At what HP do I need to start worrying about Chassis flex, twisting or body stress? I have a SB 406 with the holley systemax kit, which claims over 350 hp, and as soon as it warms up outside I'll be getting the 3.55's, I got from biggearhead, (moving up from 3.08's) put in. So I'm a bit worried about twisting with the change. :confused:

Last year when I went to a 700r4, I noticed the car was missing the cross brace, so I got the hotchkis one. I'm just wondering when I need to start thinking about something like the hotchkis chassis max kit, if ever.

Any thoughts or advice here?

Here is the kit:
http://www.hotchkis.net/6769_camarofirebird_convertible_chassis_max_kit.ht ml


Thanks!

Now would be a good time to add subframe connectors and solid body bushings. Converts really benefit from them.

I wouldn't worry about it with 350hp. If it's a nice car I wouldn't start welding things on it either, it will take away from the value. My 408 is 450hp and 500ft/lbs of torque in my convertible and I'm not doing anything to it to stiffen it up.

Also you will experience the most flex when you start using sticky tires and launching hard...if the car doesn't hook hard you wont experience much flex...

Thanks for the insight all, I will see what kind of middle ground I can find. I am not planning to do anything else that would take me above the power I am at now (famous last words). All the projects I have slated for now are about drive-ability, looks and performance on the road (suspension, brakes, rims, tires, etc).

Thanks again!

Jack one side of the car up and see how the door behaves. You will be shocked.
Amazing how quick these twist up.
All verts should have frame connectors.

If the body bushings have never been replaced, then they are probably badly deteriorated.
I've heard the solid bushings do not hurt the ride.

If the body bushings have never been replaced, then they are probably badly deteriorated.
I've heard the solid bushings do not hurt the ride.

Fortunately the bushings were replaced 8 years ago when the stock suspension was rebuilt.

Jack one side of the car up and see how the door behaves. You will be shocked.
Amazing how quick these twist up.
All verts should have frame connectors.

X2 After putting them in my 68 vert with a 427 SBC 550HP I was shocked at how much the door openings moved when the car was jacked up with out them and then after the door openings didn't move at all zero nata nothing. The car handels better now also and I don't feel any more bumbs than before.

At what HP do I need to start worrying about Chassis flex, twisting or body stress? I have a SB 406 with the holley systemax kit, which claims over 350 hp, and as soon as it warms up outside I'll be getting the 3.55's, I got from biggearhead, (moving up from 3.08's) put in. So I'm a bit worried about twisting with the change. :confused:

Last year when I went to a 700r4, I noticed the car was missing the cross brace, so I got the hotchkis one. I'm just wondering when I need to start thinking about something like the hotchkis chassis max kit, if ever.

Any thoughts or advice here?

Here is the kit:
http://www.hotchkis.net/6769_camarofirebird_convertible_chassis_max_kit.ht ml


Thanks!

We’ve installed our Hotchkis subframe connectors (http://www.hotchkis.net/6769_camarofirebird_convertible_sub_frame_connecto rs.html) on convertibles with completely stock engines and experienced a huge difference in the chassis flex. Your engine power levels would only be a major concern if you were taking the car to the drag strip with racing slicks. Other than that, chassis flex is more associated with driving. If want to cruise your car around town or have some real fun with the car, you’d be surprised at how much the first gen Camaro coupe twists. The convertible is 10 times worse. Next time you’re driving around town and you’re sitting in the passenger seat, place your hand against the body bridging the gap between the door and quarter panel and feel for body flex. You’ll be amazed.

http://www.hotchkis.net/_uploaded_files/products365promo_pic.jpg (http://www.hotchkis.net/6769_camarofirebird_convertible_sub_frame_connecto rs.html)

Our convertibles are flexi-fliers with even low HP/torque motors. One of the best things I did was the X-brace and SFC's from Hotchkis (same as the chassis max kit). Makes a huge difference that you really can feel.

It's cheap insurance. I bent the pan on a '69 big block convertible back in the 80's. It had a 454, approx 475 hp and 500+ lb/ft of torque and a 4-speed. Just romp on it once and get better than expected traction and it'll twist. I closed the drivers door after just such an event and paint chipped off the edge of the door when it clicked against the body. It's a sick feeling for sure.

Just ordered the subframe connectors! Thanks for the advice all.

You'll really like them. Follow the instructions on how to install. Pre-fit them and clean all the areas to be welded really good. I used a combination of sanding discs and a flap wheel. I don't weld so I hired a local welder to do the work, cost me $120.00 for 2 hours labor. Well worth it given how nice his welds look.

Ps. good time to replace the j-nuts in the spring pockets if you haven't already.

You'll really like them. Follow the instructions on how to install. Pre-fit them and clean all the areas to be welded really good. I used a combination of sanding discs and a flap wheel. I don't weld so I hired a local welder to do the work, cost me $120.00 for 2 hours labor. Well worth it given how nice his welds look.

Ps. good time to replace the j-nuts in the spring pockets if you haven't already.

Thanks RJ!

When you do replace the J-nuts, use a bit of antiseize on the bolts.
It will make life easier later.

When you do replace the J-nuts, use a bit of antiseize on the bolts.
It will make life easier later.

Thanks Everett!