How much power is lost through drivetrain?
How much power is lost through drivetrain?
Author
Discussion

headhoon

Original Poster:

268 posts

242 months

Wednesday 7th May 2008
quotequote all
I'm thinking it could be about 70 bhp (motorbikes are about 20 to 30 bhp) but do ya reckon it's different between manual and auto with a car? Just curious as to setting my expectation for when I get the RO dyno tuned.

Gelf VXR

713 posts

230 months

Wednesday 7th May 2008
quotequote all
headhoon said:
I'm thinking it could be about 70 bhp (motorbikes are about 20 to 30 bhp) but do ya reckon it's different between manual and auto with a car? Just curious as to setting my expectation for when I get the RO dyno tuned.
I had my totally stock 6.0 VXR dyno'd at 303 RWBHP, Vauxhall standard quoted figure is 398FWBHP, thats 95BHP or 24% losses.



VXR_Daz

1,830 posts

243 months

Wednesday 7th May 2008
quotequote all
90bhp + 7.5% for every rwhp over 300 would be roughly right :-)

Disclaimer: This is purely based on my own very rough calculations and would not stand up in a court of law.

crisisjez

9,209 posts

228 months

Wednesday 7th May 2008
quotequote all
VXR_Daz said:
90bhp + 7.5% for every rwhp over 300 would be roughly right :-)

Disclaimer: This is purely based on my own very rough calculations and would not stand up in a court of law.


Every thing about you is a bit rough mate (How`s the eyes)

Drivetrain losses are much higher on the `Ro` than similar european rivals, its the downside of such a strong drivetrain I guess.

Paul--C

145 posts

215 months

Wednesday 7th May 2008
quotequote all
I should be able to tell you soon (ish). Arranging an Engine Dyno test on an HSV VT2 after some internal mods and will compare with a Hub Dyno and then a couple of Rolling Roads. Should be interestingwink

Fluffsri/cv8

3,361 posts

219 months

Wednesday 7th May 2008
quotequote all
On the last roller run i did i had 393.7 at the fly and 317 at the wheels, so 77 bhp loss.

stevieturbo

17,958 posts

270 months

Wednesday 7th May 2008
quotequote all
Vixpy would be better placed to say.

But when run in 4th gear, losses shouldnt be huge ( as 4th gear isnt a gear as such, just a locked shaft )

And it will vary depending on tyres, pressures, gearbox, gear oil, oil temperature etc etc etc...

Just stick with wheel HP smile it makes life easier, even if the numbers appear lower.

hsv_rulz

957 posts

245 months

Wednesday 7th May 2008
quotequote all
stevieturbo said:
Vixpy would be better placed to say.

But when run in 4th gear, losses shouldnt be huge ( as 4th gear isnt a gear as such, just a locked shaft )

And it will vary depending on tyres, pressures, gearbox, gear oil, oil temperature etc etc etc...

Just stick with wheel HP it makes life easier, even if the numbers appear lower.


Don't forget bonnet up/down hehe

stevieturbo

17,958 posts

270 months

Thursday 8th May 2008
quotequote all
Always down for me. Thats the correct way the car was designed to cope with airflow.

Vixpy1

42,697 posts

287 months

Thursday 8th May 2008
quotequote all
I've still never been able to get to the bottom of why the LS2 corvettes make 20 more at the wheels than the LS2 VXR's. Quoted power is the same, and as far as i'm aware the drivetrain is similair.

Gelf VXR

713 posts

230 months

Thursday 8th May 2008
quotequote all
Vixpy1 said:
I've still never been able to get to the bottom of why the LS2 corvettes make 20 more at the wheels than the LS2 VXR's. Quoted power is the same, and as far as i'm aware the drivetrain is similair.
I believe my results are from your dyno last Novemeber (Dyno Day)

eliot

11,988 posts

277 months

Thursday 8th May 2008
quotequote all
VXR_Daz said:
90bhp + 7.5% for every rwhp over 300 would be roughly right :-)

Disclaimer: This is purely based on my own very rough calculations and would not stand up in a court of law.
So on my range rover based car, with an Auto box, agricultral transfer box, front diff and rear diff both running in thick EP90 gear oil (so thats twice as many diffs and twice as many gearboxes) how many BHP is lost?
If its anything over 130BHP in theory the car wouldn't even move, considering the early V8 range rovers only produced 130BHP..

VXR_Daz

1,830 posts

243 months

Friday 9th May 2008
quotequote all
crisisjez said:
Every thing about you is a bit rough mate (How`s the eyes)


Like this:

VA: c Rx RE 6/4.8 LE 6/95 (c effort) Logmar

CT: c Rx N+D mod/mkd LCS poor left fixation

OM: slight limitation of left eye in adduction (due to surgery)

CONV: nil binocular

ACCOMMODATION: RE: to 12cm, 14cm, 14cm

PCT: c Rx N- 45„½ BO
D- 40-45„½BO

PODT: N- >45„½BO crossed diplopia noted
D- >45„½BO crossed diplopia noted


Glad u asked?

Monnington

234 posts

225 months

Friday 9th May 2008
quotequote all
crisisjez said:
VXR_Daz said:
90bhp + 7.5% for every rwhp over 300 would be roughly right :-)

Disclaimer: This is purely based on my own very rough calculations and would not stand up in a court of law.


Drivetrain losses are much higher on the `Ro` than similar european rivals, its the downside of such a strong drivetrain I guess.



Why is it such a 'strong' drivetrain then? According to Tremec, the T56 is a 'light duty' gearbox, and I can't really see BM or Audi, et al, using anything lesser in their models.

