I realize this is a exterior question but it has to do with tracking the car. I have a cf roof overlay and was thinking about using it to cut weight out of the z by cutting the center of the stock roof out because I am not one to just use cosmetic parts. Now my question is would it decrease chassis regidity even if I have a full 12 point cage? Also i cant find anything in the rule book that says it would change my class of sp. Any help would be appreciated.

 

My question would be, will that really cut that much weight? There are other ways to cut weight that would probably have more impact and be less dangerous/destructive to the vehicle.

 

I figured it would probably save 5-6 lbs at the most. The roof is aluminum I think but there is a few cross braces that look like they could be taken out. I seen a few porche guys with older 964s do this at the track though.

 

I personally don't think it would be worth it, unless maybe your car is 100% track/0% street, which is unlikely. To me it would just be opening up a can of worms, but I digress.

 

The roof is actually a integral part in the Z's rigidity....cutting this completely out is a bad idea not to mention trying to patch in a overlay as a replacement and then attempting to seal it for leaks.. more than likely you'd end up redoing the CF overlay anyway after the fitting was complete. If the roof was to come out there would need to be a custom cage installed to compensate for the lack of support.

 

The cage does tie into the a and b pillars and also in the front of the roof line. I think I will probably just leave the roof alone in any caseThanks for the help.

 

While the 350Z's roof is made of steel (not aluminum, like the 370Z's), safety is the prime concern here. In a rollover, an overlay would likely be stripped away and the roof panel compromised. Also, unless you're in a unlimited prep class, I can't think of any way this would be allowed.

So, you made the right choice in NOT pursuing this any further!

 

I thought so. I was asking because a friend of mine wanted it so just sold it to him for the same price I got it for. Couldn't think of any other reason to keep it. No show here. By the way its preped for sp class, havent really had a chance to get on the track though because of constant deployment.

 

If you were to use a real CF piece that decreased weight, then you could see an appreciable lowering in the center of gravity.

I'm not familiar with the construction of the 350Z roof, but from other cars such as the e46 M3, the roof is welded on. To install a CF roof which can be found as OEM piece, the welds are removed and the CF roof is glued on. I remember asking if rigidity is decreased, but did not get a specific answer. From what I recall, rigidity does not suffer, but is likely different for the 350Z.

You might want to look into what the convertible Zs do to maintain rigidity.

 

If this is a track-only car and you use a proper pre-preg or dry-carbon for the roof skin (which needs to be glued in as others have said), then I don't think ridgidity would be an issue because the cage is tied into the A and B pillars, and I think you would beneficially reduce the CG and weight.

I've seen this done on a few Time Attack EVOs and BMWs with good results.

 

beat me to it by 13 hours

 

if you have a properly installed 12 point roll cage, i would suspect that would be enough chassis rigidity, if properly welded to A pillar/B pillars (dimpled frame) and into the floor (box frames). i would then seriously consider cutting the roof, since its pretty much at that point, keeping wind off of the driver's head-

if you're going to all that trouble, might as well look into extending it to a single piece roof/hatch!

 

saving 6-7 lbs while going through all the customizations seems like a lot, especially since this type of modification could easily put you in an Unlimited class.

 

Well last time i was at the track was to compete in the redline time attack series in the modified class, but because of the no interior panels on the doors no passenger seat and the tires they placed the car in unlimited. I really havent been home to get into storage to put some pannels back in yet because my lack of track time has put my skill on a lower tier.