Complete suspension build


Sam, what IYO are the cons to decoupled torque arms? Thanks in advance
From my understanding, This basically acts as a short length torque arm under acceleration, moving the instant center rearwards for improved acceleration/traction. Under Deceleration, it acts as a long torque arm, moving the instant center forwards for improved braking. (Using short length torque arms such as BMR's cross member mount or UMI's tunnel mount can generate wheel hop / brake chatter under heavy deceleration). I remember hearing a pretty big con about the UE decoupled torque arm, but I forgot what it was.
Last edited by allmotor; Oct 29, 2008 at 01:52 PM.
Second, while it's claimed to get rid of brake-hop I've driven 2 UE equipped cars, and 1 Herb Adams car, and brake hopped all 3. The claim was "not properly setup", which is fine but my car with a full length arm hardly ever brake hops anymore, and it goes back to being overly complicated.
Three, while I don't disagree the short side of the TA plants power better than a longer one it does it be moving the instant center backward. That unloads the front end, and suddenly it's hard to power out of corners (if that's your think like it is mine) and can causes a power on push. You can "fix" it with big springs and bars, but then you have more wheel rate which makes the car not as nice over bumps.
Four, I dislike floorpan mounted TA's as the sheetmetal is in no way intended for those loads.
www.stranoparts.com --814-849-3450
Results matter. Talk is cheap. We are miles beyond the success anyone else has had with the 4th gens, and C5, C6, C7 Corvettes,
10 SCCA Solo National Championships, 2008 Driver of they Year, 2012 Driver of Eminence
13 SCCA Pro Solo Nationals Championships
2023 UMI King of the Mountain Champion
Second, while it's claimed to get rid of brake-hop I've driven 2 UE equipped cars, and 1 Herb Adams car, and brake hopped all 3. The claim was "not properly setup", which is fine but my car with a full length arm hardly ever brake hops anymore, and it goes back to being overly complicated.
Three, while I don't disagree the short side of the TA plants power better than a longer one it does it be moving the instant center backward. That unloads the front end, and suddenly it's hard to power out of corners (if that's your think like it is mine) and can causes a power on push. You can "fix" it with big springs and bars, but then you have more wheel rate which makes the car not as nice over bumps.
Four, I dislike floorpan mounted TA's as the sheetmetal is in no way intended for those loads.
In theory.... yes. But again, all 3 I drove brake hopped. Considering it's not "supposed" to and claimed to eliminate it, why did all 3 do it?
And again, I don't buy it. Brake hop, tramp, whatever you want to call it happens with a solid axle. Nextel cup cars have NO torque arms at all, and in 2007 *both* Jeff Gordon and Tony Stewart, who are both very good road racers brake hopped themselves out of the lead of the race @ Watkins Glen (going into turn 1). And it happens all the time @ Martinsville too.
I have no brake hop issues that cause me any sort of trouble, and I have a full length arm on my car. And my car turns in a variety of situations and corners.
www.stranoparts.com --814-849-3450
Results matter. Talk is cheap. We are miles beyond the success anyone else has had with the 4th gens, and C5, C6, C7 Corvettes,
10 SCCA Solo National Championships, 2008 Driver of they Year, 2012 Driver of Eminence
13 SCCA Pro Solo Nationals Championships
2023 UMI King of the Mountain Champion
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Second, while it's claimed to get rid of brake-hop I've driven 2 UE equipped cars, and 1 Herb Adams car, and brake hopped all 3. The claim was "not properly setup", which is fine but my car with a full length arm hardly ever brake hops anymore, and it goes back to being overly complicated.
Three, while I don't disagree the short side of the TA plants power better than a longer one it does it be moving the instant center backward. That unloads the front end, and suddenly it's hard to power out of corners (if that's your think like it is mine) and can causes a power on push. You can "fix" it with big springs and bars, but then you have more wheel rate which makes the car not as nice over bumps.
Four, I dislike floorpan mounted TA's as the sheetmetal is in no way intended for those loads.
Yes, I agree with your points 3 and 4.
But what type of complicated are you talking about? ackermans theroem complicated or pro-touring forum complicated? Could you elaborate on the complexities please?
There's nothing wrong with doing things differently and to some extent I understand the desire to "tinker" with stuff (hell, I do it myself sometimes) but I personally like driving and competing a WHOLE lot more than testing / tuning / tweaking / testing / tuning / tweaking.
I think that is what Sam was getting at.
. If you do have one then you should also post it there, Sam.I suppose since no one on pro-touring has gone in depth on the de-coupled TA, and Sam has driven 3 cars with them or similar and experienced brake hop that it should be stayed away from. especially since there is a 13 page long thread just about getting it set up correctly. I was just curious about it since I like learning about such engineering issues and I figured someone would know. And complexity does not phase me, I'm an engineering student.
Last edited by allmotor; Oct 29, 2008 at 04:12 PM.
Go over the frrax.com and read the thread, I think most would see the complexities involved.
www.stranoparts.com --814-849-3450
Results matter. Talk is cheap. We are miles beyond the success anyone else has had with the 4th gens, and C5, C6, C7 Corvettes,
10 SCCA Solo National Championships, 2008 Driver of they Year, 2012 Driver of Eminence
13 SCCA Pro Solo Nationals Championships
2023 UMI King of the Mountain Champion

http://www.frrax.com/rrforum/index.php?showtopic=4630
. If you do have one then you should also post it there, Sam.I suppose since no one on pro-touring has gone in depth on the de-coupled TA, and Sam has driven 3 cars with them or similar and experienced brake hop that it should be stayed away from. especially since there is a 13 page long thread just about getting it set up correctly. I was just curious about it since I like learning about such engineering issues and I figured someone would know. And complexity does not phase me, I'm an engineering student.
www.stranoparts.com --814-849-3450
Results matter. Talk is cheap. We are miles beyond the success anyone else has had with the 4th gens, and C5, C6, C7 Corvettes,
10 SCCA Solo National Championships, 2008 Driver of they Year, 2012 Driver of Eminence
13 SCCA Pro Solo Nationals Championships
2023 UMI King of the Mountain Champion

http://www.frrax.com/rrforum/index.php?showtopic=4630
"The error returned was:
Sorry, the link that brought you to this page seems to be out of date or broken."

I'm a trial and error guy. I have understanding of engineering, but in the end function is what matters to me, and a lot of things that have added up, don't always pan out.
And the link Korry posted worked for me, but I belong to the site.
www.stranoparts.com --814-849-3450
Results matter. Talk is cheap. We are miles beyond the success anyone else has had with the 4th gens, and C5, C6, C7 Corvettes,
10 SCCA Solo National Championships, 2008 Driver of they Year, 2012 Driver of Eminence
13 SCCA Pro Solo Nationals Championships
2023 UMI King of the Mountain Champion
If getting a car to handle was only about theory and crunching numbers, why do the NASCAR teams struggle each and every single weekend to find and keep a handle on their cars? Surely with their enormous technical resources, both mechanical and human, they should be able to set the car up at the shop, unload at the track and run perfect laps at the very limit of adhesion, right? Doesn't happen, does it? Why not?
What drives the car? Theory? Math?
That stuff may explain why a car does what it does but it takes a human with experience to tune a car to their particular liking.
And once again I'm speaking for Sam.... sorry Sam.
I really don't know how he goes about it or what the procedure is these days.





