I Got to Settle Something

[BigGreen06]

I doubt this is the right place to put this, but I had an argument this morning w/ my 2 brothers on the way to work about HP and torque loss in cars and trucks.
To start off, both my brothers have high-powered cars and suvs (S4 & ML430). I started off by saying that every vehicle loses power in the transfer from the engine to the rear wheels. My brothers believe that to be false. My brother w/ the S4 has 340hp, and says that the power is the same at the rear wheels as it is at the engine. I know some magazines will show their numbers of what rwhp should be, but I know those numbers are less than the factory HP settings for the engine. I know my f250 loses a certain amount of HP and Torque in the transfer to the rear wheels. I got to settle this dispute, can you guys help me with this. My other brother believes that it is solely due to the gearbox and that you have less hp at the peak of the rpms than you do at the lowend, thats sortof different for us diesel owners, our power is around the low-middle end of the rpm range (1600-2400). But regardless I need to get some answers so I can show them the truth.
Thanks.

-James, aka BG06.

[Hawkins115]

Every car, truck, van, whatever, loses power to the drive train. The factory rates the engines with flywheel horsepower numbers, the only thing is, is that AFTER the flywheel, the engine has to turn the added weight of the transmition, drive shaft, and then the wheels themselves. All of these things cause a loss in power. And if all else fails, tell your brother to throw his car on the dyno and compare it to what the stock numbers are...assuming his car is still stock.

[jfines@cox.net]

I think thier jellous of your powerstroke, and are looking for a way to ruffel your feathers.

[MrJohnWayne]

every vehicle looses power through the driveline unless it is super low geared which can kinda compensate for it. how much power it loses depends on what the configuration is. A 4x4 will loose more power then a 2x4. If you have too trucks that are 100% percent identical and put bigger tires on one, the one with the bigger tires will have less power at the wheels. etc.. etc..

As for the HP being less at peak. That is backwards. 95% of the time on gas motors torque is peak at lower rpms. HP peaks in the high rpms.

I heard this saying along time ago and for the most part it stays true.

Torque gets you moving, horsepower keeps you moving.

[Builttuff]

You lose about 25% of you hp thru your drivetrain... Your bros are kinda right on the gasers having more of their power on lower end than at peak rpm... Assuming their cars are stock.... With the stock cam in their engine its going to make its power way before it redlines...And as for as HP and torque....Torque is amount of work an engine can do....HP is amount of work an engine can do over time...

[dercody]

You are correct, you do loose power from the engine to the rear wheels that is why it is said "at the rear wheels" to clarify that. I read about that in diesel power magazine and other ones as well.

[bigcountrysg]

Tell them to take it to a dyno. Bet them a case of beer each that you are correct. Then go home with your 2 cases and enjoy.

They are wrong you are right.

[BigGreen06]

I can bet then $1000 each and they still won't take thier cars to a dyno, because they are stubborn, I can tell you they may in their own way be a little jealous of my truck, but they onle like fast cars and suvs (mostly German and Italian) the only american cars they like are the CTS-V and the Jeep SRT-8, they absolutely hate trucks and especially diesels, they would never give their cars more power unless it was something that the dealer would authorize and install. The one w/ the ML wants to get a Jeep Hennessey, but thats about the extent. I'm the onle one in my family that has ever liked trucks. My father drives and Escalade, CTS-V and a Porsche Carrera 4S, my Mother a Range Rover 4.6 HSE. My brothers (4 of them) 2 you already know, one of the others has an S4 as well and a Land Rover Discovery Modified for offroad (the only other modified vehicle in the family) and my other brother lives in NYC and just rents a car when he needs to go somewhere. Its just a mentality w/ my family. And my brothers believe because I have a big P/u w/ train horns and a scanner that I don't know anything about cars and trucks and the I'm just a stupid redneck now (No offense to anyone on the forum for my remark there). Thaks you to all for the quick replies on this, hopefully I get at least one of my brothers to read these replies.
Thanks Again.

-James.

[MrJohnWayne]

hahahaha. I'm sorry about laughing but for someone who won't put anything on a vehicle unless it is done by the dealer to be saing what they said then calling you dumb. Thats just funny to me.

And No i'm not laughing at you. I'm laughing at your brothers.

[bigcountrysg]

Tell your ignorant brothers that they can come to my house and I will pull there little toy cars all over my empty corn field. They maybe faster then my truck. But when they run out of gas trying to out run me I will pull up and hook up to them and tow them away.