Our basic guide to a Nissan M35 Stagea manual conversion.
Hi everyone! Recently at R&D Mechanical we had the opportunity to convert our customer Beau’s Nissan M35 Stagea from automatic to manual. As soon as Beau came to us regarding this job, instantly we knew it was going to be an exciting one! Not only was it an adventure hunting down the right parts but to convert a model of car that came off the production line predominantly automatic to a 6 speed manual, we just had to do it!
Due to this conversion not being popular as of yet, the information on what model parts to use was minimal. Over two months the R&D team researched, measured and tested parts that would be suitable for the conversion. We have written this guide to share with those wanting to tackle this conversion in the future with ease.
Throughout the build, we have tried to keep the modifications/customization to a minimum and use as many Genuine Nissan parts as possible.
Vehicle: Nissan M35 Stagea
Gearbox: Nissan 350z/Z33 6 speed
Upper & lower sump – Nissan V35 VQ25DE sump (requires modification)
Gearbox – Nissan 350z, 6 speed (no modification required)
Gearbox mount – Nissan 350z (no modification required)
Gear shifter – Nissan 350z (no modification required)
Clutch & flywheel kit – Nissan 350z (no modification required)
Starter motor – Nissan G35 Infinity (American version) Converting the starter motor from left hand side to right hand side. (no other modification required)
Pedals (brake & clutch) – Nissan 350z (clutch pedal requires modification)
Clutch slave cylinder – Nissan 350z (no modification required)
Clutch slave cylinder line – Custom braided line required
Clutch master cylinder – Nissan 350z (drilling required)
Tail shaft – Custom made front section. Nissan M35 Stagea rear section.
Handbrake – Nissan 350z manual handbrake. (modification required – extended cable)
Center console + shifter surround – Nissan V35 manual Skyline (minimum modification required)
With the wiring side of things, there wasn’t much information available. After many hours of research we got the car to start and drive without major issues. Here is some basic wiring tips to make the conversion easier.
- Bypassing the starter motor relay to allow the car to start (if this isn’t done, the car will not start)
- Reverse lights – The reverse light plug has two pins. One pin was tapped into the reverse relay for power. The second pin was used as an earth, which we ran to the gearbox. (the reverse switch is on the passenger side)
- Extended power cable – this is needed as the starter motor is now located on the drivers side.
The electronics side of this conversion can be complicated. As straight forward as it may sound, we do recommend using a professional auto electrician.
ECU – Currently Beau’s vehicle is running a stock M35 Stagea automatic computer with a Greddy E-manage. At the moment the engine and 4WD check lights stay on. The engine light was on before the conversion due to the E-manage and the 4WD light was expected as the car is now RWD. The transmission check light does flicker after the car is started but soon goes away. The vehicle hasn’t gone into limp mode and is driving under load with no issues. As you can imagine the flyby wire takes a little getting use to in manual mode as it is slightly delayed. This could possibly be made better with a aftermarket ECU + tune or converting to a cable throttle. (In the future Beau will be looking at aftermarket ECU/Tune options – we will keep this article updated.)
We do recommend a aftermarket ECU to get the full potential from this conversion. However the car is very drivable with the stock ECU.
Scan tool findings – All codes regarding transmission (understandably)
THE BASICS OF THE JOB
The M35 manual conversion is like most other manual conversions, easy! – once you have all the parts you need sorted. We do recommend this conversion to be done by a professional or someone experienced.
NOTE: These are not instructions, this is just a basic guide to help those wanting to give this conversion a go. Please contact us if you need to know more.
– The 350z/Z33 6 speed manual gearbox will bolt straight up to the VQ25DET using a VQ25DE RWD sump. (use a 350z gearbox mount). Note: you can not use the AWD M35 sump as it won’t mate up to the gearbox.
– VQ25DE (V35) upper & lower sump: modification is required- A turbo drain hose fitting and a turbo oil feed is required on the left hand side of the V35 sump. (3 holes are required to be drilled and tapped). Use the M35 oil feed cross over pipe in the sump.
– Clutch & flywheel kit: for this conversion we used a Exedy HD cushion button clutch kit and a lightened flywheel. It needs to be a 350z clutch and flywheel kit. The flywheel needs to be fitted at TDC or the vehicle won’t start. (Note: the spigot bearing will not fit inside the crank however the 350z input shaft is very close to the thickness required and works without a spigot.)
– Clutch and brake pedal: using a Nissan 350z set up. The brake pedal bolts in and the clutch pedal requires a custom bracket + bracing.
– Clutch slave cylinder requires a custom length braided clutch line. No other modification required.
– Clutch master cylinder requires some holes drilled to be mounted and for the clutch line. No other modification required.
– G35 Infinity right hand starter motor – due to the M35 left hand side starter motor hitting the added turbo drain hose/turbo feed on the V35 sump, it is best to convert it to the drivers side as there is a lot more room. We purchased a G35 starter motor from the USA.
– Tail shaft – A custom front section is needed, use a Nissan 350z slip and a M35 center bearing flange. The rear section (center bearing to diff) remains M35. Be sure to measure the distance correctly for the custom front section.
– The handbrake needs to be converted from foot to a standard handbrake and requires a custom extended handbrake cable. It also requires a custom mount inside the car. Use a 350z manual handbrake center cable + assembly – the two main handbrake cables remain M35.
Note: when removing the front drive shafts, the outer CV joint needs to be modified to be bolted back in as they hold the front wheel bearings together (refer to photos). Although this works, we recommend replacing the brake/hubs with a 350z set up (even better a track 350z with some nice Brembo’s)
A FEW PHOTOS
If you would like any photos explained, please contact us.
Here are a few video’s of the first drive!
Thank you for reading our article on converting a Nissan M35 Stagea to manual. If you wish to do this conversion yourself (or your mechanic) please don’t hesitate to contact us for any questions. We are very happy to help, from the team at R&D Mechanical.
Phone: 08 8386 1861