SoCal parts sources

[Papak]

If I end up buying a Birkin kit, is there a local source for trans/diff? The engine issue seems a bit easier to resolve. How about wheels/tires?

TIA

[magnusfeuer]

Apart from the junk yards (Mercur xr4 had the T9 gear box and matching diff) and Hillbank in Irvine (official Caterham dealer / distributor), I would go source our tranny parts from http://www.batinc.net/merkur.htm in Florida. I haven't dealt with them in a while, but they have traditionally been the go-to company for us.

/Magnus F.

[magnusfeuer]

Disclaimer: I am suddenly unsure if Birkin features the Sierra diff or something else (Miata?).

/Magnus F.

[super7guy]

Goto guy is Dick Brink, TexasMotorWorks, Arlington, TX.
Don't know his present supplies, but got SPC 5, bought new a while ago.
Wayne in San Diego

[Doug Liedblad]

I believe the current diff in Birkins is from a Subaru.

That's on the IRS version.

Also tiprider reports that BAT was not of much help with the T9 parts he needed. He went to the guy in Oregon. Just search on Merkur XR4ti parts.

Or it was the other way around. I forget.

Doug

[slomove]

I am pretty sure the wheels come with the roller kit and some simple tires used to be on there with the live axle version as well. If you want different size Birkin uses 4x100 wheels that means any Miata wheel with the right offset will work.

The live axle car came with the diff/axle and propshaft and I would guess the IRS will be the same but not sure.

Quantum mechanics has a rebuilt T9 for $1100 and a semi-close for $1600

[Papak]

The Colorado distributor says that the new chassis is set up for other the Sierra diff or the Subaru. The Suby unit uses a viscous (?) LSD while the Sierra needs a Quaife or such. Do any of the Miata diffs come with an LSD? How much torque can they handle? What is the necessary offset for the Birkin suspension? As for transmissions, aren't there two different input shaft lengths on the Sierra unit? Can this be changed out as necessary during a rebuild? I presume most any used box will need to be rebuilt from what I hear about the bearing issues. Do the Zetec and Duratec require different input shafts?

Sorry for all the questions but I a trying to minimize the guessing as I move forward. Thanks to all.

[Papak]

Thanks so much for the link.

[Doug Liedblad]

As for transmissions, aren't there two different input shaft lengths on the Sierra unit? Can this be changed out as necessary during a rebuild? I presume most any used box will need to be rebuilt from what I hear about the bearing issues. Do the Zetec and Duratec require different input shafts?

Sorry for all the questions but I a trying to minimize the guessing as I move forward. Thanks to all.

There are two different input shaft lengths for the T9 used on Birkins and Caterhams. Caterhams typically use the longer input shaft. A new local Birkin has the short input shaft.

They can be changed but it's a complete tear down of the transmission. Unless you have the long input and need the short, then you could cut it to length.

No bearing issues with my T9 after 25K+ miles. I have the SPC Close ratio semi helical. The only bearing issues I've heard about was if used at high RPM a lot. Then you'll want the heavy duty version. Ask SPC, Steve Perks Components in the UK or Slomove's source.

I strongly recommend the long first, otherwise you are going 25 mph at 6000 RPM in first.

Doug

[JohnCh]

The Colorado distributor says that the new chassis is set up for other the Sierra diff or the Subaru. The Suby unit uses a viscous (?) LSD while the Sierra needs a Quaife or such.

The Sierra diff was also available from the factory with a viscous LSD in the XR 4x4. That variant was never imported to the US, so not easy to find here, but they are available in the UK (I run one in my Westfield.)

Do any of the Miata diffs come with an LSD? How much torque can they handle?

The 1.6L cars had an available viscous LSD, and the 1.8L cars had the option of a Torsen LSD. The 1.8L rear end is stronger, and although I don't know the limits, 250+ rwhp turbo Miatas are pretty common, and that rear end is not considered a failure point. Lots of information available at Miata.net.

-John

[Papak]

Thanks to all. Sure I'll have more questions as we move on. Right now, it looks though I'll get a kit in February if I don't find a better option before then. Nothing like a road trip to Colorado in the winter. In the meantime, I'll pick up a Duratec and start on the rebuild/updating. Can anyone recommend a good reference book for the rebuild?

[moosetestbestanden]

Thanks to all. Sure I'll have more questions as we move on. Right now, it looks though I'll get a kit in February if I don't find a better option before then. Nothing like a road trip to Colorado in the winter. In the meantime, I'll pick up a Duratec and start on the rebuild/updating. Can anyone recommend a good reference book for the rebuild?

I don't know of any. Magnus built his own engine, w/ Cosworth bits to Cosworth specs. So he's the book I guess. There is a wiki out here that has some technical tidbits.

A number of us have done engine-ectomies multiple times, and have diddled about w/ a wide variety of supporting kit - alternators and such like. So ask. It's free and w/ any luck the opinions / advice may be worth more than you have to pay. :-D