69 Camaro Convertible - Pro-Touring Suspension Advice

[qwikz28]

Hello All:

My name is Jacob and I own a 2002 Camaro Z28 of which I am the original owner. It was my first car and it has great sentimental value. My father's first car was also a Second Gen Camaro, and my mother's second car was a Second Gen Firebird. My car has become a bit of a broken, rust bucket from hard use and a tough life from my teenage years. I enjoy driving it, but don't drive it as much as I should. I'm ready to retire it, and ready for something different. Since the drivetrain in my Camaro is still strong, why not build a first gen in the spirit of my car utilizing the drivetrain from my current car? I use my current car for spirited driving and occasional autocrosses. The engine will be a Heads/Cam LS1 making about 500hp and a T56.

That being said, a gentleman who is well respected in the first gen f-body community is selling a 69 Camaro SS 350 Convertible shell which he has owned longer than I've been alive. The shell needs some metal work before it will be ready for paint, but he has everything needed to reassemble the car. He is willing to sell me only what I need for my build (he has other 69 Camaro convertibles so he would either keep the parts or sell them). I never considered a convertible, but I would rather do business with this Seller since he has always been available for me to offer advice and is a generally great guy, and three months ago, my wife gave birth to our daughter, who I'm sure will really enjoy riding in a convertible when she's older.

My question is: Am I crazy for trying to build a convertible pro-tourer given the lack of chassis rigidity? What kind of suspension and chassis set up would work with a convertible? I thought about a Roadster Shop Spec chassis since it is a full frame, but I'm not sure it will work without modification.

I've done a bunch of a research on here and other sites, but I can't seem to find many convertible first gens built for much other than straight lines or cruising. I appreciate any insight.

Thanks,

-Jacob

[dhutton]

I just sold one that I built for my wife. Did a few things to stiffen it up. No cowl shake etc. Some details here:

http://lateral-g.net/forums/showthre...571#post676571

Don

[pittpens24]

Definitely need to stiffen it up with weld in frame connectors and a little extra bracing will suffice for a modest build

[qwikz28]

I just sold one that I built for my wife. Did a few things to stiffen it up. No cowl shake etc. Some details here:

http://lateral-g.net/forums/showthre...571#post676571

Don

Do you mind if I ask you how you solved the cowl shake? Did your car still have the cocktail shakers? How would you say it compares to your coupe?

Sorry for the multiple questions, but looking at your signature, it seems you are the person to ask.

[Mean 69]

Hi Jacob,

What is your timeframe on the build, and where are you located? Would you be doing the work yourself, or farming it out? A 69 Camaro Convert is a seriously coveted car (I am partial in that I have one as well), since you say it's a shell I assume that it is not an original numbers matching car? If so, perfect. There is a lot that you can do to the car.

Incidentally, a full frame option "might" offer an improvement in torsional rigidity, but it's marginal and a lot of added weight. In the end, it is still a ladder frame and not a good approach for torsional rigidity - a statement I am sure will upset the fans of the full frame options out there.

Mark

[dhutton]

Do you mind if I ask you how you solved the cowl shake? Did your car still have the cocktail shakers? How would you say it compares to your coupe?

Sorry for the multiple questions, but looking at your signature, it seems you are the person to ask.

Hotchkis Handlebars and weld in DSE subframe connectors. I kept the cocktail shakers, no idea if they were still needed. Car seemed to be the same as my previous coupes aside from top related wind noise etc. Door gaps barely moved when put on a two post lift. Solid body bushings.

Handlebars required modification to fit with LS3 and Holley accessory drive.

Don

[qwikz28]

Hi Jacob,

What is your timeframe on the build, and where are you located? Would you be doing the work yourself, or farming it out? A 69 Camaro Convert is a seriously coveted car (I am partial in that I have one as well), since you say it's a shell I assume that it is not an original numbers matching car? If so, perfect. There is a lot that you can do to the car.

Incidentally, a full frame option "might" offer an improvement in torsional rigidity, but it's marginal and a lot of added weight. In the end, it is still a ladder frame and not a good approach for torsional rigidity - a statement I am sure will upset the fans of the full frame options out there.

Mark

Mark, oddly, I'm looking to finish in two years. I'm just not ready to chop up my 2002 Z28 just yet. I'm located about twenty miles northwest of Manhattan. I'll be doing some of the mechanical work, but definitely none of the body or interior work.

The car has a matching engine but not trans, I believe. It is an original SS 350 with power front discs, 4 speed car, frost green with white standard interior and a 12 bolt.

I've seen many comments on this board saying that subframe connectors really solidify convertible cars, I can only imagine a full frame car would be even better. Not that there's any science or data to back up this thought...

Hotchkis Handlebars and weld in DSE subframe connectors. I kept the cocktail shakers, no idea if they were still needed. Car seemed to be the same as my previous coupes aside from top related wind noise etc. Door gaps barely moved when put on a two post lift. Solid body bushings.

Handlebars required modification to fit with LS3 and Holley accessory drive.

