15" wheels: In the meantime me and the "frog" made some progress.
The ordered set of 15 inch wheels arrived from Vintage Wheels in the US.
Unfortunatelly they sent me a "Trigo" wheel set instead of the ordered "Vintage" wheel set. The set I ordered is the CSX or Shelby set:
http://vintagewheelsus.com/index.php?main_page=product_info&cPath=59_71&products_id=575 After a short mail conversation everything was discussed and we agreed that I will keep the delivered set.
Difference between Trigo and Vintage is in the rear wheel where the Vintage wheel has an 3.5" backspace and the Trigo wheel has 3.65".
So the Trigo rear wheel sits 3.8mm more inboard.
Front wheels from both suppliers have 2.75 backspace, no difference.
Trigo front wheels have some free cut inside the wheels to clear bigger disks and calipers.
Vintage is offering an optional rework (welding in some aluminum spacer before the pin drive bores will be done) to adjust the backspace of the Vintage wheel to the original Autokraft 15" backspace if required.
Vintage has a special "Autokraft" set with front BS of 2.5" and a rear BS of 3.5"
See their web page:
http://vintagewheelsus.com/index.php?main_page=product_info&cPath=59_74&products_id=588 Trigo was not offering such an option.
The new Trigo set even came with "ET" markings on the inside of the wheel, allowing a much easier documentation with German TÜV authorities.
The above mentioned 3.8mm more BS on the Trigo rear wheels does not sound like such a big problem but newertheless all standard MK IV owners with silencers/resonators in the rear wheel arch should be aware of that.
On my car the rear silencers are removed but I had to loosen all exhaust pipe clamps from the front muffler on rearwards. Then rearrange all tubing, move them as much as possible inbord, check the look and tighten all clamps again.
That gave me some 10 to 15 mm clearance (with a Vintage wheel BS) between upper inner tire surface and exhaust loop in the wheel arch.
So maybe the routing of the exhaust tube loop need to be changed or eliminated in the near future with the Trigos BS.
Spinner investigation on 15" wheels: After receiving the wheels I started a clamping investigation with 7.5 inch front wheels from Trigo and Vintage using Autokraft hex nuts and Autokraft winged spinners.
Both wheels did not clamp between the Autokraft hex/ three ear spinners and the hub.
Reason is:
A: the hubs thread is 4 mm too long(or in this specific case the wheel clamping width in the center is 3mm too short) to allow clamping without bottoming out the Autokraft spinners.
B: the outer diameter of the AC 16" wheel cone is some 3mm smaller because of the steps or free cuts done to the wheels.
That will position the Autokraft spinner more "inside" the aftermarked wheel cones and the arms will interfere before the cones will have a tight fit. In case of the hex nuts the small flange will be too close to the wheels centers, no more safety wiring.
To solve that problem I had different possibilities:
1: I ordered a set of stainless spinners from Cobraracing, Torrance Ca
They are shorter and have a free cut directly at the inboard base of the three wings. They fit the new Trigos.
2: add some 3mm free cut on the original supplied Autocraft spinners at the wing or arm base and shorten them 3mm at the end of the cone. Now they fit on the new 15" Trigos
Without free cut the Autokraft spinner arms will interfere with the center of the 15" wheels and the cones will in most cases not come together.
Without shortening the spinners or hex nuts will bottom out on the front hub and not clamp.
The use of Autokraft hex nuts would need some rework on the wheels. The center of the front wheels needs to be turned down to allow usage of the hex nuts with the Trigos or Vintage Wheels.
Autokraft 16" wheels with spinners or hex nuts: All Autokraft 16" wheels i saw using winged spinners instaed of the hex ones from the beginning had some more or less flatter turned down centers arround the spinners to avoid interference with the spinner arms.
All 16" wheels I saw, using the hex nuts from the beginning and not prepared for spinner use had a small vertical step arround the center to allow safety wiring. Without that small step the hex nut flange with bores for safety wiring would sit too close to the wheel center and the safety wire would not be feasible between the parts.
Conclusion:
1. Autokraft winged spinners used on Autokraft hex nut wheels will sit too close to the 16" Autokraft wheel center and sometimes they have interference with the wheels.
2. Autokraft hex nuts will fit every 16" Autokraft wheel
3. All 16" Autokraft wheels delivered solely with hex nuts need some machining to avoid binding or close to binding situation of the spinner arms.
4. Autokraft Spinners need to get a free cut at the spinner arm base and need to be shortened by 3mm as well if used with 15" aftermarked wheels
I'm waiting to assemble my rear suspension (the reengineered drive flanges are still out for plating) to check final fitment of the 15" combination front and rear and to leave some feedback with more details here.
