Part 6: And I Won’t Call It Drivetrain Tech … (part 1)

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Ok, maybe I will but in any serious car buildup the obligatory drivetrain tech installment invariably comes up. And that my friends is what we are about to embark on. The drivetrain includes any system that takes rotation from the motor and translates that movement to the wheels. In this case, I will talk about the flywheel and the driveshaft. Any amount of weight that is removed from the rotating mass of these components will ultimately result in a quicker revving motor that more directly communicates driver input to the wheels. For a drift car, this is a good thing.

The Flywheel

The fidanze 9lb flywheel and exedy clutch test fit in the ca18det's transmission

The sr20det flywheel test fit in the ca18det’s bell housing.

The flywheel on a car is the disk that bolts to the back of the crank shaft. This is where the clutch makes contact with the motor and by replacing the factory 30+ lbs flywheel with a lightweight unit, the crankshaft will be responsible for rotating a smaller mass and therefore the entire motor will rev smoother and quicker. This will allow the car to reach its power band quicker and makes rev matching much more precise.

And when choosing the flywheel, I went the slightly unorthodox path. One thing the ca18det doesn’t enjoy is a large aftermarket for lightweight flywheels. Most flywheels are ordered from Japan and in all seriousness, who wants to wait weeks for parts. As is common in the ca18det crowd, if you do a little research, you can just borrow what you need from another Nissan, and that happens to be the sr20det. Anyone with a sr20det knows the ridiculous amount of flywheel and clutch choices they have and for project ca18det, I went with the Fidanza 9lb unit. To fit the sr components, the alignment pin must be removed from the crankshaft, two bumps must be ground off the inside of the ca’s bellhousing and then a 1986 Nissan 200sx hoodless starter must be used in place of the factory ca18det starter. For those interested in the details of this swap, the full write up is found here (Installing a SR20DET Lightweight Flywheel and Clutch into the CA18DET) but be warned, the new starter will make an interesting noise at start up that may scare a few onlookers.

The Driveshaft

Image of the new lightweight aluminum driveshaft to be installed on the ca18det swapped nissan 240sx.

The new single piece aluminum driveshaft.

The 240sx’s driveshaft is a two piece unit with a flex joint in the center. It weighs roughly 20 lbs and is one of the contributing factors to the clunk that many a 240 owner complains about. This unit was replaced with a 12lb aluminum, single piece unit from the Driveshaft Shop. Installing the new driveshaft was surprisingly one of the easiest mods I have done to the 240sx, taking literally less than 30 minutes from start to finish. The full install write up is found here (Aluminum One-Piece Lightweight Driveshaft Install)

Driving Impressions

With the lightweight flywheel and driveshaft and the hockey puck motor mounts I recently added, I am surprised at how communicative the 240sx now feels. Combined with the 8000 rpm redline of the ca18det, the car absolutely screams to its power band and even at the low 6psi break in boost it is amazingly quick.

Check back soon for part 7 where things get truly interesting as project ca18det gets larger injectors, stand alone engine management and 1bar of boost.

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About the Author:

Chris Simmons

Chris Simmons is a race car driver, instructor, business owner and all around gearhead. His passion for motorsport started in the drifting community and progressed into wheel to wheel racing of all kinds. When off track Chris can be found training and working on a myriad of projects. After a hiatus from writing, he is back to share his passion, knowledge and experience in regard to motorsports on and off the track.

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