Don

Thank you, that is very helpful. The Hotchkis Handlebars look great, but didn't know they needed modification to fit an LS motor.

[MAGONSTERZ68]

Don,
do you have pic of modded top bar for handlebar set up?
currently installed on my 68 w/ls2 and not sure how to proceed with making or modding tower connecting rod.
thx.

[dhutton]

Don,
do you have pic of modded top bar for handlebar set up?
currently installed on my 68 w/ls2 and not sure how to proceed with making or modding tower connecting rod.
thx.

No pics. I made approximately 3” long extensions where the bar mounts to move it forward. Got the idea from a thread here but photobucket killed the pics.

The other bars wouldn’t fit around the Holley accessory drive without a lot of mods.

Don

[MAGONSTERZ68]

gotcha, i wound up notching and boxing in lower cross frame to clear low mount sanden a/c compressor and ctsv alternator mount on a single belt set up so all clears minus the crossbar due to contacting top of intake manifold right behind the throttle body.
thanks

[Mean 69]

"I've seen many comments on this board saying that subframe connectors really solidify convertible cars, I can only imagine a full frame car would be even better. Not that there's any science or data to back up this thought..."

That is the general consensus, but it's actually not true. The main torsional rigidity comes from 3 dimensions, i.e. the body (and/or roll cage, etc), not the frame work itself be it a full frame, or a properly executed subframe connector setup. Actually, my vote is for the subframe connector approach, FAR less weight and because they (should be) are welded direct to the floorpan, it will be a superior setup.

Seems like that is a good car to research a bit, I never buy numbers car because I know I will cut them up, but not sure what the restored value of you car would be in original form. Engine numbers are far more important apparently than the transmission.

Cheers,
Mark

[MAGONSTERZ68]

by no means a numbers matching car for sure, anymore, i have no prob cuttin up a non concourse ss/rs/etc matching number candidate otherwise fair game modify to suit as i did in my ca
se with weld in subframe connectors as well.

[ragz]

I am biased... but .. i think with updates they can make an more than adequate pro-tour ride.. i am finishing up my 67 rag, if you are interested my build thread is ,Alice 3 ,

[qwikz28]

"I've seen many comments on this board saying that subframe connectors really solidify convertible cars, I can only imagine a full frame car would be even better. Not that there's any science or data to back up this thought..."

That is the general consensus, but it's actually not true. The main torsional rigidity comes from 3 dimensions, i.e. the body (and/or roll cage, etc), not the frame work itself be it a full frame, or a properly executed subframe connector setup. Actually, my vote is for the subframe connector approach, FAR less weight and because they (should be) are welded direct to the floorpan, it will be a superior setup.

Seems like that is a good car to research a bit, I never buy numbers car because I know I will cut them up, but not sure what the restored value of you car would be in original form. Engine numbers are far more important apparently than the transmission.

Cheers,
Mark

Mark, not all subframe connectors weld in the same way. Which do you recommend?

[dhutton]

Mark, not all subframe connectors weld in the same way. Which do you recommend?

Not a suspension guru but DSE is the only way to go since they integrate right into the floor.

Don

[MAGONSTERZ68]

i would agree with DSE although at the time i went with hotchkis for my convertible, seems to work well for a non cut and weld application when handlebars are also used.

[Nativefx]

No pics. I made approximately 3” long extensions where the bar mounts to move it forward. Got the idea from a thread here but photobucket killed the pics.

The other bars wouldn’t fit around the Holley accessory drive without a lot of mods.

Don

Hi Don, the extension you are talking about is the center of the bar in you pic? Or did you add an extension to the tabs towards the top of the triangulated handles which are attached to the upper control arms? I stuck with the stock sub and the ridetech Airride Level 2 & TruTurn suspension for my 69 Firebird coupe, and I've been trying to figure out the best way to stiffen the chassis besides just the welded sub connectors that we are going to use. The connectors I have are the Hotchkis as well, but I was also looking at the Chassisworks G-connectors since it also has a driveline loop. My only concern was the space for 3" dual exhaust and whether it was more marketing (and higher $$) for a product that didn't offer much more stiffness/rigidity. Anyone have any input on those connectors as well?

[dhutton]

I added extensions to the tabs. Tried to make them beefy to avoid having them flex too much. The center adjustment is now standard on the Handlebars.

Don

[Nativefx]

I added extensions to the tabs. Tried to make them beefy to avoid having them flex too much. The center adjustment is now standard on the Handlebars.

Don

Thanks Don. Did you ever get a chance to drive it before you got the handlebars installed to see if you notices a big difference? Also, I am replacing the entire firewall for a smooth, clean finish. Is there additional metal behind the firewall where the bars attach to the stock firewall? Not sure we still have the parts we cutout to check. thanks

[dhutton]

I did not drive it without the handlebars but I feel they were well worth it. Not too many first gen convertibles out there that don't suffer from cowl shake. I don’t see how subframe connectors alone could cure cowl shake but I guess it is possible.

No additional reinforcing added where they attached to firewall. It is where the fenders bolt on.

Don