Drive Shafts
I have been through quite a lot to try and get drive shafts for this car. After obtaining the correct length (12.5") I have had to deal with the bolt circle diameter on the transaxle output shafts differing to the standard 108mm CV bolt circle.
Basically the CV's I have measured have a bolt circle diameter of 93.7mm, close to the standard of 94mm. The Ricardo output flange circle diameter's measure ~95.75mm. I will need to try to open up the holes in the CV's a little, well by 1.025mm radial to be exact!
After elongating the holes to fit the Ricardo output flanges I wanted to ensure the CV and output flange remained concentric. Elongating holes allows the bolts to bend more than normal and I did not want them to allow the CV to move out of centre. I therefore machined a step in the CV that corresponds to a small machining land on the inside of the transaxle output flange (near the bolt threads). The two parts now lock together perfectly without any movement before the bolts are inserted. All load will now be tangential on the bolts. I'm sure this has not weakened the flange and its only extended the CV length by ~3mm so that will not be a problem. I have also shortened the ball races but if they are out that far I would have to be airborne and I would have more pressing issues to deal with!
I feel a little better now about the CV's I have however if they blow I will replace them with a matched PCD unit.
Details on the CV Joint used is below (visit http://www.empius.com).
Update : 17th March, 2009
Gear Shifter
With the transaxle chosen I moved to the gear selector system. An original Ford GT selector was purchased to ensure good shift quality. It is planned to use the OE bracket at the transaxle end as per below. This has also been obtained with the transaxle. The second photo shows how the Ford GT routes the cable under the supercharger, I will try to do the same. This will require a custom bracket.
The transaxle selector cables will be routed over the engine in the same manner as the Ford GT. This should provide a very similar shift quality (depending on the cables used as well). The image below shows the basic installation in the Ford GT.
Also above is the gear lever and mounting plate. This has also been purchased (normal shifter, not the aftermarket short shifter). I would like to possibly get a set of Ford GT cables to complete the OE link, however they will be the wrong length (I gather) and may be quite expensive. I would also like to get a Ford GT gear knob as well - why not, will have everything else!
Update : 7th May, 2008
The decision to buy a Ricardo Ford GT Transaxle
After numerous hours calculating the potential power developed by my engine, after fitment of a supercharger, left me with little choice. Numerous calculations and investigations left me with 3 main options.
1) Albins Sequential Transaxle
This transaxle has heaps of headroom for power but to fit in the GT40 the AGB10 sequential is the only choice. Made in Australia and very capable I strongly considered this option. One of the main issues was the sequential shifts, great for track work but a little difficult for the occasional road use the car will encounter. For a true track car I would say its an excellent choice. Cost is approx USD14,000.
2) The ZFQ is another good transaxle but it is very much an unknown quantity at this time. Its only just achieving initial deliveries and a bit too risky right for me right now. Cost is USD11,950 plus shipping to Australia.
3) The third option is a Ricardo transaxle. This was going to be difficult to purchase after Ford Racing withdrew it from their catalogue. However I was lucky and Fran Hall from RCR was able to help me out with one. He seemed to have a corner in the shop where they just sprout out of the ground!
The Ford Ricardo transaxle met my needs but was expensive and large. Fitments were required to see if it would live inside a GT40.
The space was tight but as can be seen it "should fit"
Further checks will be done in Australia when the car arrives. I expect some shortening of the engine pulleys etc.may be required! Videos of the preliminary installation check can be found here.
Update : 4th May, 2008