lexan targa top project........

[Joeaksa]

Peter,

Do not believe that the solid roof will fit in the trunk on the later model cars with the vacuum boosted brakes. Believe it will fit in the others. What I do is slide the roof behind the seats and it fits there fine.

The Targa is a nice car and provides the "open air" feeling of the convertable but with the safety and security of a rollbar. Its a nice mix of the two and after owning both I like the Targa better. Will own a coupe again but will keep both...

Joe

[JMPRO]

This thread has been very interesting to me as i have been kicking this targa hard top idea around for 10 years or so. The idea came to me even before i knew there was an oem part. After doing a lot of research and noodling with many people in various kinds of manufacturing{hand layed fiberglass, chopper glass,injection molding,vacume formed asb, the list goes on } i decided the hand layed fiberglass is the best,most economical way to go and to use the exisiting frame as the substruture provides all of the hardware for free.{ to buy all of the hard top hardware from porsche,if it was available would cost about $370.00 and thats before mark up} To make all the hardware from scratch would be equally expensive because of the low quanity required. To make the latches i checked with a co that does just that, make latches. Thier responce was $2500.00 for tooling and a min run of 1000 parts at $19.00 each, not to bad $42.00 for each top{cost} but the inventory can kill you
[$21,000.00} All of the other hardware including the rubber side seals wound up being roughly the same $ .
To all the people that would like to make thier own, i say go for it , but to make one is not the same as making 20 or 30 or 57 or more. With one mold i will be able to make one part a day, not exactly break neck speed. If sales warrent, i will commission another mold to be made to double production{ where am i going to put all this inventory?}
Yesterday{mon} i saw a sample of what the carbon fiber part will look like and i can't wait to get one on my car although it will look better on a black car.
I know all of this back room book keeping stuff can be boring but it is necessary to the creation of a high quality product ,at a decent price the won't be shot down in flames by the residents of this BBS.
Thanks for listening
Jerry

[mr914]

OOH! Carbon Fiber! I'd like one of those....


I agree with JMPRO, the best way would be to adapt to the existing top frame. We would have to determine what spacers are necessary and how to attach it. I called one of the salvage yards and a top in need of recovering is $320.

Opticaly clear is much more of a ***** to do. Requiring Decicant dryers (to elimate mosture/bubbles/splay), polishing etc....

Smoke would be much better. More forgiving in clarity and less chance of visual defects.

Using urethane trim strips on the edge would eliminate costs associated with edge polishing.


The other concern I have with manufacturing the entire top is liability. In this sue happy era we are in. Someone could sue the pants off of you if the top blows off, hits the car behind and causes an accident. I'll have to check with a lawyer freind of mine for advise (good think I fix his 911 every once in awhile). Probbably selling in a kit form would be best. I can see it now...
Why spend $800 recovering your tagra top when you can convert it for $350!

Checked with the higher ups....

Assuming I have a digitized model.


Design and Manufacture prototype mold - $1,200-1600

6 hrs design time
$500 for material and buildup of Renboard buck
4 hrs CNC Time.

Prototype parts - about $70 each (including bad ones), plus machine setup.

Trimming

3 hrs design time for trim path.
4 hrs CNC time to cut holding fixture
$300 in plumbing and vac cups


Depending on the volume - A production tool would cost betwen $3000-$6000. Just like a turbo, the faster you want to go and the longer you want it to run, the more money you have to spend.

The prototype mold would probbably make 80-100 parts.

Finished plastic part. No Hardware, Some Assy required (Just had to say that ) Would be in the $150-180 range plus costs associated in amortization of the tooling. Not including shipping or packaging.

Trimming would be +-.030" Wish my targa was that accurate...

Forming would be about 8-10 per hour.

How many hundreds do us pelicanheads think we would need? And what would we be willing to pay for a kit?

I'm not sure about posting url's. So PM me if you'd like the link to the company website.


Can somebody with a Saratoga top measure the thickness of their top? I'm thinking .250-.325" range.

Now for the disclaimer: The times and costs are rough estimates (without going thru formal quotes) for discussion purposes. The acutual costs may be higher but are belived by the author to be very accurate. The cost may be lower because the author also needs a top for himself and may be able to negotiate a beter rate. Your actual mileage may vary depending on how you drive. Always wear your safety belt and observe the traffic laws.

[bell]

good info mr914, you said yourself "polishing", that's half the battle to get this top idea to look great. i've been utilizing poished POLYCARBONATES in car audio systems for about 11 years, i can almost say that i'm the king of polishing this stuff, this is why i'm going for a full fledged new frame/top. i've already looked into the liability things and can have a disclaimer drawn up by my attourney in no time.

and another step made today......
i actually have a meeting with a freind of my fathers who owns a full plant who specializes in special products, i spoke with him today and he seemed pretty interested and fully understood my goal. he says he also has owned many porsches, i'll get specifics off him later.

and one last thing, the responses i'm getting here in my thead (mainly the ones giving details on similar projects) are what make me tick, i see this as a challenge and this lets me use my brain and all the knowledge i've gained over the years to use. last year i had scca nationals to utilize my skills, this summer was just to play, now i'm ready to get to work.........it's ALL porsche until i get my goals done (the top along with turbo flares/repaint/tranny/brake/suspension rebuild).
now if i could just find my wallet.................

