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I'm interested in improving the handling on the V. I have an '06, and the suspension part numbers don't jive with the ones on cadillacfaq.com. I doubt they're sport tuned, or as good as I can get, but I can get those GM part # 12499241 shocks for a little over 1k. Anyone have any other recommendations? I have no interest in looks/lowering unless it's specifically for improving handling.
 

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I'm interested in improving the handling on the V. I have an '06, and the suspension part numbers don't jive with the ones on cadillacfaq.com. I doubt they're sport tuned, or as good as I can get, but I can get those GM part # 12499241 shocks for a little over 1k. Anyone have any other recommendations? I have no interest in looks/lowering unless it's specifically for improving handling.
Here's the deal. How hard core are you? I'll be honest, the FG2 is a good strut. And it will help your handling. But it's not that well matched to the stock spring. If you decide to go to the FG2, it works much better with a stiffer spring, ala Ground Control 500/550 coilovers...
 

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I have the GM performance shocks on my '07....I test drove 2 identical models...one with the upgrade and one without. I believe that the 1 K expense if worth it....less washout with cornering, and absorbs compression, but resists extension - no bounce.
 

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Here's the deal. How hard core are you? I'll be honest, the FG2 is a good strut. And it will help your handling. But it's not that well matched to the stock spring. If you decide to go to the FG2, it works much better with a stiffer spring, ala Ground Control 500/550 coilovers...
Did you resolve the issues you had with the Hotchkis sways and Ground Contol 500/550 coilovers?
 

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Did you resolve the issues you had with the Hotchkis sways and Ground Contol 500/550 coilovers?
I still need to find a long term solution for the endlinks. I didn't install the Z06 links because I may need to raise the suspension when going to tracks as vicious as Grattan. So right now, when I track, I raise the suspension. When I cruise, I lower it. Counterintuitive, but for now it works...
 

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Discussion Starter #6
I have the GM performance shocks on my '07....I test drove 2 identical models...one with the upgrade and one without. I believe that the 1 K expense if worth it....less washout with cornering, and absorbs compression, but resists extension - no bounce.
That's exactly the kind of answer I was hoping for. I'll order a set.. how's newcadillacparts.com for prices?
 

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Pretty much what everyone here is saying is correct. My 06V was supposed to have the FG2 shocks already installed, but because Tustin Cadillac sucks, they decided not to install the shocks on the v. I drove around for about 2 days with the stock shocks until I got the car in the air and saw that the shocks were not the FG2. After getting the FG2 shocks installed, there was a noticeable difference.

After going over the same exact roads with the FG2 shocks, you can notice some differences. The ride is pretty much unaltered over normal roads without any cornering force. There was no noticeable difference in ride quality on the freeway (as it should be, since you're not loading up the suspension), but the FG2, while pretty good for increasing cornering ability, is too much shock for the springs. To be able to understand what I'm talking about you must first understand what the shock actually does.

A springs main purpose is to keep the tires planted on the road. After you hit a bump, the spring is compressed and it stores the energy from the impact and then as the tire crests over the maximum point of the bump, the spring uses that stored energy to push the tire back down so that the tire doesn't lose contact with the road. When going over a dip, the same thing happens, except in this case, the spring elongates instead of contracting. As you might remember, a spring is an oscillator following the equation m(dz^2/dt^2) + mg(dz/dt) + kz = F(t). M is the mass, z is the travel in the z axis, g is your dissipation factor, and k is your spring rate and F(t) is an externally applied force. After you hit a bump, the spring compresses and begins following this differential equation and it will keep oscillating until the dissipation factor stops this motion from occurring. This is why a Buick century or an old 80's Cadillac will keep trampolining after it hits a bump. The spring in these cars are doing their job, but the motion is not being dissipated enough, and this dissipation of energy is the purpose of the shock. As any driver of these cars might tell you, it makes for a smooth and comfy ride, but its not very sporty and adversely effects the handling of the car.

Like I explained above, the shock is there to control the unwanted oscillations of the spring. Having a stiff shock will stop any bounce from occurring and thus you eliminate any erratic shifts in your loading or tire contact patch. A shock also plays a major role in weight transfer. The stiffer the shock, the faster weight transfer occurs. This will help with acceleration, braking, and cornering. A stiffer shock will also improve the responsiveness of the steering since weight transfer is now faster. It is however possible to have too much shock. A shock with too high of a rate can cause weight transfer to occur too quickly for the driver to control if they are inexperienced, and it can also overpower the springs. This overpowering of the springs occurs since the dissipation factor is too high for the springs to travel the way they are supposed to and so the springs don't do their job properly, i.e. not being able to absorb a bump.


