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Bodyshell - why's a non-sunroof more desirable?
Posted: Tue Sep 15, 2009 9:30 pm
by BEERBOY123
Seen many a post on here commenting that a non-sunroof bodyshell is more 'desirable'.
Why is this? Is it because a sunroof bodyshell is more of a faff to paint and prep as a replacement or is there an inherent structural weakness with a sunroof shell?
I personally really like the sunroof in mine and specifically sought out a sunroof car.
Thanks
Re: Bodyshell - why's a non-sunroof more desirable?
Posted: Tue Sep 15, 2009 9:34 pm
by gooner1
Inherent structual weakness, that,s why most trackcars are non sunroof.
Personally, i,d die from claustraphobia.
Re: Bodyshell - why's a non-sunroof more desirable?
Posted: Tue Sep 15, 2009 9:35 pm
by e30topless
rust !
sunroofs are a known rusting point on any e30 and difficult/expensive to fix

Re: Bodyshell - why's a non-sunroof more desirable?
Posted: Tue Sep 15, 2009 9:35 pm
by Kedge
Rust issues are the reason, the panels rust easily from the inside but the main problem is the tray the roof slide in to, water can run into that and there's little or no paint in there and so it can start to bubble the roof up from the inside.
Re: Bodyshell - why's a non-sunroof more desirable?
Posted: Tue Sep 15, 2009 9:35 pm
by Felix79
Like gooner said , it's because the shell is stiffer and better for track use.
Re: Bodyshell - why's a non-sunroof more desirable?
Posted: Tue Sep 15, 2009 9:36 pm
by BEERBOY123
I thought the track car argument was more to do with weight saving?
Rust, yes that makes sense. But in terms of physics does it really make much structural difference?
Re: Bodyshell - why's a non-sunroof more desirable?
Posted: Tue Sep 15, 2009 9:40 pm
by fuzzy
its only desirable to those who prefer no sunroof.
Re: Bodyshell - why's a non-sunroof more desirable?
Posted: Tue Sep 15, 2009 9:40 pm
by GrindCulture
BEERBOY123 wrote:I thought the track car argument was more to do with weight saving?
That too, and not having a sunroof and all the associated gubbins it lowers the centre of gravity, although I doubt by a noticeable amount.
Re: Bodyshell - why's a non-sunroof more desirable?
Posted: Tue Sep 15, 2009 9:41 pm
by magpie
i was told for track cars it's easier to fit a roll cage in a none sunroof car,
i had one once but it never stopped the rear arches rotting out

Re: Bodyshell - why's a non-sunroof more desirable?
Posted: Tue Sep 15, 2009 9:51 pm
by Cotty
BEERBOY123 wrote:I thought the track car argument was more to do with weight saving?
If it is electric there is a lot of weight up there with the motor, runners etc. Track cars often have the motor, runners etc removed and a pannel welded in, one of the people who have done this can probably advise how much weight they have saved.
Re: Bodyshell - why's a non-sunroof more desirable?
Posted: Tue Sep 15, 2009 10:30 pm
by Jhonno
Weight, stiffness, roll cage fitment, rust
Re: Bodyshell - why's a non-sunroof more desirable?
Posted: Wed Sep 16, 2009 1:30 am
by ross_jsy
probs my post?
well for me its as its a track car. my sport has a fake sun roof now to meet regulations
Re: Bodyshell - why's a non-sunroof more desirable?
Posted: Wed Sep 16, 2009 1:52 am
by Dave_M3
Jhonno wrote:Weight, stiffness, roll cage fitment, rust
Sumed it up in one Dan!
Think the whole sunroof assembly is about 36kgs when I took the one out of my track car...
Did the same to an E36 M3 Evo recently and we weren't far from 50kgs with all the bits associated with taking it out
My iS' sunroof panel has a little rust on it so hopefully that's all will need replacing when re-spraying it.
My other latest aquisition is a tatty but solid non-sunroof shell and running gear

Re: Bodyshell - why's a non-sunroof more desirable?
Posted: Wed Sep 16, 2009 9:07 am
by DanThe
I just prefer the non-sunroof models as its less to go wrong, everything else is a benefit

Re: Bodyshell - why's a non-sunroof more desirable?
Posted: Wed Sep 16, 2009 4:22 pm
by e30bmlover
one word... rigidity.
Re: Bodyshell - why's a non-sunroof more desirable?
Posted: Wed Sep 16, 2009 4:50 pm
by Morat
Rigidity isn't anything to do with it. Show me the figures!
Sunroof is a lot of weight high up, and a rust trap.
Re: Bodyshell - why's a non-sunroof more desirable?
Posted: Wed Sep 16, 2009 4:53 pm
by steve_000
surely rigidity has something to do with it.... Its a hole in the middle of the roof?
Re: Bodyshell - why's a non-sunroof more desirable?
Posted: Wed Sep 16, 2009 5:40 pm
by E30Gheko
The reason I bought my 318. No sunroof & dolphin grey. Two big boxes ticked for me. There were rusty bits, but they are fixed now. It's just awaiting a motor with the correct number of cylinders.

