RX8 gearbox into 5a

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CarlosVanDango
Posts: 193
Joined: Wed Jan 02, 2019 7:37 pm
Location: Rotherham

RX8 gearbox into 5a

Post by CarlosVanDango » Tue Jun 16, 2020 7:27 pm

my almost finished mount (from my build thread) in case anyone wants to copy the idea

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scimjim
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Joined: Sun Oct 01, 2006 10:08 pm
Location: Gloucester

RX8 gearbox into 5a

Post by scimjim » Mon Aug 10, 2020 1:40 pm

Copied from a very helpful guy on Facebook

Jim King
1) 5 speed box used 6 not required as 1st on 6 speed is low. 2. 3. 4.5 & 6 are same ratio as 5 speed I believe
2) standard Essex clutch
4)adaptor plate is 6mm thick and quite flimsy and has no spigot for the starter to locate into I therefore had it modified as shown in the photos
5) when I purchased the plate I was told it was a straight swoop so fitted the plate on the engine and put the gearbox in
This was I lie as there is not enough clearance for the thrust bearing so I had to remove engine and box together and sort it on the bench.
To get round this I lowered the clutch arm pivot point until the bearing touched the front of the gearbox
This was not enough so I then fitted the 2mm plate to the back of the engine
This still gave no clearance so I skimmed 2mm off the flywheel
6) slave cylinder is Maxda 6 with rod from RX8. Spacer needs making to get the correct angle
7) clutch flexi I used S1 etype front brake flex in PTFE as they are long
8) SE5A tunnel needs small mod for reverse switch to clear but this is very small and carpets still fit
9)bellhousing needs cutting for Essex starter motor but if hi torque used it's very small mod
10)replace gearbox oil with 75-90 fully synthetic
11)tap holes in the bottom of adaptor plate to fit lower flywheel cover
12) there are no fixings for approximately 40% of the circumference from above the starter going round the bottom. I did not like this and managed to get a bolt through the bellhousing and into the starter (only possible with high torque)
13) I had a new propshaft made and replaced the propshaft seal
14) gearbox is great with 225-50-15 wheels 70 mph is approx 2500rpm and you can be in 5th from 35 mph
15) gearbox mount see photos that is easy
If anyone wants help or advice no problem
just get in touch
I am in East Yorkshire
If the plate was 10mm thick I think it would be great. Input shaft should still locate in spigot bearing and have the starter spigot on the plate would make it stronger
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Jim King

SECURE DRY STORAGE FOR YOUR SCIMITAR

Current: SE5 (8Ball), 1400 1600 1800 Zetec ST170 powered SS1 (G97), 2.5TD SE5a (diesel 5a), 6 x random other SS1s.
Previous: SE5, 3 x SE5a, 2 x SE6a, 3 x SE6b, GTC, 2.9i GTC, 3 x 1600 SS1, 1300 SS1, Mk1 Ti Sabre, Mk1.5 CVH Sabre, TI SS1 (snotty), 1600 SS1 (C686CCR).
Chief mechanic for: 1400 K series SS1 (Megan3), 1400 CVH EFi SS1 (Grawpy), 1300 SS1 (Number One) & Sarah's coupe.
CURE THE FAULT - NOT THE SYMPTOMS

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scimjim
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Posts: 40772
Joined: Sun Oct 01, 2006 10:08 pm
Location: Gloucester

RX8 gearbox into 5a

Post by scimjim » Mon Aug 10, 2020 9:59 pm

Here’s a comparison of the current setup, LH overdrive, 205/60R15 and I’ve assumed 3.31 diff (because I’ve never checked :D ) and the 6 speed RX8 with 2.88 LSD from diesel. I’ve capped it at 5000 rpm - I wouldn’t go there with the current engine but the engine that’s going in is more than capable if I wanted to.

The 2000 rpm drop between first and second isn’t much worse than the current one between second and third (and I don’t notice any great problem with that gearchange at the moment?) and the new engine is around 200 BHP so I think it should be okay?
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Jim King

SECURE DRY STORAGE FOR YOUR SCIMITAR

Current: SE5 (8Ball), 1400 1600 1800 Zetec ST170 powered SS1 (G97), 2.5TD SE5a (diesel 5a), 6 x random other SS1s.
Previous: SE5, 3 x SE5a, 2 x SE6a, 3 x SE6b, GTC, 2.9i GTC, 3 x 1600 SS1, 1300 SS1, Mk1 Ti Sabre, Mk1.5 CVH Sabre, TI SS1 (snotty), 1600 SS1 (C686CCR).
Chief mechanic for: 1400 K series SS1 (Megan3), 1400 CVH EFi SS1 (Grawpy), 1300 SS1 (Number One) & Sarah's coupe.
CURE THE FAULT - NOT THE SYMPTOMS

User avatar
scimjim
RSSOC Member
Posts: 40772
Joined: Sun Oct 01, 2006 10:08 pm
Location: Gloucester

RX8 gearbox into 5a

Post by scimjim » Mon Aug 10, 2020 10:09 pm

Here’s the 5 speed box - the first/second gap is huge?
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B9375E93-26F5-4B5C-B8A9-C00358BFD574.png (173.5 KiB) Viewed 199 times


Jim King

SECURE DRY STORAGE FOR YOUR SCIMITAR

Current: SE5 (8Ball), 1400 1600 1800 Zetec ST170 powered SS1 (G97), 2.5TD SE5a (diesel 5a), 6 x random other SS1s.
Previous: SE5, 3 x SE5a, 2 x SE6a, 3 x SE6b, GTC, 2.9i GTC, 3 x 1600 SS1, 1300 SS1, Mk1 Ti Sabre, Mk1.5 CVH Sabre, TI SS1 (snotty), 1600 SS1 (C686CCR).
Chief mechanic for: 1400 K series SS1 (Megan3), 1400 CVH EFi SS1 (Grawpy), 1300 SS1 (Number One) & Sarah's coupe.
CURE THE FAULT - NOT THE SYMPTOMS

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