Competition The Ultimate Diesel Drag Racing Engine

[Sled Puller]

"revability" I looked that up, and couldn't find it. Has Fletcher been teaching you vocabulary, or COMP? :-laf



I could ask you the same thing-lighten your Cummins to the edge,, squeeze way more air than it was designed for with the heavy parts, add a decent amount of fuel, do this over and over again, and watch how long it lasts.



Comp has peaked. He has stretched that tupperware as far as it will go. If he ever gets his lightened engine to go with his lightened truck, it will melt down, come apart before 36 trips down the old quarter mile.



If you insist on going that route, you may as well add spark plugs, and run alcohol. The parts are available, anyway.



And Racing, I have yet to see a Cummins from out this way, "lay over" The hot ones keep pulling to 6000 rpm, and the "small" ones pull right to 4500- with "heavy" pistons, rods, cranks. If yours lays over, you need to tune it a bit more, or gear it right, or make a tire change.



Ya know, I once had a drag racer tell me we pullers needed to build aluminum driveshatfs, to reduce rotating mass... rightttttt! LOL.



Knock the drag racers? Me? Never! Well, maybe once or twice, just joshing about...

 

[COMP461]

And I guess that why your sled pulling engine builder are dominating drag racing diesels



Torque is not what makes a drag racing engine, horsepower is the only constant. One more time, if you have a 1000 hp at the fly wheel you have the same hp at the tire, less parasitic drag. Torque on the other hand is nothing more then a gear away from being what you want at the time.

Here is one for you, take the mighty 1400 hp diesel sled puller and put it in a ProStock chassis. , now the same 1400 hp 500 inch normal aspirated ProStock motor. Which one will put more torque to the tire?



If you guessed the diesel you would be wrong



1400 hp Diesel………………………1400 hp prostock

Max torque ………. . 2000 lbs. @ 3500 …………………. 920 lbs @8000

Max power ………. . 1400 hp . @ 4600…………………1400 hp @ 9200

Max rpm………………. . 5000……………………………………10,000

Rear gear @ 200 mph 2. 50 ……………………………………. . 5. 13

First gear …………… 2. 20 ………………………………………. . 2. 75





Starting line torque at the tire



Diesel 2000 x 2. 20 x 2. 50 = 11,000 ft lbs torque on the starting line

Gas 925 x 2. 75 x5. 13 = 13049 ft lbs torque on the starting line





Next the term Rev-Gain you don’t like was invented by a guy named “grumpy “



You take the same 1400 diesel sled puller engine you are so proud of and strap it to the engine dyno where it made that big number, this numbers was made step testing, meaning a steady RPM pull. And I have talked to the guys that did this, to that very engine so I know a little about this. Now besides the fact that it takes a long time to spool, and makes smoke that no drag strip will allow. Now you take and do a accelerated pull, a mild one of say 600 rpm per second you would get a number way less then the 1400 , way way less. Now this is the reason your sled pulling heroes can’t get out of their own smoke drag racing and people like me , Fletch and Scott , are running and setting the records ,





So in conclusion if you cant buzz it up and make power, and REV-GAIN you will still be setting on the starting line in your own smoke.

 

[DavidTD]

Thinking outside the box is good. Greg, you are trying some things that hopefully many will learn from. Until it is successful, it is theory though.



Scheid has lead the way on power from these engines since as early as I can recall. To discount what they have learned and applied to the track I don't think is smart. I understand they are known for Sled Pulling and there are differences vs drag racing. But HP has been developed for years at big rpm to generate wheel speed. Wheel speed we need in drag racing too.



In Sled pulling RPM is made then load applied. Not much different than leaving on a transbrake at 4000+ rpm. But RPM will need to be made quicker on the drag strip at the tree, then when hooked to the sled. Meaning you will have less time to get on top of the turbo's staging then when hooked to the sled. I don't think that is a problem for anyone including Scheid.



Piers has also proven to develop HP. I wouldn't discount his development either.

 

[John_P]

Very good points Gene!!



I agree with you on the RPM's too! Heck, my little 5. 9 Cummins that Scheid built will easily rev to 4500 RPM just like you said. I know Greg is looking for alot more than that, but as you pointed out all the sled pullers are making the high RPM's (including yourself ) and IMO the power and torque are defintiely there. It will be interesting to see the new times this summer on the Scheid Rail. IMO,..... they will show that low E. T. 's and high trap speed can definitely be acheived with our Cummins 5. 9 Engines!



-------

John_P

 

[Teamropin983]

Sleddy

Just face it Sled pulling will always be a backyard sport. Drag racing on the other hand will be on the forefront and leading diesel technology will be the choice of use whatever it may be.

