I posted this under my ongoing thread, but decided to also start a new thread as this is pretty important.
At Hallett race track on Tulsa, OK I had seen cars going off at a high speed turn all weekend. I entered the turn fast (maybe 80?) but all was well. Suddenly I was backwards. I believe I did about a 360 on the asphalt before going into the grass. It was very bumpy and I did another 360+, it was very jarring but I stopped shy of the tire wall which was 50+ yards off the track. Somehow the car didn't die and I drove back on to the track. I had to complete 70% of the track to get to pit exit. I wasn't sure if I damaged anything but I went slow.
When I got back to the paddock I saw my passenger rear body was nearly on the ground. I was able to get a jack under the rear and we discovered the broken suspension mount. I am sure this broke before I spun and was the reason for the spin. It was so sudden and unexpected.
I am now trying to figure out if I have the FFR "fix" or the original part. I called FFR and they were not super helpful. If this is not the fix then my next question is how does the FFR fix compare to the Vendor's fix which can be purchased?
Some say, that I only know two facts about ducks, (both being wrong); and that if I could be bothered, I could solve the "da Vinci Code" in 47 seconds...
All I know is that I'm called "The Stig". GTM #0081
You mount was the original mount without the "fix". The new bracket bolts on overtop of the old bracket to reinforce it:
Shane Vacek
VRaptor SpeedWorks, LLC www.vraptorspeedworks.com
Turn-key GTM, SL-C & Ultima GTR Built to Your Specs!
Offering a full line of GTM Upgrades and Custom Parts
I got a reply via email from ffr:
" You do have the original designed bracket on that control arm, however it
is strange that the original owner/builder did not install the retrofit
parts that was sent to him and all other GTM customers that were affected by
that problem at that time. We will get you out a set of updated brackets
once they are back in stock, which should be by the end of the week.
Interestingly it appears my reply has been completely removed?
In any case, for future reference about this issue, there is an outside vendor that sells a retrofit rear shock mount that we have stress tested for over 8 years now and it has never failed. Unlike the two versions from FFR, the other fix puts all components into compression instead of tension, which makes the mount that much harder to fatigue and have come apart.
I will post a link on the sister thread in the "other forum" for those that are interested.
Interestingly it appears my reply has been completely removed?
In any case, for future reference about this issue, there is an outside vendor that sells a retrofit rear shock mount that we have stress tested for over 8 years now and it has never failed. Unlike the two versions from FFR, the other fix puts all components into compression instead of tension, which makes the mount that much harder to fatigue and have come apart.
I will post a link on the sister thread in the "other forum" for those that are interested.
That's the one I'm using as well.
Mike
The Stig
Some say, that I only know two facts about ducks, (both being wrong); and that if I could be bothered, I could solve the "da Vinci Code" in 47 seconds...
All I know is that I'm called "The Stig". GTM #0081
As a point of information. I have been using the new strengthened bracket from FFR under racing conditions for years without issue. I like to jump curbs and have been known to do a little off roading as well. I'm satisfied they are strong.
John
XTF #2
build start date June 19 2023
GTM # 344
Build Start December 2010
First track day April 2013
Very helpful John, thanks. One of these days I will be ready for race slicks but my Michelin Pilot Sport Cup 2 tires did this and from other comments in the other forum I think anyone could break this part eventually even on normal street tires with the occasional wheel turned spinning tires in the parking lot move, aka skid pad.
You mount was the original mount without the "fix". The new bracket bolts on overtop of the old bracket to reinforce it:
Hey guys, i have posted about this before on a separate thread, but thought i would revive this one and mention it here also. This "fix" that factory five supplied, its insufficient. While my mounts didnt break off (so at least thats good), they did warp up as if they were made of play doh.
So like i said on the other thread, get these things switched out with the quick racing products version, quick smart. After bending, the bend basically forced the upright inward on my car, rubbing the rear rotor against the knuckle of the lower wishbone. So it was almost like someone yanked on the handbrake for me when i was driving it when it happened.
Do you have any pics of this....I'm having a tough time envisioning what's going on? It seems to me that if the rotor came in contact with the LCA....that would indicate lower ball-joint failure? Also trying to figure out how the shock mount could bend upwards when the only way you could apply an upward load on the mount is with just the weight of the wheel/tire/knuckle assy if it was up off the ground.
Shane Vacek
VRaptor SpeedWorks, LLC www.vraptorspeedworks.com
Turn-key GTM, SL-C & Ultima GTR Built to Your Specs!
Offering a full line of GTM Upgrades and Custom Parts
Do you have any pics of this....I'm having a tough time envisioning what's going on? It seems to me that if the rotor came in contact with the LCA....that would indicate lower ball-joint failure? Also trying to figure out how the shock mount could bend upwards when the only way you could apply an upward load on the mount is with just the weight of the wheel/tire/knuckle assy if it was up off the ground.
Hey Shane,
Here are some pics. As you can see, the left side is normal (apologies for the rotated pic, the pic was oriented correctly when taken, the forum pic upload plugin rotates the pic for some reason): IMG_20190914_112605.jpg
You can see the original FFR mount has broken, the fix FFR sent saved the day, but warped out of shape to do so. The change in angle here pulled the bottom of the upright inward, forcing the rotor to rub against the apex of the lower wish bone. Probably caused the bottom ball joint to fail perhaps. So yea, if you drive over bad roads, don't screw around and waste your time with the stock (including the fix) rear shock mounts. Go for the quickracingproducts equipment by default. In fact, consider them as a necessity.
You would definitely be ok with a 2016 GTM. I'm thinking that the FFR fix came out really early....like 2007 or 2008.
Shane Vacek
VRaptor SpeedWorks, LLC www.vraptorspeedworks.com
Turn-key GTM, SL-C & Ultima GTR Built to Your Specs!
Offering a full line of GTM Upgrades and Custom Parts
I don't think it was that early. Pretty sure PDG was the first to break these as we were stressing the parts under race conditions in about 2009? So probably somewhere in 2010-2013 the change was made? FFR waited to see some failures in street trim as I recall after we brought their attention to the issue.
I don't think it was that early. Pretty sure PDG was the first to break these as we were stressing the parts under race conditions in about 2009? So probably somewhere in 2010-2013 the change was made? FFR waited to see some failures in street trim as I recall after we brought their attention to the issue.
Yeah i dont know when it was, i just remember receiving the shock mount reinforcements back in 2010. But here are some more pics of the mounts after i had pulled them off the right rear.
You can see, in spite of the factory five fix, the mount gave way. After i inspected the mounts, i noticed that the add on fix FFR sent me, barely held it. It had a massive stress crack too.
What we did is straighten out the mounts, both the original and the fix then TIG welded the two elements together instead of relying on just the bolts to hold the two together. We also added a lot more reinforcement plates in and around the areas where the original had given way and cracked. I dont have any pix of the repaired and strengthened versions we had modified, as i was just happy we got it done and dusted and just wanted it over with. But here are some pix pre-fix..
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Originally Posted by crash
