Structural Rigidity - Is there a solution?
05-20-2018, 09:56 AM
#21
Melting Slicks
Like many of us here, I have had C-3's C-4's and C-6's. I recently sold a 90 Z and still have a 93 Z that I have owned for 19 years. The C-4 without the top installed is a noodle 
. Every C-4 I have owned is night and day without the top in, and honestly fellas, it is not a car I would drive fast on a track without the top in. These cars were originally engineered to have a T bar in place, as such, the front frame section is a little twisty without the top in place. I know many of you will say it's not that bad, however, If you drive a C-5 or 6 without the top in place and then jump into the C-4, there is a very big difference. The front engine cradle and suspension moves around a lot! On my 86 coupe I installed a vert X brace from a 88 as well as a cross brace connecting the top A arm's together and it made a world of difference although not perfect. The C-4 is one car that gets a huge benefit from a light cage or some custom fabricated bracing in the front suspension area and under the car. A friend had a 1.5" tube, 8 point cage welded into his ZR-1 connecting the front frame through the firewall to the frame under the dash then to the frame behind the seat and onto the back beside the speakers. This car would lift the front wheel when going into a driveway, it was amazingly stiff and improved the handling with or without the roof panel in place.
To me there are negatives to the cage as everyone can imagine, it was pricey, permanent, more or less eliminated the good looks with the roof panel out, even though it was tucked up neatly and professionally done, it does take up room inside the car, makes getting in and out just a little bit more difficult, adds weight and to me makes the car too stiff for street use.
In My opinion, the X brace, Cross brace and coil over suspension seems to be the way to go for a street car. and although I have heard it before, from what I see here, the Truss Bar is a great idea as well.
. Every C-4 I have owned is night and day without the top in, and honestly fellas, it is not a car I would drive fast on a track without the top in. These cars were originally engineered to have a T bar in place, as such, the front frame section is a little twisty without the top in place. I know many of you will say it's not that bad, however, If you drive a C-5 or 6 without the top in place and then jump into the C-4, there is a very big difference. The front engine cradle and suspension moves around a lot! On my 86 coupe I installed a vert X brace from a 88 as well as a cross brace connecting the top A arm's together and it made a world of difference although not perfect. The C-4 is one car that gets a huge benefit from a light cage or some custom fabricated bracing in the front suspension area and under the car. A friend had a 1.5" tube, 8 point cage welded into his ZR-1 connecting the front frame through the firewall to the frame under the dash then to the frame behind the seat and onto the back beside the speakers. This car would lift the front wheel when going into a driveway, it was amazingly stiff and improved the handling with or without the roof panel in place. To me there are negatives to the cage as everyone can imagine, it was pricey, permanent, more or less eliminated the good looks with the roof panel out, even though it was tucked up neatly and professionally done, it does take up room inside the car, makes getting in and out just a little bit more difficult, adds weight and to me makes the car too stiff for street use.
In My opinion, the X brace, Cross brace and coil over suspension seems to be the way to go for a street car. and although I have heard it before, from what I see here, the Truss Bar is a great idea as well.
05-20-2018, 04:11 PM
#23
Team Owner
Pro Mechanic
What does the coil overs do? That a good set of adjustable shocks (that come with coil overs) can't do?
05-21-2018, 05:28 AM
#24
Le Mans Master
Like many of us here, I have had C-3's C-4's and C-6's. I recently sold a 90 Z and still have a 93 Z that I have owned for 19 years. The C-4 without the top installed is a noodle . Every C-4 I have owned is night and day without the top in, and honestly fellas, it is not a car I would drive fast on a track without the top in. These cars were originally engineered to have a T bar in place, as such, the front frame section is a little twisty without the top in place. I know many of you will say it's not that bad, however, If you drive a C-5 or 6 without the top in place and then jump into the C-4, there is a very big difference. The front engine cradle and suspension moves around a lot! On my 86 coupe I installed a vert X brace from a 88 as well as a cross brace connecting the top A arm's together and it made a world of difference although not perfect. The C-4 is one car that gets a huge benefit from a light cage or some custom fabricated bracing in the front suspension area and under the car. A friend had a 1.5" tube, 8 point cage welded into his ZR-1 connecting the front frame through the firewall to the frame under the dash then to the frame behind the seat and onto the back beside the speakers. This car would lift the front wheel when going into a driveway, it was amazingly stiff and improved the handling with or without the roof panel in place.
To me there are negatives to the cage as everyone can imagine, it was pricey, permanent, more or less eliminated the good looks with the roof panel out, even though it was tucked up neatly and professionally done, it does take up room inside the car, makes getting in and out just a little bit more difficult, adds weight and to me makes the car too stiff for street use.
In My opinion, the X brace, Cross brace and coil over suspension seems to be the way to go for a street car. and although I have heard it before, from what I see here, the Truss Bar is a great idea as well.
. Every C-4 I have owned is night and day without the top in, and honestly fellas, it is not a car I would drive fast on a track without the top in. These cars were originally engineered to have a T bar in place, as such, the front frame section is a little twisty without the top in place. I know many of you will say it's not that bad, however, If you drive a C-5 or 6 without the top in place and then jump into the C-4, there is a very big difference. The front engine cradle and suspension moves around a lot! On my 86 coupe I installed a vert X brace from a 88 as well as a cross brace connecting the top A arm's together and it made a world of difference although not perfect. The C-4 is one car that gets a huge benefit from a light cage or some custom fabricated bracing in the front suspension area and under the car. A friend had a 1.5" tube, 8 point cage welded into his ZR-1 connecting the front frame through the firewall to the frame under the dash then to the frame behind the seat and onto the back beside the speakers. This car would lift the front wheel when going into a driveway, it was amazingly stiff and improved the handling with or without the roof panel in place. To me there are negatives to the cage as everyone can imagine, it was pricey, permanent, more or less eliminated the good looks with the roof panel out, even though it was tucked up neatly and professionally done, it does take up room inside the car, makes getting in and out just a little bit more difficult, adds weight and to me makes the car too stiff for street use.
In My opinion, the X brace, Cross brace and coil over suspension seems to be the way to go for a street car. and although I have heard it before, from what I see here, the Truss Bar is a great idea as well.
I had a rippie 4 pt cage on my 90 and that car was stiff looked great but interfered with mounting the top. the top brace works great.
I like the ohio bars better than my R&D!
