Just testing the waters to see how many folks would be interested in a conversion mount to put a R180 Subaru Diffy into a Spitfire/GT6. I am thinking of putting one in my car and am drafting up the mount. Looking to make it a single piece of laser/plasma cut and flooded sheet with weldments for the spring seat and studs. I might be talked into a group buy or cutting a deal with someone who would want to sell them. 2D and 3D models and full sheet metal layouts provided. If there is not much interest I will probably just make a welded up mount.
- Tim
Tim, I think one reason there aren't more Spitfire conversions is the lack of a suitable rear axle. Your idea has merit for sure. The key for a conversion is both being strong enough for the larger engines torque as well as having a variety of gear ratios available to suit different combinations. That would be the first thing I checked, ratio availability. No sense building a mount for a rear that only has a 4.11 set for example or a 2.78 for that matter. Bill Russell did a nice conversion using a BMW axle and with the competition use of the BMW I'd think there would be a load of ratios available for that one. http://forum.britishv8.org/read.php?3,15977,page=2
I know the R160 Subby Differential is available with 3.7, 3.9, and 4.11 ratios and I believe there are 3.54 and 4.44 out there. There are open and LSD versions available. The stock rating is 300 ft-lbs input torque and 200 Hp. There are report of people running 250HP into a R160. Datsun also used these units in the 510.
- Tim
The 3.7 or 3.54 would probaby fit the needs for most guys with a V6 or V8 while the 3.9 would work pretty well for the smaller 4s. I have a 3.43 in my V6 powered car and probably should really have a 3.23 for the best match with my 13" wheels. If you could find a rear with ratios from around 3.0 up to 4.0 that would have all the bases covered.
The BMW rear axle would seem to be a good choice. The small ones came in the 2002, 320 and 318s. Medium sized ones which came in the 325 and over 6 cylinder versions would be more than strong enough for most applications. The V8s and M series car got the large differential. Every BMW since 1970 has one of these version. Gear ratios and limited slips abound, as do rear cover, mounting configurations and axle lengths. I have several of the early ones laying around here. They have a complete flat rear subframe that carry everything except the spring and shock upper mounts. They would be a snap to mount into just about any car. Personally I would look at one from an E30 325i. That would be from around 85 to 89ish. They had tons of ratios, simple mounts, a medium sized case good to about 300 horse, still carried a 4x100 wheel bolt pattern, and came with rear disc brakes. Axle components also compare favorably with Porsche and VW.
Tim,
The diff mounting and and adaption to half shafts isn't that hard, and in different formats has been done quite a few times.
The big problem is upgrading CVs, and control arms to handle the torque that most engine conversions require.
Brakes are also needed to be upgraded.
I chose to replace the lot, but this is a lot of work.
Non independant conversions are the common solution but, I can't say I could bring myself to replace an irs with a non irs arrangement.
Our friends in new Zealand have a long history of working with these.
The link below has links to drawings for some simple plates to mount a subaru / datsun / nissan diff centre to a herald/ spitfire / vitese
http://homepages.paradise.net.nz/lghrnrm/redwitc.htm
I folded some plate and welded across the rear suspension (a bit of an overkill) and fabricated some substantial brackets of the chassis to support the front of the diff. I went the all Subaru route. (custom axles to suite)
See
http://www.facebook.com/album.php?fbid=1827964070949&id=1595737255&aid=2100607&l=02d5ad1fcb
http://www.ado13.com/dohczuke/dohc.htm
Regards,
Stephen from Sydney
SpitSuziFire Spitfire with Sukuki DOHC1600 EFI
221636_1827966431008_1595737255_31802238_3154191_n1.jpg
I was going through your pictures on the ado13.com site and was interested in the size and brand of your electric cooling fan. Do you have that inormation?
Thanks
Dale
I was going through your pictures on the ado13.com site and was interested in the size and brand of your electric cooling fan. Do you have that inormation?
Thanks
Dale
Hi Dale,
What size fan are you looking for?