Can someone please explain to me why they think that the drivetrain losses on a Lightning(or any vehicle) would be a percentage of HP and not a specific loss at a given rpm? Factory tech has stated that the drivetrain loss of our L's is 11.2% at peak torque. Now, if you take 380hp x 11.2% you get 42.5. This means that at peak torque there is a 42.5hp loss through the drivetrain. Why would the drivetrain loss increase once the vehicle is modified and now makes 450hp?


Hopefully what I am asking makes sence.

 

The loss all has to do with heat, the more hp you make the faster you can get to red line. So the loss is geared to movement, which is dynamic, you might be thinking static hp, which is potential hp only. This isn’t taking any abnormal harmonics into consideration.

Can you imagine spinning our trucks up to 0-120 mph in ½ second? Do you think that we would only lose 45 hp with the type of hp that it would take to do that?

Our drivetrain would melt in about a microsecond.

While the BS 11.2% stuff could be a totally locked transmission figure, this probably doesn’t take into consideration the drive shaft flex, and differential ect..

 

If someone actually belives that the peak loss is 11.2% on the lightning powertrain (flywheel-tire/road), then yes, I know far more than (s)he does about the lightning powertrain.

 

Gonna stick with factory_tech on the 11.2% loss. When you plug in the numbers they come out matching published statistics. With your methods all that come out are excuses and assumptions. While your rule of thumb numbers may work for the inefficient GM drivetrains they don't match Fords published numbers.

 

First of all I'd just like to say that I don't believe for two seconds that the total driveline loss is 11.2%, MAYBE just MAYBE I'll buy that the loss through the transmission is 11.2 but even that is still hard to believe because our trucks have one hell of a big transmission, but anyway, that still doesn't account for the two U-joints, the length of the driveshaft (think of it like you are using a ratchet with an extension, the longer the extension, the more torque it takes you to break a nut/bolt loose), the big heavy 9.75 differential, the axles (length again) and don't forget those big *** 18" wheels and tires (just take one off and pick it up, they weigh plenty). Power is used up moving these parts before you even get to put any down to the road. This is just my .02 since I have no way of proving/disproving this.

Now here is the dyno information that I got.

I usually made two runs with each setup to get a backup number.

BTW, I kept the engine running with the trans in Neutral the whole time in between runs (except when I installed the chip etc) to keep the coolant flowing(for fear of heat soak). There was a large cooling fan in front of the radiator/intercooler heat exchanger at all times, I ran the inside heat on high between runs to help dissipate some engine heat.

The correction factors on all of my dyno sheets say 1.03 SAE with one 1.02 and one 1.04 , is this good?

Initial setup: BONE STOCK TRIM (paper filter, no chip, etc):
*1st run: time? downshifted, aborted.

*2nd run: 1:05pm 349.1HP / 414.3TQ

*3rd run: 1:07pm 347.0HP / 415.0TQ
---------------------------------------------------

Second setup: Insert K&N Drop in filter:
*4th run: 1:11pm 356.5HP / 424.9TQ

*5th run: 1:13pm 352.2HP / 419.1TQ
---------------------------------------------------

Third setup: Factory Airbox with NO FILTER installed:
*6th run: downshifted, aborted

*7th run: 1:30pm 347.3HP / 415.4TQ

*8th run: 1:32pm 346.1HP / 415.5TQ
Note no filter in factory box gave lower numbers than stock paper
---------------------------------------------------

Fourth setup: Completely remove airbox, running open MAF sensor:
*9th run: 1:40pm 339.8HP / 411.9TQ
Note in addition to not idling properly, lost HP & TQ, did not waste time backing up this run, I was attempting to eliminate all restriction going into the MAF to determine if the factory airbox is really a restriction, but the test didn't really work out.
---------------------------------------------------

Fifth setup: K&N panel back in, Ice bag on intake. Note: I didn't take time for a real cool down with the ice (only about 14mins) but I did leave the ice bag on during the run. Take this for what it's worth, but I suppose you could assume that this would sort of simulate the conditions you'd achieve after icing down at the strip for a while between runs?
*10th run: 1:54pm 360.0Hp / 430.6TQ

*11th run: downshifted, aborted

*12th run: 1:56pm 355.8HP / 422.8
Note as you can see the ice works great, but the engine heat overcomes it quickly.
-------------------------------------------------

Sideline: My girlfriend just took my L and went to McDonalds for breakfast scary huh :o? but anyway she's back (I peeped out the window and the truck looks OK) so I've gotta go eat. I'll come back after breakfast and finish this.

later,
chris
-------------------------------------------------

OK, I'm back, those Bacon Egg& Cheese bagels are pretty good from McD's

anyway, where was I? ok, run 13

Sixth setup: JDM CHIP installed street side, K&N panel, Intake iced for about 20 minutes:
*13th run: 2:14pm 379.9HP / 453.9TQ

*14th run: downshifted, aborted

*15th run: 2:16pm 381.7HP / 455.1TQ Best of the day!

