In my 91 si I have an SL3 transmission. Im not sure if its the stock tranny bacause its mated to a d16y7. I also have an L3 tranny and im not sure which one would be better to use (both are open dif). Im trying to get more acceleration than top speed. This is my first time ever experimenting with transmissions and i want to learn a little more about gearing and ratios.

Any and all advice is welcome

Thank you
$ilver

 

Look for a small circle cast in the case between the fill plug and drain plug by the axle seal. It will be cast with PL3 in the top half of the circle and the lower half will have A100, A000, 3000, or 9000. If it has the 3000 or 9000 it is the 40mm Si with faster gearing.

 

Which transmission do i check for this

 

The L3 and SL3 are the same models but may have different ratios. Check both for the casting codes to see if one has the 3000 or 9000. You will also want to make sure they both have the 20 tooth splines for the clutch. If the tip of the mainshaft has 1 or 2 lines it is a 20 spline and no line is a 21 spline.

 

The L3 is 3000 and the SL3 is 9000, the L3 has one line and the SL3 is in the car. What does the 3000 and 9000 mean?

 

9000 is a 90-91 Si model - use this one.

3000 is a JDM model with 40mm bearings but you will need to open it and count the teeth to be sure of the ratio.

 

So the 9000 will pull harder than the 3000?

 

It depends on the gear ratio of the 3000. You will need to open it and count the teeth to know for sure. Some of the 3000 L3 transmissions were from the JDM ZC model with closer shaft gearing but a longer 3.89 FD and larger axle holes. If this is what you have, you can use the diff and 4.25 FD from the SL3 with the shaft gears from the 3000 to make an extreme hybrid. The 9000 is the fastest USDM model. If you do not want to get into them just stay with the SL3 PL3/9000 Civic Si trans.

 

ok thank you very much for all the help