FWD VS AWD Drivetrain Loss

[REDspydergst]

I have always wondered about drivetrain loss between fwd and awd. For instance, If a FWD 2g put down 410whp and a AWD 2g put the same power on the same dyno how much power would it be putting down if the 2g awd was FWD?

 

[lil corb]

I have always wondered about drivetrain loss between fwd and awd. For instance, If a FWD 2g put down 410whp and a AWD 2g put the same power on the same dyno how much power would it be putting down if the 2g awd was FWD?

The General rule I have always learned is about 15-17% drive train loss for FWD and 20% for AWD loss.

 

[lasthope05]

The General rule I have always learned is about 15-17% drive train loss for FWD and 20% for AWD loss.

You cant really go by percentages. It might work for stock figures but is not a linear loss.

I.E. Say a stock awd makes 200 crank and 160whp. That's a 40 hp loss from drive train. Now letssay you have a 800whp car. With the above loss percentage, do you really think the car losses 200 hp just from the drive train?

With friction and drag lost staying constant with only power increasing it "should" take a similar amount of power to over come the same drive train and not 160hp extra just because the engine is make more power.

There is also unsprung rotational weight etc that plays a role...

 

[boost97gst]

Also, AT lose more power than MT. Thats a consideration as well. On the flip side they dont lose boost between shifts so the powerloss from an AT might feel more like a gain. Thats another story though

 

[crash89]

Not only do you lose a bit of power between the two, fuel milage as well. For example, before my AWD swap I was on a 20g and 1000s blah blah. Drove down to the shootout and back (7 hours one way) 36mpg. Did my AWD swap, no change to the tune or anything! Drove down to MOD apx 3 hour drive one way. 27mpg. 9 miles per gallon difference JUST from swapping to awd. Same fuel, all highway driving, no pulls either.

 

[4gfun]

Not only do you lose a bit of power between the two, fuel milage as well. For example, before my AWD swap I was on a 20g and 1000s blah blah. Drove down to the shootout and back (7 hours one way) 36mpg. Did my AWD swap, no change to the tune or anything! Drove down to MOD apx 3 hour drive one way. 27mpg. 9 miles per gallon difference JUST from swapping to awd. Same fuel, all highway driving, no pulls either.

That is pretty substantial. I'd expect closer to 5 mpg, but don't have anything to base that on....your numbers freak me out a bit.

 

[StarionGSX]

You aren't factoring in tire spin loss. Try putting 410whp to the ground in a FWD. Gonna have a fair amount of tire spin even with sticky tires. AWD will do much better at that HP level. Especially with sticky tires.

 

[an orange crayon]

You aren't factoring in tire spin loss. Try putting 410whp to the ground in a FWD. Gonna have a fair amount of tire spin even with sticky tires. AWD will do much better at that HP level. Especially with sticky tires.

Tire spin loss? WTF tire spin has nothing to do with how much hp you put to the ground.

 

[StarionGSX]

It has everything to do with it. If you have 500 whp in a FWD and can't get traction then all you have is a burnout machine and not a fast car. If on the other hand you have the same car but it's AWD and can get traction then the extra AWD drivetrain loss is meaningless because you are getting the power to the ground.


Lots of HP means nothing if the tires can't handle it. And most of the time FWD can't get traction with lots of HP.

 

[wkmitsu]

That is pretty substantial. I'd expect closer to 5 mpg, but don't have anything to base that on....your numbers freak me out a bit.

Those numbers are about what I have seen between FWD and AWD cars as well.

Tire spin loss? WTF tire spin has nothing to do with how much hp you put to the ground.

Speaking in terms of how much power is transferred to the wheels, you are correct. He's speaking in terms of how much power is transferred into forward motion, which is what really matters when you get right down to it. Unless you want to do burnouts.

 

[lasthope05]

It has everything to do with it. If you have 500 whp in a FWD and can't get traction then all you have is a burnout machine and not a fast car. If on the other hand you have the same car but it's AWD and can get traction then the extra AWD drivetrain loss is meaningless because you are getting the power to the ground.


Lots of HP means nothing if the tires can't handle it. And most of the time FWD can't get traction with lots of HP.

It has nothing to do with it. If you don't know how to drive a fast fwd car. Its your problem, not the cars. It takes a lot more skill and experience to drive a high power fwd then an awd. Anybody can mash a throttle.

 

[boost97gst]

^^^ Takes a ton of skill to do good 1/4s in a fwd. And a whole lot of money in suspension/rims/slicks. Ive run near 500whp on street tires. Mine never got sticky tires but really lost its fun factor past 40lbs/min. The torque steer, no traction, the danger factor on the road. It was fun for awhile, being my first dsm and all. After killing a ring (i guess), i decided awd automatic was the next step.

 

[haddixjl]

Just curious if any other awd owners expierenced that much of a loss of mpg? I would have only thought a few not 5-7

 

[Mello]

I have a '95 GST & '97 GSX. In town, stop 'n go mileage is really close between them with a GST maybe 2 mpg more. On the highway my GST does about 10mpg better than my GSX.