*16th run: downshifted, aborted

*17th run: 2:19pm 372.2HP / 443.0TQ

*18th run: downshifted, aborted

*19th run: 2:22pm 372HP / 442TQ

All in all I am very pleased with my numbers, I just can't wait to get a pulley (or two) on the truck and see what she'll do then.

I didn't have an open element filter to test to compare, I wish I did but as you can see on my truck the K&N drop in added anywhere from 3-10 HP at the rear wheels which is not bad considering some folks told me it wouldn't make any difference at all.

Just something else to think about, have any of you ever tried using one of those horsepower calculators? I know that they are not 100% accurate or anything, but isn't Horsepower just a calculation of how quickly a specified amount of weight can be moved a specific distance (or something to that effect) math people help here...

anyway, just how much HP does it take to get a 4700lb truck (at least that including a driver and fuel probably closer to 4950) to go accelerate to 104+mph in just 1/4 mile??? just curious, I think I'll go check.

try this: http://www.corral.net/cgi-bin/hpower.pl

later,
chris

 

I have actually seen the Ford Test results for power loss for each of the lightning powertrain components (axle, 9.75 rear), and they add (multiply) up to more than a peak loss of 11.2%.
Furthermore, my truck was spun on an eddy current dyno in and saw what equated to more than a torque 11.2% loss.

 

Well it's not exactly rocket science.

1) Machines are made to measure drivetrain losses.

2) Machines are made to measure the HP on a freestanding engine.

3) Ford more than likely has both of these types of machines.

4) Ford employees use these machines.

5) They publish the HP numbers from the machines.

6) The employees also state the drivetrain losses observed while testing.

7) Joe Blow comes along and says they're wrong. No basis as to why, they "just know better". Why "they know better" credentials are never published.

8) Joe Blow has in essence said there is a conspiracy to cover up published HP numbers and it is backed even by rank and file Ford employees.

9) Joe Blow is yet to say why there is a conspiracy. The only one that has a detrimental effect on us for high published HP numbers are insurance companies. Is Ford thwarting insurance companies for our benefit?

10) Joe Blow is probably incorrect in his assumptions.

 

quote:Well it's not exactly rocket science.
1) Machines are made to measure drivetrain losses.
2) Machines are made to measure the HP on a freestanding engine.
3) Ford more than likely has both of these types of machines.
4) Ford employees use these machines.
5) They publish the HP numbers from the machines.
6) The employees also state the drivetrain losses observed while testing.
7) Joe Blow comes along and says they're wrong. No basis as to why, they "just know better". Why "they know better" credentials are never published.
8) Joe Blow has in essence said there is a conspiracy to cover up published HP numbers and it is backed even by rank and file Ford employees.
9) Joe Blow is yet to say why there is a conspiracy. The only one that has a detrimental effect on us for high published HP numbers are insurance companies. Is Ford thwarting insurance companies for our benefit?
10) Joe Blow is probably incorrect in his assumptions.

oh jeez, this is rediculous. I suppose you've never heard of a manufacturer providing incorrect horsepower numbers right? Manufacturers are famous for underating performance vehicles.

Oh and will one of you people that keeps talking about all of Ford's measuring equipment PLEASE explain to me what the hell happened with the 99 Cobras????? I guess Ford FORGOT to use all that fancy equipment to measure those babies before they sold them right 4D THNDER??? All the publishings had them rated at 320, but they were lucky to make 285 on a good day? care to explain that to me?

chris

 

This is my opinion and isn't fact. I happen to have a Mechanical Engineering degree, but that doesn't always mean a whole lot.

