Got my car Dyno'd yesterday......

[DivideBYZero]

We use 4 wheel dyno's in the UK for testing AWD cars such as my Impreza.

 

[MasterAndCommander]

Originally posted by: Theguynextdoor
Really good there, considering my C5 with 345HP at the crank puts down only 295 at the wheels.

Congrats. Do you have any plans to lighten? If you can shave off 100lbs off the car it'll be pretty quick. BTW anybody know the gearing config on the GTs?

Standard 5-speed manual (Tremec 3650)
Gear Ratios
- 1st 3.38:1
- 2nd 2.00:1
- 3rd 1.32:1
- 4th 1.00:1
- 5th 0.68:1
- Final Drive 3.55:1

 

[Zenmervolt]

Originally posted by: MIKEMIKE

Originally posted by: andylawcc
how much did the Dyno cost?

they run anywhere from like 30-50 per run from what i know

Around $100/run normally. I'm going with a group on the 17th and we have a group deal for $75/run. Of course, this is for runs with a full exhaust analysis as well so that we can get things tuned properly.

ZV

 

[Zenmervolt]

Originally posted by: 91TTZ

Originally posted by: DaTT
Me thinks nowadays, powertrain loss is somewhere in the range of 10-12% RWD......or they under rated the motor.

They intentionally under rated the motor. The drivetrain loss is still around 15%-18%. There's no way that a RWD transmission has only a 10-12% loss.

Driveline loss on a 951 is in the 10% neighborhood and it's RWD. Factory rating was 217 at the crank, people have dyno-ed stock 951's with 100,000 miles and still gotten 198 at the wheels. (Mine gets a touch more... 275hp/300 torque at the wheels @ 15PSI.)

Believe it or not, RWD typically has less parasitic driveline loss than FWD.

ZV

 

[Apex]

Originally posted by: Zenmervolt

Originally posted by: 91TTZ

Originally posted by: DaTT
Me thinks nowadays, powertrain loss is somewhere in the range of 10-12% RWD......or they under rated the motor.

They intentionally under rated the motor. The drivetrain loss is still around 15%-18%. There's no way that a RWD transmission has only a 10-12% loss.

Driveline loss on a 951 is in the 10% neighborhood and it's RWD. Factory rating was 217 at the crank, people have dyno-ed stock 951's with 100,000 miles and still gotten 198 at the wheels. (Mine gets a touch more... 275hp/300 torque at the wheels @ 15PSI.)

Believe it or not, RWD typically has less parasitic driveline loss than FWD.

ZV

Have those people dyno'd the engine out of the vehicle to see what the crank HP is? That should be the only way to tell if its low driveline loss or if the engine is underrated by the factory.

 

[cbehnken]

Originally posted by: DaTT

Originally posted by: cbehnken

Originally posted by: DaTT

Originally posted by: andylawcc
speaking of which, how do they Dyno 4WD cars? jack up the front so it's spinning in the air?

I actually asked the guy that...he said, if he can, he pulls one of the drive shafts out.

Are you insane? You will toast the center diff in a few seconds doing this.

Ever seen an AWD car? They ALWAYS say "Must be towed on flatbed, do not tow by 2 wheels".

This is because there is a limited slip component designed to keep the front and rear tires turning approximately the same speed. If you have a limited slip center diff it will burn up instantly trying to transfer power to wheels that aren't hooked up. If you don't have a limited slip the unhooked drive shaft will be the only drive shaft received any power as an open diff spins the end with LESS traction.

This is what he said, and I assume he knows what he is talking about.

Going ahead and let him pull a driveshaft on an AWD car and dyno it on two wheels, we'll see what he knows, lol

 

[cbehnken]

Originally posted by: DivideBYZero
We use 4 wheel dyno's in the UK for testing AWD cars such as my Impreza.

We do in America too.

 

[DaTT]

Originally posted by: cbehnken

Originally posted by: DaTT

Originally posted by: cbehnken

Originally posted by: DaTT

Originally posted by: andylawcc
speaking of which, how do they Dyno 4WD cars? jack up the front so it's spinning in the air?

I actually asked the guy that...he said, if he can, he pulls one of the drive shafts out.

Are you insane? You will toast the center diff in a few seconds doing this.

Ever seen an AWD car? They ALWAYS say "Must be towed on flatbed, do not tow by 2 wheels".

