Vette2Vette No-Flex Chassis Stiffening Bars Don't Work
10-04-2015, 01:16 PM
#61
Pro
I have installed a set, I will go back after reading the thread and ensure the torque is the same on both sides. Thank you gentlemen. My 95 Vert was sans factory x brace so this seemed like a good solution to replace what was missing anyway. It certainly decreased flexing as the name states. Feels like a 95 c4 should. They are not sold as magic bars that turn c4 into c6 frame stiffness 
On the pricey side, but what does a production run for v2v constitute, 25 sets ? I'm sure they are not making a c7 payment with the monthly profit from selling these. Just my humble...
On the pricey side, but what does a production run for v2v constitute, 25 sets ? I'm sure they are not making a c7 payment with the monthly profit from selling these. Just my humble...
10-04-2015, 01:18 PM
#62
Burning Brakes
I see a lot of disagreements between members on this one. This crap has become the new "opti threads"
Well, let's do this. If you have the money to "spare" and buy these bars knock yourself out.
I drove the bejesus out of my 1992 Vert, and Betty Boop (95), drive the bejesus with extreme prejudice out of The Ghost, and I don't have them.
Bryan had a racer C4 with 500 HP+, and he didn't have them.
Many others in here that actually drive their C4s don't have them.
If you want a stiffer car buy a Jeep.
Well, let's do this. If you have the money to "spare" and buy these bars knock yourself out.
I drove the bejesus out of my 1992 Vert, and Betty Boop (95), drive the bejesus with extreme prejudice out of The Ghost, and I don't have them.
Bryan had a racer C4 with 500 HP+, and he didn't have them.
Many others in here that actually drive their C4s don't have them.
If you want a stiffer car buy a Jeep.
However, some of us want to explore what else is available from the guys who were actually in on its design.The OP felt his braces weren't doing the job and most of us (for whom the braces work admirably) are trying to assist him in finding out why.
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CF-105 (02-15-2021)
10-04-2015, 02:24 PM
#64
Team Owner
Pro Mechanic
I am not an engineer but would ask if it isn't more important than having the the same number of threads on both sides to rather have both rods torqued the same. It appears to me that following MavsAK's explanation failing to do so will result in the main frame members reacting fundamentally differently and perhaps even amplifying problems rather than eliminating them.
I use a 1/2" drive Harbor Freight torque wrench (although their 3/8" drive will go to 80ft/lbs), a 1/2" to 3/8" adapter and a 3/8" drive 7/8" crowfoot flat wrench. I've heard the offset may result in a slight inaccuracy in the measurement but I'm after an approximation rather than trying to be exact.
This makes the MOST sense of anything I've seen posted, regarding the installation of these. Well said, AustinJohn! The tq precise torquing of the bars using Crowsfeet is slightly inaccurate...but it doesn't matter the precise tq value...what matters is using the same value left and right, and car to car.
10-04-2015, 04:26 PM
#66
Team Owner
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PLRX, I fail to see what contribution your post makes to this thread. If you're happy with your car, great! However, some of us want to explore what else is available from the guys who were actually in on its design.
The OP felt his braces weren't doing the job and most of us (for whom the braces work admirably) are trying to assist him in finding out why.
However, some of us want to explore what else is available from the guys who were actually in on its design.The OP felt his braces weren't doing the job and most of us (for whom the braces work admirably) are trying to assist him in finding out why.
Let me know if you don't get it this time.
10-04-2015, 07:37 PM
#67
Burning Brakes
Thanks for the reply, John, and especially for catching that MavsAK's post is #19 and not #21. Thanks also for emailing Jason; I look forward to his response.
Here's a little elaboration on why I focus on torque rather than thread count. As several posters have suggested the amount of pre-loading that works best on an individual car depends on various factors including not only mileage and condition of the car but probably the day of the week the frame was fabricated.
I've tried various amounts of pre-loading but one that works for me is 70ft/lbs of pre-loading on the passenger side rod which I've found is my most critical side. However, if I adjust both sides to the same thread count, I get 70ft/lbs of pre-loading on the passenger side rod but 100ft/lbs on the driver side rod, an unequal pre-loading and unequal pre-loading - in my experience of adjusting for maximum benefits from the No Flex System - leads to additional problems rather than benefits. Thus my goal is similar pre-loading on both sides but not identical thread counts.
As the No Flex System was never a part of the C4 design I've seen little discussion of the concepts involved (MavsAK's post is one of the few) but Chapter 10: "Handling Dynamics and Active Safety in the Corvette" of Dave McClelland's Corvette From the Inside discusses some of them.