Re: Bodyshell - why's a non-sunroof more desirable?
Posted: Wed Sep 16, 2009 6:50 pm
by Simon13
who cares?!
Re: Bodyshell - why's a non-sunroof more desirable?
Posted: Wed Sep 16, 2009 8:42 pm
by bss325i
If anything a sunroof car has a more rigid roof due to the sunroof tray bonded to the roof skin.
The fact it has a void in it makes little difference as the roof skin will flex with or without a hole.
Its the frame work that you can see that give strength. A sunroof car has more of this.
Re: Bodyshell - why's a non-sunroof more desirable?
Posted: Wed Sep 16, 2009 10:10 pm
by DanThe
Sunroofs are for plebs, aircon is for executives

Re: Bodyshell - why's a non-sunroof more desirable?
Posted: Wed Sep 16, 2009 10:21 pm
by beemerbird
All E30s are now getting on a bit; motors are getting a bit slow, rust is attacking from all sides. Having had my E30 resprayed at great cost, I felt empowered to make my sunroof work more efficiently. I pressed the operational buttons until the sunroof dutifully disappeared, then liberally applied aircraft grade lubricant.
I then pressed the operational sunroof buttons to get the bloody thing back into its closed mode. After about an hour of swearing, ripping out the sunroof liner in frustration, developing deep gouges in the paint from to - ing and fro - ing....
I have decided that a non sunroof model is the way forward.
Hope this helps

Re: Bodyshell - why's a non-sunroof more desirable?
Posted: Wed Sep 16, 2009 10:22 pm
by Dave_M3
I kinda agree on that side of it but in making a track car, your more than likely going to be cutting it out and just putting in just the panel to fit a cage etc and reduce weight so in that respect one with no sunroof would ...
In saying that.... a sunroof car may not be that strong either these days as rusty framework isn't that rigid

Re: Bodyshell - why's a non-sunroof more desirable?
Posted: Wed Sep 16, 2009 11:10 pm
by bss325i
Dave_M3 wrote:I kinda agree on that side of it but in making a track car, your more than likely going to be cutting it out and just putting in just the panel to fit a cage etc and reduce weight so in that respect one with no sunroof would ...
In saying that.... a sunroof car may not be that strong either these days as rusty framework isn't that rigid

The design and lack or corrosion protection is so poor and very un-BMW like.
Posted: Wed Sep 16, 2009 11:15 pm
by beema_boy
I dnt kno about track cars but as far as rust is concerned ive sorted all patches of bubble rust on my sunroof and a few others and resprayed them easy enough
also you can never say the roof is more rigid than a sunroof as there is more surface area on the roof. seems quite obvious tbh :S
as for motors going wrong etc. one word answer. . . manual hahahaha put yer arms to work

just my opinion personally dnt mean to step on anyones theory here
Re:
Posted: Wed Sep 16, 2009 11:22 pm
by DanThe
PARDON?
Re:
Posted: Wed Sep 16, 2009 11:47 pm
by psychochild187
rust no. rigidity no. reliability no.. weight . no
roll cage fitment yes
thats all i ever thought on it.
and thats that
Re:
Posted: Thu Sep 17, 2009 12:03 am
by George
If it's not rusty and we're talking road car - sunroof all the way imo. Going for a blast with all the windows down and the sunroof open =
All this talk about weight saving, centre of gravity etc...you'd have to be a pretty decent driver to tell the difference imo.
Re:
Posted: Thu Sep 17, 2009 3:12 pm
by BEERBOY123
I totally agree GerogeUK: nothing better than both windows wound right down and roof right back: could almost be in a Baur!!!
Re:
Posted: Thu Sep 17, 2009 3:53 pm
by ImysE30
BEERBOY123 wrote:I totally agree GerogeUK: nothing better than both windows wound right down and roof right back: could almost be in a Baur!!!
Just have the whole roof off

Re:
Posted: Thu Sep 17, 2009 4:06 pm
by Z3I
Back in the 80's/90's you couldn't sell an E30 secondhand without a sunroof, the lack of it knocked twice the cost of the roof new!
Only company car users whose allowance only just stretched to a poverty-spec 316's had no sunroofs.
Re:
Posted: Thu Sep 17, 2009 9:27 pm
by Morat
Strange isn't it. Nowadays having your sunroof open just means you're a pleb without aircon. I've just checked my sunroof tray and there's definitely some rust appearing now. I think its time to get busy with the kurust and see if I can hold it back

Re:
Posted: Fri Sep 18, 2009 2:33 am
by DRIFTBOY
GeorgeUK wrote:If it's not rusty and we're talking road car - sunroof all the way imo. Going for a blast with all the windows down and the sunroof open =
All this talk about weight saving, centre of gravity etc...you'd have to be a pretty decent driver to tell the difference imo.
I totally agree too.
When I was looking for an E30 it had to have one, as it's my daily driver.
When this photo was taken I was nice and cool inside the car, and I definately wasn't thinking "It's all slow because it's heavy and it might fall over because of all the weight in the roof!"
I love to have the sunroof open, on both hot and cold days, you don't get the wind in your face like having a window open yet there is still a nice cool breeze.
That's more important to me than knocking a tenth of a second of my (probably very amature) lap times!
Of the all round enjoyable experience I have driving my car, the sunroof is a good part of it, and it has a roll cage too!
Re:
Posted: Fri Sep 18, 2009 3:23 am
by Blitz
Whats the best way from preventing rust in the roof?
Re:
Posted: Fri Sep 18, 2009 9:48 am
by DanThe
The best way is to strip the headlining out of your brand new fresh from the factory car and give the roof a serious dose of waxoil. If there is already rust there its not going to be as easy