In regards to personal experience, when cornering aggressively with the FG2, the car does feel more planted, however this is only the case with smooth weight transfer. If you drive erratically, the car is a little more nervous in the handling department. Pulling .9g + on the g-meter comes easier if you drive smoothly. There is however a downside. Going over a bump while cornering at speed does unsettle the car. When going onto a freeway on ramp that had a pothole at speed, was far less nerve racking with the original shocks. Going over the same bump at about the same speed with the fg2 almost made me lose control since the car didn't respond quickly enough for the bump (this was a very large pothole that thankfully didn't bend the rim).

IMHO if you have nice roads around where you are the fg2 are a great upgrade. If you have lots of bumps around, I would hold off unless you do the Ground Control coil over upgrade as well (though this will give you a slightly harsher ride).

Cliffs: while handling and response is improved, the ability to absorb bumps is diminished since the shock overpowers the spring. Worthwhile upgrade if you don't plan on pulling .9 g on roads with bumps
 

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Pretty much what everyone here is saying is correct. My 06V was supposed to have the FG2 shocks already installed, but because Tustin Cadillac sucks, they decided not to install the shocks on the v. I drove around for about 2 days with the stock shocks until I got the car in the air and saw that the shocks were not the FG2. After getting the FG2 shocks installed, there was a noticeable difference.

After going over the same exact roads with the FG2 shocks, you can notice some differences. The ride is pretty much unaltered over normal roads without any cornering force. There was no noticeable difference in ride quality on the freeway (as it should be, since you're not loading up the suspension), but the FG2, while pretty good for increasing cornering ability, is too much shock for the springs. To be able to understand what I'm talking about you must first understand what the shock actually does.

A springs main purpose is to keep the tires planted on the road. After you hit a bump, the spring is compressed and it stores the energy from the impact and then as the tire crests over the maximum point of the bump, the spring uses that stored energy to push the tire back down so that the tire doesn't lose contact with the road. When going over a dip, the same thing happens, except in this case, the spring elongates instead of contracting. As you might remember, a spring is an oscillator following the equation m(dz^2/dt^2) + mg(dz/dt) + kz = F(t). M is the mass, z is the travel in the z axis, g is your dissipation factor, and k is your spring rate and F(t) is an externally applied force. After you hit a bump, the spring compresses and begins following this differential equation and it will keep oscillating until the dissipation factor stops this motion from occurring. This is why a Buick century or an old 80's Cadillac will keep trampolining after it hits a bump. The spring in these cars are doing their job, but the motion is not being dissipated enough, and this dissipation of energy is the purpose of the shock. As any driver of these cars might tell you, it makes for a smooth and comfy ride, but its not very sporty and adversely effects the handling of the car.

Like I explained above, the shock is there to control the unwanted oscillations of the spring. Having a stiff shock will stop any bounce from occurring and thus you eliminate any erratic shifts in your loading or tire contact patch. A shock also plays a major role in weight transfer. The stiffer the shock, the faster weight transfer occurs. This will help with acceleration, braking, and cornering. A stiffer shock will also improve the responsiveness of the steering since weight transfer is now faster. It is however possible to have too much shock. A shock with too high of a rate can cause weight transfer to occur too quickly for the driver to control if they are inexperienced, and it can also overpower the springs. This overpowering of the springs occurs since the dissipation factor is too high for the springs to travel the way they are supposed to and so the springs don't do their job properly, i.e. not being able to absorb a bump.


In regards to personal experience, when cornering aggressively with the FG2, the car does feel more planted, however this is only the case with smooth weight transfer. If you drive erratically, the car is a little more nervous in the handling department. Pulling .9g + on the g-meter comes easier if you drive smoothly. There is however a downside. Going over a bump while cornering at speed does unsettle the car. When going onto a freeway on ramp that had a pothole at speed, was far less nerve racking with the original shocks. Going over the same bump at about the same speed with the fg2 almost made me lose control since the car didn't respond quickly enough for the bump (this was a very large pothole that thankfully didn't bend the rim).

IMHO if you have nice roads around where you are the fg2 are a great upgrade. If you have lots of bumps around, I would hold off unless you do the Ground Control coil over upgrade as well (though this will give you a slightly harsher ride).

Cliffs: while handling and response is improved, the ability to absorb bumps is diminished since the shock overpowers the spring. Worthwhile upgrade if you don't plan on pulling .9 g on roads with bumps
Yeah, like Big Jim said, you need stiffer springs.
 