John
Here's a little elaboration on why I focus on torque rather than thread count. As several posters have suggested the amount of pre-loading that works best on an individual car depends on various factors including not only mileage and condition of the car but probably the day of the week the frame was fabricated.
I've tried various amounts of pre-loading but one that works for me is 70ft/lbs of pre-loading on the passenger side rod which I've found is my most critical side. However, if I adjust both sides to the same thread count, I get 70ft/lbs of pre-loading on the passenger side rod but 100ft/lbs on the driver side rod, an unequal pre-loading and unequal pre-loading - in my experience of adjusting for maximum benefits from the No Flex System - leads to additional problems rather than benefits. Thus my goal is similar pre-loading on both sides but not identical thread counts.
As the No Flex System was never a part of the C4 design I've seen little discussion of the concepts involved (MavsAK's post is one of the few) but Chapter 10: "Handling Dynamics and Active Safety in the Corvette" of Dave McClelland's Corvette From the Inside discusses some of them.
John
10-04-2015, 10:44 PM
#69
Burning Brakes
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CF-105 (02-15-2021)
10-05-2015, 07:21 AM
#70
70# but as I said, that worked for me. Let me go back over the procedure I followed.
When I began my installation my goal wasn't 70ft/lbs, that's just where I ended up. I began, as Jason suggests, tightening both sides the same number of thread turns. I then went to my "test spot" which conveniently is a single lane, 15 foot long washboard surface about 100 yards from my place and drove over it several times to see the result of my initial setup. Before installation of the No Flex System it was obvious my problem was with the passenger side frame member and driving back and forth over my test spot I could drive all four wheels over the test spot or just the passenger wheels or just the driver side wheels and feel the result of my tinkering.
When I got what I considered my best result I checked torque on the passenger side rod, found it was 70ft/lbs, checked torque on the driver side rod, found it was 100ft/lbs and loosened the driver side rod slightly, achieving 70ft/lbs and found with further passes over my test spot that was an improvement so that's my setting. Whether someone knowledgeable would suggest 70ft/lbs is too high or too low I don't know but it works for me but again it wasn't a goal, it's just where my adjustments ended up.
One other observation: At the end of the assembly line in Bowling Green there is a row of raised bumps that every car has to drive over before testing and my guide told me the purpose is to "set" the suspension. I found that the same thing needed to happen after my initial No Flex System installation and any later adjustment. It takes some hours or days of driving for the system to "normalize" so making additional changes without allowing the suspension to normalize may give a false feeling. (I found the same thing to be true after installing new shocks.)
As you can see, all this takes some time but I felt it was worth it. Hope that explanation helps. John
When I began my installation my goal wasn't 70ft/lbs, that's just where I ended up. I began, as Jason suggests, tightening both sides the same number of thread turns. I then went to my "test spot" which conveniently is a single lane, 15 foot long washboard surface about 100 yards from my place and drove over it several times to see the result of my initial setup. Before installation of the No Flex System it was obvious my problem was with the passenger side frame member and driving back and forth over my test spot I could drive all four wheels over the test spot or just the passenger wheels or just the driver side wheels and feel the result of my tinkering.
When I got what I considered my best result I checked torque on the passenger side rod, found it was 70ft/lbs, checked torque on the driver side rod, found it was 100ft/lbs and loosened the driver side rod slightly, achieving 70ft/lbs and found with further passes over my test spot that was an improvement so that's my setting. Whether someone knowledgeable would suggest 70ft/lbs is too high or too low I don't know but it works for me but again it wasn't a goal, it's just where my adjustments ended up.
One other observation: At the end of the assembly line in Bowling Green there is a row of raised bumps that every car has to drive over before testing and my guide told me the purpose is to "set" the suspension. I found that the same thing needed to happen after my initial No Flex System installation and any later adjustment. It takes some hours or days of driving for the system to "normalize" so making additional changes without allowing the suspension to normalize may give a false feeling. (I found the same thing to be true after installing new shocks.)
As you can see, all this takes some time but I felt it was worth it. Hope that explanation helps. John
Last edited by AustinJohn; 10-05-2015 at 11:06 AM.
10-05-2015, 11:00 AM
#71
Race Director
Well, PLRX, I get it! And, while I'm obviously not as C4 knowledgeable as you are, I do know the word that describes someone's opinion of something they've never tried. It's called... ignorance. So, save your money and don't ever try the frame braces. Otherwise, you may be come... enlightened.
