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I had been working on this off/on since 2018 and realized I never posted here.

Background:
A glass sunroof is near impossible to find for a Giugiaro Esprit (Turbo Esprit 83 and 86-87).
The few I've seen in photos have non-compatible latching systems.
Furthermore, a Stevens Esprit glass roof will not fit on Giugiaro Esprits (the clamps are different position and the glass curvature is higher than leading roof opening edge.

So I measured and had Tap Plastics cut a top for me.
Polycarbonate panel is 41" x 24.5" with front edge curved down to 23.5" with 1/4 x 2" on back edge to clear hatch hinges. Esthetically, I recommend 23.5" front edge to revise to 23.75 as the Gap is uneven on mine. Not worth a $195 do over.

Installing the hardware is more difficult than I like - trying to measure the hole placement not easy - have to 'eyeball' for final adjustment.

Hardware used. The titanium taper head bolts are M6x50mm and the hex flat head lock nuts are M6 bought on eBay 'omelette88' and 'longlived28'. The rest are marked on plastic bags in picture. Drilling holes are painful to align. Use original roof for measurements. The front tongues are Lotus OEM items from SJSports Cars in UK

I did figure out the issue - at ~60MPH, the front edge lifts up; enough to open a 60 MPH air gap. For a long time, I could not figure out why it would not respond to adjustments to tongue position, spacers to raise panel corners. It still keep lifting the edge. Then I figured it out - it would not lift if I had the side windows DOWN. Good old Bernoulii's principle at work - air flowing faster over top surface will produce lift. Opening side windows allowed top to stay sealed (it does flex easily). The cure (someday) will be to install a stiffening bar between the from tongues and possibly glue it to increase rigidity. May look ugly on a clear top, but may paint it black to hide the glue.

Here are some pictures of what I had done:
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One may want to use 'Lucite SAR' or equivalent, plexi tends to be stiffer than polycarbonate, and it can be solvent glued. meaning a stiffener can be bonded to it almost invisibly
On this maybe if you painted the edge black on the inside[underside], like they do on oem window glass on many cars and bonded the stiffener with black Sikalfex urethane glue, it would be invisible.
 

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Now that you have a pattern for the holes and a parts list, I smell a kit...
 
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1987 Lotus Turbo Esprit HCI - Pearl white w/ Blue interior - No mods
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Dude! This is awesome! I was just recently thinking the same!

Imagining how to fabricate a roof with Plexi or some other material & the different color tint films that could be used, like the brownish tint they used back those days.

Good idea, Mike! 👍 I'd be your 1st customer for the kit, Sleekgt. Lol

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fluorescent green anyone?
 

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1987 Lotus Turbo Esprit HCI - Pearl white w/ Blue interior - No mods
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fluorescent green anyone?
👍

Crossing 'Tinted film' off of the list..
 

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Discussion Starter #9
Now that you have a pattern for the holes and a parts list, I smell a kit...
No - the holes I do not have a pattern - it really was difficult to 'fettle' this one and I suspect every car's tolerance in the pin locking mechanism is different.

I'll try to clean up the parts list and stuff when I get a chance. But yes - given the difficulty of finding Giugiaro glass tops, this is next up.
 

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This is a great project I would love to pursue someday. Please keep us posted on how it works out and how/where you sourced the parts - or better still if someday you want to offer a kit with the fasteners and tabs I'm in. Thanks!
 

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Discussion Starter #11
Good effort sleekgt. What thickness is the plexiglass you used?

Andy.
It's 1/4" polycarbonate (I mistakenly put 'plexiglass'). It's not as dark as I had hoped. But it's a really nice top in the 'winter' (I live in Northern California so it's not 'harsh winter') as you have the airy view but not the cold breeze. In the summer, I have a working AC so it's not too bad. Not sure I would recommend it without AC as it does not tilt up like my late 88 Esprit (Steven) glass roof.
 

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1987 Lotus Turbo Esprit HCI - Pearl white w/ Blue interior - No mods
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It's 1/4" polycarbonate (I mistakenly put 'plexiglass'). It's not as dark as I had hoped. But it's a really nice top in the 'winter' (I live in Northern California so it's not 'harsh winter') as you have the airy view but not the cold breeze. In the summer, I have a working AC so it's not too bad. Not sure I would recommend it without AC as it does not tilt up like my late 88 Esprit (Steven) glass roof.

