Skip to main content

Transmission Options

I ended up going with a 2008 RX8 S2 gearbox as it was stronger than the S1 gearbox and newer and cheaper than an RX7S5 turbo box. I considered the gearbox form an RX7 FD but they have a pull style clutch which would mean I couldn't use my existing clutch. The choice of the RX8 gearbox came down to availability, cost and the fact I could use my existing clutch.

I think I'll need to change the Diff Ratio from 3.27 to 4.11 to make the gearbox more usable, below is a simulation with a 4.11 Diff and the RX8 Gear ratios shifting at 8000rpm with 15inch tyres.


Some of the options
Jatco 3 speed automatic box including torque converter $7,000

JK40C/CD transmission from 350/370Z

Adapter kits:


they all seem to need:
Does Not include (but requires) the following:
T56 Slave Cylinder (throwout bearing)
13B REW Automatic bell housing
FC FD Counter Weight
FD Automatic Flexplate (required if you do not select the Billet flywheel)
FD Automatic Starter
FD Automatic Counter-weight
Automatic Rear housing is required.

Which seem like a lot of work.

Tremec TKO Transmissions:



Tremec TKO to Rotary Adapter
CNC machined billet alloy adapter. Allows 13B turbo bell housings to be bolted to Tremec TKO transmisions. Two adapters available - one to suit FC (S4/5) bell housings, and one to Suit FD (S6-8) bell housings. In both caes the existing 13B turbo clutch/flywheel/starter is all retained - only the clutch spline must be changed to suit. Fitting instructions included.

Green Brothers racing offers a steel bell housing to adopt a TKO, $1,200

Steel Bell Housing - Tremec TKO to Rotary
This bellhousing is built to NZDRA and ANDRA specifications from cold rolled 6mm steel and laser cut 10mm flanges. Approx weight 10kg. Designed to be used with hydraulic release bearing. Bolts up to 12A, 13B and 20B. No scatter shield or blanket required. No adapter required, bellhousing bolts directly to the TKO gearbox (minor modification to TKO case is required to clear starter motor). Bell housing is designed to suit 320mm ring gears, and uses a S4/5 13B turbo starter. Photo is a sample only.



Comments

Popular posts from this blog

Shortening the Diff

I have a Ford 8.8 inch diff from a EF/EB Ford Falcon with a Limited Slip Differential. I want to shorten it down to suit the 323. Due to the RX7 LCA in the front, the front tyres(205X50X15) now protrude from the front guards by 65mm. Making the overall front track width 1,675mm. With 225X50X15 tyres on the rear and the standard diff the rear is 1,610mm. Meaning that the rear track width is 32.5mm narrower on each side. To widen the rear when I shorten it, I'll make the rear axle 65mm wider than the standard rear axle. The standard 323 Diff width is 1,338mm and the Ford 8.8 is 1,547mm for a total difference of  209mm. So the Diff needs to be shortened by 209mm - 65 =  144mm or 72mm per side.

The Journey continues

"It was the best of times, it was the worst of times" C.Dickens Long time no blog post, I guess most of the time I post on Instagram and neglect to come on here. In some ways it has been a good time for the shed and in other ways not so much. After moving house and getting a bigger shed I have more space, I've managed to purchase a Mill and a band saw as well as some other tooling. I've spend a fair bit of time mucking around with the front suspension and I think I have it how I want it now. Unfortunately with four children, the property, kids sport etc there is not a lot of time to spend in the shed, mostly later in the evening once everyone is in bed. I made a bit purchase and brought an RX7 FC, S5 13B motor in unknown condition with a MicroTech LT-9c for $3,000. I've started stripping it down and will clean it up and rebuild it, with the view of running it on E85. I've reworked the design of the steering rack location to have it correctly in f...