From ‘72T to 2.5 S-R: GeLo Racing #44

[rich73]

Oh wow, the arches going on will really transform it.
The big decision when I did mine was MIG or TIG.

[matteo68]

And what did you decide Rich? Also how did you do the front arches, especially at the bottom where the inner wing is close to the outer one?


Matt

[anglophone1]

I do like a bit of Butt!
Keep it up Matt- glad to see it back under way......................
C

[rich73]

I went for TIG in the end. With TIG you accept that the panels will distort but as the TIG weld is soft you can hammer out the distortion as you go. With MIG you less likely to get distortion if you do it as a series of small spot welds, but of you do get distortion its harder to hammer out as the welds are harder. That was my thinking as I seem to remember but happy to be corrected.

This is basically the process I followed as the guy really seemed to get a great result.

https://youtu.be/FVFQBhYE-ks?si=E594gSnZlXf82-nT

For the measurements I think I did an online survey of images and scaled some measurements from them using the height of the indicator as a unit. I think I got the front measurement first and the rear found itself if that makes sense.
You may be driven by where your bumpers fit to, but I went with arches first and modified the bumpers. This was only because I got the arches before the bumpers.


Front arch Spacing by richard cannings, on Flickr

[matteo68]

We’re also going to be fabricating a cover plate spot welded on from the outside to cover the hole in the inner wing where the standard fuel tank pipe went through - this is my shell before the outer wing was temporarily bolted on:



and this is the shell of the first customer 2.5 ST built by the factory (911 230 0495) - ex-Vasek Polak, currently being restored by Matt Blast of Eurometrix in the USA:





However the fuel flap will remain in place as, like at least four others (0910, 0921, 0934 and 0983), it was there on the original car for reasons unknown, despite the 110l plastic tank with big tank inlet under the lid…

0910 (the 9th one built and arguably the most successful of the 21) at round 1 of the 1972 European GT Championship At Nurburgring:



0921 (the 10th one built) at Daytona in ‘73:



0934 (No.11) in 1973:


0955 (No.12) at Monza 1000kms in 1972:


0955 again - at Le Mans 24hrs during practice:


0983 (No.13):


The rest all had no fuel flap on the wing as you would have expected with the 110l tank fitted:

0909 (No.:


We just need to decide what to do with the hole on the underside of the outer wing beneath the aperture for the flap as there is no info on what the factory did here…

[stretch]

Great research Matt. I assume Matt gave you the file on his car.?

[matteo68]

Yes he did thanks Dave - about 4,000 photos!

[matteo68]

I went for TIG in the end. With TIG you accept that the panels will distort but as the TIG weld is soft you can hammer out the distortion as you go. With MIG you less likely to get distortion if you do it as a series of small spot welds, but of you do get distortion its harder to hammer out as the welds are harder. That was my thinking as I seem to remember but happy to be corrected.

This is basically the process I followed as the guy really seemed to get a great result.

https://youtu.be/FVFQBhYE-ks?si=E594gSnZlXf82-nT

For the measurements I think I did an online survey of images and scaled some measurements from them using the height of the indicator as a unit. I think I got the front measurement first and the rear found itself if that makes sense.
You may be driven by where your bumpers fit to, but I went with arches first and modified the bumpers. This was only because I got the arches before the bumpers.


Front arch Spacing by richard cannings, on Flickr

Thanks Rich, that’s really helpful

[RobFrost]

Plenty of interest from me. No need to notify us when you're starting it up - with those trumpets on we'll hear it anyway.

[matteo68]

I went for TIG in the end. With TIG you accept that the panels will distort but as the TIG weld is soft you can hammer out the distortion as you go. With MIG you less likely to get distortion if you do it as a series of small spot welds, but of you do get distortion its harder to hammer out as the welds are harder. That was my thinking as I seem to remember but happy to be corrected.

This is basically the process I followed as the guy really seemed to get a great result.

https://youtu.be/FVFQBhYE-ks?si=E594gSnZlXf82-nT

For the measurements I think I did an online survey of images and scaled some measurements from them using the height of the indicator as a unit. I think I got the front measurement first and the rear found itself if that makes sense.
You may be driven by where your bumpers fit to, but I went with arches first and modified the bumpers. This was only because I got the arches before the bumpers.


Front arch Spacing by richard cannings, on Flickr

Thanks Rich, that’s really helpful

We’re going TIG too having watched this excellent comparison video by the same guy…

https://youtu.be/E3LRyFJPN3w?si=VwsM6RbqHBk4pqUt

[matteo68]

Getting ready for fitting rear wheel arches next week - old suspension arms temporarily hung and ready for 9” Fuchs to be bolted on (no spacer required after May ‘71)…

[matteo68]

Look closely and it seems even the factory mounted the suspension arms on the car at this stage too…




Matt

[911hillclimber]

To allow good alignment of the wing extension torsion bar hole to the bar tube I think?

[matteo68]

Yes that too probably! But I’m sure you know more than I do about such things!


Matt

[matteo68]

First of the standard arches cut off (the rear half were brand new)…


And the new one tacked in place…