Subaru/Datsun Differential mount Testing the waters.

[tbush]

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

[Bill Young]

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

[tbush]

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

[Bill Young]

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.

[tr8todd]

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.

[salty1960]

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

[tr6turbo]

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

[tr6turbo]

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

[74ls1tr6]

Hi Dale,

What size fan are you looking for?