FYI the ultimate drag racing engine will not have mechanical injection.



David Lott

 

[COMP461]

This is a misconception of sled pulling vs. drag racing a sled puller gets to its maximum RPM on the starting line , and as the motor goes in to the pull it pulls down until it is either stopped or pulls down to peak torque and possible breaks something.

On the other side a drag racer goes to the line and revs to a rpms or stall where the motor makes good power , once the motor leaves the line it must accelerate at some times a 1000 rpms per second till gear change, the do this over and over again till its in high gear. In drag racing you need to set the motor in high gear at maximum hp.



I am sure that some of the big engine builders like Dan and a few others know a lot about the Cummins, and will some day be able to build good drag racing engines, people like John Russin at Buddha power have the right ideal, and have been running very well on single turbo for a while now. My contention with sleddie is he has zero respect for accomplishments of others. It’s the old hot rodders story, of “wait till my buddies car shows up, it’s the fastest “well the buddies never seems to show up.



I have proven my self in the diesel world. My motor will accelerate and will run the number; everything else is just talk until it puts a number on the score boards. I have respect for others, and even learn from them. You forget two years ago, the only diesel motor I was interested in was the one on my fire truck. I have been doing this on almost no money , wow theirs a big shock to most , after I set the record at a NHRA sanction event , the truck was not a priority any more . Now when I mean no money, it means from the R&D budget I am accustom to in the comp world. If I could do every project I want to in a diesel, first it would be a Duramax.



I am sure that I can run a 7 second pass in a diesel, this is easy, and finding the time to do everything is the problem. I have to leave my motor project till this winter, because its time reblock my tired motor in a common rail block, it’s a 53 block and cracked front to rear. From the 5. 20 1/8 miles passes the truck should easily run a low 8 second pass, but until it dose it on the score board , I will not claim it .

 

[COMP461]

I run a aluminum drive shaft, aluminum torque converter, aluminum spool, Titanium axels, carbon fiber brakes, Gene weight is everything,



David is right; an electronic controlled motor is the way to go, I witnessed a Duramax on the dyno making 800 + hp on #2 only, and this motor is intended to be 24 hour endurance motor. Just think infinite timing curves, idle at 10 degrees, and at 6000 rpm 50 degrees. I predict a 1000 hp easy from a CR Cummins soon. And believe me the fuel is there with a stand alone computer. Which I have at my disposal when I have a motor built for it

 

[Hohn]

Gene raises some good points. He would be 100% correct if the engine was connected to a CVT or 'Glide. In these cases, the engine doesn't have to gain much in terms of RPM, because the TC is allowing the engine to maintain more constant RPM.



This is common with really light cars. Most superlightweights are usually faster with a full race 'Glide, from what I understand.



But we are dealing with diesels that are 1) heavy, and 2) have a much narrower RPM range. This narrower RPM range means you need more gearing than a 'Glide can give you.



That means that the engine has to be able to gain rpm quickly after each shift, of which there will be at least two, maybe three events.



Now, my mild CTD has a six-speed transmission. It gives fastest acceleration in THIRD gear, not first or second. Why?? Because in the lower gear ranges, that rate of "rev gain" is the limiting factor because the load is so light. But when you get to 3rd gear, the engine now gets more "rpm-gain-resistance" (load) from the trans than it gets from its own heavy internals.



Now comparatively, you don't see this in a gas engine. They are almost ALWAYS faster in first gear. This, because their own INTERNAL limits to "rev gain" are much lower relative to that posed by the transmission.



This is TOTALLY different than pulling. Heck, I could build a SWEET pulling package just by bolting a 2000# flywheel to the engine. I could sit on the line, slowly spin up my huge flywheel and store energy in it. Then, I let out the clutch, and all that energy is released to the driveline. The inertia that is your ENEMY when drag racing becomes you biggest friend when pulling. You DO NOT need need rev-gain when pulling, what you need is to simply keep the revs you have. Maintaining RPM as load increases (pulling) is MUCH different than GAINING rpm at a relatively constant load (racing).



That's why you see diesels dominate at the pulling track, but they are conspicuously absent in NASCAR, F1, and all but unique diesel-only or sportsman drag racing classes.



Now, there's nothing to say that a diesel can't be developed into a formidable package for ANY of the above mentioned race classes. But it would require re-engineering the diesels that are generally available on the market.



