Drivetrain loss? - GM Forum - Buick, Cadillac, Chev, Olds, GMC & Pontiac chat


Performance, Brainstorming & Tuning Talk about modifications, or anything else associated with performance enhancements. Have a new idea for performance/reliability? Post it here. No idea is stupid! (please use Detailing and Appearance for cosmetic ideas)

Reply
 
 
 
Thread Tools Search this Thread
Old 09-15-2003, 12:41 PM   #1
Junior Member
Posts like a Ricer Type-R
Thread Starter
 
Join Date: Aug 2002
Posts: 10
Thanks: 0
Thanked 0 Times in 0 Posts
willwren is on a distinguished road
Default Drivetrain loss?

Anyone know what % a typical bonneville loses before it puts the power to the ground? The % difference typical between crank hp and torque and wheel hp and torque?

I've heard as high as 25%, but don't see much out there on it.
willwren is offline   Reply With Quote
Old 09-15-2003, 11:12 PM   #2
Senior Member
True Car Nut
 
Join Date: May 2003
Location: Holt, MI & Lima, OH
Posts: 3,022
Thanks: 0
Thanked 0 Times in 0 Posts
dbtk2 is on a distinguished road
Default

Between 18 & 20%.
dbtk2 is offline   Reply With Quote
Old 09-15-2003, 11:17 PM   #3
Senior Member
True Car Nut
 
Join Date: Jun 2003
Location: Climax Springs, Missouri
Posts: 2,493
Thanks: 0
Thanked 0 Times in 0 Posts
LittleHoov is on a distinguished road
Default

so were losing like 46 ft lbs of torque?! so its only putting like well in my case like 184 lbs of torque to the ground? or am i confused beyond measure.
LittleHoov is offline   Reply With Quote
Old 09-15-2003, 11:20 PM   #4
Senior Member
Expert Gearhead
 
Join Date: Dec 2002
Location: Mississauga, Ontario
Posts: 20,892
Thanks: 0
Thanked 1 Time in 1 Post
Jim W is on a distinguished road
Default

The power at the crank and the power to the ground are totally different, now imagine lesser cars with WAY less torque...only getting double digits to the ground
Jim W is offline   Reply With Quote
Old 09-15-2003, 11:24 PM   #5
Senior Member
True Car Nut
 
Join Date: May 2003
Location: Holt, MI & Lima, OH
Posts: 3,022
Thanks: 0
Thanked 0 Times in 0 Posts
dbtk2 is on a distinguished road
Default

Quote:
so were losing like 46 ft lbs of torque?! so its only putting like well in my case like 184 lbs of torque to the ground? or am i confused beyond measure.
Thats exactly right. For instance if you make 200hp on the dyno it sounds a little low, when really the engine is putting out 250. If you make 320hp to the wheels the engine is putting out 400hp! That is why I have always said Series II L67'* have way underrated torque, because GM rates them at 280lb.ft, but I have seen stock L67'* pull 270lb.ft to the wheels which is over 330lb.ft at the crank. Once you get up into high horsepower numbers it gets really really crazy.
dbtk2 is offline   Reply With Quote
Old 09-15-2003, 11:33 PM   #6
Senior Member
Certified GM nut
 
Join Date: Jul 2003
Location: Chicagoland
Posts: 1,712
Thanks: 0
Thanked 0 Times in 0 Posts
TaylorD is on a distinguished road
Default

Very interesting. On my Aurora when I dynoed it I figured and many others that a Northstar weither 4.0 Aurora or 4.6 caddy will lose 24% through a 4t80-e tranny. My baseline dyno was 190HP at wheels =250 crank. I'm sure Jim liked this little fact.
TaylorD is offline   Reply With Quote
Old 09-15-2003, 11:36 PM   #7
Senior Member
Expert Gearhead
 
Join Date: Dec 2002
Location: Mississauga, Ontario
Posts: 20,892
Thanks: 0
Thanked 1 Time in 1 Post
Jim W is on a distinguished road
Default

Da na na na na HEY da na na na na na HEY



190 HP at the ground is nice...still 35HP more then my 89 ( and it was 165 at the crank)

Thanks for that little tid bit Taylor...
Jim W is offline   Reply With Quote
Old 09-15-2003, 11:45 PM   #8
Senior Member
True Car Nut
 
Join Date: Jun 2003
Location: Climax Springs, Missouri
Posts: 2,493
Thanks: 0
Thanked 0 Times in 0 Posts
LittleHoov is on a distinguished road
Default

so im guessing the numbers that GM advertises are at the crank? to make it sound more impressive.
LittleHoov is offline   Reply With Quote
Old 09-16-2003, 01:39 AM   #9
Burgundy_Boat
Guest
 
Posts: n/a
Default

Quote:
Originally Posted by 89BonnieSE89
The power at the crank and the power to the ground are totally different, now imagine lesser cars with WAY less torque...only getting double digits to the ground
lol i've had the misfortune of driving cars that only put doubble digits to the crank...
  Reply With Quote
Old 09-16-2003, 01:40 AM   #10
Senior Member
Certified Car Nut
 
Join Date: Mar 2003
Posts: 12,432
Thanks: 0
Thanked 0 Times in 0 Posts
J Wikoff is on a distinguished road
Default

me too, 85 Buick Somerset, 92hp. My first car.
J Wikoff is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
A good read on horsepower and drivetrain loss. MyLittleBlackBird Lounge 3 04-07-2006 12:44 AM
PLEASE HELP!! drivetrain issue BOMB 1st 1992-1999 8 02-12-2005 08:51 PM
Drivetrain Power Loss Formula Sol Performance, Brainstorming & Tuning 26 11-10-2004 12:37 AM
Drivetrain Swap mark2112 1992-1999 6 05-11-2004 06:42 PM
3800 drivetrain question, please help!! h1081dan General GM Chat 14 10-19-2003 02:55 PM


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 10:10 PM.


We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.