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View Full Version : The best possible discussion about Nissan RB25


Kingtal0n
05-19-2018, 01:51 AM
I Know you all wanted to hear this

but

my friend just bought an R32 GTS RB20 Auto and one minute we are looking at how crisp and perfect the undercarriage looks, how amazing the girl owned the stock RB20 sounds, what a perfect daily &c&c

The next minute, like a week later, I pull up and the car is pulled apart for paint and we are discussing size turbo and what transmission to use for a local highway pulls kind of car.

The engine is already at the machine shop and there is a huge pile of parts in a corner.


So the question of the day is what turbo what trans. I'm explaining a TH400 is probably the most reliable of the 3-speed options but its a significant drivetrain loss on such a small displacement engine. A huge shame.

Since it isn't using a T-brake and drag slicks (just DR prolly 555 style) I was hoping there was a better trans option. I figured he could try a TH350 maybe at the very least. Or he was wondering stock RB25 trans with some parts changed could do the job would be GREAT. I never did an RB auto car though so no clue. I wish we can start there if any volunteer knows which auto trans is likely to survive the 500~ torque/hp this thing will produce and best mates an RB25. I am guessing early RB25 block.

And if you know what control the OEM RB20 ECU has over the RB20 transmission. Like if it adjusts shift pressure or just provides 1-2-3-4 gears.

smoked240
05-19-2018, 04:27 PM
From what I remember when doing my RB swap years ago, the rb25det 5 speed is a rather strong transmission and can take some power. Not sure around how much anymore. Keep good fluid in it and inspect accordingly.
Only downside is limited parts for them. I have not checked to see on availability for a rebuild on the manual yet.

I love the simplicity of a manual transmission. Have you ever rebuilt an auto?( Or said friend) It's not a horrible job but time consuming and picky. One wrong step and it potentially can be trash. Especially if you plan to throw some big power at it.

I have a 6266 on mine but has been needing a tune for 3 years so It only has 50 miles on it. I plan for a compound setup one day which would put me around 680whp.

Kingtal0n
05-19-2018, 06:01 PM
From what I remember when doing my RB swap years ago, the rb25det 5 speed is a rather strong transmission and can take some power. Not sure around how much anymore. Keep good fluid in it and inspect accordingly.
Only downside is limited parts for them. I have not checked to see on availability for a rebuild on the manual yet.

I love the simplicity of a manual transmission. Have you ever rebuilt an auto?( Or said friend) It's not a horrible job but time consuming and picky. One wrong step and it potentially can be trash. Especially if you plan to throw some big power at it.

I have a 6266 on mine but has been needing a tune for 3 years so It only has 50 miles on it. I plan for a compound setup one day which would put me around 680whp.

haha, yes I did rebuild a 700R4 back in 2002. You are right about them autos being picky.

But I am not building/doing anything here. My friend does everything himself.

I am just trying to help him sort out the best options. He won't be doing any trans internal work himself either; it would need to be a place that specializes in the trans. So if you or anybody knows a place that specializes in RB25 auto-builds or something like that... it would be ideal.

I am going to tune on an E85 flex-fuel platform (haltech prol) so before I send him off to get a TH400 adapter etc... I am just hoping for some more economical options (clarification: not cheaper, just better on fuel and drivetrain loss).

EnnEssEnnKAT
05-19-2018, 08:18 PM
I thought the rb26 was the engine offered in the r32 gt-r what engine is in there

Sent from mTalk

Kingtal0n
05-19-2018, 10:13 PM
I thought the rb26 was the engine offered in the r32 gt-r what engine is in there

Sent from mTalk


This is a R32 GTS

https://s19.postimg.cc/4e2a6fu4z/IMG_0857.jpg

Comes with RB20 powa

Apparently these are getting super easy to get. The guy who sold it was bringing a whole bunch of them ove.

derass
05-19-2018, 10:16 PM
So its a GTS-t. Okay. That clarifies things. Don't know why you called it a GT-R in the OP.

Kingtal0n
05-19-2018, 10:56 PM
LOL Habit. I mean, how many times I put GT-R, over 9000.

How many times in my life have I written GT-S... maybe like 2 times. my brain refused to switch.