How Badly Does Sunroof Impact Body Rigidity?

[wgreenlee4]

Just had my first day at the track with my GT40 engine build. Couldn't get out of the 14 second range due to bad 60 ft :/ Always either wheel hopping or spinning the tires through first. I'm looking into sub frame connectors and boxed lower control arms (avoiding slicks). Now I'm wondering, I know already that the hatchback cars aren't as ideal as the notch's because the body is less stiff/heavier. But what impact does having a big hole in the roof have? Do non-sun roof cars have any bracing there or is it just thin steel? I've noticed that my car is small dents right above the B pillar behind the sunroof and I wonder if this is from body flex. It also appears to bulge out to the side slightly but barely noticeable. Please see the pictures below of the roof in the reflection of some straight door frames for reference and tell me what you think.

 

[2000xp8]

I'd say the difference is negligible. Not something i'd worry much about.

With that said, I probably wouldn't going to the track without subframe connectors.
They are probably #1 on the required mod list.
These cars are getting older and they were flexible to begin with.

I'd also figure out why the car is wheel hopping, wheel hop destroys the car.
Bad shocks, springs, bushings, missing or worn out quad shocks are the places i'd look.

 

[wgreenlee4]

Thanks for the good tips. Glad to hear about the sunroof being negligible. Unfortunately the glass is still really heavy. I took it out and they yelled at me to "close my sunroof" when I was staging and I had to explain I left it back in the parking lot XD

The car already has 4 new shocks in rear, but has stock arms. I am purchasing boxed lower control arms and sub frame connectors before I go to the track again. Trying to decide between mid length or full length (obviously full length is better but I am always trying to be budget minded with this car and not just throwing money to over build it for the next owner).

 

[Shakerhood]

That does not look stock at all so I imagine it impacts structure quite a bit more than the factory one.

 

[Mustang5L5]

That sunroof doesn't seem to be sitting in it's "moat" correctly. Is that a factory sunroof?

If so, it's sitting pretty high. Should be flush with the roof line.

 

[wgreenlee4]

Huh I didn't know it should be flush. I think it was closed all the way. The latch and props where the sunroof metal tabs go in look exactly like any other foxbody sunroof though so I was under the impression it was factory. Also, my door jamb sticker says it was a sunroof car.

 

[Mustang5L5]

It's looks factory to me...but it's sitting pretty damn proud.

 

[General karthief]

Do the paper test, open the sunroof and place a sheet of notebook paper between the glass and the seal on both ends, close the sunroof, you shouldn't be able to pull the paper out or at least it should be difficult.

 

[Mustang5L5]

Here's how my sunroof sits...which is why those photos struck me as odd.

 

[mikestang63]

60 foot time is traction or lack of- period.

 

[wgreenlee4]

Exactly, and when I DID get traction I got wheel hop instead of a good ET.

That is weird how much lower than sunroof sits. Mine is tight and sealed at the height you see in the pictures. And yes if I put a piece of paper in there you cannot pull it out of either side. It doesn't leak or anything.

 

[Mustang5L5]

Have you replaced the inner weather strip recently? Is it seated all the way down? Is it the correct strip? Or did someone previously swap in generic weather stripping that is too large?

 

[wgreenlee4]

I have not replaced the weather stripping no. The previous owner did a lot to the car. I get the distinct impression the car was completely apart and was then put back together poorly. There's a possibility the latch or sunroof or weather stripping is not original. But hey either way no one really notices that it sits high and it doesn't leak so whatever. What is more important to me is seeing if it hurts the cars rigidity which is sounds like it may not. I'm hoping future drag strips let me pull it out to save weight because the glass is soo heavy.

 

[Mustang5L5]

My local drag strip requires all sunroofs or T-tops to be installed and closed. I got yelled at once for trying to race with it popped up before.

 

[wgreenlee4]

Huh that's disappointing. And yeah like I said earlier, I was yelled at this past weekend for it. So I guess in conclusion, if a sunroof hole does not impact the cars rigidity, then at the very least most of the impact will be from the added weight. I imagine with T tops this is doubly so.

 

[wgreenlee4]

I think this means I have the third worst foxbody in terms of weight; (behind the GT and Conv) I have an airbag/power window/power lock/sunroof hatchback.

 

[2000xp8]

I think this means I have the third worst foxbody in terms of weight; (behind the GT and Conv) I have an airbag/power window/power lock/sunroof hatchback.

Don't worry about the weight.
At 100lbs per tenth, the sunroof, locks, air bag etc... don't matter much.
It's cheaper and easier to add power than it is to lose weight.
And stripping your car down to get .1 to .2 is insane unless you drive a race car.

 

[Mustang5L5]

I wouldn't sweat it. I'd rather be a tad slower than give up my sunroof.

 

[Noobz347]

Back to the sub-frame connectors... I think I would want to know that the car were actually straight before welding them in.

Has to be done though.


Edit:
While I'm thinking, I saw/read "Track" somewhere. This says to me:

After sub-frames

• Battle Boxes
• upper/lower control arms
• bushings (all of em) (what about the ....? Yep. Those too)

 

[wgreenlee4]

I wouldn't sweat it. I'd rather be a tad slower than give up my sunroof.

I've never really understood the sunroof thing. My car just came with one. Do people like it because it makes it seem more roomy?

Back to the sub-frame connectors... I think I would want to know that the car were actually straight before welding them in.
While I'm thinking, I saw/read "Track" somewhere. This says to me:
After sub-frames

• Battle Boxes
• upper/lower control arms
• bushings (all of em) (what about the ....? Yep. Those too)

I hope the car is straight. I'm not sure what I'd have to do to verify that. My current plan is to have the local blacksmith weld them in but that's not set in stone. Local performance shop quoted me about $700 to weld them in if I provide them. Blacksmith said he charged $80/hour and that it looked easy to do.

For now I am installing mid-length connectors and boxed lower control arms. I will then see how it feels at the strip. Torque boxes, upper control arms, and all the bushings could come later.