Yeah some kind of tint is really needed here in SoCal to avoid frying in the sun. If I had one, I'd really put that 'Tilt mechanism' to use, more than removal. I was thinking which model car 'Tilt hinge mechanism' could be used from an older 80s or 90s Japanese or American car. I recall using them back in the day, but can't quite remember exactly which cars had them.
 

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Discussion Starter #14
Yeah some kind of tint is really needed here in SoCal to avoid frying in the sun. If I had one, I'd really put that 'Tilt mechanism' to use, more than removal. I was thinking which model car 'Tilt hinge mechanism' could be used from an older 80s or 90s Japanese or American car. I recall using them back in the day, but can't quite remember exactly which cars had them.
The next idea I don't have time to execute is using an aftermarket sunroof on a plywood frame (don't want to sacrifice the OEM composite top) - just get a piece of 1/4" plywood, cut hole for aftermarket lift-out sunroof like this CRL AP1735B5H 17" x 35" AutoPort Sunroof Universal Trim Ring. 92% U.V Protect (can't post URLs) on eBay for $414. and get the tongues/pins as shown in my parts list. This is the largest aftermarket roof that will fit in a Giugiaro roof opening (38" x 18"). This would be nice if it's not too curved - can't tell from the photos.
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1987 Lotus Turbo Esprit HCI - Pearl white w/ Blue interior - No mods
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The next idea I don't have time to execute is using an aftermarket sunroof on a plywood frame (don't want to sacrifice the OEM composite top) - just get a piece of 1/4" plywood, cut hole for aftermarket lift-out sunroof like this CRL AP1735B5H 17" x 35" AutoPort Sunroof Universal Trim Ring. 92% U.V Protect (can't post URLs) on eBay for $414. and get the tongues/pins as shown in my parts list. This is the largest aftermarket roof that will fit in a Giugiaro roof opening (38" x 18"). This would be nice if it's not too curved - can't tell from the photos. View attachment 1264626

Yeah, always cringed seeing these universal roofs cut into a roof of an older Esprits, but a plywood removable isn't a bad idea, but then you'd have to paint the frame to match somehow. But overall the universal roofs are much smaller so it doesn't give that cool green house effect of the factory version.

What do you think of using another type of plexiglass or thicker so it doesn't flex, as you mentioned?

Wonder if there's a glass company out there that could make one..
 

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Discussion Starter #16
Yes the aftermarket sunroof isn’t as big but close and offers an easy way to have flip open top on Giugiaro Esprit. There is no easy way to modify my polycarbonate top to flip up/ down because of the locking pin design.

Tempered glass would be nice but may not be curved enough to seal. The polycarbonate top at least flexes enough for a better seal. Drilling the holes for the hardware tongues and stuff would be harder too.


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I have been thinking about your uplift issue more than someone without an Esprit should

Can you mod the body to take third front clip like the other two?
Or perhaps one of those expanding rubber 'well nuts' which would fll the hole when the top was not on and be invisible with the factory top on?

Or finally, when I did my roof scoop only for the Exige, I made a 'thumb' that grabs in the center and is the main front support gripping on the hard plastic trim. You could bolt it a bit further back and fab it in an arc to grab onto the windshield frame
 

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Discussion Starter #18
I have been thinking about your uplift issue more than someone without an Esprit should

Can you mod the body to take third front clip like the other two?
Or perhaps one of those expanding rubber 'well nuts' which would fll the hole when the top was not on and be invisible with the factory top on?

Or finally, when I did my roof scoop only for the Exige, I made a 'thumb' that grabs in the center and is the main front support gripping on the hard plastic trim. You could bolt it a bit further back and fab it in an arc to grab onto the windshield frame
I'm not willing to modify the body for the lifting top.

The current design with an unframed polycarbonate sheet is too flimsy to do the center hand clamp (and would require interior body mods)

The possibility of a complex hinge that plugs into the 'pin well' might be possible, but I hadn't given it much thought as even with left and right rear 'clamps, the polycarbonate will flex way too much in the wind without a metalframe.
 

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This is brilliant - I am thinking of it from a different angle.

It gives bit more head room for a helmet. And it saves weight. I might do a simplified one for track days since they wont let me run with the sun roof in the up position.

Love the titanium bolts!
 

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Interesting project - reminds me of the Saratoga tops that were popular in the 80s for other targa or t-top vehicles.
 
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