s2 rb25det engine swap into my gtst

[cschepp]

I will be putting in this motor shortly and I am wondering what kind of problems i will run into. I am also looking for some suggestions to make this swap as easy as possible.

Now i will have a shop to do it at as my buddy and I have recently found a shop, so i will have tons of space to do this!

Please feel free to provide feedback as everyones info will be appreciated!

Thanks, Chris

[kyles_r32]

if your putting the s2 tranny in you will have to make a custom drive shaft and im not to sure about motor mounts

[cschepp]

Motor mounts will work and as far as the drive shaft goes I can use a rb25 driveshaft right? if not i would be interested in knowing why i wouldn't be able to. But definately noted!

[Fairladyz]

You supposed to be ok, just have to hammer your floor where your tranny goes in, You need more space if i remember correctly.

[cschepp]

well.......

You supposed to be ok, just have to hammer your floor where your tranny goes in, You need more space if i remember correctly.

Thats makes sense because that freaking tranny is so big compared to the rb20 tranny. That sucks though. I'll have to get someone else to do it when i'm not there. I couldn't take a hammer to the car even if i tried.

Keep up the feedback every little bit helps. Thanks Fairladyz

[judasentinel]

No you dont need to hammer anything to make the RB25 tranny fit. There is ample space for it in your car. And no, you cannot use the RB25 driveshaft either. It is a tad too long. Plus, RB25 motor mounts wont work either. You will have to use your RB20 motor mounts.

If you are like most GTS-T owners with an M/T car, the tranny crossmember holes wont match up either when you use an RB25 tranny crossmember.

I have done 3 swaps on my car in the last 4 years, and two of them were RB25s. Fairly straightforward, but you need some custom work done, eg: getting an RB25 yoke fitted onto an RB20 driveshaft and then balancing the driveshaft with the RB25 yoke.

If I remember correctly, I had posted a full length DIY on the RB25 tranny swap in a GTS-T. Search for it. It has some useful info for you to use.

S2 RB25 coils also seem to be different, if I remember correctly. What ECU will you be using? If you plan on using the RB25 ECU, then you will need to do some custom wiring as well, to make it work with your dash harness. If you use the RB20 ECU (like I did), you will need to find a way to run your NVCS.

[joecrack]

yes just do what juda said .
use your rb20 ecu
run a window switch for your nvcs
get a drive shaft made.
rb20 engine mounts.
its pretty straight forward.

[cschepp]

ok sounds good, couple questions though!

No you dont need to hammer anything to make the RB25 tranny fit. There is ample space for it in your car. And no, you cannot use the RB25 driveshaft either. It is a tad too long. Plus, RB25 motor mounts wont work either. You will have to use your RB20 motor mounts.

If you are like most GTS-T owners with an M/T car, the tranny crossmember holes wont match up either when you use an RB25 tranny crossmember.

I have done 3 swaps on my car in the last 4 years, and two of them were RB25s. Fairly straightforward, but you need some custom work done, eg: getting an RB25 yoke fitted onto an RB20 driveshaft and then balancing the driveshaft with the RB25 yoke.

If I remember correctly, I had posted a full length DIY on the RB25 tranny swap in a GTS-T. Search for it. It has some useful info for you to use.

S2 RB25 coils also seem to be different, if I remember correctly. What ECU will you be using? If you plan on using the RB25 ECU, then you will need to do some custom wiring as well, to make it work with your dash harness. If you use the RB20 ECU (like I did), you will need to find a way to run your NVCS.

I have seen your diy and man you worked in a tight space man, as long as you have beer it's ok i guess. I already have the driveshaft worked out. As far as the crossmember goes can i still use my rb20 crossmember for my m/t???? If so that would be great. As for the ecu i will be using i actually bought a power fc that i plan to manage and tune the car.

Guys I really appreciate the info please keep it coming. I want to get all the snags worked out before tackling this swap!

Judasentinel thanks for all the info man!

[BrianV8]

For the cross member i used the rb20 one and it didn't line up either, i just slotted the 4 holes into 2 big holes on each side and just run 2 bolts that u can fit. Call her done.

As for the driveshaft here is a little secret i'll let you guys in on, 91 Nissan 300zx N/A 2+2 5speed 1 piece driveshaft bolts right up. No custom nothing!!.

[Skym]

That's good to know.

Can run a early Z32 ECU (can fit EPROM socket like R32 ECU and has VVT control) with repinning of ECU plug (or use adaptor loom and do the pin changes on adaptor loom plugs). Then fit Nistune to Z32 ECU with R33 RB25DET maps.

Similar to what was done on this N/A RB25DE powered R33 -

http://www.youtube.com/watch?v=UyDWsDmYejA

[judasentinel]

I am one of those very very few fortunate ones whose car was originally an A/T. The holes for the A/T car line up perfectly with the RB25 tranny crossmember, so in my case I had to do absolutely nothing.

Do not forget to use RB20 motor mounts. RB25 ones dont work.

Since you are using Power FC, I am not sure if it would give you the capability to use your NVCS. Top be perfectly honest, after having driven four types of RB engines on my car (RB20DET, RB25DE, RB25DET, and RB26DETT), I can tell you from experience that going the RB26DETT route is almost as simple as going for RB25DET, yet you see wayyyyy nmore power somehow, perhaps due to the twin turbos. I found the RB25 to be not as rev happy and it seems like a mule compared to the godzilla motor. There aren't many GTS-Ts with RB26 in them, but man is it worth it!!!!!! Despite having a 90 compression in one of the cylinders, my car still can give me a whiplash.

[Skym]

I think they use a S13 cross member (don't know if it's manual or auto cross member, but they should be the same) when converting to RB20DET manual transmission on R32 auto chassis, so that could be the other mod that needs to be done.

[cschepp]

nvcs? Just want to know what that stands for......

And are you saying that i shold go with the auto crossmember? Anyone have one?

[RSi]

yes just do what juda said .
use your rb20 ecu
run a window switch for your nvcs
get a drive shaft made.
rb20 engine mounts.
its pretty straight forward.

You will have to rewire the S2 ignition to S1 for the 20 ecu to work...

[RSi]

nvcs? Just want to know what that stands for......

And are you saying that i shold go with the auto crossmember? Anyone have one?

The cam timing.