 

[an orange crayon]

It has everything to do with it. If you have 500 whp in a FWD and can't get traction then all you have is a burnout machine and not a fast car. If on the other hand you have the same car but it's AWD and can get traction then the extra AWD drivetrain loss is meaningless because you are getting the power to the ground.


Lots of HP means nothing if the tires can't handle it. And most of the time FWD can't get traction with lots of HP.

we are talking about how much power you would lose in the drive train in a AWD vs FWD , to figure out how much power you dyno the car correct? Have you ever seen tire spin be a problem in a dyno? If we were talking about a FWD vs an AWD in a race yes the AWD will launch harder, but doesn't mean it has more power getting to the wheels.

 

[Archer Fabrications]

Especially cause both the gst and gsx would have the same hp on an engine dyno. Put that in a go kart, you will keep most of the power the crank has.

Throw it in a dump truck, and you have lost everything, i believe it's mostly about weight in this instance

Motorcycles are only, what 130hp? But hell of a lot quicker then a 195hp eclipse.

If you lighten your awd to the weight of a fwd you have the same drive train loss.

 

[StarionGSX]

we are talking about how much power you would lose in the drive train in a AWD vs FWD , to figure out how much power you dyno the car correct? Have you ever seen tire spin be a problem in a dyno? If we were talking about a FWD vs an AWD in a race yes the AWD will launch harder, but doesn't mean it has more power getting to the wheels.

I'm not talking about power to the wheels. I'm talking about power to the ground which is more important.


Yes I have seen tire spin on a roller dyno many times.

RWD

[ame=http://www.youtube.com/watch?v=A8Z88YtsM1Q]2004 Cobra spinning the tire @ Dyno day - YouTube[/ame]


FWD

[ame=http://www.youtube.com/watch?v=ZS-rExVnQ_8]East Coast Performance - Spinning tires on the dyno! - YouTube[/ame]

 

[an orange crayon]

I'm not talking about power to the wheels. I'm talking about power to the ground which is more important.


Yes I have seen tire spin on a roller dyno many times.

RWD

[ame=http://www.youtube.com/watch?v=A8Z88YtsM1Q]2004 Cobra spinning the tire @ Dyno day - YouTube[/ame]


FWD

[ame=http://www.youtube.com/watch?v=ZS-rExVnQ_8]East Coast Performance - Spinning tires on the dyno! - YouTube[/ame][/

Its the slimmest chance you will spin on a dyno, u wanna talk about why awd is better cause they don't slip go start your own thread about it, there are FWD cars running a wheele bar and don't slip, its all in your set up and how you drive it, don't morph the OP question so there has to be more pointless comments, stay on track, don't just post to get yourself out of probationary period.

 

[Archer Fabrications]

Pwnd

 

[Hillala]

I can say from owning both FWD and my current AWD DSM, both being the turbo six bolt five speed. The awd does feel faster in factory forum from a launch but otherwise the difference from the two aren't that much. Both setups have their pros and cons, AWD seems to hold the power better while FWD (in corners) is all about understeer if you're on it but it mainly works around your style of driving.

In short the AWD does have more of a power loss but it's more efficient at putting the same power down. Out of stock form I can't say much, my FWD didn't have much while my AWD is what it is, a long way from stock.

As for fuel milage, I pulled close to 30mpg in my FWD, I get around 20mpg (while i'm not on heavy boost) in my AWD (note the FWD was close to stock and the AWD is not)

Hopefully some of this information will help answer your question.

 

[black97spyder]

Ive noticed the same. My 97 spyder gst (stock cams and valve size) would get 26mpg in town with me boosting all over the place with a 16g... With the same setup on my 97 awd talon (bc280 cams and +1mm oversized valves) gets about 18mpg in town without me boosting very much..... I personally think weight is the biggest factor between the two

 

[4gfun]

Ive noticed the same. My 97 spyder gst (stock cams and valve size) would get 26mpg in town with me boosting all over the place with a 16g... With the same setup on my 97 awd talon (bc280 cams and +1mm oversized valves) gets about 18mpg in town without me boosting very much..... I personally think weight is the biggest factor between the two

I have always read that weight makes no difference for 2 vehicles with the same aerodynamics and engine on the highway. Not sure if your commute is 100% highway though. Mine is pretty damn close to it. I appreciate the data.

Wow 8-9 mpg penalty. I couldn't find a 1g at all and after waiting for months just got one with a blown head gasket. Was trying to get a FWD for my daily commute. Oh well, I'll be better off in the snow.

 

[Diamond Star Werks]

I have always read that weight makes no difference for 2 vehicles with the same aerodynamics and engine on the highway. Not sure if your commute is 100% highway though. Mine is pretty damn close to it. I appreciate the data.

Wow 8-9 mpg penalty. I couldn't find a 1g at all and after waiting for months just got one with a blown head gasket. Was trying to get a FWD for my daily commute. Oh well, I'll be better off in the snow.

Weight is big difference.