The problem with these is that the only way anyone can measure their effectiveness is through ancedotal evidence, 'butt-o-meter', etc.
Its not like putting on some headers and running it before/after on the same dyno!
Somebody, well-connected here, needs to have access to a frame twist machine.
The type that car manufacturers use to say : the new porsche is 600% stiffer than the old porsche in frame torsion, 1 degree twist takes 27600 lb-ft .
We need to see some before/after measurements on a machine like that.
Buy a couple junk c4's - make sure one is a vert with x-brace. (they are so cheap!) and do this measurement both before and after.
I would also do the coupe (and vert) with top on/off (or for the vert, top down) ,..
Then put this vette 2 vette brace on and see if improves results.
10-05-2015, 11:14 AM
#72
the bumps at the end of the line don't set anything but do settle things for roll test that follows for final ajustments at speed just before shipping.
so with this info it will change your alignment a bit
so with this info it will change your alignment a bit
Last edited by antfarmer2; 10-05-2015 at 11:25 AM.
10-05-2015, 11:25 AM
#73
10-05-2015, 04:10 PM
#74
Race Director
All I can say is the bars got rid of any flex creaks when on uneven pavement, pulling onto a driveway, going over railroad track etc.
I don't have proven data, heck I cannot even confirm the torque on my bars (no hexes on the ends) but I still have the very first set Jason made on my car (since 2009 I think)
If others think they don't work that is fine, they are entitled to their opinion.
I can tell there is a difference, unfortunately I cannot prove that difference, but I wish I was able to prove that difference..
I don't have proven data, heck I cannot even confirm the torque on my bars (no hexes on the ends) but I still have the very first set Jason made on my car (since 2009 I think)
If others think they don't work that is fine, they are entitled to their opinion.
I can tell there is a difference, unfortunately I cannot prove that difference, but I wish I was able to prove that difference..
10-05-2015, 05:14 PM
#75
Team Owner
Member Since: Aug 2005
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10-05-2015, 05:53 PM
#76
Pro
Maybe you are not as superior to everyone as much as you believe you are.
10-05-2015, 08:24 PM
#78
Pro
10-07-2015, 11:10 AM
#79
Team Owner
Pro Mechanic
The problem with these is that the only way anyone can measure their effectiveness is through ancedotal evidence, 'butt-o-meter', etc.
Somebody, well-connected here, needs to have access to a frame twist machine.
Buy a couple junk c4's - make sure one is a vert with x-brace. (they are so cheap!) and do this measurement both before and after.
I would also do the coupe (and vert) with top on/off (or for the vert, top down) ,..
Then put this vette 2 vette brace on and see if improves results.
Somebody, well-connected here, needs to have access to a frame twist machine.
Buy a couple junk c4's - make sure one is a vert with x-brace. (they are so cheap!) and do this measurement both before and after.
I would also do the coupe (and vert) with top on/off (or for the vert, top down) ,..
Then put this vette 2 vette brace on and see if improves results.
SO...I've already TRIED to do this. I have female threaded lugs in the floor of my garage. It would be relatively easy for me to bolt a frame to the floor, make a jig to measure, and do exactly that; measure the #'s/degree in torsion of the frame, make changes and remeasure.
Here is the real challenge (as I've seen it): GETTING A FRAME! obviously, shipping a frame isn't practical, or cheap, so I'd need to fine one locally. Well, there is "Corvette Recycling" only about 45 minutes from my house. They ought to have C4 frames they send to scrap pretty frequently (every time the dismantle and part out a C4, right? I've called and emailed them numerous times. NUMEROUS times. No replies, no call backs, no effort, nothing. I don't get it...do these people want to make a buck, or what??
Maybe everyone on this thread could shoot them a PM or email and see what happens. I could easily go up there, throw the frame in the back of my truck and bring it home...and start testing.
10-07-2015, 08:43 PM
#80
Burning Brakes
Butt-o-Meter
I would respectfully like to point out that although torsional numbers would be interesting, the Butt-O-Meter can at least offer some evidence as to whether or not the frame braces work. If you have gone over the same railroad tracks for months and your C4 goes "clickity, clickity clack" and, after installation your C4 just goes "click," an improvement has been made. Speaking for myself, I can tell you they work. You can believe me (and dozens of other C4 owners) or not. Numbers may tell you how well they work but for me, they work at least $500.00 worth.
Last edited by DrDyno; 10-07-2015 at 10:37 PM.
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