HP/Weight ratio to performance

[lurker]

I am new to this site but not new to modding german cars as having had volkswagen both water and aircooled, mercedes and porsche. There are some very nice modded cars on this site and some good information shared. I would like to make my own contribution with regards to horsepower to weight ratio. I recently read a post where another user removed his sub box from his trunk and noticed a difference in the way his car handled and performed. I realize most cars on the site are daily driven and music is hard to live without but take into consideration the cost or penalty of adding weight. From the butt dyno every 100 pounds of weight is equal to 10 horsepower. Here are a couple of great links to hp to weight calculations including performance numbers like 0-60 times and 1/4 mile times. Check these out and play with the weight of your car you will be amazed what deleting weight will do.


http://www.letstorquebhp.com/calculator.asp

http://www.rennlight.com/cgi-bin/hp.cgi

[Charlescrs6]

very interesting, thanks

[dirtybrd]

Correct, 100lbs is equal to 10HP or .10 of a second. I can tell a big difference if someone is riding with me.

[texasboy21]

Correct, 100lbs is equal to 10HP or .10 of a second. I can tell a big difference if someone is riding with me.

Very true, especially if you drive by yourself a lot! Ive been considering removing the back seat along with some trim and other things i come across in the process in order to gain some performance. My reason for and against is i would only do the back seat and areas i dont see so it wont be an eye sore, but i thought it would throw off the balance. also due to 17 tickets and insurance reasons i have to keep this car until im 25 so i dont want to mess it up, i have very big, but very very long term dreams for this car so i consider all costs in any mod.

barrett

[Yasek]

Are all required hp ratings at the flywheel?

[mike-2ptzero]

Correct, 100lbs is equal to 10HP or .10 of a second. I can tell a big difference if someone is riding with me.

I think it wont have such a big effect on a car that is running 9's as it does to one running 13's.


Just look a how big of effect on the 1/4 mile time a chip has on a K03 vs what the car runs stock at 150-170hp.

[F16HTON]

This is why I told Tracee to lose some weight

[diagnosticator]

I think it wont have such a big effect on a car that is running 9's as it does to one running 13's.


Just look a how big of effect on the 1/4 mile time a chip has on a K03 vs what the car runs stock at 150-170hp.

Driver's skills typically influence 1/4 mile times as much if not more than +/- several hundred pounds curb weight also.

[Redgoat]

The first mod should be driving school ;)

[mxrz]

From the butt dyno every 100 pounds of weight is equal to 10 horsepower.

Not true. You can have two cars with the same power to weight ratio, but if one is less than a ton with little horsepower and the other weighs two tons with lots of horsepower, 100 pounds is not going to affect both equally. There are too many variables, even between the various versions the A4 comes in (engine type, drivetrain type, transmission type). You must specify a single base vehicle, and then you can use a rule of thumb like that.

[dubbin.t.rex]

^^ It's a rule of thumb, and it's pretty accurate

Power to weight ratio is the best way to compare two cars on paper.

Also to the 9 vs 13 second car comment its not true. Its relative to overall weight. If you loss 100 lbs on a 3700 lb car, it will be much less noticeable than if you lost 100 lbs on a 2900 lb car.

[dirtybrd]

Everything is just a guesstimate, like you said rule of thumb.

[Exanimas]

Not true. You can have two cars with the same power to weight ratio, but if one is less than a ton with little horsepower and the other weighs two tons with lots of horsepower, 100 pounds is not going to affect both equally. There are too many variables, even between the various versions the A4 comes in (engine type, drivetrain type, transmission type). You must specify a single base vehicle, and then you can use a rule of thumb like that.

This man is correct. 100 pounds = 10 HP only if the the weight/HP ratio is already 10/1.

[diagnosticator]

Sure, as a Rule of Thumb, that's fine, but noone really knows how accurate the published flywheel hp rating is compared to the average typical AMB actual output is. Some engines will be lower, and a few hgiher than the published value. It would be very few production engines actually make exactly the published value.

[OCMI_Teddy]

Correct, 100lbs is equal to 10HP or .10 of a second. I can tell a big difference if someone is riding with me.

http://www.youtube.com/watch?v=edthG9ObzF4

[AudiA4_20T]

http://www.youtube.com/watch?v=edthG9ObzF4

yes

[ThreePointOhh]

lol, that video is funny.

[[email protected]]

http://www.youtube.com/watch?v=edthG9ObzF4

OK.

Now I know why I'm single.

[lurker]

The first mod should be driving school ;)

Karl,

Does the NWQuattro Club run DE days at Pacific or do you run with the Audi Club?

[Maverick]

lmao@that video.

[PRVWing]

Im starting a new diet today!!! lol

[BNZ TOY]

This is why I told Tracee to lose some weight

haha, was waiting for someone to say something about the GF.

Oh and I don't carry my spare tire.

[Redgoat]

Karl,

Does the NWQuattro Club run DE days at Pacific or do you run with the Audi Club?

We have not looked into doing DE days since ACNW does them. Much easier to just jump on with them than to set one up ourselves and go through the hassle of insurance etc.