Jump to content
SAU Community

Rb25det To Rb Non-turbo?

Dorigecko

By Dorigecko,
in Engines & Forced Induction

 Share

Recommended Posts

Dorigecko Proficient

Dorigecko

Posted
Posted

Hey guys, I'm wanting to rebuild my RB25DET, but seeing as how a) it'll take some time and b) it's a daily driver.

What needs to be changed over in a conversion like that? I've got a standard computer and loom, RB20 gearbox, and a 3" exhaust *gulp* and am wanting to go a bog-stock RB30. I've had a soft-spot for NA for a while.. so yeah.

Any help would be awesome, thanks.

Link to comment
https://www.sau.com.au/forums/topic/287736-rb25det-to-rb-non-turbo/
Share on other sites
N-DAWG Mentor

N-DAWG

Posted
Posted

You're rebuilding your current engine as in strapping on a RB30 block? Or you want to go either RB25DE or RB30DE? There was/still are a few listings on ebay for a RB25DE reconditioned block, RB25DE 10:1 CR Pistons, the crank and I think a few other bits.

Dorigecko Proficient

Dorigecko

Posted
  • Author
Posted

No no. I'm not doing anything flash, just wanting to bust in an engine I can destroy and do it fairly simply, while building my RB25DET to factory standards (yes, that's right. no forged internals)

The idea is to drop in an RB30E or RB25DE while retaining the RB25 loom and all that, so it's a simple conversion back to the 25. but in the mean time, i'm wondering exactly what needs to be changed to run the RB30E.

I gather that i'll need to run the RB30 computer, but is there any similarity that I can utilize between the 25 and 30 which would allow me to retain the 25 loom?

elsewise, it shall be a bigger job than anticipated.

mad082 Grand Master

mad082

Posted
Posted

i would be checking on the legal side of things of just putting in a stock rb30e. i don't know if you will be able to do it because you are fitting an older motor to a newer car.

it may be easier to just buy a second hand turbo motor and dropping that in while you do the rebuild. should be able to pick one up reasonably cheaply since you don't need to buy the gearbox, loom (if you get the same series as your current motor), etc. or if your current engine is still going but you just wanted to rebuild it, leave it in there and rebuild the motor you buy. saves the hassle of changing motors twice

SKiT_R31 Experienced

SKiT_R31

Posted
Posted
I gather that i'll need to run the RB30 computer, but is there any similarity that I can utilize between the 25 and 30 which would allow me to retain the 25 loom?

nup, completely different.

You best bet is RB25DE, which as its only temporary, will run fine even n/a with turbo gear (ecu/loom/sensors/injectors etc) or if you get one with injectors etc, using the N/A ecu on the det loom will be fine, the car will drive perfectly.

Dorigecko Proficient

Dorigecko

Posted
  • Author
Posted

pretty sure that's a retarded response. no offense, but check location next time.

thinking i'll wait for another 25det to show itself to me. either build that one or bung it in. problem solvered. thanks dudes.

PandaR33 Enthusiast

PandaR33

Posted
Posted
pretty sure that's a retarded response. no offense, but check location next time.

thinking i'll wait for another 25det to show itself to me. either build that one or bung it in. problem solvered. thanks dudes.

you dont have a location set mate.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • MBS206
      What brakes on R34 GTT(Europe)

      By MBS206 · Posted

      For DBA, check out their guide table here. https://dba.com.au/wp-content/uploads/2023/01/Direct_Replacement-Guide-2021.2.pdf   Additionally they have some other guides and info on how to make sure you choose the right pad.
    • GTSBoy
      What brakes on R34 GTT(Europe)

      By GTSBoy · Posted

      Sorry, just assumed that talk of coloured pads meant EBC red/green/yellow/shit stuff. I don't know the DBA pads, but it's a reasonable bet that they will be OK. DBA make good stuff generally. Those 4000 series rotors I linked to are very good. I may well replace the RDA rotors I have with those when required.
    • joshuaho96
      Unpeeling the Orange

      By joshuaho96 · Posted

      The average previous owner for these cars were basically S-chassis owners in the US. Teenagers or teenager-adjacent. I often tell people that neglect is easier to fix than something that was actively "repaired" by previous owners.
    • MBS206
      Mistakes were made, my R34 Story