[Ed S]

I measured my Saratoga top for my 914, and it is .225 - .245 along the edges.

Can we assume that it was probably .250 before forming, polishing, etc.?


Ed

PS I grew up in Akron, going to Akron University, so I can 'polish off' a lot of beer, if that helps...

[mr914]

Ed S - Thank you for your posting. Probbably was done out of .250.

The only polishing I was referring to was for the edges. We'd all like soft round edges right? That process would take less than 10 minutes per part.

The rest of the surface would be nothing but Sparkle (the purple glass cleaner) and Glass Wax.

Bell - What project on my part? I've only been thinking about it for less than 24 hours. I'd be glad to help you out in any of the forming issues. I'm located in the Detroit Metro Area.

Wonder if the factory shop manuals give the dimensions on the top?

I'd still be very wary of a disclaimer. Plus how would Wayne and the guys at Pelican handle selling one. "I am going to fax you this disclaimer, you have to sign it and send it back to me via mail before we can sell/ship this part to you"

Not to be a pain, but my .014 cents worth...

[mr914]

Bell - you have PM!

[Joeaksa]

Bell, JMPRO and mr914,

It would not surprise me to see sales, should things work out, of 200-500 units without a problem. Our one limitation is the lack of "extra" top units. I have an extra Targa top that is ready for restoration and would be a perfect candidate for this modification.

Should this thing work out, whoever is successful, and it may be more than one of you, could keep the Targa community happy for years to come and while not becoming rich, it would provide a descent bit of income.

As well.. we would all come on bent knee to you guys, offering lesbians in a lexan barrel, and begging for tops!

Joe

[JMPRO]

Joe, ya the lack of an extra top will be a draw back but i think there are enough T-owners that would be willing to give up the folding aspect just to have one good solid top.
One good thing about my project is that i can always go ahead and make another mold for the frame and that way offer a complete top{big money, but complete}
Another aspect that has not been discussed is how good the top looks over a folding top. No saging, no wrinkles, just one flowing line from front to back.
My hard top has been covered with oem vinyl most of the time and most people don't even know that its a hard top, they just say "boy, thats the nicest targa top i've ever seen" then i tell them its a hard top. One thing i've found is that there are many coupe owners that don't know much about targas and when told its a hard top , they didn't know that all targas wern't hard tops.
If in fact i do make money on this deal is not really important, just to be there and feed the souls of the Porsche community will be my payment.{but if you feel the need , donations will be accepted at " JERRYS, SAVE THE TARGA AND BUY JERRY A RED 89 SPEEDSTER FOUNDATION"} a tax exempt Cal. Corp.
I wrote a big check yesterday for tooling and the first two parts, so i really hope there is enough of you T-guys that will support this effort with your $.
Jerry

[9XI]

I would buy this product if it is what we have all dreamed of. I'm rooting for you, MR914.

Is shiny really the right look? What about tinted AND a little frosted? It would show scratches less and it would look more like a stock top. Just an idea.

I have an extra "beater" top that I use in the summer and keep folded. I figure that if it gets deformed or cracked, no biggie. It is just an emergency top for an unexpected shower. You can pick up marginal tops like this for 300-400 max. Getting a hard top, and paying a bit extra for a backup soft top is not that big of a deal.

[old_skul]

mr914, I'd pay $299 for a lexan top I could attach my existing Targa hardware to. And if you placed ads in Pano/Excellence/9/911PW, you'd sell a lot. How many? Well, how many '69 - '94 Targas are there?

If you sold 50 tops at $299 each, you'd be looking at about a $15,000 return. I would hazard a guess that you could sell at least that many on this BBS alone, and probably many more through Pelican and other distributors. There's thousands of Targa owners out there, so the sky's the limit. Most of them are DIY folks now, too.

1000 tops? $300k. That'd probably pay for the tooling. And a house. And a new 911 or two.

[wcballance]

Just a suggestion here about the liability issues.... Any finished product could be sold for the sole purpose of protecting the car while NOT IN MOTION. So basically it would be sold as a specialized car cover. What the consumer does with it is there business, of course. It would be kind of like selling cable descramblers "for educational use only."

Disclaimer: I am not a lawyer and do not play one on TV. I have no way of knowing if this would be sufficient to cover your @ss. Advice given in this message is to be used AT YOUR OWN RISK. As always, please consult a lawyer before doing anything that could cause you a great loss of cash. Don't taunt happy fun ball.

---
Will Ballance
'82 911SC coupe

[Ed S]

Bell,

It looks like your 'pebble' has start down a steep hill and is at high speed and considered dangerous!

When you stop over this weekend, being a project manager on projects such as this, I can at least help you put some handles on this beast, before it is all consuming!

Ed

PS
You can bring the barrel full of lesbians for our break....

