Major GTX1 Surgery...


Empty Pockets

ex-GT Owner
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Oct 18, 2006
1,361
Washington State
"Again, there is no point in inventing a solution to a problem someone has solved with more resources." - Kip


Absolute gospel.

The design/engineering you've applied to that top is way ABOVE first rate. :thumbsup:thumbsup
 

Kip Ewing

CF Vendor
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Feb 23, 2007
288
Suburban Detroit
Thanks

"Again, there is no point in inventing a solution to a problem someone has solved with more resources." - Kip


Absolute gospel.

The design/engineering you've applied to that top is way ABOVE first rate. :thumbsup:thumbsup

Hey thanks!

We are getting close.
 

Kirby Vieira

GT Owner/B.o.D
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Sep 22, 2005
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Thanks for the continuing update. You have to love what you're doing to do what you're doing :cheers
 

fjpikul

GT Owner
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Jan 4, 2006
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Kip, Jaguar has similar stuff for you to look at (just a suggestion)
 

timcantwell

Le Mans 2010 Sponsor * Moderator
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Jan 22, 2006
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Kip, I've really enjoyed this thread. Thanks for posting your process. This has been fascinating to read. I'll see you at the rally!
 

Shelby#18

GTX1 Owner/Moderator
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Dec 15, 2006
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Kip,

Thank you for taking the time to talk with me today. A lot of good info exchanged regarding this top. I look forward to your comments with your visit to my car at Rich's. If you need to call me while your there with Rich, please do.
 

Kip Ewing

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Feb 23, 2007
288
Suburban Detroit
Hey Tim

Kip, I've really enjoyed this thread. Thanks for posting your process. This has been fascinating to read. I'll see you at the rally!

Hey Tim

Thanks!
It's loads of work, so I am glad a lot of people find the process entertaining.
It is about to get real entertaining...

Oh, yah. I am ready for the rally!
Be sure and stay through Monday.
Dale Watson usually plays the Continental Club every Monday.
 

Kip Ewing

CF Vendor
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Feb 23, 2007
288
Suburban Detroit
Hey Rick

Kip,

Thank you for taking the time to talk with me today. A lot of good info exchanged regarding this top. I look forward to your comments with your visit to my car at Rich's. If you need to call me while your there with Rich, please do.

Hey Rick
It was great to catch up today.
I think I can get to Rich's on Friday.
 

Kip Ewing

CF Vendor
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Feb 23, 2007
288
Suburban Detroit
Hey Kirby

Thanks for the continuing update. You have to love what you're doing to do what you're doing :cheers

This one is a lot of work, but it is gratifying to see it come together.
You are making Austin, right?
 

Kirby Vieira

GT Owner/B.o.D
Mark IV Lifetime
Sep 22, 2005
1,768
Atlanta
This one is a lot of work, but it is gratifying to see it come together.
You are making Austin, right?

I hope to. Most of the obstacles are out of the way and the road to Austin is almost clear. :cheers
 

Kip Ewing

CF Vendor
Mark II Lifetime
Feb 23, 2007
288
Suburban Detroit
Now for the window, and some other cool stuff.

Every time one of my design or fabricator buddies comes over to the shop the question about the GTX1 is "What are you going to do for a rear window?".

The concept car was supposed to have just a flat plane of glass, but it never got fabricated correctly. After getting into this car, it was clear that sealing was going to be tough, if we did go with just a flat plane of glass. The final straw was when a hot rod builder friend (Bill Jagenow of Brother's Customs) said "It would be too easy to just do a flat plane of glass." I take that as a dare, so no flate planes of glass...
Having my buddy Larry Erickson (of Cadzilla and Alumacoupe fame) come over to bless the design direction gave confidence too.

The more observant readers of this post will have noticed a blue fine line tape line in prior photos of the roof. This was "thinking in progress" for how I eventually changed the profile of the roof, to not have to just have a flat plane of glass.

After some pretty major surgery on the roof pattern, we came up with a pretty cool way of exectuting the rear window.

