Review: GW 240sx 5 speed into 77 810

[afracer]

Car is a 77 810 wagon, stock L24E w/4 speed. I bought godzillaraceworks.com bellhousing mod to put a 240sx FS5W71C 5speed behind the L24. I also got their RB flywheel swap adapter ring, lightweight RB 14lb flywheel and Exedy 350Z clutch.

 

You have to swap the bellhousing which is fairly straightforward if you have a 240SX  FSM. I don't recommend taking the back half/tailshaft apart if you can avoid it. Once all together you have to use the front trans cover from the 240sx 5 speed but use your original 810 long throw out bearing (TB) carrier assembly. I couldn't find my 240sx TB carrier to verify if it was long enough to work or not.

 

If you use the 350Z clutch you'll be short 3 clutch bolts, so order a full new set with 9 bolts online before starting the swap. You'll also have to grind the bellhousing in a few spots to clear the clutch. I just installed and pulled the trans a few times and rotated the engine to see the marks in the bellhousing where it was hitting and then  grinded a little aluminum away there. This RB flywheel/clutch setup also pushes the flywheel back supposedly 1mm, so I got a new reduction starter with a removable mounting plate that I'll take off and mill down 1mm to ensure full starter engagement.

 

Upon install the driveshaft will need to be shortened 2 inches as everyone says, but what nobody said is also the mount and shifter sit too far back as well! There is almost enough adjustment in the mount to push it into place, so you'll have to elongate a few holes to make that work. The shifter hole unfortunately HAS to be cut open more. This is where I'm at now. My plan is to cut some new sheet metal and bolt it on the front of the hole so I can reuse the stock shifter seal. I don't know yet if the console will need modifying...we'll see. 

 

The stock driveshaft is a 2 piece. Dorman makes "problem solver" 1 piece driveshafts for these cars, so I'm going to see if I can just get a custom one made. It's either that or have the front of the 2 piece shortened 2 inches. The distance from the tip of the trans tailshaft to the diff flange is 47.5 inches, with full weight on wheels. The driveshaft shop will need this measurement (and maybe more) to make your new driveshaft.

[afracer]

Also, cheat code to help stabbing the trans...have someone turn the crank pulley while you stab the trans. If you're good you can do both at the same time by yourself. I've never had to do this before on other cars but the transmission was being difficult going in and this 100% solved the issue immediately. 

[datzenmike]

I have saved a few drive shaft splines to stick in the end of transmissions when storing them. When shoving the transmission in, place in any gear, push the spline in the end and twist it back and forth as input spline enters the clutch disc. 

 

The KA has to be both lighter and more powerful than the L24.

[afracer]

Probably is, but I never cared for my KA24DE. My 5 speed transmission is actually from an SR20DET, so it doesn't have as much of an overdrive as the KA 5 speed, but its 10x better than none.

[datzenmike]

Ah, I should read more carefully. Just the 71C then. The 5 speed was an option from '79-80 before becoming the 910 Maxima.

 

SR20 5 speed from a 240sx must be an import transmission then. The KA 5 speed had an overdrive similar to the 280zx around 25.5%.  

[afracer]

Yeah the SR trans has a .83 5th gear and the KA as with most USDM import cars has a longer .76 5th gear. JDM transmissions and diffs nearly always have shorter gearing as they don't really have a ton of open, high speed highways compared to the US, so most USDM equivalent cars they make have had taller gearing. Otherwise the KA and SR 5 speeds are interchangeable with a bellhousing swap. 

[datzenmike]

Don't think I would care for a 25% OD makes it less usable. My 5 speed is an '85 S12 wide ratio (with L series front case swap) from a CA18ET and the car has a 4.11. It has a .813 18.7% OD. With 4.11s it gets lots of use and in town if just rollin' along you can use it at 30 MPH. Forth to fifth feels like third to forth and keeps pulling. The wide ratio has 3.592 first gear to spool a turbo faster and with 4.11s it gets to second a lot faster.

[afracer]

16 hours ago, datzenmike said:

Don't think I would care for a 25% OD makes it less usable. My 5 speed is an '85 S12 wide ratio (with L series front case swap) from a CA18ET and the car has a 4.11. It has a .813 18.7% OD. With 4.11s it gets lots of use and in town if just rollin' along you can use it at 30 MPH. Forth to fifth feels like third to forth and keeps pulling. The wide ratio has 3.592 first gear to spool a turbo faster and with 4.11s it gets to second a lot faster.

 

Depends how much freeway driving one does. I do a LOT since I don't live in a city, I'll take as much overdrive as I can get. This car will eventually get a turbo too so it'll have no problems pushing these gears out. I prefer wider gearing on turbo cars myself.

[datzenmike]

Turbo applications require RPMs to get them spooling and why they used a wide ratio in the S12 plus a 4:11 differential. A close ratio will have a much longer delay between stepping into it and when it actually starts pulling. Turbo lag.

[afracer]

Correct but loading up gears also helps  produce boost and reduces spool time. But nowadays you can get turbos that'll spool faster while flowing more air. The only real question is how much power do you want to make and gearing is nearly irrelevant in regards to spool/lag. It started with the billet wheels, then redesigning blades, then using sexy alloys, and now you've got the Garrett G series and BW EFR turbos. They'll spool the same or faster than stock turbos, but flow 500+ hp!

[afracer]

This swap is great. One caveat is the shifter barely contacts the center console when shifting to 2nd and reverse. If the shifter stick itself wasn't fat in the meddle like all 240sx shifters are,  it would be perfect. I may look into modifying it somehow.