I'm in the process of building a turbo LQ4 for my 1984 Trans Am with t-tops. I'm already upgrading all the suspension including adding subframe connectors. I'm also going to install a BMR trak pak torque arm kit to get the stress off the tranny tail shaft. At what HP level should I be concerned with cracking my sail panels or stressing the unibody? Would a four point roll bar help at all or does it really not matter since the car has no actual frame?

 

SFC's will dramatically increase the chassis stiffness.

Stock hard tops tend to crack at the sail panels. I don't think you'll need anything with SFCs as long as you really aren't launching hard.

 

2,000 rwhp

 

This is true, when I had my 'Z' painted there were tiny fractures about 1/8" long at the top of the B pillars that were welded up by the body shop. Mine is a hard top car with an original L98 engine. SFC's are a must on these cars, then HP is a non issue.

 

 

Really hard question to answer. Put subframes and or a rolld cage in it. You wouldnt put a big power motor in any car and forgo the suspension/chassis mods would you?

 

No. I was hoping to not put a roll bar in though. I will if need be, but wanted to limit it to a 4 point bar. This will mainly be a street car so I didn't want bars in the way of the doors and at the t-top edges. I was hoping suspension upgrades will be enough.
I already purchased all these parts except the brakes:

• UMI tubular a-arms, adjustable panhard bar, adjustable lower control arms, wonderbar and caster / camber plates
• Hotchkis subframe connectors
• BMR Trak Pak torque arm setup (I'll weld the crossbrace to the subframe connectors)
• Koni yellow shocks & struts
• Brakes: LS1 or C6 kit from bigbrakeupgrade.com

Here's my build threads if you want to see more:
Overall thread
Engine only thread

 

Some guys are running both inner and outer SFCs, I'm inclined to do the same. Mine's T-Top also, and I want to end up around 1200 HP. Inners are Mac or Alston, TopDownSolutions has them. Just about all the other brands are outers.

 

Only seen cracks on b pillars on hard top cars....
I have both Alston & Spohn... each and both made a noticeable difference...
I don't have tons of power, but do have t tops.... (tons of other mods)...
The Spohn torque arm also made a big difference.

 

I had cracks on my b pillars. Mine t top. If you dont want to do a cage at least min do subframes.

 

One thing I love about my SFC's is the ability to single point jack the car to get both wheels off one side of the car. Kind of nice if you do a front to back rotation on a car with the same size tires all around.