This is because there is a limited slip component designed to keep the front and rear tires turning approximately the same speed. If you have a limited slip center diff it will burn up instantly trying to transfer power to wheels that aren't hooked up. If you don't have a limited slip the unhooked drive shaft will be the only drive shaft received any power as an open diff spins the end with LESS traction.

This is what he said, and I assume he knows what he is talking about.

Going ahead and let him pull a driveshaft on an AWD car and dyno it on two wheels, we'll see what he knows, lol

If you read my post...he said "if he can".....I guess not all cars can be done that way, and I'm not going to argue with you about it.

 

[cbehnken]

Originally posted by: DaTT

Originally posted by: cbehnken

Originally posted by: DaTT

Originally posted by: cbehnken

Originally posted by: DaTT

Originally posted by: andylawcc
speaking of which, how do they Dyno 4WD cars? jack up the front so it's spinning in the air?

I actually asked the guy that...he said, if he can, he pulls one of the drive shafts out.

Are you insane? You will toast the center diff in a few seconds doing this.

Ever seen an AWD car? They ALWAYS say "Must be towed on flatbed, do not tow by 2 wheels".

This is because there is a limited slip component designed to keep the front and rear tires turning approximately the same speed. If you have a limited slip center diff it will burn up instantly trying to transfer power to wheels that aren't hooked up. If you don't have a limited slip the unhooked drive shaft will be the only drive shaft received any power as an open diff spins the end with LESS traction.

This is what he said, and I assume he knows what he is talking about.

Going ahead and let him pull a driveshaft on an AWD car and dyno it on two wheels, we'll see what he knows, lol

If you read my post...he said "if he can".....I guess not all cars can be done that way, and I'm not going to argue with you about it.

I don't think there is ONE instance where he can on a "car". Not talking about trucks here.

 

[blckgrffn]

Someday, my 99 GT will be traded in.... someday...

 

[Zenmervolt]

Originally posted by: Apex

Originally posted by: Zenmervolt

Originally posted by: 91TTZ

Originally posted by: DaTT
Me thinks nowadays, powertrain loss is somewhere in the range of 10-12% RWD......or they under rated the motor.

They intentionally under rated the motor. The drivetrain loss is still around 15%-18%. There's no way that a RWD transmission has only a 10-12% loss.

Driveline loss on a 951 is in the 10% neighborhood and it's RWD. Factory rating was 217 at the crank, people have dyno-ed stock 951's with 100,000 miles and still gotten 198 at the wheels. (Mine gets a touch more... 275hp/300 torque at the wheels @ 15PSI.)

Believe it or not, RWD typically has less parasitic driveline loss than FWD.

ZV

Have those people dyno'd the engine out of the vehicle to see what the crank HP is? That should be the only way to tell if its low driveline loss or if the engine is underrated by the factory.

There is no fuggin' way anyone would take the engine out of a 951 for any reason short of a re-build... There's probably 24 shop-hours of labor involved in doing that. They could probably do a coast-down test to figure out what the driveline loss is though... Hmm...

Historically Porsche hasn't under- or over-rated their engines, though they do have a history of being conservative with acceleration figures.

ZV

 

[DJSfurry]

BMW likewise.. also conservative of their figures. Haha looking at all these american cars makes me laugh. firstly they dont handle, then cars like the viper have 8.3 litre engines and only make 500 horsepower. Come on! It doesnt even handle either. yeesh. all that added weight from such a huge engine just isnt worth the overall impact it will have on the car..

Even worse was the previous gen of viper, 8.1 litres and 400 horsepower??? My friends 360 has 400 horsepower out of a 3.6 litre V8... Nowhere near the torque of a viper, but it would beat it in practically anything. one more thing. whats up with nascar? Bunch of cars going around in circles.. not saying its easy, as of course with everyone else running such similar cars on the track will make it hard and dangerous... however how is it exciting and what does it prove? Rally cars.. now that takes some serious skill and IMO is SO much more interesting to watch. Im pretty sure most of you here dont really care for that anyhow.. but thats my view anyhow. to each his own.

 

[MasterAndCommander]

Tell me DJSfurry - what new BMW, Porsche, Lexus, etc, etc. can you get for a starting price of $25k that puts out a conservative 300HP/320 lb-ft TQ, does the 1/4 mile in mid 13's, 0-60 in 5s?
The Mustang was never meant and never will be sophisticated, luxioruous, or rally monster, etc., etc. It is what it is - a fun ride at a low price.

