You're forgetting the weight of the trailer! You may have a ~2,300 lb weight advantage, and that will mean that empty truck vs. empty truck yours may be reasonably close.

But that 11,000 lb trailer doesn't magically get lighter because you're using an OBS truck either.

So instead of 18,500 lbs up the hill we'd be at 16,200 lbs up the hill with your truck. Your 28.75% weight advantage slims down to a 12.4% advantage with the trailer. Assuming the transmission can keep the engine near peak HP through the pull(mine can), as well as assuming your 38.5% horsepower deficit, it wouldn't even be close.

Now let's try and figure this out...

215 HP/350 HP means you have 61.4% of the power of a 6.4L engine. So to equal my performance with 18,500 lbs combined weight you'd have to have 61.4% of the combined weight, which would be 11,400 lbs. Subtract your 5,700 lb truck from that and...

You could tow a 5,700 lb trailer up that hill as fast as my 6.4L can tow 10,500 lbs.

 

And also, since this is a "V10 vs. PSD" thread, let's compare yours to Mike's 2000 V10 truck.

For the purposes of this we'll guess Mike's truck to be 6,500 lbs. So, your 215 HP / Mike's 310 means you have 69% of Mike's power output.

So we'll guess Mike's latest weight going up the hill to be 17,500 lbs. Remember he had the extra 800 lbs of pellets in the bed? Anyway, 17,500 lbs x 0.69 = 12,137 lbs. Subtract your weight and...

You could tow a 6,440 lb trailer up that hill as fast as Mike's truck pulled 11,000 lbs.

Of course this is assuming he can maintain peak HP up the hill. And if it were a fair comparison, like you said above, he'd have the same 4.10 gears that you did. If he had I think he would have been able to pull far more than 3,000 RPMs in 1st gear...

 

In higher gears you are correct. Oversight on my part there. But in lower gears, the trailer weight doesn't matter because I am putting more tq to the ground than you due to gearing. So no matter what the trailer weight is, I will get it moving faster. I will also have no trouble getting it to peak hp rpms either.

Where you will have the biggest advantage is with a trailer that prevents me from getting the rpms up like happened to the 2v v10. If the v10 could have gotten above 3k rpms it would have continued to accelerate and would have reached pretty much the same speed as you. The weight was just too much for that little gearing for him to get get in his powerband. With a 5.08 1st gear and 4.10's in the rear, I can assure you my truck would have no trouble hitting any rpm I wanted it to with a trailer that size. I would even bet that my 5.4 would have been able to beat the v10 or the 7.3 in that test due to the simple fact of better gearing letting me get get in my powerband. A 5.79 1st gear and 4.10's will do wonders.

Edit-I am not saying my 5.4 is better than his v10, before anyone starts bashing me. His gearing prevented him from passing 3k rpm. My 5.4 would have no trouble hitting 6k rpm with my gearing and it makes more power at 4-5k rpm than his v10 does at 3k rpm....

 

The problem with deep reduction gearing is how fast you can go with such a gear.

Your truck can go 12 MPH in 1st gear.


Your second gear is a 2.94 ratio, which is VERY close to the 4R100s 2.71. Remember how he was able to reach 3,000 RPM in that gear? So in this gear you might be able to equal his speed.

Your third gear is 1.61. Output here is 55% of the torque you see in 2nd. Interestingly your PSD has the same 425 ft-lbs as Mike's V10.

So Mike's V10 with it's 2.71:1 1st gear puts out 1152 ft-lbs to the rear axle. And it could barely pull it. Your truck puts out 684 ft-lbs in 3rd gear.

So here you're 41% short on power trying to pull 90% of the weight. There is NO WAY your truck could pull the grade in 3rd gear.

 

That is also assuming that I would have the same tranny, which I don't. MY truck would beat his up a hill even with both having 4.10's due to my better tranny gearing. You would be correct if I had an e4od. But a FAIR test would be his v10 vs a 7.3 from the same generation (SD 7.3) with both having a 4.10 and 4 speed auto.

I am heading out to meet my wife at work so we can have lunch together, so I am getting off of here for now. But I will make a deal with you. I am going to be moving sometime in the next couple of months(however quickly my house sells). I have 11 cars, 2k lb of landscaping stone, engine lifts, engines, etc, that I will be moving. The road leaving my house is a stop sign on an 18% grade hill that is 1/4 mile long. I just bought a new camcorder the other day(I jumped straight from VHS to something that uses a memory card), so give me time to figure out how to use it and let me know how to post a video. I will stop on the hill with either my 5.4 or my 7.3(your choice) and film me getting them faster than 25 mph.

