.



Why take a perfectly good Diesel engines amazing advantages and try to make it act like a gasser V-8?



Answer, because a few certain drag racers have their heads STUCK there.



There is compromises to make in rpm and tq, but it makes no sense to screwup a Cummins because somebody doesn't understand how to apply tq properly to get the job done.

 

[COMP461]

you seem to know it all don't you ,

 

[Sled Puller]

I only know the ideals that makes a Cummins work.

 

[COMP461]

and what about Drag racing diesels

 

[JLackman]

Do gassers ever break driveline parts?



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The thing is if gasser torque broke parts you didn't make the pass right?



And what good is gasser torque, or your understanding of it, if you don't make the pass?



Do gasser pullers ever run up over the peak torque RPM?



==================================



If diesel drag racers really were treating the drag diesel like a gasser they would be running the RPM up to 8000-10000 rpm where the gassers run.



Seems to me the real difference between SI and CI engines is the RPM at which they make TQ and HP. The reason CI engines can make power at a lower RPM might be because diesel fuel has more BTUs per gallon than gasoline. A diesel at 8 MPG has much better pulling power than a gas at 8 MPG because the fuel has nearly twice the BTUs per gallon.



-->>EDIT; diesel is not twice the btu per gallon.



It is interesting that the operating RPM range difference between gas and diesel engines is remarkably similar to the BTU difference between gasoline and diesel fuels.



One difference between pulling and drag racing I haven't seen address here too much is the fact pullers want wheel speed / wheel spin, and drag racers want the tires to hook up. Pullers don't want to get stuck with the tires hooked up at below their TQ peak RPM, they seem to want to be above that RPM with the wheels spinning. Pullers want to keep the engine above the TQ peak RPM so when the pulling gets tough the engine RPM falls against a rising torque curve. That is what the term "torque rise" is all about.



Drag racers on the other hand don't want the wheels spinning, max driveline torque is at the start of the run, and so their only choice might be to leave the line at above the peak driveline TQ which means high RPM. That doesn't mean the diesel drag racer "doesn't understand diesel torque" it means he does understand it - and he is deliberately choosing higher RPM.



Pullers don't need to care so much about what Comp461 calls rev gain, the engine RPM remains far more constant than drag racing, lightweight rotating and reciprocating parts would be more for reliability. On the other hand a drag engine is accelerating almost 100% of the run so lightweight parts become a major issue. That is why you see things like Honda rod journals (1. 88" diameter) in some ProStock engines.



==================================



It seems like everyone here knows where the other's buttons are - and really enjoy pushing them.

 

[JLackman]

Umm... don't know if all that is clear.



Gas engines need to run more RPM to get the same amount of BTUs through the engine because of the BTU difference in the fuel.



It takes TQ/HP to spin up rotating and reciprocating parts, the lighter they are the less TQ/HP it takes. This is a bigger deal in drag/road racing than it is in pulling. The only real way to test this is fast rate engine dyno sweep tests without using inertial correction.

 

[RacinDuallie]

I only know the ideals that makes a Cummins work.

For the purpose that YOU choose= Sled Pulling.

Drag racing with a Cummins= ?




Can we just get back to the origonal thread already???

LPreston- So what has been the outcome/fix with the failures 'on kill mode'?

 

[firemanmarc]

Racin Duallie, I couldn't agree more... ... ...

 

[KLockliear]

LPreston... so is that the 1350 joint MW uses? The stock Dodge unit is a 1410, but greaseable.

 

[LPreston]

LPreston... so is that the 1350 joint MW uses? The stock Dodge unit is a 1410, but greaseable.

It was. Keating's thought on the Dodge piece is that the holes for the grease negate any improvement over a 1350, plus everything else. MW's new Yk6 stuff is now available, (the newer, higher strength setup). Keating is going a different route. Hopefully we will be back at Steele in 2-3 weeks.