[jsmsustudent]

Just wondering why our drivetrain losses are so great. I mean how is it that an STI with 300 hp only puts 225-255 whp, and an evo for example with 287hp put 255-275 whp. What is it about our cars that causes these losses. What mods can we do to improve our losses. Just trying to learn everything i can about our cars.

[fry_ed]

AWD cars have a lot of drivetrain loss.

For comparison, EVOVIII's put out about 215 -240 whp.
Yes EVOIX's put out alot. They're horsepower is underrated. They don't have a sweet hoodscoop though

[jsmsustudent]

Originally Posted by fry_ed

AWD cars have a lot of drivetrain loss.

For comparison, EVOVIII's put out about 215 -240 whp.
Yes EVOIX's put out alot. They're horsepower is underrated. They don't have a sweet hoodscoop though

So what you are saying is that the evo IX doesn't necessarily have less of a drivetrain loss than us but that the 287 hp should be higher than mitsu states.

[evilSTi7]

all awd cars have about the same amount of drivetrain loss (which is more than fwd or rwd cars since and extra set of wheels must be driven), but the evo IX engines are underrated. so yes, mitsu isn't giving the most accurate numbers.

[jsmsustudent]

Originally Posted by evilSTi7

all awd cars have about the same amount of drivetrain loss (which is more than fwd or rwd cars since and extra set of wheels must be driven), but the evo IX engines are underrated. so yes, mitsu isn't giving the most accurate numbers.

Those bastards.

What mods could i do to help the drivetrain loss. (CF driveshaft, etc.)

[FlyinbySTi]

I wish we were under rated, then I would save money on my car insurance. My company says 300 is the cut off for high performance. Anything rated 300+ pays high premium. lol, I told them the Evo is the same car just under rated. They told me should have bought the Evo.

[SilverSurfer]

And that's exactly why car companies underrate horsepower. SRT 4 is underrated quite a bit too. So are Cobras.

I think insurance companies are watching the wrong thing - or at least are not looking at the whole picture. They should focus on torque or at least focus on both HP and torque. When considering control aspects of a vehicle big torque is more dangerous than big HP...

For the thread starter, the drivetrain loss does suck in AWD vehicles, but you gain alot more in vehicle traction and practicality over traditional RWD sports cars. For me, the tradeoff is worth it.

[mxpop]

Good lubricants and tire pressures are your best and only friends in the driveline whp loss saga. Sometimes I feel like my e-brake is slightly on because my car just doesnt coast very well (it's not).

That's partly why I only get 5.5 mpg on track days but it sure accelerates well! That's the trade off I guess.

[SilverSurfer]

Originally Posted by mxpop

Sometimes I feel like my e-brake is slightly on because my car just doesnt coast very well (it's not).

Haha... No doubt there.

I've never drove a car that slowed down soooo much when I took my foot off the gas. To the point I barely ever have to use my brakes on the interstate. I just take my food off the gas and I decelerate fast enough that it feels like I'm slightly pressing the brakes.

I've gotten so used to it I like/prefer it now. Kinda weird.

[MGizzle]

Loose weight and you will help your car being faster. Lighter wheels, drive shaft, flywheel, clutch etc. Pretty much, the leas load the less heat the less drivetrain loses. Good lubrication obviously helps because you don't waste energy heating stuff up.

Also, I am not sure if you ever rad the article from Road & Track or Car & Driver, don't remeber which one, where they compared the EVO and STi engineering quality on the drivetrain. The STi drivetrain is superb in making sure wheel velocities are what they need to be. So yes, we might be making less WHP, but we have better hardware. Also, I am very appreciative of the little DCCD knob in our cars that actually functions.

[mxpop]

Originally Posted by MGizzle

Loose weight and you will help your car being faster. Lighter wheels, drive shaft, flywheel, clutch etc. Pretty much, the leas load the less heat the less drivetrain loses. Good lubrication obviously helps because you don't waste energy heating stuff up.

Also, I am not sure if you ever rad the article from Road & Track or Car & Driver, don't remeber which one, where they compared the EVO and STi engineering quality on the drivetrain. The STi drivetrain is superb in making sure wheel velocities are what they need to be. So yes, we might be making less WHP, but we have better hardware. Also, I am very appreciative of the little DCCD knob in our cars that actually functions.

While you are correct that less weight equals better performance, i believe that the topic refers to driveline drag/losses, not overall weight etc.

[Web_Foot_STi]

Just try and push your STi in your flat driveway, or a staging lane. With the limited slip diffs it just doesn't move!

This is a very old topic.

[merrill.p]

holy engine braking batman!

[TR11]

Originally Posted by mxpop

While you are correct that less weight equals better performance, i believe that the topic refers to driveline drag/losses, not overall weight etc.

well, isnt reducing rotational mass reducing driveline drag? The less rotating mass the engine has to spin to get the car moving, the less hp loss at the wheels.

[mxpop]

Originally Posted by TR11

well, isnt reducing rotational mass reducing driveline drag? The less rotating mass the engine has to spin to get the car moving, the less hp loss at the wheels.

You're thinking inertia, not drag, as in a heavy flywheel etc.

Drag is the resistance to move such as gears in thick oil or bad bearings or draggy diffs, low tire press, etc.

Rotating mass (as in flywheel) wont reduce horsepower but it will reduce acceleration. Drag will ruin hp and acceleration.