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Good morning. Thanks for your reply. I'm big on keeping my vehicles stock and very little if any at all aftermarket parts but yes the ride is too ridgit Feeling every little rivit on the road especially here in South Jersey. Looking for a smoother ride with this beautiful automobile.
 

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RU sure that the suspension is stock? Sway bars or coil overs might have been changed already resulting in a harsher ride. The Solstice never had a soft ride, it wasn't meant to have.
 
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DO NOT CHANGE YOUR SUSPENSION!!!!

the suspension is not the problem.. The problem is frame twisting. The problem can be solved for < 1000.00 USD.

Get a Werks Racing front shock tower brace, a Werks Racing rear frame brace and a DDM Pro Beam.

Make a trip to home depot and pick up a 6' piece of 1"x1"x1/8" Steel L Channel. also pick up 3/8" x 3/4" Stainless Bolts and nylon stop nuts. You will need about 30 of them. you are also going to want to pick up 8 1/2" stainless steel 1" bolts and nylon stop nuts. Last thing is a piece of 3" x 1/4 x 2' steel flat bar.


tools you will need.

High output Torch
3/8" and 1/2" high speed drill bits
SawZall with metal blade or grinder with cutoff wheel
Clamps
Sharpie
Measuring tape
Vice Grips
large block of wood like a 6"x6"x12" or something similiar
5lb steel mallet
large masonry chisel
Drill
Oil
Wrenches
Sockets
Jack
Patience

You will want to do this while the vehicle has the weight of the car on the suspension. so you can use wheel ramps or you can use a jack and then put blocks under the tires. Get the rear of the car up in the air so you can work on it while keeping the weight on the suspension. Install the DDM Pro Beam. the Frame brace you will be reinforcing with the L channel. Cut piece of L channel the same length as the 2 sides and the back. If using a sawzall oil is your friend. lubricate as you cut.

You will also have to mate 2 notches at either end of the piece for the back. you will know what I am taking about when the time comes.

Measure out equal spacing along the back and 2 side pieces you cut. I believe the magic number is 7 for the sides and 8 for the back. on the back piece you need to move the outside most bots as far outaise that you can get you want to not have a bolt going through starting from 3/4" from the ends to 3" from the ends. Clamp a piece of L Channel into place on the frame brace. using the 3/8's bit drill the holes on your marks. you want to go through the L Channel and the frame brace. Use oil to not burn the bit. Put a bolt in each and every time you complete a hole. Once you have all 3 pieces done install the frame brace into the car.

If you look at the orientation of the frame brace and the pro beam from the back of the car it should make a rectangle. we want to sure up this rectangle at this point and keep it square. That is what the 3"x 1/4" flat bar is for. measure the distance from the top of the pro beam to the bottom of the frame brace. add 2 inches to it. Cut 2 pieces off that are this length from the flat bar. measure in 1.5" and draw a line across the bar. make it square to the bar. Take the block of wood and cut a v out of it. the v need to be 1" deep along the sides of the V. the side of the V need to be 90° or 45° to the surface to the block of wood. Take a piece of the left over L channel and place it into the V. Heat the flat bar until it is cherry red. Holding it with the vice grips. You will need a second person for this part. have the other person hold the steel on top of the L channel you placed in the block of wood. You line you marked is not going to be visible but the cherry red spot is. using the 5lb hammer and the chisel you want to hammer that flat bar into the L Channel this is going to bend it. You want as close to a 90° bend as possible. You may have to heat the flat bar up several times to do this. Have a bucket of water handy.

Once you have both piece made take out the top bolts on the rear of the pro beam. place one piece on either side hanging off the pro beam. use the sharpie and mark the 2 holes for the bolts that go through that you just removed. mark for 2 holes on each side where the flat bar intersects the L Channel on the frame brace you want to be close to the top of the L Channel. if you are too low you will not be able to get the nut on on the back side you want to be 5\8" up from the bottom of the L channel. make sure you are within that 3/4" to 3" area where you will not hit a bolt going through that holds the L channel onto the frame brace. Then mark 2 holes on each side that go through the flat bar and into the pro beam bracket. these 2 holes will be vertical.

Take the flat bar out and drill the first 2 holes you marked on each piece. Put the pieces in and bolt them into place. You can now drill the last 4 holes in each bracket using the 1/2" bit. You may want to start with the 3/8" or even something thinner to make it easier to drill. remember oil is your friend here.. after each drilled hole put a bolt in and tighten it. once finished using your Sharpie mark the brackets at the bottom so you can cut off the excess. Remove all pieces from the vehicle. Unbolt everything sand, primer and paint. reassemble and reinstall into the vehicle.

I will grantee that you opinion of the suspension will change once you do this. Corners that I could not take over 55mph because the tires would start complaining. Same corners I am now able to take at over 80 mph. same suspension and same tires.

It will look something like this. I am not finished in this photo but you will get the basic idea.. It will also help with the directions.

