Pfadt Transmission Brace
Safety Car
Joined: Jun 2009
Posts: 3,888
Likes: 2
From: Frederick, Maryland
In the case of the Corvette's IRS, you can't cure it the same way because of the design, so if I'm correct, the Pfadt bar is not needed if you have the brace connecting the diff to the trans. Like I said, I'm getting an ECS brace when I re-install my diff, which should be sufficient for a non-race car.
To put this very clearly, ECS brace and Pfadt Trans brace serve two different functions:
ECS Brace: To strengthen the joint between the diff and Transmission.
Pfadt Brace: The Minimize/Eliminate Wheel hop and drivetrain movement under hard acceleration.
BOTH Braces can be used together.
ECS Brace: To strengthen the joint between the diff and Transmission.
Pfadt Brace: The Minimize/Eliminate Wheel hop and drivetrain movement under hard acceleration.
BOTH Braces can be used together.
Melting Slicks
Joined: Jun 2005
Posts: 2,396
Likes: 52
From: Sicamous BC
Wheel hop has been discussed many times on this, and other forums. In the case of straight axle cars, the culprit is axle windup, which ruins the angle of driveshaft to pinion. On these cars, the fix is to keep the axle housing from twisting by bracing it against the leaf springs, or adding welded links. On our Corvettes, it's been called "driveline shake", and will break things if you continue to have it. I believe it's caused by much the same phenomenon that's the cause in straight axle cars; namely axle windup. In the case of the Corvette's IRS, you can't cure it the same way because of the design, so if I'm correct, the Pfadt bar is not needed if you have the brace connecting the diff to the trans. Like I said, I'm getting an ECS brace when I re-install my diff, which should be sufficient for a non-race car. If ECS could chime in, regarding my theory, that'd be good, 'cause I'm just guessing.
The driveline is really supported on that small mount on the rear diff, so I think the driveline could start moving any direction once the shuttering begins, maybe even begin to oscillate. The Pfadt brace would prevent the side to side tipping as the width of the brace would spread that load. Then the up/down movement would be controlled the mount improvement & probably again by the width of the brace.
Looks like a very important piece of the puzzle.
Tech Contributor
Joined: May 2008
Posts: 2,843
Likes: 16
From: Howell Michigan
St. Jude Donor '09-'10-'11
If you are willing to do some reading it would be worth going through this thread to better understand how the powertrain in the C5 and C6 works and why this brace may or may not be right for you.
http://forums.corvetteforum.com/c5-t...xle-mount.html
http://forums.corvetteforum.com/c5-t...xle-mount.html
Safety Car
Joined: Dec 2009
Posts: 3,724
Likes: 9
To put this very clearly, ECS brace and Pfadt Trans brace serve two different functions:
ECS Brace: To strengthen the joint between the diff and Transmission.
Pfadt Brace: The Minimize/Eliminate Wheel hop and drivetrain movement under hard acceleration.
BOTH Braces can be used together.
ECS Brace: To strengthen the joint between the diff and Transmission.
Pfadt Brace: The Minimize/Eliminate Wheel hop and drivetrain movement under hard acceleration.
BOTH Braces can be used together.
This sums the situation up exactly. Our transmission brace is there to reduce power train shake and help our customers put more power effectively to the ground. The ECS brace is there to help eliminate part failure in extreme conditions. They are two different parts with two different functions that happen to share the same name and bolt to the same region of the car.
Both braces can be used together for extra effectiveness.
Safety Car
Joined: Jun 2009
Posts: 3,888
Likes: 2
From: Frederick, Maryland
THIS.
This sums the situation up exactly. Our transmission brace is there to reduce power train shake and help our customers put more power effectively to the ground. The ECS brace is there to help eliminate part failure in extreme conditions. They are two different parts with two different functions that happen to share the same name and bolt to the same region of the car.
Both braces can be used together for extra effectiveness.
This sums the situation up exactly. Our transmission brace is there to reduce power train shake and help our customers put more power effectively to the ground. The ECS brace is there to help eliminate part failure in extreme conditions. They are two different parts with two different functions that happen to share the same name and bolt to the same region of the car.
Both braces can be used together for extra effectiveness.
Race Director
Joined: Sep 2005
Posts: 11,060
Likes: 291
From: Pasco WA
Well, to clarify; on C5s, the axle hop isn't actually that, it's driveline shake. If it is caused by axle windup, then bracing the diff/trans interface should eliminate the problem. I don't guarantee this, it's just a theory, and the manufacturer's opinion is great, but not exactly objective.
Le Mans Master
Joined: Feb 2004
Posts: 8,629
Likes: 16
From: York PA
I believe the ECS braces are still on sale.
http://forums.corvetteforum.com/drag...c6z-379-a.html
I have the Pfadt & ECS brace, both products work great.
.
http://forums.corvetteforum.com/drag...c6z-379-a.html
I have the Pfadt & ECS brace, both products work great.
.
Last edited by 4DRUSH; Dec 7, 2011 at 01:54 AM.
Melting Slicks
Joined: Jun 2005
Posts: 2,396
Likes: 52
From: Sicamous BC
Good read Tx's 
To bad Pumba drawings are gone, I would have like to seen those.
The other night when I was out looking at the C5 rear mount I could easily see what was being discussed. Driveline shake is probably a much better way to describe the problem rather than wheel hop.
As you modify you aggravate the condition & violence increases. Reacting torque, I liked that one.
So I'm in for Pfadt mount, once I have the drive line out & see what is wrong this time.....I will also look closely @ the coupler's.........I keep wondering if that was the tinkling sound I heard hmmmmm.
To bad Pumba drawings are gone, I would have like to seen those.
The other night when I was out looking at the C5 rear mount I could easily see what was being discussed. Driveline shake is probably a much better way to describe the problem rather than wheel hop.
As you modify you aggravate the condition & violence increases. Reacting torque, I liked that one.
So I'm in for Pfadt mount, once I have the drive line out & see what is wrong this time.....I will also look closely @ the coupler's.........I keep wondering if that was the tinkling sound I heard hmmmmm.
If you are willing to do some reading it would be worth going through this thread to better understand how the powertrain in the C5 and C6 works and why this brace may or may not be right for you.
http://forums.corvetteforum.com/c5-t...xle-mount.html
http://forums.corvetteforum.com/c5-t...xle-mount.html
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Pro
Joined: Nov 2006
Posts: 563
Likes: 2
From: San Mateo CA
I've heard more than one person describe this with the pfadt mount too.
Drifting
Joined: Feb 2010
Posts: 1,310
Likes: 99
From: Arlington Texas
I have a Hinson poly transmission mount and have noticed the same phenomenon. Right around 2200 rpm at light throttle you start to feel and hear this audible vibe through the chassis that doesn't seem to be there at higher rpm (or anywhere in the rpm range when at WOT).
I've heard more than one person describe this with the pfadt mount too.
I've heard more than one person describe this with the pfadt mount too.
Melting Slicks
Joined: Sep 2003
Posts: 2,062
Likes: 117
My recently installed PFADT Trans Brace (last version) following the PFADT instruction to the letter and applying the recommended preload DO NOT CREATE any added vibration or generate any frequencies of any sort...
The only things that this PFADT part is doing...improving traction and stability plus predictability on off the corner throttle application of my monster torque engine through my monster tires.
Christian
The only things that this PFADT part is doing...improving traction and stability plus predictability on off the corner throttle application of my monster torque engine through my monster tires.
Christian
Le Mans Master
Joined: Feb 2007
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From: Oviedo Florida
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