There isn't a constant percentage of power lost in the drivetrain. There are several factors involved and a blanket statement of 20% (or 11.2%) no-matter-what with an auto and 15% with a manual is unrealistic. It is possible that you could determine a percentage of horsepower lost, if you had a flywheel number and a rear-wheel number. If anything changes, all bets are off (including engine power output). Just like HP the percentage lost will vary from vehicle to vehicle.

Higher horsepower mustangs with C-4's that are making 600 at the wheels aren't losing 120+ HP in the drivetrain. 120 HP is a lot of energy to be dispensed by friction and drag. Friction creates the heat......but the drag of components is also a factor and is proportional to fluid viscosity and velocity.

You can argue this several different ways, but the only way to determine true loss is by having a flywheel and rearwheel measurement on your exact vehicle. Otherwise it turns into bench racing. If people insist on putting an exaggerated increase on the rear wheel numbers, let them. The race track is the true equalizer.

On another note......it's silly to argue or resort to name calling on such a trivial point. If you are that emotional about this subject pull your motor and put it on a test stand.

 

Agreed 351. There is more to it. To say it's equal all the way through the powerband would be unrealistic. The 11.2 or 20 or whatever is an average.

superfords, do you think they recalled 'cuz Billy Bob "thought" it was underpowered? They wouldn't test every single one that leaves the factory. They probably used these same exact machines to find out they weren't meeting specs though. As far as 285HP you're talking rear wheels unless someone yanked the engine out and put it on a dyno(and those style dynos are rare as most people aren't gonna go to that trouble). And I did see people over on BON crying because they thought a 320HP Mustang was supposed to put that much to the rear wheels. Unless you got a valid reason other than conspiracy and Billy Bob's rule of the thumb I stand by factory_tech's 11.2%, those numbers fit published numbers. The rule of thumbs are about as accurate as those on-line HP calculators. Mine is listed at 452 HP to rear wheels and 587 HP at the flywheel. Bow to the HP God! Well, Billy Bob anyway.

 

Based on the link below:

Your car weighs about 4950 pounds and has a trap speed at the end of the 1/4 mile of 104 m.p.h. . That calculates to approximately 378.08 HP at the wheels.

http://www.smokemup.com/utilities/calc/hp_mph.cfm

Plug in some different figures, makes for interesting conversation.

Take it with a grain of salt, no flames intended, names have been changed to protect the innocent, yada, yada . . .

 

WHAT?? I agree that a longer extension will increase the rotational displacement noted at the end of the ratchet handle - but the extension doesn’t consume the torque.

 

I'm not trying to be a smartass (in fact maybe I'm just a dumbass ), but what the crap is rotational displacement? All I know is that when you are torqing a fastner that you loose torque the longer the extension you use. Example: if you tighten a bolt using a torque wrench with a 12" extension to 100 ft/lbs then you remove the extension and torque it again with no extension you will find that the bolt will turn further before reaching the 100ft/lb mark again. I am not an engineer or a rocket scientist, but I would assume this would also apply to a driveshaft. maybe I am wrong, I'm sure somebody will tell me so if i am

 

listen folks, I posted my dyno times for two reasons...

first: to provide information to other Lightning owners about how my truck reacted to some different variables.

secondly: to post my trucks numbers because I am proud and excited about the outcome of my first dyno experience with my L.

I was not aware of Factory Tech's statement about 11.2 drivetrain loss, I still have not done a search on this topic to see for myself what exactly was quoted on this subject. However from what I understand Factory Tech is in the business of rebuilding and testing transmissions, NOT LIGHTNINGS. He may have access to a 7 million dollar piece of test equiptment, but I doubt that machine test vehicles or entire drivelines, rather it tests transmissions, as this is his profession and area of expertise.

Regardless of all of this, my point is this if my truck makes 425 Horsepower (based on 11.2% average loss) or it makes 450 Horsepower (based on 18% loss) I LOVE MY TRUCK. that 25 HP doesn't make a difference to me, it is still freaking unbelievable that a basically stock pickup truck is making numbers like these.

I thoroughly enjoy my truck and am impressed with the numbers that it put out no matter how they are interpretted at the flywheel. that is all I have to say about that.....

have a good labor day all.

sincerely,
chris haynie

 

Regardless of all of this, my point is this if my truck makes 425 Horsepower (based on 11.2% average loss) or it makes 450 Horsepower (based on 18% loss) I LOVE MY TRUCK. that 25 HP doesn't make a difference to me, it is still freaking unbelievable that a basically stock pickup truck is making numbers like these.

No argument.