As for RPM, the only value of high RPM is that it allows more mass flow through the engine. If you can achieve the same mass flow with lower RPM, you are better off. The problem becomes optimizing a "package" around the lower RPM-- trans, tire, clutch, etc...



jlh

 

[Teamropin983]

That's the ticket! To compare the two types of specific engines built for different types of competition would be like comparing pumpkins to grapefruits... ... ...



You know that people used to knock the Import Racing thang in the beginning- but look at them now... .



Will the Diesel Racing scene follow the same path that the Import Racing scene did?









I hope so!!!!

It will, a few of us are just hard headed enough to prove a point even if we lose money doing it.

A couple of years back we were told a Power stroke would never go into the 12's then for sure never in the 11's,10's would definitely be out of the question. Mid 11's @119 striping the track is a long way from breaking into the 10's but I am sure we will get there. I may have to add some hotrod parts to do it though,this street motor produces too much instant torque to hook up even with the 4 link.

 

[Sled Puller]

Until it is successful, it is theory though.



.

COMP, that is Davids nice way of saying when you use imaginary numbers in your formula, you can get the answer you want to promote your way of thinking. (?) :-laf



John,

I can hear the crying now, how did that PULLING engine just beat us on the strip? The answer? DIESEL POWER, not gasser trash old technology.

 

[McRat]

Carbon fiber driveshafts have more than just weight going for them. Safety.



When the carbon fiber shaft fails, it splinters like bamboo. It does far less damage than either a steel or aluminum shaft. And it has less "whip" per length, which costs HP and accelerates failure.



It is of interest to note that Banks is building Dmax engines for racing. There is some serious engineering going on there for maximum effort projects. Obviously to those with smaller pocketbooks, the Cummins is King, but if you have big resources and are willing to push the envelope, the larger displacement and better head design gives you a head-start.

 

[COMP461]

This is common with really light cars. Most superlightweights are usually faster with a full race 'Glide, from what I understand. jlh

The glide was king because of the light rotation weight , a glide was worth a tenth over a TH 400 or 727 or C6 , the problem is a glide didn’t have enough low gear for some applications , and when you did put a low gear in it the spread would knock the wend out of a motor on gear change. Now that would not be a problem in a diesel except a glide will not hold up. I have made mush out of the best COAN TH 400 I had in one pass, but that was with a tight torque converter. In comp we have went to the proflite 727 or the TH200 3 speed this is about . 05 faster and is very expensive, and fragile. The reason is the ability to have a low gear and a split in the middle.





The torque converter is a wonderful thing, it’s a variable gear ration ,



Ok guys this is a run sheet from the 8. 72 pass, I must be nuts showing this , but you can see what Rev Gain is

 

[JRichard]

Well, slightly off-topic but since someone mentioned it -- although the olds 5. 7L diesel did originally start out as a gas engine, it was never intended as a "truck use" diesel, in the owners manual for early 80's chevy trucks with an olds 5. 7, it said not to tow heavy as the engine was intended for economy -- not towing power.



To address the 6. 2 and 6. 5 familiy of engines, these were engineered by Detroit Diesel company originally. They were never based on a gas engine of any kind, and although the design was insufficient to generate horsepower or torque in the range of a cummins, i have to say it was a better effort than a "converted" 5. 7 olds gas engine.



That said -- i have a question for the racing guys. Ive never had a 5. 9 cummins like ours apart so i dont have the knowledge to answer my own question, but is oil interference (i. e. need to use a windage tray) of the crankshaft a problem on these engines? I know the crank is heavy but when it comes right down to it, every little bit helps.



Thanx in advance



Jake

 

[COMP461]

your right on the carbon fiber drive shafts, but I might when I get another one , my new trans is in shipment and is 11 inches shorter the lenco . the big gains Pro Stock is now seeing in in the ability to rev-gain, and to run up higher .





there is only one way to make a engine make more power , MAKE IT PUMP MORE AIR, AND BURN THE CORRECT CORRESPONDING AMOUNT OF FUEL.



The way to do this is after everything else is optimized is either make the motor bigger, or make it do the cycle more times. The advantage to this in a diesel is you stop it from breaking things; you also get to work with real world gear and transmission, ands not the imaginary ones in Genes head, turn the motor up higher an try and keep the torque up , and it makes more hp period. Now use this hp and you go faster.

 

[McRat]

... there is only one way to make a engine make more power , MAKE IT PUMP MORE AIR, AND BURN THE CORRECT CORRESPONDING AMOUNT OF FUEL... .

More air = mo better. You can cram more air in a bigger engine than a smaller one, if it stays together. It remains to be seen what the realistic limits of the Dmax or 6. 0 (soon to get bigger?) Ford.



If you have to race today, Cummins is where you must start. If you are racing next year? That remains unknown.



