Mechanical Drivetrain Loss in our 2013-2014 Shelby GT500'S

Vinnie_B

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Can anyone help educate me in drivetrain loss? What is the standard percentage rate of mechanical drivetrain loss 12-15%? How is it diagnosed? What are some of the most common and/or biggest contributors to drivetrain loss and lastly how can drivetrain loss be improved?
 
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1 Alibi 2

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The 12 - 15 % is an old standard loss #.
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How is drive-train loss calculated?

Two parts to this – first we take the wheel horsepower figure (WHP) that the car has made on the dyno. BHP-WHP= Horsepower Loss. We then divide HP loss by BHP and multiply by 100 to get our drive-train loss percentage.
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Vinnie_B

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The 12 - 15 % is an old standard loss #.
.
How is drive-train loss calculated?

Two parts to this – first we take the wheel horsepower figure (WHP) that the car has made on the dyno. BHP-WHP= Horsepower Loss. We then divide HP loss by BHP and multiply by 100 to get our drive-train loss percentage.
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Ok. So a dyno run is needed to identify your BHP and WHP to calculate drivetrain loss. Make sense! I do understand there is alot to consider such as friction and heat in gearing and if you dont physically see, feel vibration and/or hear a noise that a dyno comparison of your BHP/WHP would identify a possible drivetrain issue and cause of horsepower loss to the wheels. Thanks for chiming in @1 Alibi 2 I appreciate it!!
 

DSG2003Mach1

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I imagine a bunch of lighweight components in the driveline would help.

this, gotta reduce rotating mass and friction starting at flywheel to the tires basically.

I still would like to see someone throw a motor on an engine dyno and make pulls at various boost/power levels. Then put the motor in a car and repeat the pulls at the same boost levels.

If you're making 500hp at the motor and 450 on a chassis dyno for 10% or 50 hp whats it losing at 1000hp? does it maintain that flat 10% you're losing 100 or does it only go up incrementally and you're losing say 65hp at 1000hp

this is the kinda shit I'd do if I'd won that billion dollar power ball
 

Vinnie_B

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this, gotta reduce rotating mass and friction starting at flywheel to the tires basically.

I still would like to see someone throw a motor on an engine dyno and make pulls at various boost/power levels. Then put the motor in a car and repeat the pulls at the same boost levels.

If you're making 500hp at the motor and 450 on a chassis dyno for 10% or 50 hp whats it losing at 1000hp? does it maintain that flat 10% you're losing 100 or does it only go up incrementally and you're losing say 65hp at 1000hp

this is the kinda shit I'd do if I'd won that billion dollar power ball
From what ive read. The more power you make the more drivetrain loss. As @98 svt said lightweight drivetrain components are a good way to reduce friction. So its one way to improve. Im thinking that NVH testing along with Dyno testing that @1 Alibi 2 mentions is the best way to identify and make improvements to our drivelines. I believe I can provide my customers NVH testing with a module called VCMM (Vehicle Communication & Measurement Module) I'll conduct a test on my 2013 Shelby GT500 SS and provide a video and info so I can make it an option for ppl who might be interested in getting a NVH testing done by me locally. Here is some info.







Lightning Fast⚡Electrical Automotive Repair
PM Me or [email protected]
Website: Home
Remote or Local (On Site) Technical Repair
 
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gimmie11s

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The power put down to the ground (WHP) is what is important.
 

gimmie11s

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Be careful of the "crank" hp trap.

It's easy to get sucked into that only to be laughed at by true car guys who know the only measure that matters is what the car puts down to the ground.

Only lookin out for you Vinnie! :p
 

decipha

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There is no way to quantify this because all dynos read differently. The only true and accurate way to measure horsepower is at the track. Most people fail to realize that horsepower is a measurement of time distance and weight. Distance is a given at the track and you can weigh your vehicle. Then simply plug in the xx distance at xx weight in xx time and only then will you have an accurate horsepower number.

With that said Ive personally had a customer say his engine dynod 580 on an engine dyno. It put down 320 on the chassis dyno. For reference it was a 302 sbf engine in a fox stang.

I've had another customer whos engine put down 465 on an engine dyno and 380 on the chassis dyno. Was in an ls1 camaro for what its worth.

Ive had some customers who put down 700 on other chassis dynos only put down 550 on mine.

I have an md2000 mustang dyno.

I used to use a 220? dynojet many many moons ago and it used to put down almost the exact same numbers as my current so it really depends on the shop and how accurately they calibrate it.

Also it seems like high horsepower engines have less drivetrain loss. I didnt personally chassis dyno alot of engines that the customer has had on the engine dyno but thats my take or so it seems.
 

Vinnie_B

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That very interesting @decipha and a very important factor (Various dyno calibrations) that could really change the outcome of real true RWHP. Thanks for taking the time to chime in on the thread and share valuable info.....(y)
 

raustin0017

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Back in 2014...I remember someone a lot smarter than I....said the stock 13/14 GT500 had a 8% drivetrain loss due part to the carbon fiber driveshaft and other factors.

Who knows? But I would bet it is 8-10% loss from the crankshaft to rubber.
 

Vinnie_B

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Back in 2014...I remember someone a lot smarter than I....said the stock 13/14 GT500 had a 8% drivetrain loss due part to the carbon fiber driveshaft and other factors.

Who knows? But I would bet it is 8-10% loss from the crankshaft to rubber.
Depending on wear and tear I agree..... it could very well be even more from shelby to shelby.
 

Vinnie_B

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Well, darn. Should probably remove mine to speed up the car!

J/K and thread is interesting to read.
I think there is alot to gain from knowing if you have significant drivetrain loss @fearthesnake. This is definitely a learning experience hearing from all these very bright minds here on svtp
 

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Back in 2014...I remember someone a lot smarter than I....said the stock 13/14 GT500 had a 8% drivetrain loss due part to the carbon fiber driveshaft and other factors.

Who knows? But I would bet it is 8-10% loss from the crankshaft to rubber.
5.0 Mustang & fast Fords had an article where a Ford engineer stated 8 % drive train loss.
Couldn't prove it by 14's baseline of 585....( my tuners dyno is known to be stingy )
.
 
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