So, You Want an SR20DE/SR20DET Engine-- Everything You Need To Know

[Vinnyz]

Any particular cold air approaches for the SR engines that fit well? I want to keep mine out of heat zones and possibly in front of the radiator.

[Jdflyer]

Part III-- Prepping the SR20DE / SR20DET for installation into your Datsun Roadster

Ok, in part 2 of this post, we will do some service work and more inspection, and then prep everything for re-installation.

Michael

Hey Michael,

I know these post are a ton of work, but do you have any time to do a part 2. Even an abbreviated version would be so appreciated. Thanks

[kennyele11]

Is this topic dead?

[spriso]

Kenny wrote:

Is this topic dead?

What else would you like to see?

As for the SR20 story for late 2021, well, they are thin on the ground to find these days-- limited containers arriving due to Covid backlog, expensive container prices, and just the general age have not helped situations. Engines can still be found, it is not a matter of picking between a couple dozen of them on eBay like a few years ago...

We have several more SR20 powered roadster projects in the works, so I can continue to this build thread if there is interest.

Michael

[Solex68]

There is interest from me

[family_2k]

Yes, please! Always interested in learning more and seeing all the hard work that goes into the doing the engine swap.

[eye]

I have a lot of photos on my Instagram account if you want to look there. Michael was my go to source when I did my swap. He can answer any questions you have and the best out there IMO.

IG is 329art

[rbhenderson]

Maybe not the right post for this but I haven’t found a better one so starting here… I could just be search handicapped though.

I’ve been trying to find information on fitting the various transmissions into the chassis/body. I’ve done a bunch of searching and found lots of speculation but minimal photos/documentation. Michael, are you willing to post some info on that?

[spriso]

Ben wrote:

I’ve been trying to find information on fitting the various transmissions into the chassis/body. I’ve done a bunch of searching and found lots of speculation but minimal photos/documentation. Michael, are you willing to post some info on that?

Transmissions:

For the SR20-series engines, there are three main choices, and then two other alternatives.

Standard SR20DE/T 5-speed transmission FS5W71C:



Offered in two versions, RWD SR20DE/T transmission (FS5W71C) has the same gearing set, the only difference is the SR20DE transmission has a .85 OD, and the DET has a .75 OD 5th gear. The 5-speed transmission fits the tunnel with almost no modifications other than removing the reinforcement rib on early 1600s, and reversing the shifter hole on the later 2000 model cars. The X-member needs a modification for the mount, where we do something like this, and set the transmission height using a 2x4 on end to get the driveshaft angle correct. The 1600-series driveshaft needs to be shortened, but and the dust shield removed from the yoke, but otherwise will slide into the end of the transmission-- thank you Nissan!

The FS5W1C transmission is used in a lot of 90s RWD Nissan products, including KA24E/DE engines, VG30E engines, etc. Changing out the bell housing to an SR20 version allows you plenty of replacement choices (with different gear ratios) if you have an issue with your gearbox.

This transmission is robust, reliable, rebuild able (with domestically sourced parts from Nissan USA), fits the car well, and will suit 98% of roadster owners.





S15 6-Speed Transmission FS6R92A



The 6-speed found in the S15 Silvia (with SR20DET engines) is one of my favorite modifications to do for a roadster. It is a close ratio box adding an additional gear between 1-5th gears, so you can always be in the right gear. It really brings the SR20-series engine alive, and when mated with a SR20DE, makes the car super fun to drive. The 6-gear is a .76 OD just like the other DET gearboxes.







The 6-speed is physically a larger transmission, so we often will modify the transmission tunnel, and the front legs of the X-frame will also need to be rebuilt to accommodate the larger 6-speed case. See photos below of some of the mods we have done in the past. The driveshaft has a different yoke, but after a lot of research, we found that it is the same as a KA24DE automatic (from a 240SX) so use that yoke when you have the driveshaft built.

There is an alternate version of the 6-speed (aka the Nismo version) which has reinforced internals and a .86 OD instead of the .76 OD found in the standard version.

The 6-speed gets a bad reputation from drift bros who abuse the hell out of them, but again, for most roadster owners, this is a great gearbox IF you are willing to do the extra work to get it to fit into your car. Negatives for this gear box are parts have to be ordered directly from Japan, and a surprising amount of them are now NLA. Finding a good gearbox that has not been destroyed by drift bros can also be difficult. Still, if you find a good one, it is a sweet swap for a roadster!

SR20DE/T Automatic Transmission

We have also modified roadsters to use the automatic transmission often found paired with SR20DE/T engines. This modification needs similar modifications to the 6-speed-- with the passenger side of the transmission tunnel needing to be modified to clear the shifter linkage. We have modified Datsun 280ZX automatic gear shifters to work with this swap, and then added a button for the electronic OD. The driveshaft yoke is unique to the automatics, but using a 240SX automatic (with KA24DE engine) will get you what you need.

X-Frame Mods:









Transmission tunnel modification:



Automatic shifter:



Other choices:

Z32 300ZX 5-speed RS5R30A



Many drifters have complained about the "weak" 5-speed transmission on 300hp+ drift cars, and have opted to to swap to a modified Z32 300ZX 5-speed transmission. These gear boxes are shorter in length than the 5-speed, have a remote shifter, reward facing starter, and are HEAVY, but they are bullet-proof. In my opinion, total over kill for the car.

This transmission does NOT bolt to the SR20-series engines and will require modifications such as a kit like this:

https://frsport.com/products/xcessive-n ... nissan-s13

Z33 6-speed Transmission CD09



The CD09 6-speed transmission found in 350/370Zs are probably one of the strongest RWD gearboxes that can be used with a SR20DE/T (with an adapter or bell housing swap). These will require MAJOR surgery to the X-frame, transmission tunnel, etc. but they have been done into the roadster chassis-- really suitable for 400hp+ applications with a LOT of tire.

[rbhenderson]

For the SR20-series engines, there are three main choices, and then two other alternatives.

Thanks for this! You're so fast I thought it was an older post I had missed for a second!

Will take me some time to digest it...

[Alvin]

Great summary Michael!

[spriso]

Thanks for the comments-- I'll keep flushing this out when I have spare time. With the S15 Silvia's arriving stateside in 2024, lots of those SR20DE's are going to be pulled out as the S15 chassis get upgraded to more powerful engines-- which will be good for Roadster owners.

I have a S15 engine which will be getting the tear down/clean reseal process this winter and I will be documenting that process as we turn a rather tired looking SR20DE into a jewel. Watch this space.

Michael

[Alvin]

Thanks for the comments-- I'll keep flushing this out when I have spare time. With the S15 Silvia's arriving stateside in 2024, lots of those SR20DE's are going to be pulled out as the S15 chassis get upgraded to more powerful engines-- which will be good for Roadster owners.

I have a S15 engine which will be getting the tear down/clean reseal process this winter and I will be documenting that process as we turn a rather tired looking SR20DE into a jewel. Watch this space.

Michael

I had no idea about the S15 coming of import age!

[rbhenderson]

Thanks for the comments-- I'll keep flushing this out when I have spare time. With the S15 Silvia's arriving stateside in 2024, lots of those SR20DE's are going to be pulled out as the S15 chassis get upgraded to more powerful engines-- which will be good for Roadster owners.

More SR20 inventory will be nice! Think it will drop the prices some?

Next topic I’m curious about when you have time is how you do the engine management, add on unit? Total new system? Really appreciate your willingness to put this info together for all of us to benefit from!

[Florida Roadster]

Not mine, just saw it while browsing.

https://www.facebook.com/marketplace/it ... 112l%22%7D