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IMHO if you have nice roads around where you are the fg2 are a great upgrade. If you have lots of bumps around, I would hold off unless you do the Ground Control coil over upgrade as well (though this will give you a slightly harsher ride).
Excellent explanation! :yup: (The whole thing, not just that which I quoted)
 

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Pretty much what everyone here is saying is correct. My 06V was supposed to have the FG2 shocks already installed, but because Tustin Cadillac sucks, they decided not to install the shocks on the v. I drove around for about 2 days with the stock shocks until I got the car in the air and saw that the shocks were not the FG2. After getting the FG2 shocks installed, there was a noticeable difference.

After going over the same exact roads with the FG2 shocks, you can notice some differences. The ride is pretty much unaltered over normal roads without any cornering force. There was no noticeable difference in ride quality on the freeway (as it should be, since you're not loading up the suspension), but the FG2, while pretty good for increasing cornering ability, is too much shock for the springs. To be able to understand what I'm talking about you must first understand what the shock actually does.

A springs main purpose is to keep the tires planted on the road. After you hit a bump, the spring is compressed and it stores the energy from the impact and then as the tire crests over the maximum point of the bump, the spring uses that stored energy to push the tire back down so that the tire doesn't lose contact with the road. When going over a dip, the same thing happens, except in this case, the spring elongates instead of contracting. As you might remember, a spring is an oscillator following the equation m(dz^2/dt^2) + mg(dz/dt) + kz = F(t). M is the mass, z is the travel in the z axis, g is your dissipation factor, and k is your spring rate and F(t) is an externally applied force. After you hit a bump, the spring compresses and begins following this differential equation and it will keep oscillating until the dissipation factor stops this motion from occurring. This is why a Buick century or an old 80's Cadillac will keep trampolining after it hits a bump. The spring in these cars are doing their job, but the motion is not being dissipated enough, and this dissipation of energy is the purpose of the shock. As any driver of these cars might tell you, it makes for a smooth and comfy ride, but its not very sporty and adversely effects the handling of the car.

Like I explained above, the shock is there to control the unwanted oscillations of the spring. Having a stiff shock will stop any bounce from occurring and thus you eliminate any erratic shifts in your loading or tire contact patch. A shock also plays a major role in weight transfer. The stiffer the shock, the faster weight transfer occurs. This will help with acceleration, braking, and cornering. A stiffer shock will also improve the responsiveness of the steering since weight transfer is now faster. It is however possible to have too much shock. A shock with too high of a rate can cause weight transfer to occur too quickly for the driver to control if they are inexperienced, and it can also overpower the springs. This overpowering of the springs occurs since the dissipation factor is too high for the springs to travel the way they are supposed to and so the springs don't do their job properly, i.e. not being able to absorb a bump.


In regards to personal experience, when cornering aggressively with the FG2, the car does feel more planted, however this is only the case with smooth weight transfer. If you drive erratically, the car is a little more nervous in the handling department. Pulling .9g + on the g-meter comes easier if you drive smoothly. There is however a downside. Going over a bump while cornering at speed does unsettle the car. When going onto a freeway on ramp that had a pothole at speed, was far less nerve racking with the original shocks. Going over the same bump at about the same speed with the fg2 almost made me lose control since the car didn't respond quickly enough for the bump (this was a very large pothole that thankfully didn't bend the rim).

IMHO if you have nice roads around where you are the fg2 are a great upgrade. If you have lots of bumps around, I would hold off unless you do the Ground Control coil over upgrade as well (though this will give you a slightly harsher ride).

Cliffs: while handling and response is improved, the ability to absorb bumps is diminished since the shock overpowers the spring. Worthwhile upgrade if you don't plan on pulling .9 g on roads with bumps
:worship:
 

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Pretty much what everyone here is saying is correct. My 06V was supposed to have the FG2 shocks already installed, but because Tustin Cadillac sucks, they decided not to install the shocks on the v. I drove around for about 2 days with the stock shocks until I got the car in the air and saw that the shocks were not the FG2. After getting the FG2 shocks installed, there was a noticeable difference.

After going over the same exact roads with the FG2 shocks, you can notice some differences. The ride is pretty much unaltered over normal roads without any cornering force. There was no noticeable difference in ride quality on the freeway (as it should be, since you're not loading up the suspension), but the FG2, while pretty good for increasing cornering ability, is too much shock for the springs. To be able to understand what I'm talking about you must first understand what the shock actually does.