Edit-I will not be moving all 11 cars at one time lol. But I will load my truck and trailer down to where my load is 10,700 lbs like you did in your test. My road is a little bit steeper, but close enough that it shouldn't make a difference.

 

Sounds like a plan, Josh!

In the interests of credibility I'm hoping you can get a weight ticket to ensure we're in the same ballpark. It's a shame I didn't move south instead of north. I'd have loved it if I were able to meet you there and we could do another comparison.

 

You also need to remember that his low end torque is not the same as my 7.3. We have the same peak tq, but he hits his 1250 rpms higher than I do(at an rpm he couldn't even reach). From idle to 3k rpm I am putting down more power than his v10 by a pretty decent margain. In a shoot out that has enough weight to prevent him from passing 3k rpm(like the one you did) I know mine will at least stay even with his(whether we have the same tranny, gearing, etc). Give him 4.10's or drop the weight on the trailer enough to let him reach his peak hp and he will outpull my 7.3 by a mile. And that is the problem with your calculations of him being able to pull 11k lbs faster than I can pull 6k. With 11k lbs he couldn't even sniff peak hp.

I don't know how you are getting your numbers for me in 3rd gear, but I got something waaaaay different. Since Mike was able to reach 3k rpm in 1st gear, let's say I will reach 3k rpm in 2nd gear also(more low end power and better gearing, why wouldn't I?). Say I shift from 2nd to 3rd and drop from 3000 rpm down to 2k rpm. With a 1.61 3rd and 4.10 gear that gives me a 6.6 final drive ratio. 2,000 rpms/6.6=303 wheel rpms. 161 hp x 5252/303=2,791 rear wheel tq.

If Mike was in 1st at 3k rpm then he was making 415 tq and 237 hp. His 1st gear is a 2.71 and his rear end is a 3.73 for a final drive ratio of 10.1. 3000 rpm/10.1=297 wheel rpm. 237 x 5252/297=4,190 rear wheel torque.

Let's say I hit 3k rpm in 2nd and you are correct that I can't shift to 3rd. My 2nd gear is 2.94. That is a 12.05 final drive ratio. 3000/12.05=249 rpms. 225 hp x 5252/249 rpms= 4,746 rear wheel torque. At that point I am going a few mph slower than him, but putting a lot more power to the ground. He has reached the point that he can't pull any faster. I still have 600 more rpms that I can pull before I redline. At the LEAST, I would have pulled it the same speed and easier than he did.

In that test I would actually benefit from having 3.73's if I couldn't hit 3rd gear. 3.73 x 2.94= 10.97 final drive. 3000 rpm/10.97=273 rpm. 225 hp x 5252/273=4,329 rear wheel tq. Now I would be doing closer to his speed, still putting more power to the ground and would still have 600 rpm left to gain more speed. That's why I question a 7.3 with much more power than mine struggling to keep up with it.

 

I don't know where the closest scale to here is, but I will look around and see if I can find one. I know there is one in Knoxville, but I can't waste 3 hours worth of time and gas just to weigh it. If I can't find a scale, the stuff I will be hauling will be easy to get pretty darn close. You can look up the weights of my cars online, we all know how much a small block ford engine weighs and I know I bought two pallets of 1,250 lb stone. I used less than half of one pallet at this house, so I have about 2k lbs left over. It may take a while, but I could weigh the stone in 100 lb increments on my bathroom scale lol. What kind of weight are you looking for? Trailer weight or gcw? If we want stock vs stock, run what you brought, I can get 10,700 lbs on my trailer and in my bed to make it the same weight trailer. If we want gcw let me know what I need to shoot for. One of the cars I will be pulling is a 1988 thunderbird turbo coupe, manual tranny. Here is a link to the weight on it. 3415 lbs. http://autos.msn.com/research/vip/sp...bird&trimid=-1 Keep that in mind when the time comes.

Edit-I have two roads leaving my neighborhood and I can use either one you want. One goes from 1440 feet to 1680 feet over .25 miles for a grade of 18%. The other goes from 1300 to 1590 over .3 miles for a grade of 18.3%. I can send you a PM of my address and the roads if you want to google them and verify.

 

You mention yours would be pulling harder but you failed to address the speed differential. Of course nearly the same HP applied at a higher speed would equal less torque.

So when you compare his V10 at 3,000 RPMs to your PSD at the same RPM and proceed to mention that your PSD is pulling harder you HAVE to take into consideration that you're going slower!

So let's figure this out. For the moment I'm going to assume your wheel RPMs are correct and adjust from here.