Even TOPGEAR got the essence of what it is right:

Though, I can't understand why Richard tested the 5-spd automatic version

 

[iamwiz82]

http://videorat.videohh.com/cobrasruleafix.wmv

 

[DJSfurry]

@ Masterandcommander I didnt say anything about the mustang, I know its not trying to be all flash like the vipers and such. I know theres a lot of heritage to the mustang too, and i think thats great I personally think the shelby cobra gt500 looks great. But its just details about the majority american cars that are laughable.. like corvettes using leaf spring suspension. i mean.. i would expect that from a thirdworld country, not a modern corvette. and yes, you would be hard pressed to find any cars with specs like that for 25k US however ii would get some nice performing european cars second hand. but thats just me.

 

[MasterAndCommander]

Originally posted by: DJSfurry
@ Masterandcommander I didnt say anything about the mustang, I know its not trying to be all flash like the vipers and such. I know theres a lot of heritage to the mustang too, and i think thats great I personally think the shelby cobra gt500 looks great. But its just details about the majority american cars that are laughable.. like corvettes using leaf spring suspension. i mean.. i would expect that from a thirdworld country, not a modern corvette. and yes, you would be hard pressed to find any cars with specs like that for 25k US however ii would get some nice performing european cars second hand. but thats just me.

First of all - the leaf spring in the 'vette is not the same kind you find in your typical horse-drawn carriage - it's a single leaf made out of a composite material transversly mounted...there were reasons why GM went this route:

-It weights A LOT LESS than coil springs. One leaf replaces two coils.
The two coil springs weigh 3 times as much as the one leaf.
Additionally the leaf is placed at the bottom of the car. In addition
to removing weight you lower the CG.

-It acts as an anti roll bar. The advantage is you can run lighter anti-roll bars
because the springs are taking care of part of the job for you.

-The leaf springs never wear out like coil spring.

If your looking for more 'outdated' technology in the 'vette - They also use pushrods in the LS2 engine you find in both the Monaro/GTO and 'vette - while everyone else uses OHC technology. Yet again - it works for them.

I'd be more than happy to own a $45k C6 'vette and race it against the best Europe and Japan can offer NEW at that price range

Second - yes I could get a nice used BMW or a MkIV Supra for $25k, but I'm not a used car type of guy. I just don't trust the previous owner

 

[DaTT]

Originally posted by: DJSfurry
BMW likewise.. also conservative of their figures. Haha looking at all these american cars makes me laugh. firstly they dont handle, then cars like the viper have 8.3 litre engines and only make 500 horsepower. Come on! It doesnt even handle either. yeesh. all that added weight from such a huge engine just isnt worth the overall impact it will have on the car..

Even worse was the previous gen of viper, 8.1 litres and 400 horsepower??? My friends 360 has 400 horsepower out of a 3.6 litre V8... Nowhere near the torque of a viper, but it would beat it in practically anything. one more thing. whats up with nascar? Bunch of cars going around in circles.. not saying its easy, as of course with everyone else running such similar cars on the track will make it hard and dangerous... however how is it exciting and what does it prove? Rally cars.. now that takes some serious skill and IMO is SO much more interesting to watch. Im pretty sure most of you here dont really care for that anyhow.. but thats my view anyhow. to each his own.

Who mentioned nascar? Is this a nascar thread?

And as Pacfanweb mentioned back a page or two,

Originally posted by: Pacfanweb

Originally posted by: DaTT
I would never argue the handling of a North American car to an overseas car.

And I would never care. There isn't a dime's worth of difference in real-world handling in any comparable car to a Mustang, anyway.

Look at skid pad numbers all you want. Or slalom. I could care less.

When did you ever race someone that pulled up next to you at a stoplight through a slalom?

If you're going to race someone, it's going to be in a drag race. Or maybe you get into it at highway speeds occasionally.
But how many can honestly say that they've ever raced anyone on a twisting, turning mountain road?

That's right, either none or nearly none. And you never will.

So everyone keep arguing about which car handles better if a professional driver is behind the wheel.
And keep trying to read the license plate of the Mustang, Camaro, GTO or Vette that's busy leaving you in the dust from the stoplight.

Maybe at the next light you can tell the driver how Car and Driver had an article that said your car will handle better than his. Better talk fast, though.

