Is it possible to make the bodies on these cars too stiff? Too stiff, to the point where i'm breaking welds or windows?

My car is an 89 formula t-top car 305 5 speed that's got 180k miles on it with rusty floors (which i'm in the process of grinding off before i ad the subframe connectors). The inner half of the rear wheel wells were rotted out, but i just finished replacing them and the next step in my plans was going to be stiffening up the chassis. I've already got a set of perimeter style subframe connectors from spohn welded onto the car and i just got a set from top-downsolutions that i was also going to install. The reason i'm asking about making the body too stiff is that someone i work with mentioned that it's possible to make the body too stiff. I kind of doubt that i could make a t-top 3rd gen too stiff but better safe than sorry. (I don't really feel like going out and buying a new back window or new t-tops should they shatter)

I'm not sure of my exact goal for the car yet besides making it something that's solid to drive so that i can take it out on a road course and autocross it this coming season with confindence it's not going to rattle apart. I'd also like to take it down the 1320 but i'm thinking that i'll have more fun on a road course. I'm not putting a cage in it because, at this point, it's primarily a street car and it's only got a 305 with a mild cam and headers.

Let me know what some of your opinions are. Thanks.

 

the only issue making the body too stuff is weight. Only with massive torque and a rigid chassis are you going to start breaking things.

 

I would say that if you're going to break windows or anything, it'd be because of flex. not because its not flexing. so, I agree with 86TA

 

What Alan says is correct, your windshield IS part of your chassis structure. Most people do not know this. Your car is designed for accident struture strength WITH your windshield in place so you need to think of your sindshiled as in essence chassis supports. If the windshield breaks, you have major chassis flexing going on.

Can it break? Yes anything can break if the suspension is too ridgid not to absord individual wheel impact and twist the chassis to extreme. But how much is too stiff? I would guess you would have to get into the 3000lb spring rate and then hit a boulder with on frnt tire only at about 100mph, but then again... more things than your sindshield are going to bend and break.

Seriously though, the thing to watch on these cars is the little cracks that form in the body just up and behind the side windows. That alone tells you your chassis or unibody struture is flexing.

 

I already welded the cracks behind the windows before i put in the first set of subframe connectors. haha. Thanks for the input guys. I put the other set in yesterday. I'm really impressed with how well they fit. (Save for removing the heat shield above the cats.) They don't fit with my dual cat 2 1/2 y-pipe but that's because it's custom. Other than that, they contour to the floor very well.

Thanks again guys.

 

You reminded me of this video

http://www.streetfire.net/video/LG-M...ver_166065.htm

 

1st off, Gilotti has more money than god...yes I am jealous

I have spoken to him a few times in pts of trans Am series racing in past years, nice guy.

...but... I guarantee they are fudging that video..How?

1st, lets look at the facts. The have removed the fender etc from that corner making the car lighter to raise intot he air.
2nd, Look at the MASSIVE swaybar (aftermarket) that obviously if they took the time to install a coilover and remove the fender on the right side- they also took the time to install a massive swaybvar and A high compression rate shock AND a high rate coiulspring on the left side...WHY? So when the right wheel hits the log, the left wheels massive spring rate connected throught he massive swaybar and lighter sprung weight removed fender lifts the right side front MUCH EASIER without collaping that coilover (which is what the video is solely focused on)

Lets look at something else. Watch the hood fly open whent he chassis hits that log....ouch. Lucky that windshield did not break!

Dean

 

any updates?

 

Um.... those fenders only weigh a couple pounds. I dont see that being an issue. So now you know