      By MBS206 · Posted

      All I hear is ROADTRIP!
    • sunsetR33
      Unpeeling the Orange

      By sunsetR33 · Posted

      Update 3: Hi all It's been a while. Quite a lot of things happened in the meantime, among other things the car is (almost) back together and ready to be started again. Things that I fixed or changed: Full turbo removal, fitting back the OEM turbo oil hardlines. Had to do quite a bit of research and parts shopping to get every last piece that I need and make it work with the GT2860 turbos, but it does work and is not hard to do. Proves that the previous owner(s) just did not want to. While I was there I set the preload for the wastegates to 0,9bar to hopefully make it easier for the tuner to hit the 370hp I need for the legal inspections that will follow later on. Boost can always go up if necessary. Fitted a AN10 line from the catch can to the intake hose to make the catchcan and hopefully the cam covers a slight vacuum to have less restrictive oil returns from the head and not have mud build up as harshly in the lines and catch can. Removed the entire front interior just shy of the dashboard itself to clean up some of the absolutely horrendous wiring, (hopefully) fix the bumpy tacho and put in LED bulbs while I was there. Also put in bulbs where there was none before, like the airbag one. I also used that chance to remove the LED rpm gauge on the steering column, which was also wired in absolute horror show fashion. Moved the 4in1 Prosport gauge from sitting in front of the OEM oil pressure gauge to the center console vents, I used a 3D printed vent piece to hold that gauge there. The HKB steering wheel boss was likely on incorrectly as I sometimes noticed the indicator reset being uneven for left vs. right. In the meantime also installed an airbag delete resistor, as one should. Installed Cube Speed premium short shifter. Feels pretty nice, hope it'll work great too when I actually get to drive. Also put on a fancy Dragon Ball shift knob, cause why not. My buddy was kind enough to weld the rust hole in the back, it was basically rusted through in the lowermost corner of the passenger side trunk area where the wheel arch, trunk panel and rear quarter all meet. Obviously there is still a lot of crustiness in various areas but as long as it's not rusted out I'll just treat and isolate the corrosion and pretend it's not there. Also had to put down a new ground wire for the rear subframe as the original one was BARELY there. Probably a bit controversial depending on who you ask about this... but I ended up just covering the crack in the side of the engine block, the one above the oil feed, with JB Weld. I used a generous amount and roughed up the whole area with a Dremel before, so I hope this will hold the coolant where it should be for the foreseeable future. Did a cam cover gasket job as the half moons were a bit leaky, and there too one could see the people who worked on this car before me were absolute tools. The same half moons were probably used like 3 times without even cleaning the old RTV off. Dremeled out the inside of the flange where the turbine housing mates onto the exhaust manifolds so the diameter matches, as the OEM exhaust manifolds are even narrower than the turbine housings as we all know. Even if this doesn't do much, I had them out anyways, so can't harm. Ideally one would port-match both the turbo and the manifold to the gasket size but I really didn't feel up to disassembling the turbine housings. Wrapped turbo outlet dumps in heat wrap band. Will do the frontpipe again as well as now the oil leak which promted me to tear apart half the engine in the first place is hopefully fixed. Fitted an ATI super damper to get rid of the worn old harmonic balancer. Surely one of the easiest and most worth to do mods. But torquing that ARP bolt to spec was a bitch without being able to lock the flywheel. Did some minor adjustments in the ECU tables to change some things I didn't like, like the launch control that was ALWAYS active. Treated rusty spots and surface corrosion on places I could get to and on many spots under the car, not pretty or ideal but good enough for now. Removed the N1 rear spats and the carbon surrounding for the tailpipe to put them back on with new adhesive as the old one was lifting in many spots, not pretty. Took out the passenger rear lamp housing... what do you know. Amateur work screwed me again here as they were glued in hard and removing it took a lot of force, so I broke one of the housing bolts off. And when removing the adhesive from the chassis the paint came right off too. Thankfully all the damaged area won't be visible later, but whoever did the very limited bodywork on this car needs to have their limbs chopped off piece by piece.   Quite a list if I do say so myself, but a lot of time was spent just discovering new shit that is wrong with the car and finding a solution or parts to fix it. My last problem that I now have the headache of dealing with is that the exhaust studs on the turbo outlets are M10x1.25 threaded, but the previous owner already put on regular M10 nuts so the threads are... weird. I only found this out the hard way. So now I will just try if I can in any way fit the front pipe regardless, if not I'll have to redo the studs with the turbos installed. Lesson learned for the future: Redo ALL studs you put your hands on, especially if they are old and the previous owners were inept maniacs. Thanks for reading if you did, will update when the engine runs again. Hope nothing breaks or leaks and I can do a test drive.
×
×
  • Create New...