rb20 to rb25 in my s14

[DoctorD]

Ok so i have a rb20 with a rb25trans in my s14, but i want more power and want to do a rb25 swap. I also want to put a gt30, side mount intake, 750 or so injectors and a nice tune to try n reach 400 to 450 hp is that possible ? with that type of set up and what else do i need to do the swap as in doo i need a new harness? I want to run @ 18psi. What size fuel pump should i get and what size throttle body should i get? What will be the best way for me to tune this set up? Any advice is appreciated thanks.

[DoctorD]

No one has any advise?

[TimTurboZ]

Just get the aftermarket intake manifold and a Q45 TB like everyone. Im not 100% but I'm pretty sure yes you need a new harness (which hopefully would come with your motor, if not they are like $100) The motor mount kit only is different if you are going from a 20 transmission to a 25 but you already have a 25 transmission in place so your mount setup now will be fine. Yeas your 400whp goal should be easy with a tune stock bottom end should handle it fine (ppl will cross hairs on that prolly but if you wanna push OEM internals it's been done)

As far as fuel system look at others builds

GL

[chad b.]

Will your motor not make 400whp for less money than it takes to actually buy another motor and do another swap? If I were only wanting 400whp and another motor, I'd get an sr20. They're a hell of a lot cheaper, and parts are more readily available with more stateside R&D. An sr20 red top with a set of cams and a 2871RS will make that power on stock bottom end all day long. That's just me being practical.

[DoctorD]

Will your motor not make 400whp for less money than it takes to actually buy another motor and do another swap? If I were only wanting 400whp and another motor, I'd get an sr20. They're a hell of a lot cheaper, and parts are more readily available with more stateside R&D. An sr20 red top with a set of cams and a 2871RS will make that power on stock bottom end all day long. That's just me being practical.

rb20s are old and will break alot just like if i made a sr20 make 400whp, if i get a rb25 ill make 400whp @like 14psi and be safe, plus then when i get money to build it ill make like 600plus whp.

[TimTurboZ]

RB's are plenty easy to get parts for, motor accessories can be swapped (Alternator, PS), plenty of aftermarket and OEM parts up for grabs online, just not in your friends backyard like SR's. Initial cost may be a bit higher but the motor is cheaper so really it semi balances out. Also a RB25 trans is like having a R-154 vs a 20's or SR's KA styled weakness. So you get a way better deal buying a 25 series 1 vs a red/blacktop s13 sr and s14 sr. I'd say a Series 2 is better than a S15 SR or comparable (tho you definitely have a better transmission)

I think more than 450ish WHP range is where the money spent on an SR would easily make you much more on a 25. for quick plenty of power for drifting a SR is cool but I'll take all the plus's RB's have to offer