Picking a transmission for a front wheel drive sr20de, sr20det, and sr20ve is more of a science than an art. There are many different sr20de compatible transmissions to choose from some are weak and others are almost indestructible; some have limited slip differentials and some don't and they all have different gear ratios, in this article I will describe the different transmissions available for the sr20de and variations of that motor to help you select the best transmission for your application. I will also include information for aftermarket sr20de transmission parts, tips, and things to watch out for.
P10 91-93 Infiniti G20 sr20de transmission.--this transmission has the longest gears of all the sr20de transmissions and is best suited for someone that does a lot of interstate traveling, it's a good transmission for fuel economy and works best on motors that are modified with a smaller turbo such as a t25 or a t28, it does not work well with larger turbos because the gears are so long it's practically impossible to load the engine down hard enough to get a good spool. This is a weak transmission, not good for much over 250 horsepower and does not handle 4 and 6 puck clutches very well; the transmission seems to self destruct with use of these clutches. Limited slip differential versions of these transmissions are hard to come by as it was only an option, most are one wheel spinners.
P10 93.5-96 Infiniti G20 sr20de transmission--this transmission is exactly the same as the one mentioned above except for the fact that it has a steeper 4.176 final drive, which would allow it to be suited for a slightly larger turbo such as a super 60 T3 or at biggest a T3/T04E 50 trim with a 48. A/R exhaust housing or a gt2871r. This transmission and the one listed above are not suited for all motor performance and are best left to turbo applications because of the wide gear spread they also have a lesser tendency for wheel spin after first gear with good tires.
P11 1999 Infiniti G20 sr20de transmission--This transmission is similar to the transmissions listed above in first gear, second gear, and final drive; but it has tighter 3rd, 4th, and 5th gear spreads. This transmission would be a better turbo transmission for racing from a 40 or 50mph roll and has a lower gear limited top speed which is good because there's no point in racing in speeds over 130mph anyway. This transmission still has a weak case, so don't be fooled if it looks different on the outside. This transmission also comes limited slip or not. This sr20de transmission is also suitable for all motor and nitrous applications, it has exactly the same gearing as the 91-99 B13 and B14 Sentra and 200SX.
P11 00-02 Infiniti G20 sr20de transmission--The transmission with the improved case. This sr20de transmission is similar to the one above, but it has a stronger improved case and first and second gear are tighter. This is a good all around transmission, it works well in most situations and is normally pretty hard to come by in its lsd (limited slip) format.
B15 00-01 Sentra 2.0 sr20de-This transmission is the most sought after, especially when its lsd. This transmission has a 4.437 final drive which is quite a step up from the 4.176 final of the transmissions previously mentioned, first and second gear end quick with this transmission making it a good tranny for all motor sr20ve or turbo usage with good tires. This transmission is good for about 450 horsepower stock without failing.
N14 Pulsar VZR sr16ve-this is the bad boy for all motor, it has the same tight first and second gear ratios as the B15, but has tighter (shorter) third, fourth, and fifth gears. You'll rip through the gears like you're on a motorcycle with this one. This transmission is not normally recommended for turbo sr20de's unless you're using a fairly large turbo and you have a high revving engine with slicks. This is a very strong transmission and like the B15 it takes well to puck style clutches, the B15 and the sr16ve transmissions will cost you the most, but they are the best front wheel drive bolt in transmission that Nissan has to offer.
TIPS
**Modifications can be made to your weak B13, B14, P10, and early P11 sr20de transmissions to make them more capable of higher horsepower and torque levels. You can aluminum fill weld the crescent shape around where the passenger side cv axle enters the sr20de transmission differential. Having your transmission gears shot peened and cryo treated will also improve strength.
**Use Redline shock proof gear oil, it's makes for smoother shifts and is better at protecting your sr20de transmission than conventional gear oil.
**Always use a light weight sr20de flywheel, this reduces the amount of rotational inertia that the transmission has to absorb when selecting a gear, it can help make your sr20de transmission last longer.
**Avoid puck style clutches on your sr20de transmission unless it is necessary at your power level. Also, when using puck style clutch disc, try and mismatch them with a lighter duty clamping force pressure plate, this will allow the clutch to slightly slip.
**This is a link to sr20de transmission gear ratios, engine rpm in gear, and mph for each gear:
http://www.sr20forum.com/driveline-tran ... 5Cp11.html**There are semi-synchro and straight cut dog box gear sets available for these sr20de transmissions from PAR engineering, but you'll have to put down a pretty penny to have an indestructible transmission.
**Fifth gear pop out is a common problem on the early sr20de transmission, here's a link to the replacement parts:
http://www.gspec.com/s-14-transmission.aspx**The only good replacement sr20de differentials for racing applications are made by Quaife and Nismo, do not get a phantom grip.
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