Here's the first step.

I wanted to bring the window all the way back to the joint at the clamshell.
This would allow for the rear window to essentially be shingled. Any water running off the window would get directed back to the clamshell and drain out past the sides of the seal.
Here's a photo of the mock-up, before we modified the roof pattern.
GTX1roof019.jpg


Once I was satisfied with the concept, I then started to make the window pattern while one of my crew started to modify the roof.
We need a consistent margin around the rear window structure to allow for some volume for the seal. We accomplish this with "sheet wax". This wax comes in calibrated thicknesses and is adhesive-backed. If you need to change the surface of a pattern by some measured thickness, you cover the area with the required thickness of wax. In this case, we are allowing for a 0.25" seal gap.
003.jpg

For the rear window pattern, I started with a substrait made up of "Home Depot" grade insulation foam. This stuff works fine for this sort of work. If we were making a precision model out of foam, we'd use urethane foam. We form the substrait to be smaller than the desired final shape. To match the surface of the window model we "squeeze" body filler between the foam substrait and the sheet wax. This gives us a form that is exactly 0.25" off the surface of the bodywork.
006.jpg

After matching the surface, we build up body filler on what will be the window surface and sculpt that to shape.

Now, I didn't take a lot of photos along the way (it was just a ton of noise and dust anyway) but here is what we ended up with.
244-1.jpg

Essentially, we sculpted the form of the head fairings to flow into the roof.
This allows us to resolve the surface of the rear window.
229-Copy.jpg

236.jpg

Right now the rear window looks pretty "square" in section. The radius is the last thing you model.

These photos don't really do justice to the surfacing of the roof.
It is very 'concept car' like. It makes the car look even more "mid-engined" with the roof window lining up on the window over the intake plenum (this one is twin turbo-ed!).
We'll finish the surfacing of the roof and make the production tool later this week.
 

AtomicGT

GT Owner
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Apr 12, 2006
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Los Angeles
problems stimulate great inventions, looks awesome!
 
Last edited:

Empty Pockets

ex-GT Owner
Mark IV Lifetime
Le Mans 2010 Supporter
Oct 18, 2006
1,361
Washington State
Oooooooooooooh, HECK ya!!! :thumbsup:thumbsup
 
H

HHGT

Guest
Great work Kip. I also noticed that Red interior. Do you have any full interior pictures. I always said, my third will be Silver/Red...
 

AtomicGT

GT Owner
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Great to see a skilled person salvaging a good idea.
 

Piana

GT Owner
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Jul 12, 2006
330
Northern California
Kip,
Great work! I love what you are doing with the shape of the top and the window!
 

Kirby Vieira

GT Owner/B.o.D
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Sep 22, 2005
1,768
Atlanta
Wow. That's incredible. It is truly beoming an exotic top befitting the car :cheers
 

HeritageBruce

GT Owner
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Mar 13, 2006
748
Southern CA
Most outstanding solution to the rear window issue.:thumbsup

Kip,
Have you considered adding Gurney bubbles to the roof also?
 

Kip Ewing

CF Vendor
Mark II Lifetime
Feb 23, 2007
288
Suburban Detroit
Silver / Red

Great work Kip. I also noticed that Red interior. Do you have any full interior pictures. I always said, my third will be Silver/Red...

Right now, we have most of the interior out of the car.
We'll get a bunch of photos when we are finished.
It really looks cool.

Steve Helmstock stitched this interior. Perhaps he could post some.

Cheers
Kip
 

Kip Ewing

CF Vendor
Mark II Lifetime
Feb 23, 2007
288
Suburban Detroit
Gurney Bubble

Most outstanding solution to the rear window issue.:thumbsup

Kip,
Have you considered adding Gurney bubbles to the roof also?


We could definately do a roof with a Gurney bubble.
Anything is possible.

After seeing the car with this roofline, I am really keen on doing a coupe with a GTX1 clamshell and this roofline. If someone wanted to go with conventional doors (to make parking lots and garages easier) we could do this treatment on a coupe.