will i have a any problems with my t-tops poping off during a auto-x event.

I've never heard of it happening. But it would be good to take them off anyway for that extra weight savings. Unless it's raining, just take them off.

I have over 1000 autocross runs on my 87 with t-tops and haven't had any problems with it yet. True the weight savings would help on a slow course, and coupled with the weight of tops being at the highest point of the car they would slightly contribute to body roll, but I don't know of anyone that could realistically tell the difference with them on or off.

We run a few high speed courses and always have the windows rolled up and the tops on. The reason is that I've heard many times you get better gas milage running 55 with your windows up and the air conditioner on, than it is to run 55 with the windows down and the AC off.

When we are out racing during really hot days, I'd rather have my tops on keeping the sun off me instead of sitting there being cooked in the staging lanes.

I don't have T-tops on my car, but if I did, I'd never race it with them out. But, if you have SFC's its probably okay. It doesn't seem like t-tops would add much structural integrity, but they do help resist some body flex. Without them in, nothing is tying the corners of you roof together and if you either do any real hard launches or take some high speed, tight corners, you run a risk of causing yourself some problems. I don't mean to state the obvious or sound condescending, but when cornering hard or doing a really hard launch, the front of the car applies stress to the rear of the car in an "X" pattern. Both lines of that "X" go right through the roof, so just picture the potential for twisting and flexing under these conditions without anything but a little bar down the middle tying the front and back halves of the roof together.

Aside from that, I also agree with Alloy about the decrease in wind resistance. It's like adding a tonneau cover to a pickup bed; you don't get all the drag created by the air being pushed into the box (passenger compartment).

Isn't it illegal to run w/o tops? I know it is in NHRA.

Sheesh, we're talking about autocross, not high-speed runs at Bonneville. I really doubt wind resistance plays that big of a factor (if any) in autocrossing when talking about windows being rolled down or T-tops removed. Peak speed might reach 60 mph, if that. I've seen plenty of fast F Bodies run w/o T-tops. Such as:


(One of the fastest stock 3rd gens in the country.)

and:


(Former F Stock national championship car.)

I'd also argue that stress on the body and/or frame isn't going to be that great if you're running regular street tires or R-compound tires. Again, I'd point out the cars above, which have been running for several years. With slicks or if I was running a 500hp car, yeah, I'd want some extra bracing.

Not to get too far off topic, do you also think a truck gets better mileage with its tailgate down? I don't. My Lightning has also run nearly identical times at the drag strip with it's tailgate up or down.

Not for autocrossing.

Pat

Please refresh my memory and tell me where I said there weren't fast autocross cars that run with windows down?

We said that with the windows down it increases wind resistance. This is a documented fact. Whether your pickup (or mine also) doesn't get better mileage with the tailgate on or off isn't the point. We all know it's 90% driver and 10% car. And, the statistics put out by the us government state that it's more fuel efficience to run with the windows up and the ac on instead of the windows down with the ac off. The difference averages around 8% more drag according to the government study I read.

that was my question all along. i didnt want to take a corner to fast and put a lot of stress on the chassis causing one of the top to pop off.

seems like if you have the t-tops locked in, they wont be falling off during autocross..