Compare them on the same brand dyno on the same day.
Mike uses a dyno dynamics dyno-NOT a dynojet. Different dyno=different calculation method and software.
Don't get hung up on dyno numbers-my Tbird runs very close to the 11's, yet-it's never been over 270rwhp on any dyno and weighs 3600 lbs. Calculators for et and weight say that my car should be making 320+rwhp at that weight. That's approx a 50rwhp difference. Am I concerned? No. I don't need a big dyno number sheet for use as a penile extender. I've smoked too many "400rwhp" cars at the track-and they swear I've got a hidden N2O system.on the car somewhere. Reality is they're too hung up on numbers to see how a dyno is supposed to be used.
JL

 

OK, so what part of what I said didn't make sense?

You're testing an unloaded truck on a dyno, and get lower numbers than a car (mustang) because of the heavier drivetrain not to mention a tune that's setup for torque and not acceleration.

NOT TO MENTION - the dyno drum is a certain weight. NOT the weight of the truck, nor does it have the added coefficient of drag at highway speeds.

The drum on the dyno is not a variable weight. If the dyno drum were heavier to match the truck, the drivetrain loss wouldn't be as big.

AND another thing.

You can measure torque at a certain RPM. You can plug that torque into the HP=(torque*RPM)/5252 equation and get a HP number for that RPM.

That's "flywheel torque" as measured by Ford.

Now, you can put that engine into a vehicle, put all that power through a drivetrain, and THEN... wait for it...

Compute "HP" based on how fast that vehicle acclerates a fixed-weight drum (one that doesn't match the weight of the vehicle in the first place).

In effect, you are measuring two completely different types of "HP". One is the engine running at WOT, holding a certain RPM, NOT accelerating.

The other is accelerating a fixed-weight drum and computing how much HP that took.

Two completely different ways of measuring HP.

In effect, there is no correlation between flywheel HP (torque at a given RPM) and rear-wheel HP (how steep the slope of the acceleration curve can get).

 

All of it

Just kidding...

But seriously...I'm asking where did roughly 140hp and 200tq go and you're trying to tell me how a dyno works or something (I think).

Bottom Line...
Some numbers...
Ford made an engine and rated it at 362hp @ 4750rpm and 457tq @ 3250rpm.

Then Ford put this engine in a vehicle. 5 Star Tuning put this vehicle on a dyno and made a peak of 220hp @ 4900rpm and 260tq @ 4100rpm. Those numbers aren't EXACT but the best I can make of the dyno graph posted on 5 Star Tuning's website. They are pretty close.

That means roughly 140hp and 200tq disappeared between the engine and the dyno.

That just seems like a lot to me. Just say to me "That's the way it is, don't worry, you're truck will pull your car with ease". I'll say OK and believe you. I'm not changing my mind about buying a V10. Just a little shocked it takes that much power to turn a flywheel, transmission gears, a driveshaft, a rearend, two brake discs, and two wheels/tires.

I do see that after tuning, PEAK torque comes around 2900rpm, about 300rpm lower than Ford's 3250rpm rating stock. And a lot lower than where it came stock when on the dyno, which was roughly 4100rpm. I don't know why there's a 1200 rpm difference between peak torque, stock/tuned, maybe it has to do with the automatic transmission and whatever the tuner may be doing to it.

It's cool....

 

It will be same dyno, same day. He'll get a base number, then work some magic, then see what the results are. I'm not expecting much, and I'm sure it will tow my car prefectly fine 100% stock.

I'm more curious what the numbers will be through a manual versus a automatic.

 

Doesn't Ford rate the horsepower at the Crank and Dynos at the rear (rwhp)

Good Luck on your V10 Hunt

 

That is incorrect. It didn't "disappear". It's just that you can NOT compare flywheel horsepower/torque and what a rear-wheel dyno shows you.

Dynos are good for comparisons. What Mike at 5-star has done is a baseline, showing numbers for the stock configuration. Then, modified and re-dynod it as he went along. Which is great for comparing modifications to the SAME VEHICLE.

What he plans on doing is putting a PI-head engine into that SAME VEHICLE and continue doing dyno runs. Which is going to be very interesting to see. Because it will be the same transmission and driveline.

If he were to then take another vehicle with a PI-head V10, lets say a different year, different length driveshaft, maybe even different brand tires, it would mean NOTHING because you can't compare two different vehicles.

--

What I'm basically saying is that, with the way a dyno works (after going to great length to explain it - not only to you, but to others reading this thread) there is no way to quantify the difference between Ford's flywheel numbers and what a rear-wheel dyno has computed at the rear wheels.

You don't just take flywheel numbers, subtract driveline losses and come up with the same numbers a rear-wheel dyno shows.

It kinda-sorta works out for the most part with light driveline vehicles. But with bigger and bigger stuff inbetween the engine and the dyno, you're going to see a LOT lower numbers than you expect.

Like I said before, if the dyno drum were twice the weight, or three times the weight, I suspect you would see less "lost" power. Because the rotational weight of the driveline wouldn't effect the final numbers as much.

 

we have three v-10's currently, all are bone stock. One '03 is auto and the other '03 is 6 spd manual. The third one is '05 with torqshift auto. Of the three, the 6 spd is by far the weakest performing stock combo. It's very hilly where I live and the std tranny truck is never happy in any one gear for more than a moment. The engine just seems to have a very narrow power band and needs to be wound up more with the manual vs the automatics. They all get about 12.5-13 mpg and the '05 needs 89 octane to prevent spark knock when lugging. We do alot of towing (10,000 lbs) and the '05 with the torqshift is by far the best combo of the trucks we have (includes 3 '06 6.0 PSD's, too).

As for your chassis dyno concerns, the single biggest influence on hp/tq numbers is simply how you "catch" the inertia wheel. The shift points/gear ratio/inertia mass etc that effect dyno numbers seldom translate directly to the road.

 

That's a great way to describe what I am trying to say (without much luck).