Of course I stand to be corrected if we have 'Pig Iron' propshafts or something...

stevieturbo

17,958 posts

270 months

Friday 9th May 2008
quotequote all
Light duty compared to trucks and bigger. Tremec make more than little car transmissions.

Its rated by them to around 450lbft, but many have been reliable at 5, 6,700+lbft.

crisisjez

9,209 posts

228 months

Friday 9th May 2008
quotequote all
Monnington said:
crisisjez said:
VXR_Daz said:
90bhp + 7.5% for every rwhp over 300 would be roughly right :-)

Disclaimer: This is purely based on my own very rough calculations and would not stand up in a court of law.


Drivetrain losses are much higher on the `Ro` than similar european rivals, its the downside of such a strong drivetrain I guess.



Why is it such a 'strong' drivetrain then? According to Tremec, the T56 is a 'light duty' gearbox, and I can't really see BM or Audi, et al, using anything lesser in their models.

Of course I stand to be corrected if we have 'Pig Iron' propshafts or something...


Well I base my post on the fact that I`m running 50% over std and nothing has broken yet despite my best efforts so I`ll hold with my view its pretty strong.
The Euro boys have similar I`m sure but the cost of the vehicle has to have some bearing on the quality of the components used so with that in mind I`m not surprised that we will loose more horseys through our drivetrains to achieve the same margin of useability.

As for the T56 being a light duty gearbox, I can`t really comment as I`m not in the know about these things.
But IMO any box that can take a heavy car to a 10.04 sec Quarter mile time is pretty heavyweight and all I`ll ever need.

Edited by crisisjez on Friday 9th May 16:16

crisisjez

9,209 posts

228 months

Friday 9th May 2008
quotequote all
VXR_Daz said:


Like this:

VA: c Rx RE 6/4.8 LE 6/95 (c effort) Logmar

CT: c Rx N+D mod/mkd LCS poor left fixation

OM: slight limitation of left eye in adduction (due to surgery)

CONV: nil binocular

ACCOMMODATION: RE: to 12cm, 14cm, 14cm

PCT: c Rx N- 45„½ BO
D- 40-45„½BO

PODT: N- >45„½BO crossed diplopia noted
D- >45„½BO crossed diplopia noted


Glad u asked?


Was on the third line concentrating really really hard before I realised it wasn`t a formula for calculating drivetrain losses doh

broadslide

739 posts

223 months

Friday 9th May 2008
quotequote all
VXR_Daz said:
crisisjez said:
Every thing about you is a bit rough matesmile (How`s the eyes)
Like this:

VA: c Rx RE 6/4.8 LE 6/95 (c effort) Logmar

CT: c Rx N+D mod/mkd LCS poor left fixation

OM: slight limitation of left eye in adduction (due to surgery)

CONV: nil binocular

ACCOMMODATION: RE: to 12cm, 14cm, 14cm

PCT: c Rx N- 45„½ BO
D- 40-45„½BO

PODT: N- >45„½BO crossed diplopia noted
D- >45„½BO crossed diplopia noted


Glad u asked? biggrin
Bonnet up or down??

Island boy HSV

726 posts

262 months

Friday 9th May 2008
quotequote all
Monnington said:
crisisjez said:
VXR_Daz said:
90bhp + 7.5% for every rwhp over 300 would be roughly right :-)

Disclaimer: This is purely based on my own very rough calculations and would not stand up in a court of law.


Drivetrain losses are much higher on the `Ro` than similar european rivals, its the downside of such a strong drivetrain I guess.



Why is it such a 'strong' drivetrain then? According to Tremec, the T56 is a 'light duty' gearbox, and I can't really see BM or Audi, et al, using anything lesser in their models.

Of course I stand to be corrected if we have 'Pig Iron' propshafts or something...


I think you are getting confused here, I have read the page and the medium duty gearboxes Tremec do are for light trucks their lightest application is 21 tonnes! Light duty also covers the T56 variant used in the Viper.

Here is the link to the tremec site

[url]www.ttcautomotive.com/English/products/T-56.asp[/url]

Application list from Wiki for info

* Aston Martin DB7 Vantage, 1999–2003
* Aston Martin V12 Vanquish, 2001–2006
* Chevrolet Corvette, 1997–2007
* Dodge Ram SRT10, 2004–2006
* Dodge Viper, 1992–2007
* Ford Mustang Cobra, 2003–2004
* Ford Mustang Cobra R, 2000
* Ford Falcon XR6, XR6T, XR8, F6 Tornado/Typhoon, GT/GT-P 2004–2008
* General Motors GM F platform V8 cars, 1993–2002
* Holden Commodore 1998–2008
* Holden Monaro, 2001-2006
* GM M12
o 2001–2004 Chevrolet Corvette Z06
o 2004–2006 Pontiac GTO
o 2004–2006 Cadillac CTS-V
* GM MN6
o 2004–2007 Chevrolet Corvette
* GM M10
o 2005–2006 Chevrolet SSR
o 2006–2008 Holden VE Commodore
* GM MZ6
o 2005–2007 Chevrolet Corvette Z51




Edited by Island boy HSV on Friday 9th May 16:41

mackie1

8,168 posts

256 months

Friday 9th May 2008
quotequote all
Vixpy1 said:
I've still never been able to get to the bottom of why the LS2 corvettes make 20 more at the wheels than the LS2 VXR's. Quoted power is the same, and as far as i'm aware the drivetrain is similair.
More slip from the narrower tyres on the Monaro? How wide a corvette rears as standard?