[Early_S_Man]

A couple of thoughts for prospective 'builders ...

1. The fit of the Saratoga Top, brand new -- out of the mold/press, was extremely sloppy/poor at the rear curved corners! Installed, my top had a gap of 1/16" - 1/8" on each side, where the curve 'flared' out ... depending on ambient temperature!

2. A mold made from a simple digitized curve taken from a factory top won't fit properly, and will surely have wind leaks! The curves at those two corners needs to be closer together by a few thousandths ... and the curves need to be tighter, so that there is some outward pressure/tension to keep clearances to a minimum under varying temperatures.

3. NOBODY HERE has mentioned the fore and aft seals where the Lexan or fiberglass top meets the body! As I have said on multiple threads, now, that slight oversight on the Saratoga Top folks is probably why they don't want to reenter a market where they pissed off thousdands of customers with an inferior seal, and were not in the least bit concerned with a quality problem with UV deterioration after 2-4 years! I have never examined a factory fiberglass top, but it would be very interesting to know how they adressed the issue!

4. There are 'off-the-shelf' military cam-action latches for transport cases that could fit the factory 'slots' for the factory fiberglass tops. I have a couple of military surplus cases with suitable latches ... and can take pics if anybody has trouble visualizing what I am talking about. The military latches might fall in the 'ugly but functional' category ... but you would never have to worry about the top flying off at highway speeds! With a bit of work ... the 'slots' could be retrofitted to pre-74 cars, too!

5. The factory service manual has pictures and drawings, IIRC, of a jig for test fitting and adjusting factory tops ... Stoddard's has one, as does Dan at Carsinc, I'm sure. Undoubtedly, the Saratog mfr never bothered with that 'small detail!'

[bell]

the goal for the top is to have the "glass" about 1/8" clearance to an even line with the front/rear, the "glass" can be cut at any angle for the edges. the way this is going to get done accurately is to have the "glass" cut to the size/shape i need. the first one will be slightly oversized than needed so i can trim to the exact specs after the thermal forming for the first actuall top. when it goes in the oven, weighted flat panels will use gravity to form the edges leaving it undeformed.
the frame will be a slick aluminum welded triangularly and boxed, if we can get what's in my head copied to aluminum it's going to pretty badass.

[mr914]

Unfortunately, I don't own the production equipment So a new 911 out of the first 1000 would be unlikely.


Besides, I need to first worry about making 10 or so prototypes and testing on my 74 and other peoples cars. I'm here in Michigan (used to be Lincoln NE), so we don't get the brutal heat as in the south.

My thoughts on digitizing would be to run the front and rear splines at .500" per point and then digitize at 1" for the rest of the top.

HMM. Maybe we should start a new thread titled "How would you improve your existing Targa top"

As for the front or rear seals. It's just a mater of determining which current production (GM/Ford/Daimler) gasket will work best.

Never considered the thermal expansion rates between the top and the car. Maybe that's why the 914 hangs out the back.

I'd assume that the most important seal would be the front and leave some space in the rear for the expansion.

I'll take a look this weekend in the shop manuals for the alignment jig and see what it would take to make one (or more).

[JMPRO]

The front and rear seals are built into the car so the top has to be built to the specs that cause the top to seal when the latches are locked. The rear top seal will be adjustable by use of the silent blocks on the back of the frame although those adustments are small. It is a matter of the distance from the bottom surface of the top to the inside of the hook on the latch, get that right and the top will seal just fine.
On the oem hard top the front latches are adjustable ,unlike a soft tops latches.
You have to keep in mind that with a soft top the mounting points only pull on the top at the points of origin, in other words it is only tight at the corners. With the hard top those clamping forces are spread over a larger area causing a better seal.
In almost 5 years i have had my oem hard top, i have never had a single leak, and noise, you would think you were in a coupe.
The top i am making is 3 layers of fiberglass cloth, no mat and is a very ridgid part, it will not lift or flutter at speed and will be attached to the frame at at least 14 places around the peremitier of the frame.
Jerry

[schulr]

JMPRO, interested in your project. Have you priced the final cost?

Thanks

Bob

[JMPRO]

Bob, thank you for your interest. I have not yet been able to pin down a cost yet and won't be able to untill i get the first part and finalize the how to hook it to the frame aspect of it.I know what my plan is but i need to do one or two to be sure everything works right and the DIY installation is quick and easy.
The thought of some sort of disclamer i don't believe is necessary, I f it were a fender or a hood would you have a disclaimer, i think not.
I do think the final price will be under $500.00. and available from pelicanparts.com.
Jerry

[bell]

wow....i had no idea this many people would have showed intrest in my project, i'm glad it's sprouting
and who'd thought that many people would view this thread.
i love this board

i'm planning on 6 "bolts" holding the "glass" to the frame, once the first piece is formed i'll be able to design a "load" into the frame to ensure a smooth seal.
my fastener guy just ups'd a few samples to me, i should have it early next week, i'll post pics if they're worthy
i've got a busy weekend ahead of me......sat/autocross...sun/autocross..mon....cleveland airshow