A springs main purpose is to keep the tires planted on the road. After you hit a bump, the spring is compressed and it stores the energy from the impact and then as the tire crests over the maximum point of the bump, the spring uses that stored energy to push the tire back down so that the tire doesn't lose contact with the road. When going over a dip, the same thing happens, except in this case, the spring elongates instead of contracting. As you might remember, a spring is an oscillator following the equation m(dz^2/dt^2) + mg(dz/dt) + kz = F(t). M is the mass, z is the travel in the z axis, g is your dissipation factor, and k is your spring rate and F(t) is an externally applied force. After you hit a bump, the spring compresses and begins following this differential equation and it will keep oscillating until the dissipation factor stops this motion from occurring. This is why a Buick century or an old 80's Cadillac will keep trampolining after it hits a bump. The spring in these cars are doing their job, but the motion is not being dissipated enough, and this dissipation of energy is the purpose of the shock. As any driver of these cars might tell you, it makes for a smooth and comfy ride, but its not very sporty and adversely effects the handling of the car.

Like I explained above, the shock is there to control the unwanted oscillations of the spring. Having a stiff shock will stop any bounce from occurring and thus you eliminate any erratic shifts in your loading or tire contact patch. A shock also plays a major role in weight transfer. The stiffer the shock, the faster weight transfer occurs. This will help with acceleration, braking, and cornering. A stiffer shock will also improve the responsiveness of the steering since weight transfer is now faster. It is however possible to have too much shock. A shock with too high of a rate can cause weight transfer to occur too quickly for the driver to control if they are inexperienced, and it can also overpower the springs. This overpowering of the springs occurs since the dissipation factor is too high for the springs to travel the way they are supposed to and so the springs don't do their job properly, i.e. not being able to absorb a bump.


In regards to personal experience, when cornering aggressively with the FG2, the car does feel more planted, however this is only the case with smooth weight transfer. If you drive erratically, the car is a little more nervous in the handling department. Pulling .9g + on the g-meter comes easier if you drive smoothly. There is however a downside. Going over a bump while cornering at speed does unsettle the car. When going onto a freeway on ramp that had a pothole at speed, was far less nerve racking with the original shocks. Going over the same bump at about the same speed with the fg2 almost made me lose control since the car didn't respond quickly enough for the bump (this was a very large pothole that thankfully didn't bend the rim).

IMHO if you have nice roads around where you are the fg2 are a great upgrade. If you have lots of bumps around, I would hold off unless you do the Ground Control coil over upgrade as well (though this will give you a slightly harsher ride).

Cliffs: while handling and response is improved, the ability to absorb bumps is diminished since the shock overpowers the spring. Worthwhile upgrade if you don't plan on pulling .9 g on roads with bumps

That's what I was going to say. :D


Nice write-up. :thumbsup:
 

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Discussion Starter #12
I suspect that the loss of control you experienced with the large bump had to do with the weight of the stock wheels, which I think are probably too much unsprung weight.
 

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Discussion Starter #13
Oh, and nice write up, I appreciate the information. I'd edit my original post, but to reply to PM's I apparently have to have 20 posts. Useless chatter time!
 

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I suspect that the loss of control you experienced with the large bump had to do with the weight of the stock wheels, which I think are probably too much unsprung weight.
Possible, but I went over that same pothole twice with the stock shock package and the car wasn't nearly as twitchy at the same speeds. The FG2, while still controllable defiantly surprised me after going over that pothole. Didn't expect the car to react the way it did. Like I said though, these are just my experiences though. I can't speak for other members or their experiences. The only way to truly know how well it reacts is to put it on a shock dyno and sadly, I can't pony up for that. Still defiantly worth it, just gotta be a little more cautious in regards to road conditions is all I'm saying.
 

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Let me preface this by saying that right after Lindsay installed my FG2's in early August, I installed the Hotchkis sway bars.

In July I took my V to the track for the first time since adding the s/c. I had to really adjust to the new torque gain when coming out of the curves. In comp mode, the back end wanted to break free too easily. After upgrading the suspension with the mods I mentioned, I could exit much hotter than before. I didn't notice any change on entry and I could delay a little on apex.

The car is much more fun to drive at the track. Between the FG2's, their installation and the Hotchkis sways, I put a little under $2K into the car but definitely think they are worth the expense.

I am now considering the GC coil overs but as a retiree on a fixed income, I need to hold off a while. I'll have to pay someone to install the kit which adds to the cost.
 

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Discussion Starter #19
It sounds like that combination of FG2 + hotchkiss is worthwhile. How much work is installation? Is it possible to DIY or should I just take it someplace?
 
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