18% is not bad for out AWD cars, just think how bad it sucks for my buddies 94 cobra, that stang looses anywhere from 19-23% and its a RWD car. I hear FWD DSM's rock around 15pacent.

 

That's why AWD trap speeds are so low.

That's ok, make up in ET with the nice 60 ft. Hp ratings are only numbers, so don't worry about it.

 

I think he was saying...

That the 18% was for the FWD probe and that the AWD was loosing like 30%. That was a case of selective reading my friend??

 

Sorry about the confusion but BadDSM is right. I meant 18% for the probe GT and %30 for AWD cars.

 

Oops, didnt completly read the whole deal, im not sure how much % loss is on the 3SI's but I know on the AWD DSM's they are around 18%.

 

The G-Tech is about as accurate as using a stopwatch to time 1/4 mile times.

Mark

 

I quess what i'm really wondering is if anyone has ever dynoed a stock AWD turbo DSM. Because the AWD cars that i've seen so far have a %30 loss.

 

I've been trying to look everywhere for dyno results of a AWD DSM. Where do people get the 18% loss for AWD? I can't find any what so ever. Infact most FWD and RWD have around 18% loss from what i've seen. But I did find EVOs, Subarus wrx, sti, and 3000gts. Both the 3000gt and subaru WRXs loose about %30 thorough the drive train and the automatic WRX lost %40!!! The EVO VI lost about %28!! Now what makes Our cars so special to loose a lot less then other AWDs? I'm not saying that everyione here is wrong but I'm a bit skeptical about the %18 - %20 loss numbers. Here is a link to many AWD and some RWD dyno results if anyone wants to check. http://dyno.scoobynet.co.uk/

 

this is my newbieness coming through but how do you lose power through the drive train? where does it go?

 

this is my newbieness coming through but how do you lose power through the drive train? where does it go?

its through friction. thats why awd loses so much more than fwd because it has to send power to the back of the car so it has more parts to lose power through, thats why fwds have the least loss, because they just have to send power to the front. hope this helped.

-Aaron

 

Thats why if you have an awd you go for parts that build more torque as well has horsepower. What is going to bring you through that driveline loss better, 10 hp, or 10ft lbs of torque. Our cars have a lot of torque for such little engines, I bet just a lightweight harmonic balencer and other torque gains would make our cars faster, while it would just cuase a fwd to lose more tracion. then again torque breaks stuff too hehe. fwd dsms are the high speed killers...

 

Well I guess with even all the loss of power through the AWD system the Imprezza STI and EVO VI have they still manage 12s in the 1/4 mile somehow.

 

The G-Tech is about as accurate as using a stopwatch to time 1/4 mile times.

Mark

Why do you say that? Mine's never been off by more than 2/10's of a second.

 

Do you use your G*Tech at the strip? I run mine when I race and it shows my car to be 4 tenths quicker consistently than my actual 1/4 mile time.

 

Do you use your G*Tech at the strip? I run mine when I race and it shows my car to be 4 tenths quicker consistently than my actual 1/4 mile time.

That is about right, because I think in my instruction booklet that came with it said that it would be + or - 3 tenths of a second + or - 3 horsepower etc. My GTECH does a pretty good job in my opinion.

 

driveline loss < traction

so you got more driveline loss than FWDs, but the traction makes up for that. That's why AWDs launch fast, even better when timed right. Better to have your car immediately haul ass than spin the tires for 1-2 secs before getting traction.

 

yeah but then when we do take off like that we break shit. I think it basically all evens out with the advantages and disadvantages.

 

new superstreet has dyno chart for stock wrx and it has 168hp at the wheels and 227 at the motor so thats around 25%

 

new superstreet has...

i have the august 01, and i can't seem to find it. I think Turbo mag has a little info on the WRX's dyno...

 

yup your right, my mistake.. its the new turbo one .

 

damn!

I was hoping that I missed something. I want to learn more about driveline loss!

A few months ago, I heard these two guys talking and one of them was bragging that his dad has a cuda (i think), that had 900+hp at the flywheel, and 700hp at the wheels, but then getting less than 2mi/gal.

big drop in hp to the wheels.

 

I was reading about driveline loss at a Pontiac Grand Prix club and they say they loose about 23% on their FWD automatics. I guess that's not too bad for an automatic but i'm probably loosing like %30 on mine. An extra 5% loss from an automatic starts to hurt when you start to make over 300hp.

 

One possible solution for gaining back those lost ponies is
using lighter part such as TE37's etc..etc carbonfiber drive shaft, lighter brake $y$tem. Reducing the rotating mass. Is it worth it...why not just slap "MUTT" on your car and make more horses..

:-( you will still have drivetrain loss. So Its somthing we "all wheel drivers" will have to live with.

 

30% is a little hard to swallow. That just seems like an absurdly high number that doesn't jive with the times AWD people are running. Realize that the only way to know the drivetrain loss in an AWD DSM drivetrain is to measure the drivetrain loss in an AWD DSM. Looking at the 3/S and WRX dyno's is a good reference, but is still only conjecture here.

G-Tech numbers aren't reliable enough to go by. People that have actually compared them with actual 1/4 numbers (like V8SpankR) always report significant disprepancies, in both ET and MPH. I've never used one, but if it's saying that it will usually be off by +/- 3 tenths, that's ~ 30 horsepower for most people!

The AWD drivetrain loss is damn high, but I don't think it's 30% (Maybe an automatic AWD DSM, though). We should be able to find out for sure soon enough, though - a new AWD dyno is opening up by my house in Garland, TX, and the NTEX Club DSM is almost surely going to get together an AWD Dyno Day or something when it does, most likely in August or September. I'll be the first in line

 

Check it out. Everyone on my native board is an. But this may shed some light on the subject. I believe it to be a set amount and not a percent. But that's just me.