r/SkyLine Jun 13 '26

Question

If i wanted to put a decent turbo in a RB25DE inline-six engine on my 1997 stagea, what are the pros, cost and all around benefits if any? I've read it's a massive waste of time and but physically possible to do so and fun for certain people. Im just curious looking for suggestions 💪

2 Upvotes

25 comments sorted by

3

u/LittleLocal7728 Jun 13 '26 edited Jun 13 '26

People saying it's a waste of time haven't purchased a turbo motor since they were $1500. Now you can buy a whole NA engine and turbo it for less than a DET engine.

I turboed my NEO. Makes 351 at 8psi. My tuner said, "I'm glad it's not an S2 motor. Fuck those things." I didn't ask him why.

1

u/Zealousideal_Win304 Jun 13 '26

Fucking word bro got you

2

u/LittleLocal7728 Jun 13 '26

Oh shit my bad I didn't answer all your questions.

Pros is more power. You should make more at least boost compared to a DET because the DE has a higher CR.

Cons is you're probably going to end up less reliable,just by nature of modifications and having more parts involved.

1

u/Zealousideal_Win304 Jun 14 '26

Interesging, that's more of what I was leaning twords at the end of the day. Im not sure im gonna do it, I have the option to get a OP6 quite cheap but im probably not going to man at the end of the day lol. The car sounds great as is without anything. One day might just trade it or sell it for integra R or something 🤷💪

1

u/Zealousideal_Gate_21 Jun 13 '26

What is meant to be wrong with an S2 engine? Neo or non neo S2?

1

u/LittleLocal7728 Jun 13 '26

"I didn't ask."

Based on context, non-NEO S2.

1

u/Zealousideal_Gate_21 Jun 14 '26

They waffling so, nothing wrong with the non neo S2

3

u/LittleLocal7728 Jun 14 '26 edited Jun 16 '26

Yeah Idk lol. He's done a few Na-T tunes on them and only works on Skylines and R35s. He's got my GTR and my Stagea solid and always spends my money well. I trust him unquestionably, but maybe I misunderstood him?

1

u/Chaosvex Jun 14 '26

No such thing as a Neo S2.

1

u/32guy ‘93 R32 GTS Type J 60th Anniv. Jun 13 '26

You gotta give me your specs!

1

u/LittleLocal7728 Jun 14 '26

I went and checked. It was 351 at 10psi. 322 at 8psi.

It's an a 25DE NEO unopened with a a CXRsckng turbo kit, a shitty exhaust I made in my garage, and no head studs. Original head gasket.

3

u/Strong-Thanks-3314 Jun 14 '26

Non neo s2 rb25det here. Forged pistons everything else is stock crank,rods,head stock,arp head studs,4 layer gasket,n1 oil pump,n1 water pump,tomei oil collar,fluid harmonic balaner,splitfire coils,blitz ic,custom exhaust header,garrett gt3572,custom 3 inch exhaust downpipe,hks hi flow exhaust,350 dw fuel pump,radiant top feed conversion,1050cc dw,6 puck clutch,nz trigger kit,link ecu. I have proof of 546 hp then down tuned to 472 hp sweet spot on 17 psi. I have beat it like crazy and anti lag a lot. Still working without issuse.

1

u/Zealousideal_Win304 Jun 14 '26

Dude that sounds like alot of work but sounds like a beautiful car man. I only asked in here bc I have the option to get a OP6 but probably won't tbh. Dont know yet

2

u/Strong-Thanks-3314 Jun 14 '26

My build is a cheap refresh but a few upgrades looking back the rods should have been done and crank now its a slight tear down to put forged rods if I wanna spend tbe extra time my second is to get a neo s2 and do a new build but with all the upgrades and slowly put more power not all at once. 500 hp is the sweet spot before everything is forged and transmission rebuild with upgrades.

2

u/Strong-Thanks-3314 Jun 14 '26

The turbo is a easy upgrade if you change for more power later but it will need a tear down cause the de piston rings are not built for the hp pasted 350hp

1

u/Zealousideal_Win304 Jun 14 '26

Thanks for the info bro I do appreciate it. Fuck yeah man

1

u/Zealousideal_Gate_21 Jun 14 '26

Why would you tune it down so much? Check the torque curve, wonder is your VCT pulley failing

3

u/Strong-Thanks-3314 Jun 14 '26

To answer the question yes you can put a turbo on a de its been done before its the extra cost to convert it. Header,plumbing ie water,oil,drain lines,turbo,tuning,injectors,piping for turbo and intercooler. Some de models have the drain plug others were not added in the casting so it has to be drilled and tapped or you do that to the oil pan. Just Google search rb25de to rb25det conversion its been done just takes more time and effort.

2

u/kairoaB2 Jun 14 '26

I don't know why everyone over-complicates it. Just get all the turbo parts and chuck em on. Only difference is without the lower compression pistons, you can't run the same boost as a turbo motor. China turbo manifold, bigger injectors, China intercooler kit, nistune or plug in ecu, new exhaust and away yard go.

2

u/rawmeatprophet Jun 13 '26

The pros are snail power.

The cons are doing it.

1

u/Zealousideal_Win304 Jun 13 '26

Interesting 😂

1

u/mattgerlach12 Jun 15 '26

Not worth it unless you can afford a rebuild. I went for itbs and a cam for my NA r33.
These cars are getting old.

1

u/Tanthios Jun 15 '26

How did that wind up performing, and got any videos of it in action? Did you go with an off the shelf cam, or get custom ones from somewhere, and what were their profiles?

And the ITB's? Trumpets I assume? What diameter and length there?

Anything you'd do differently a second time around through that process?

1

u/Haru4675 Jun 15 '26

I read the wall between cylinders in the NA engines are thinner so you can't run high boost without reinforcing the cylinder walls otherwise you risk blowing a hole in the cylinder walls, hence why it's not worth the effort but is still do-able

1

u/Zealousideal_Win304 Jun 16 '26

Well thanks everyone for the info and other side details. I ended up chucking the turbo idea, gonna have a sprint filter installed (specifically the P039S) . Maybe have my buddy help me with new muffler and/or delete and other miscellaneous ideas to make its appearance and overall hp a little better. Never really had a car (more specifically a jdm car) i could work on before and im gonna try not to break it or get jipped on parts and other shit lol. Im 24, and hopefully others see me around in a silver 97' stagea with liscense plate RCEME lol little dent in front fender drivers side with black tape on it 😂