Zf-6
Race Director
Joined: Dec 2002
Posts: 13,348
Likes: 233
From: SCMR Rat Pack'r Charter Member..Great Bend KS
I ask because my theory is that any driveline component has a finite limit on the time it can endure any set amount of stress.
In other words, say the ZF in your car has a limit of 4 hours at 760ft/lbs. If you subject the gearbox to six WOT (760ft/lbs), of 20 seconds duration each, every year, the gearbox will last 120 years before something breaks.
If you subject it to 3 minute durations, eighteen times a week, then it will last less than 6 months. (both examples are extremes, of course)
Every driveline component, if used, will fail eventually. The frequency which you use all the power will determne how long they will last.
I love theories.
Larry
code5coupe
_________)
I ain't easily impressed....
Last edited by rocco16; Apr 27, 2007 at 11:02 AM.
Safety Car
Joined: Apr 2001
Posts: 3,525
Likes: 2
From: Houston TX
How often do you go WOT??
I ask because my theory is that any driveline component has a finite limit on the time it can endure any set amount of stress.
In other words, say the ZF in your car has a limit of 4 hours at 760ft/lbs. If you subject the gearbox to six WOT (760ft/lbs), of 20 seconds duration each, every year, the gearbox will last 120 years before something breaks. If you subject it to 3 minute durations, eighteen times a week, then it will last less than 6 months. (both examples are extremes, of course). Every driveline component, if used, will fail eventually. The frequency which you use all the power will determne how long they will last.
I love theories.
Larry
code5coupe
I ask because my theory is that any driveline component has a finite limit on the time it can endure any set amount of stress.
In other words, say the ZF in your car has a limit of 4 hours at 760ft/lbs. If you subject the gearbox to six WOT (760ft/lbs), of 20 seconds duration each, every year, the gearbox will last 120 years before something breaks. If you subject it to 3 minute durations, eighteen times a week, then it will last less than 6 months. (both examples are extremes, of course). Every driveline component, if used, will fail eventually. The frequency which you use all the power will determne how long they will last.
I love theories.
Larry
code5coupe
I am concerned that several items may be loosing life, as the above Mustang Dyno run was done at just over 10 psi. I changed to where I am steadily running in the mid 20s, which is significantly more power. The weak link will identify itself, of this I am sure.
Aaron
Melting Slicks
Joined: Mar 2002
Posts: 3,108
Likes: 126
From: S.L.C. UT
I had 790 ft/lbs (numbers in sig) at the tires, and have blown up everything behind the trans,before the 9", but the ZF still holds up. I drag race mine with 28x12.5x15 et streets with nitrous, and the trans has held up fine.
Pro
Joined: May 2006
Posts: 538
Likes: 2
From: Kansas City Mo
The ZF apparently is much stronger than I thought.
I'd kinda always heard you didn't want more than about 450Ft/Lbs of torque for this tranny if driving hard.
Team Owner
Joined: May 2002
Posts: 24,337
Likes: 25
From: San Diego , CA Double Yellow DirtBags 1985..Z51..6-speed
True, but a clutch drop will stress it more than a WOT run, it's dumping the momentum of the bottom end onto the trans all at once. And of course in 1st gear, everything downstream of 1st gear will see way more torque than for 2,3,4,etc.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Team Owner
Joined: May 2002
Posts: 24,337
Likes: 25
From: San Diego , CA Double Yellow DirtBags 1985..Z51..6-speed
Also some materials will never fail if they aren't loaded up past their endurance limit. This might only be maybe 25% of it's ultimate strengh though, and less than the fatigue strength which means it will break after some set number of cycles.
But basically the question isn't how much can the ZF6 hold.. It should be how long will it last at X power output? Its enough for me anyways.
But basically the question isn't how much can the ZF6 hold.. It should be how long will it last at X power output? Its enough for me anyways.
Racer
Joined: Aug 2007
Posts: 252
Likes: 1
From: Ellicott City, MD
My understanding is early "black tag" ZF-6 trannies were conservatively rated at 450 ft-lbs torque; later "blue tag" ZF-6 trannies I thought were rated at 425 ft-lbs but I could be wrong.
I have no idea what the differences are though i have one of each.
I emphasize the "conservative" nature of these ratings since the ZF-6 was 1) designed to handle the ZR-1 engines and 2) used by Callaway & Doug Rippie in a lot of their custom builds without modification.
Check with Bill Boudreaux (sp?) at zfdoc.com if you want the true skinny.
I have no idea what the differences are though i have one of each.
I emphasize the "conservative" nature of these ratings since the ZF-6 was 1) designed to handle the ZR-1 engines and 2) used by Callaway & Doug Rippie in a lot of their custom builds without modification.
Check with Bill Boudreaux (sp?) at zfdoc.com if you want the true skinny.
Last edited by 89FX3; Aug 3, 2008 at 08:14 PM.
Racer
Joined: Aug 2007
Posts: 252
Likes: 1
From: Ellicott City, MD
Given that type of reported experience and the Callaway & Doug Rippie program useage of the ZF-6 I've been kinda surprised that some have expressed an interest in changing their ZF-6 for a T-56.
To be sure the T-56 is a great tranny (I have one in my 94 Viper) but I don't find it anywhere near as 'civilized' as the ZF-6.
Then again I don't track my cars.
Last edited by 89FX3; Aug 3, 2008 at 08:13 PM.