I firmly believe we have seen just the tip of the iceberg with performance diesels. There is no other engine on the planet that you can double the stock engine output so easily or as reliably.



With OEM improvements coming out for these motors, the competition should get very interesting in the next 5 years.



My hats off to those who push the envelope. It will pay off in big rewards to all diesel enthusiasts. Oo.

 

[COMP461]

That said -- i have a question for the racing guys. Ive never had a 5. 9 cummins like ours apart so i dont have the knowledge to answer my own question, but is oil interference (i. e. need to use a windage tray) of the crankshaft a problem on these engines? I know the crank is heavy but when it comes right down to it, every little bit helps.



Thanx in advance



Jake

Windage is important in several ways, in all out competition motor we use a dry sump when allowed by the rules, and when not allowed we work harder on oil pan design. The wet sump theories and design have come a long way and produced a lot of power , since the first time Rehr Morrison removed a oil pan on the dyno and let the oil fly 25 years or so ago. This was worth a good amount of power, we are almost to that point with a wet sump pan now, adding in vacuum and you are way ahead of the game.



The best way is to remove the oil from proximity of the spinning parts, next you need to gather the oil leaking past the bearings and remove it from the mix. You can work the crank in to knife edge and bobtailed design; this makes the crank more aerodynamic, and reduces its tendency’s to slap the oil suspended in the path of the moving parts. Something that works well is pulling a vacuum in the crankcase. This makes the oil fall, as there is no currents whipping it around. I have pulled as much as 20 inches in a wet sump gas motor and 21 + in a dry sump motor. This is dangerous if you haven’t had experience in this in that you reduce the oil pumps ability to work and lose oil pressure, and can be disastrous if you aren’t careful.



I am sure that given time and R&D money I can build a 7000 rpm Cummins and make great average hp from 5000 to 6000 rpm’s this will be at least 1100 to 1200 hp . I have the same knowledge base and capabilities as the guys Gene touts ,and in some way I an not hindered by preconceived thoughts of what should be , I only car about what might ,work , and go down that path until it leads to a dead end of a break thru.



When all else is in question , you might have the answer

 

[DavidTD]

This is an interesting thread.



Greg, in your graph, what is your RPM span on that run?



In your TQ formula's I'm right with you. But there is a difference not mentioned. First, I would put 2500 Tq on that 1500hp diesel. This would have both examples with about the same tq to the tires. The difference is that one example is applying 2. 5 times the tq to the converter and input shaft of the transmission. Agree?



In these discussions we hear about Comp, Edge, Bentz, and Scheid. Comp and Bentz were first with the tube chassis. Neither hit the track with big hp. Comp, you were under 500hp when you ran 9. 93 in December 2003. Scott came out with similar power. Edge and Scheid do not have the same luxury. Mainly because everyone on here expects each to come out and awe the world with their first passes. You and I know that is not how it works. This is why I don't expect you will see either until they can. Shame really, because I would enjoy watching the teething that both will endure reaching their goals.



Back to rev gain. I agree, it will and does come into play. But there is still more to it. You will generate more hp with less rotating mass in the engine true, but this is your way of making the power. Again fine. You will find out with custom parts, how much they can stand before they break. This will tell us if the same or more hp can be developed and maintain reliability with lighter internals.



But are we talking motors that aren't expected to live very long? I mean a top fuel motor is good for 1320ft if lucky. Is that the goal here or sacrifice to reach our 1/4 mile goals?

 

[biggy238]

So nothing can be said for a DOHC design? I just think it deserves consideration now that you've gone to the level of a completely custom head and valvetrain design. The intake and exhaust scavenging characteristics might be usefull. I just want to hear if you've weighed it out and have the pros and cons available for us to read.



Kyle

 

[CMNS PWR]

I have the same knowledge base and capabilities as the guys Gene touts

Care to put a wager on that? They have forgotten more than you have learned so far. Anyone can go out and read up on diesel mechanical theory and quote text...

 

[GIT-R-DONE]

Drag Racing Engines are built and used in completely different from sled pulling engines- everything from begining to end is much qwicker!! Pulling involves a totally different style engine build to be competitive- Gene- ever take your puller to the dragstrip? No- why not?-

end of story... ... ...



Let's move on

Well, I do remember Quaker City Dragway, Ole Sleddy going down the track multiple times and then leaving for a truck pull in another state.



Granted the Sled pulling and drag racing are two different monsters, but I have to ask, if ole COMP has the fastest diesel out there, all he should have to do is tear down his motor and he should already know what it takes to build a racin motor... ...