I own a 92 camaro rs 25 ann. hard top. I am looking into adding a 383 tpi with a possible vortech blower. My question is how weak is the uinbody? The car right now has a fair amount of rust on the underside because it was drove in the snow for like 10 years now but the rust isnt too bad but then its rust. I know I am going to add subframe connectors and maybe have a body shop change out some of the bad floor panels for new ones. what else can i do to make this stronger or should I build a car with a frame?

 

A good set of SFCs should do the job. Get the perimeter SFCs, like SSM (they might have gone out of business) or Spohn connectors: www.spohn.net Avoid boltons, you must weld the SFCs.

Beyond that, a cage

 

The underside has mild rust on most of it. Does this matter? I am planning on taking it to a body shop and see what they all have to say. Also what else is there to do to make it stronger for say 400 to 500 I hope horsepower.

 

If its MILD rust it should be no problem, but if it has come through the floor in any places you will need to have it repaired. And i doubt SFC'c will be enough for 500 hp. U can ripple the body pretty easily at that HP level. I recomend a cage.

 

I can show you hundreds of cars on this site and others that are putting down well over 500HP to the wheels with just SFCs and no problems. Some aren't even running SFCs, and do so without and major problems.

With my perimeter SSMs, I can jack the car up just behind the front tire and have the whole side lift level off the ground. Properly done, they can be nearly as strong as a full frame car.

 

nothing wrong with bolt on sfc at all.....as long as you bolt them on, then weld them too right!
But yah sfc youll be fine!

 

the 2x3 SSM bars have to bolted in first...in the back were the LCA bolts up....then you swing in into place, then 3 inch stich weld, 2 inch gap, 3 inch stitch weld..thats how there supposed to installed...a constant weld along the rocker will "bow" the car up in the middle, as will installing them WITHOUT the car on the ground

 

and ill bet 99% of those are fourth gen cars..3rd gens are a lot weaker then 4th gens,...try running anywere 500 ponies on a 3rd gen and tell me what happens lol.....i have first hand experiance in this....both t-tops and hard top cars...ive seen my buddies t-tops crack and shatter on a launch...result=totaled car...
what about a hardtop car? ive seen one launch and the roof litteraly bucked right down the center, and tehres a crease in the roof itself....(this wasnt my buddies car) but i looked at it in the pits, and on the left side of the car the gaps were less then a 1/4 inch....the right side, i could get 2 fingers side by side into the gaps,...the dash cover was all cocked to one side...result+ totaled car...

you cant repair a unibody car...once it twists its all done but the crying, and itll NEVER be anywere near the same car...itll alsways be fubared...

SFC's should be the first mods no matter how much or little power...

 

Wait marc85z28? I though u said our cars can handle this power, obviously not. Ive seen t-tops shatter, roofs ripple, lower rear qurters ripple so bad that the driver can get the doors open and they have to climb out of thier shattered t-tops. Third gens cant handle 500 to the wheels with simply just SFC's. Dont spend all that money on a big hp motor and put it in a stock chassis car just to destroy it. Make sure your chassis is well hooked up before you drop that motor in.

 

yes thats why I am asking what all has to be done to make it a strong frame. I need to know before I do all of this. If the cars are weak to begin with I am going to go with a different car then.

 

Alston makes some fine products. I have their SFCs and they work well and fit well.

 

subframes are more then enough to 450 crank ponies, and im sure more power then that...more then that however, id suggest one of those 6 point "cages" for 500 bucks u see in summit,jegs,pace..etc...

 

A quick 5 mintue search netted me this:

http://www.thirdgen.org/rides/index....ew&rideid=5683

That's a 10 second car, making tons of torque, without a cage, and without subrames. With t-tops BTW. Would I recommend it? No. But it has and can be done without major problems.

I can find plenty more with time...

 

But what else has been done to the car and will it eventually twist the car?

 

What else is done? Did you read the reader ride info? That's about it. I remember him from years back claiming he had absolutely no chassis reinforcement. He had been running like that for years with no problems. Everybody told him he would have irreversible body and chassis damage, but he proved everyone wrong. His website is now down, and I think he still occassionally posts over there under a different name.

There is a local 91Z28, with no chassis mods at all, running 10.80s on the spray. I don't know what he dynos, but I'm sure its really close to 500 at the wheels. He's done so since the mid 90s with no problems.

SFCs are an excellent idea, regardless of power level. But they are by no means necessary. You'll end up with more damage from improper lifting techniques than running alot of power with reinforcements. IMO cages should be kept to track only cars making ungodly amounts of torque. If its remotely streetable, you don't need a cage. I don't feel like arguing this point much more.