 

[RGUN]

Originally posted by: DJSfurry
BMW likewise.. also conservative of their figures. Haha looking at all these american cars makes me laugh. firstly they dont handle, then cars like the viper have 8.3 litre engines and only make 500 horsepower. Come on! It doesnt even handle either. yeesh. all that added weight from such a huge engine just isnt worth the overall impact it will have on the car..

Even worse was the previous gen of viper, 8.1 litres and 400 horsepower??? My friends 360 has 400 horsepower out of a 3.6 litre V8... Nowhere near the torque of a viper, but it would beat it in practically anything. one more thing. whats up with nascar? Bunch of cars going around in circles.. not saying its easy, as of course with everyone else running such similar cars on the track will make it hard and dangerous... however how is it exciting and what does it prove? Rally cars.. now that takes some serious skill and IMO is SO much more interesting to watch. Im pretty sure most of you here dont really care for that anyhow.. but thats my view anyhow. to each his own.

Come on man, Vipers handle really well... and the 8.3 liter engine is not very heavy. As far as performance goes, the Ferrari 360 has absolutely nothing on the Viper... The 360 is worse in every category.

 

[Apex]

Originally posted by: RGUN

Originally posted by: DJSfurry
BMW likewise.. also conservative of their figures. Haha looking at all these american cars makes me laugh. firstly they dont handle, then cars like the viper have 8.3 litre engines and only make 500 horsepower. Come on! It doesnt even handle either. yeesh. all that added weight from such a huge engine just isnt worth the overall impact it will have on the car..

Even worse was the previous gen of viper, 8.1 litres and 400 horsepower??? My friends 360 has 400 horsepower out of a 3.6 litre V8... Nowhere near the torque of a viper, but it would beat it in practically anything. one more thing. whats up with nascar? Bunch of cars going around in circles.. not saying its easy, as of course with everyone else running such similar cars on the track will make it hard and dangerous... however how is it exciting and what does it prove? Rally cars.. now that takes some serious skill and IMO is SO much more interesting to watch. Im pretty sure most of you here dont really care for that anyhow.. but thats my view anyhow. to each his own.

Come on man, Vipers handle really well... and the 8.3 liter engine is not very heavy. As far as performance goes, the Ferrari 360 has absolutely nothing on the Viper... The 360 is worse in every category.

How much does that engine weigh?

 

[RGUN]

It weighs just over 600lbs, but as far as performance its much better than the Ferrari 360. The weight distribution in a 360 Modena is 43/57... whereas the Viper is 49/51. Viper has better brakes, better engine, much higher reliability and would be the one I would choose to have.

 

[TheSlamma]

Whats with all the fantasy land cars. The OP actually owns what he's talking about.

 

[Apex]

Originally posted by: RGUN
It weighs just over 600lbs, but as far as performance its much better than the Ferrari 360. The weight distribution in a 360 Modena is 43/57... whereas the Viper is 49/51. Viper has better brakes, better engine, much higher reliability and would be the one I would choose to have.

The weight distribution of the Ferrari is obviously much better.

 

[RGUN]

Why is that obvious? Look it up, the Spyder is worse that 43/57

 

[Apex]

Originally posted by: RGUN
Why is that obvious? Look it up, the Spyder is worse that 43/57

Wait, you were fooled by BMW and the like to think 50/50 is ideal? 42f/58r is much closer to ideal for performance.

Edit: That may have sounded unnecessarily harsh, and I didn't mean it that way. If you did take it that way, I apologize. BMW has spent millions and millions deluding people into thinking that 50/50 is "perfect" for performance. It clearly is not. There is a reason why every single F1 vehicle in existance is right around the 42/58 range. Just take a corner apart into its component pieces:

1. Braking. With 50/50, when you brake, weight transfers forward, so almost 90% of the braking is being done with your front tires. Far from ideal. With 42/58, braking is much better distributed between front and rear.

2. Initial turn in. With 50/50, your front tires are moving much more weight. Initial turn in is slow. With 42/58, you get a much quicker turn in.

3. Steady state turning. This is the smallest part of most corners. 50/50 is easier, but grips no more than 42/58.

4. Accelerating out of the corner. Because weight is already over driving wheels, 42/48 allows you to accelerate out earlier and harder.

Conclusion: 50/50: easier for less skilled. 42/58: better for performance.

 

[RGUN]

Yeah Im fooled by BMW and the fact that the viper can pull better skidpad numbers and handles better...