Auto To Manual Se Trans Swap Q's

I found a 3.5 ratio R200 Longnose differential from a 280z on craigslist. I'm excited about this because I'm almost done with my VG swap into my notch. I know the VG will have plenty of power off the line so I'm hoping the lower ratio will allow me to use 1st gear a bit more and get better mpg on road trips.

I'm assuming this different ratio will throw off my speedometer. Is it possible to use a 280z speedometer cable to correct this?

JordanI found a 3.5 ratio R200 Longnose differential from a 280z on craigslist. I'm excited about this because I'm almost done with my VG swap into my notch. I know the VG will have plenty of power off the line so I'm hoping the lower ratio will allow me to use 1st gear a bit more and get better mpg on road trips.

I'm assuming this different ratio will throw off my speedometer. Is it possible to use a 280z speedometer cable to correct this?

They went as low as 3.364 with the R-200 in the '79 zx 4 speed. (last year for the 4 spd.)

If you have a speed sensor in the tail stock I think it can be re-calibrated.

A speedo cable won't change anything. If your tranny uses a speedo drive pinion with plastic gears you will need to replace it with one from an '80 or newer FS5W71B tranny.

The gears are color coded for the number of teeth. The list below is for the 280z/zx so I don't know exactly how this compares to your car because of differences in the stock tire height. For example if your car has a 3.70 and had a 19 tooth gear then I would start by going down one sizes to 18 tooth. Very roughly, each gear change up or down is aprox. a 5% change in speedometer reading. A 5% speedo error is only 2 1/2 MPH at 50.

Yellow    16 Tooth    3.364.1
Black,    17 Tooth    3.545.1
Blue    18 Tooth    3.70:1
White    19 Tooth    3.90:1
Red    20 Tooth    4.11:1
Purple    21 Tooth    4.38:1

Lowering the number of teeth on the drive cog will speed up the speedometer to match the 3.545 axle. Be sure to only use a cog from an '80 or newer transmission, earlier ones won't fit and mate properly. Look for trannys with the speedo cog retaining bolt at the bottom or 6 o'clock position like this:



NOT LIKE THIS:

Thanks Datzennmike!

I've looked auround for info but I'm not having much luck. I have a 87 SE auto and I want that auto trans out with a quickness. the wireing for the auto ecu is no problem and i have almost all the parts needed. I have all the parts but a, fly wheel, clutch set, front driveshaft, and the trans. I plan to use the 250mm vg30et fly wheel and clutch.

What I want to know is:
I know the s13 ka trans is longer than the 5 speed Se trans, but are the bell housing's the same. I read on a pathfinder forum that they are interchangeable but I'm not sure if the sorce of the info was reliable. I really dont think that they are the same.

I'm not worried about the trans mount. If they are different I have a few different types laying auround.

In your opinion what trans has the best gear ratios set?

Any one have a SE trans and shaft for sale? I will pick it up no matter the location. I'm due for a road trip.

I found a thread on this but it didn't really shine any light on my bell housing question.

http://www.automotiveforums.com/t521033-ne...a_89_240sx.html

the bellhousing will need to be swapped if you go with the 240sx trans.
this is from my experience of swapping in a 5 spd c trans from a 240 into my 5 spd se. and the se trans mount will bolt right up in the stock location as well. basically you need to find a 5 spd se bellhousing and put it onto the 240sx c trans. and BAM, its ready to be put in.

methylprop
I know the s13 ka trans is longer than the 5 speed Se trans, but are the bell housing's the same.

if he runs a ka trans and swaps bellhousings can he use the front drive shaft half like the ka swap does? Or does it not require it.

it DOES require the hybrid driveshaft. its the front of a s13 manual driveshaft and the rear of the se, if i can remember it right.

your correct...