109876



The brackets not being square is normal. This is because the pro beam will arc up in the middle when you bolt it in. and the gapping between the brackets on the right and left sides between the bracket and the frame brace mount is normal as well. This is because of the frame twist that is happening when the car has weight on the suspension.

You can do this with the weight off the suspension but you will need to get an alignment afterwards to fix the rear camber. This is the reason why I said to keep the weight on the suspension. It is going to remove next to all of the twisting that happens to the rear frame rails because of how the lower control arms are attached in the car.
 

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the rear most lower control arm mount is at least 10" lower then the frame of the vehicle. GM has ties the 2 "towers" together but it is up close near the frame and offers minimal help. It does keep the rails an equal distance apart. While both the frame brace and the Pro beam do help neither solves the problem. using both of them together solves about 60% of the issue.

The issue is this. The front most rear lower control arm mount is attached right at the frame. the back most is not. when cornering the outside tire is seeing lateral forces pushing the bottom of the tire inwards with some forces in excess of 8,000 lbs. Think of a wrench used to turn a bolt. This is the relationship of that tower to the frame. the back of the control arm is going to move inward while the front one doesn't move at all. This is going to give you the 2 things you do not want to have in a corner. a rear tire that is toed out and a positive camber. These 2 alignment adjustments are what make or break a cars cornering ability. They will cause the vehicle to be extremely "loose" if they are not right.

This is a serious engineering blunder on GM's part. Thankfully it is not that hard to fix. The purpose to the bracket on the side is to keep the rear suspension square from side to side. This is what the pro beam and the frame brace so not do. the pro beam makes it harder for the frame to twist while the frame brace helps to keep the towers in parallel to each other neither of them keep the suspension square.

when I did this to my car I was not sure of the results. I am telling you right now that the statement "the car corners like it's on rails" does apply. The only other car I have ever driven that is about the same as what this does for the Solstice is a Lotus Elise. and that car held the claim of being the only production car able to pull a lateral G in a corner. That is a HUGE statement to make.

another suggestion is to delete the power steering. The Solstice has a steering wheel that is big enough for a Mac truck that coupled with the size and weight of the vehicle and having power steering makes the car feel loose in the front. Deleting the power steering makes the car feel tighter in the front and also transfers the feel of the road right into the steering wheel. Take the PS belt off and try it that way. It is going to be harder to turn because the fluid bottle is still attached but it is going to show you what it is going to be like in terms of feel.

A delete is a removal of the lines, cooler and bottle. The rack stays. you will need to drain most of the fluid out by turning the steering back and forth once the lines are disconnected from the bottle. get the system as empty as possible before removing the lines and cooler. You do not want to have fluid squirting out all over the place. When you pull the lines from the rack you will want to replace them with 6" long ones that are curved 180 degrees so the open ends point at the ground. This will keep debris out of the rack.
 

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Good morning. Thanks for your reply. I'm big on keeping my vehicles stock and very little if any at all aftermarket parts but yes the ride is too ridgit Feeling every little rivit on the road especially here in South Jersey. Looking for a smoother ride with this beautiful automobile.
I would seriously consider switching the springs, shocks, and ant-roll bars to their NA equivalents. You will get a very slightly softer ride, but it will be less jarring and make the car easier to control.

The only chassis bracing I recommend is the DDM ProBeam, but only if you are feeling an instability in the rear of the car while cornering.
 

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The only chassis bracing I recommend is the DDM ProBeam, but only if you are feeling an instability in the rear of the car while cornering.
I would agree and before you do that even, experiment a bit with tire pressure. At recommended PSI I found the rear end wiggled around in corners. As little as two PSI in the stock tires made all the difference.

For the record, I nopales longer have those tires on the car, about to go for my third set on the car in the spring but tire pressure makes a big difference.
 
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I would agree and before you do that even, experiment a bit with tire pressure. At recommended PSI I found the rear end wiggled around in corners. As little as two PSI in the stock tires made all the difference.

For the record, I nopales longer have those tires on the car, about to go for my third set on the car in the spring but tire pressure makes a big difference.
Absolutely. Tire pressure does make a difference, and can be easy to overlook.

I have run four different tires on Kappas: The OE Goodyears that came on the NA and the RL, Michelin MXV4, and Michelin Pilot Sport AS 3+.

All four tires have felt the best to me at between 30 and 32 PSI Cold, or roughly the 2 PSI above the 29 PSI stock recommendation that you mentioned.

For the OP's complaint about a harsh ride, the tire pressures being too high could be the problem.
 

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Oddly enough, increasing air pressure actually helped smooth the ride in my case. I use run flats and found the ride to be rather harsh due to the thicker sidewalls. Talked to my tire guy about it and he recommended upping the pressure to raise the sidewalls off the road slightly. He was right! My run flats offer a much smoother ride at 33psi than they did at 29psi.
 

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Just switching tires made a big difference for me... Giqu, what tires are on the car - and how old are they?
 

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I think the stock suspension sucks.

Been wanting to upgrade.
Hi. These two things, quoted above, tell me a story.

No matter what you do, this is going to be a sports car, not a luxury car.
 
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