74 RS - Sunroof or Not?

lindbhr · 09-12-2007, 09:10 AM

Well, my 78 SC w/ 3.6 now has 930 flares welded on and new fiberglass bumpers, so it's looking more like a 74 RS or IROC inspired car. Everything is in primer and almost ready to paint.

Now, do I delete the sunroof?

Since this will be a street car, I'm tempted to leave the sunroof and save a few bucks. I have to replace the headliner anyway, so that should not factor into my decision.

On the other hand, I never use the sunroof and do like the look of a smooth roof. Besides, it feels more like a race car w/o the sunroof. It would also be nice not to have to use black marker on the felt each year.

Thoughts on which way to go?

Thanks,

Hugh

TRE Cup · TRE Cup's Garage

Option 1: The right way to delete the roof is to carefully open the drip rails on each side, drill out the spot welds between the outer skin and inner panels, cut the side reinforcements near the interior lamps. Then "drop in" a corresponding non- sunroof section from another car. This is a lot of work to do right and the result is a solid top car with no decrease in strength. It is a little tricky getting the drip rails welded back up with the correct thickness front to back.

Option 2: Have a panel fabricator english wheel a filler for the sunroof opening. Hot rod guys usually know where there could be such a person in your area. They could plasma cut the inner sunroof pan off the car, make the panel , and weld it in. , Grind and smooth, add a small amount of filler and refinish

Option 3: Grind to metal both the opening of the sunroof and the oe panel. Weld that in and use filler- more than option 2

Option 4: If you are going for lightweight, we make a fiberglass oem sized sunroof panel that you can use SEM panel adhesive to fill the gap and bond the 'glass to the roof
As with all options you will need the headliner cross struts, available from the dealer for little money. This is so you can install a new non sunroof liner. Of course all the glass comes out, and most of the interior ( to protect it )during this process.

targa todd · 09-12-2007, 01:00 PM

Wow, TRE Cup, never would have guessed that doing it right would be so involved.

Hugh, do it anyway. Otherwise you'll always be second guessing your decision. Sounds like a great project car!

boba · 09-12-2007, 01:21 PM

It is a personal decision for sure.

The advantage in a track car is the weight reduction and lowering the COG.

For a street car it is cosmetic more than anything, so how important is it and is it worth the cost?

Since it is apart and you will be doing a new headliner a lot of the effort and cost is there anyway.

The only other consideration is the effect on value.

lindbhr · 09-12-2007, 04:28 PM

Thanks for the excellent technical information. The plan would be to weld the existing sunroof panel in place (option 3#).

Interesting comment about changing the value of the car. I'm not sure whether deleting the sunroof increases or decreases the value of the car?

I could see it going either way depending on the buyer.

Others comments?

Thanks,

Hugh

RWebb · RWebb's Garage

you save about 30 lbs.

This will help with acceleration, de-acc. and with the 3D movements of the vehicle during handling (roll, pitch & yaw).

re roll, pitch & yaw, the biggest effect will be on roll - take the distance to the Cg (some have assumed it is 19 inches above the gnd) and multiply that distance in feet times 30 lbs. yo now have a moment or torque.

Compare it to other possibilities to see if it is worth the labor + $$

RWebb · RWebb's Garage

It surely decreases the value of the car - 99% of the time.

gestalt1 · 09-12-2007, 05:18 PM

i would think if a roof panel was replaced entirely the value would increase, not decrease. it is very hard to find a non-sunroof car. has anyone tried to use the fiberglass panel held in with dzus fasteners so you get the light weight and can still take the panel out for nice days? i'm not sure what the opening looks like without all the sunroof mech. etc..

Larry_Ratcliff · 09-12-2007, 05:32 PM

Quote:

Originally Posted by TRE Cup

Option 1: The right way to delete the roof is to carefully open the drip rails on each side, drill out the spot welds between the outer skin and inner panels, cut the side reinforcements near the interior lamps. Then "drop in" a corresponding non- sunroof section from another car. This is a lot of work to do right and the result is a solid top car with no decrease in strength. It is a little tricky getting the drip rails welded back up with the correct thickness front to back.

Option 2: Have a panel fabricator english wheel a filler for the sunroof opening. Hot rod guys usually know where there could be such a person in your area. They could plasma cut the inner sunroof pan off the car, make the panel , and weld it in. , Grind and smooth, add a small amount of filler and refinish

Option 3: Grind to metal both the opening of the sunroof and the oe panel. Weld that in and use filler- more than option 2

Option 4: If you are going for lightweight, we make a fiberglass oem sized sunroof panel that you can use SEM panel adhesive to fill the gap and bond the 'glass to the roof
As with all options you will need the headliner cross struts, available from the dealer for little money. This is so you can install a new non sunroof liner. Of course all the glass comes out, and most of the interior ( to protect it )during this process.

Option 5: What I did... buy a roof from the bone yard from a non sunroof car. Make template from sunroof opening on new roof. cut out section needed. but weld new panel in old opening. Note this cost me about 3K to go this route but my car would not have looked right IMO with a sun roof.

JP911 · JP911's Garage

One other advantage is the added headroom, which is important for the tall guys and anyone 6 foot and over who will wear a helmet in the car.

Larry_Ratcliff · 09-12-2007, 05:47 PM

This is my roof after the afroementioned procedure was done. Patrick Motorsports does do awesome body work though.

PcarPhil · 09-12-2007, 06:01 PM

My vote - no sunroof. It's a lot of work though...regardless of which delete method you use.

RWebb · RWebb's Garage

Removal of stock equipment almost always lowers the value of a car.

Larry_Ratcliff · 09-12-2007, 07:09 PM

Quote:

Originally Posted by RWebb

Removal of stock equipment almost always lowers the value of a car.

Hmm... not really pertanant if you are already converting to an RS clone.

Larry_Ratcliff · 09-12-2007, 07:26 PM

BTW forgot to ask ... where are the progress pic's

love to see a project in motion.

911teo · 09-13-2007, 02:14 AM

I agree with Larry on this one... The car has little stock left from its SC days (930 hips, 3.6 motor, fg bumpers, possibly upgraded brakes and suspensions etc).

I think in this case removing the sunroof would marginally increase the appeal of the car.

I do not think you'll be able to ask more for it... but between 2 identical cars like yours one with sunroof and the other without I think the one without would sell faster.

lindbhr · 09-13-2007, 06:53 PM

I appreciate everyone's comments. I decided to delete the sunroof. Just a cleaner look for what I want. Besides, you can only open the sunroof a few days a year in Houston.

Also, Don Ramsay at Air Cooled Classics in Knoxville is doing the body work and paint. At some point I will post pictures.

Thanks again,

Hugh

RWebb · RWebb's Garage

for a really clean look, grind off the drip rails -- it will NOT be cheap as the roof has to be welded back together...

911teo · 09-13-2007, 11:15 PM

I thought abt deleting the rain gutters as well on my car. Then I decided that they were an integral part of the 911 design. I know they create lift at high speed and increase drag...

But I am willing to give the opposition .2 secs per lap

RWebb · RWebb's Garage

exactly - the benefits for his car are non-functional -- cosmetic

but you mod your car to what you want...