So if your truck is turning 3,000 RPMs at 249 wheel RPM, you would be turning 3,578 RPMs at 297 wheel RPM to get to the same speed Mike's V10 was pulling.

Here's the problem with this: Your 7.3L wouldn't make that RPMs under load! At 3,500 RPMs your truck is making around 50 HP or so. After 3,300 RPMs the 7.3L completely falls on it's face. Don't believe me?

http://www.knfilters.com/dynocharts/57-2531_dyno.pdf

So long story short, your 7.3L wouldn't pull it in third gear, and due to gearing you wouldn't be going as fast in second gear.

I think you answered your question. Did you notice in the videos the speeds between the two were nearly identical until the hill started to level off? This was because Mike's V10 was putting out within 5% of the PSD's peak power during the steepest part of the hill. Once things leveled off and it was able to rev, his V10 ran away from the 7.3L. At nearly all points above 3,000 RPMs his V10 was pulling harder.

Another interesting thing to remember is that his V10 puts out over 90% of peak torque as low as 2,000 RPMs. Therefore below 3,000 RPMs it's within spitting distance of the PSD's output. Once it gets above that it's all over.

 

I was thinking trailer weight. As you said before your truck is lighter, which is an advantage. So if you were to come up with between 10,000-11,000 lbs trailer weight I think we could call it fair.

This is fun, Josh! I love a good debate and you seem more than willing to provide one. I tried to rep you but it wouldn't let me...

 

I didn't fail to mention that I would be going a little slower than him at the same rpm(see below).

I mentioned that too(see below). Yes, the v10 makes 90% of peak torque at 2,000 rpm, but it is still only 382 tq at 2,000 rpm. My 7.3 is at 425 tq at 2,000 rpm. That's a pretty decent gap. If it can't accelerate past 3k rpm, it doesn't really matter what it makes at 5k rpm. By 3,000 rpm he has 415 tq and I have 395. By those numbers his v10 should be pretty even with my 7.3. The SD 7.3 has more tq(and hp) at 2,000(500 tq) and 3,000(438 tq) than either the v10 or my 7.3, but it ran the slowest of the bunch. Something is wrong there.

 

I just want to make sure it's something everyone thinks is fair. I'm fair game for equal trailer or equal gcw. I would say more than likely my trailer will weigh around 7k and then the rest will be in the bed.

I don't mind good debates either. It makes things interesting and is fun as long as it stays civilized

 

There are some inconsistencies here.

I mentioned that you failed to recognize the speed differential and that your truck couldn't possibly equal the same speed in second gear due to the 7.3L powerband falling off a cliff at 3,300 RPMs.

To this your replied quoting this:

So it's first a few miles slower, which lines up with what I said above...yet you still insist you could maintain the same speed. Neither truck has a CVT, so you can't have your cake and eat it too.

I just remembered how K&N has stock dyno charts for most vehicles posted on their website.

Here's the V10:

http://www.knfilters.com/dynocharts/57-2524_dyno.pdf

And the PSD:

http://www.knfilters.com/dynocharts/57-2530_dyno.pdf

Now look very closely at the stock horsepower output of each at 3,000 RPMs. As close as I can tell the SD 7.3L makes 190 HP at the rear wheels, while the V10 makes 178 HP. A difference of 12 HP.

This is less than the difference of a ride-on lawnmower engine. Consider the weight difference negated with the 800 lbs in Mike's bed for the test as well as the larger off-road style tires on the 7.3L truck, it makes sense to me.

 

I know there's a scale at the Pilot in Greeneville, exit 26 if I remember right. My truck stop books are packed away, but I'll find you the closest scale. This'll be fun!

 

What I meant is that at 3,000 rpm I would be going slower than him. He had reached his max pulling ability and was not going to go any faster. Even if you shut mine off at 3,300 rpm I would still be making enough power to pull another 300 rpm over the 3,000 he was turning. According to an online mph from wheel rpm/gearing calculator at 3,000 rpm he should have been going 28 mph. At 3,000 rpm I should be going 24 mph. Not a huge difference. If I pull another 300 rpms, at 3300 rpm I will be going 26 mph. That is the exact same speed he climbed the hill at and why I said I would climb it at the same speed as him. I would have to turn more rpms, but putting that much more power to the ground than he was, I shouldn't have any trouble squeezing a few more rpms out.

We also have to take into account that if his tc wasn't locked up, he was going to be turning more rpms than he normally would at that same speed. Remember the 5.4 in the test that you said was turning 5k rpm but only doing about 10 mph?