400 hub conversion

Okay, I never said I was perfect and down here in South Africa you sometimes just have to make compromises. So I finally gave up on the 415 rims and 'old' TRX technology and designed a little gizmo to convert the 5x108 PCD to a more 'user-friendly' 5x120.
The spacer width, which in this case is 38.85mm, works for a 15" rim, it would be slightly more for a 16, but I've gone for a 225x65x15 tyre which is within 1.25% of the original rolling radius and I can live with that.
Herecy of course for the concourse junkies out there, but extremely practical for daily use and I can always remove the spacers and replace the TRX's when authenticity requires.
I paid about $480 for the CNC machining and milling work which worked out a whole lot cheaper than importing 328 replicas from the UK.
Now that they know how to do the job, the engineering shop would be happy to produce more if required. Air freight to the US from SA is remarkably cheap in these economically stressed times.
Let me know if we can offer any help.

best for now.,

Mike
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Howard.

You need to confirm that you have original and unmodified 400 brake discs and calipers all round and that your wheel bolts are Ferrari standard 14.15mm metric fine.
If you decide, as I have done, to go for a 5x120 PCD then you have an enormous variety of after-market, as well as OEM BMW rims/mags to choose from.
The critical factor is the offset, you can read more about this on the following link:http://www.carbibles.com/tyre_bible_pg4.html.
Once you know this measurement then I will be able to quote you more accurately because this will determine not only the finished thickness, but the raw size of the block from which the spacer is machined.
Don't let all this technical stuff frighten you however, the material cost will not be too different from mine and the labour will be the same.
Once you've decided on a rim, be it 15, 16, 17 inch or more and have chosen a make and design, just let me know. Chances are that we can either take an accurate measurement of that model here in SA or find the critical dimensions on the web.
I'm amazed by the relative affordability of quality tyres in the US from places like tire-rack or discounttiresonline compared with prices here in SA. We have nothing here of any merit under US$200/tyre. You guys don't realise just how lucky you are...

 

I know that some of the 16" 308qv and the 328 rims currently available in the UK have the same PCD as the 400, namely 5x108, and they are virtually identical in looks.
Alex Aleventhal, who has discussed this on another thread, had spacers made up to compensate for the difference in offset. He recently sold them on eBay.
What I've done is to borrow his idea (thanks Alex) and create an adaptor-spacer that serves both purposes.
The big plus is that it opens up the possibility of replacing the expensive and out-dated 415 TRX's, with 15, 16 or 17" rims and all the latest technology tyres that are currently on the market. With top name brands, suitable for high speed, all season driving at around $120 -$150 a pop, that can't be too much of a bad thing, especially given the advances in tyre safety, durability, run-flats etc, etc.
There might be those who choose bling mags, its a personal thing, I'm not one of them and have opted for subtle period rims that blend well with the car's classic lines.
The point is that these adaptors offer choice and enhanced safety with the added bonus that the 415's can be stored in the garage until needed for those all-important concourse days.

 

Hi Terry.

That's a very interesting list. The one thing that stands out to me is the positive offset (inset) or ET on all those wheels, almost a staggering 88mm on the 355 !!!
What an amazing advance in wheel design technology that can pull the wheel so tight into the car by putting the rim mounting plate 88mm roadside of centre !
By way of comparison, the 400i has a negative offset (outset) of 2mm.
Don't ask me why they didn't make it dead centre (neutral) but I guess nothing that Ferrari did was ever that simple !