Dual Plenum And Turbo

[Nickzke]

hey guys, i want to turbo my Na RB25DE, would i need to change the plenum as seen below in the photo's? my Rb25DE motor has the dual one and the turbo engines are different. would it be better to get a custom made pipe with a BOV or get the rb25det plenum and bolt it into mine and get the stock crossover pipe with BOV ?

i heard if i do this it messes with the ecu and pistons 1&2 would be running insanely lean.

Thanks,

Nick

Edited January 9, 2011 by NicKzKe

[Moodles2]

Better off buying a RB25DET. NEO RB25DE has a compression ratio of 10:1.. too high for a turbo application, to put it simply I'd be worrying about ALL 6 pistons. http://www.skylinesa...pression-ratio/

[Nickzke]

yeash but it would cost me much more to drop an engine in it. compression would of dropped a little by now dont you think? cars done like 155,000km,

Nick

[tm_r33]

the compression may have dropped in the sense that instead of the maximum cylinder pressures being say 150 psi when the piston is at the top of compression stroke it may on a worn engine be 130 ish or slightly lower. this could mean either worn ring or valve not seating perfectly but to be honest that isnt gunna make shite all difference here.

its comp ratio.

and a compression ratio of 10:1 is getting up there for a petrol turbo application. a newly designed engine is going to be better at fighting early detonation but in my opinion an rb25 will not be ideal at 10:1 with forced induction. i think it will limit you severly in the amount of boost/quality of fuel you could run once turbo charged.

[Adriano]

I would put an r34 turbo and exhaust manifold on with a front mount, but you wont tbe able to run 20psi(unless on e85). What ecu are you planning on running

[Hanaldo]

Has been done. Plenty of people running reliably turbocharged DE engines. Fact remains... If you can´t afford to put an RB25DET Neo in then you can´t afford to turbocharge your motor.

Have been through this myself. Planned for a long time to turbocharge my DE Neo, but when I worked out that it would actually cost me more to convert that engine to forced induction than to put a much lower km 25DET Neo motor in I soon changed my mind. Don´t fool yourself it is no easy task to turbocharge your car. It requires much custom work, many dyno hours and a lot of frustration. All equating to requiring much money. And after all that, what do you have to show for it? A high km engine rather like a handgrenade, very much limited in how much power it can make; incredibly responsive is really the only benefit...

Anyway, if you are really keen to go through with this, I found a lot of useful info in this thread: http://www.skylinesaustralia.com/forums/topic/33407-how-to-turbo-your-na/ You might find an answer to your question in there. 666DAN and N-DAWG were both very helpful to me; given that both of them have turbocharged their NA R34´s, they could probably provide you with the answer.

[Samon]

As mentioned, there are plenty of us running reliably turboed DE engines... you've just gotta be smart about the cooling and boost... a FMIC is pretty much essential, and don't go trying to run 20PSI

Paying someone to do the work of turboing your DE would be expensive, as there's a fair bit of custom work required (depending on how much you change over)... ended up costing me about 2500 all up I think, but I was able to take my time buying all the bits I needed when they were cheap over a couple of months, etc, and did all the work myself.

In general, if your engine's in mint condition, then I'd say go for it, but if its already done 155,000KMs, you could be building a time-bomb

[GTScotT]

Turbo the DE with a minor alteration to an off the shelf intercooler kit, stock exhaust manifold and your selection of turbo.

I would say under 300rwkw to be maintained for reliability. I would aim for 260rwkw from a GT3071R .82 IW on 14psi.

[Nickzke]

thanks but im not asking should i turbo it or not, im asking what should i do? get a plenum off a rb25det to connect the crossover pipe with BOV or should i get a custom pipe made for mine. i appreciate the comments, but for now i just wanna turbo it and keep it less than 200rwkw.

[XRATED]

thanks but im not asking should i turbo it or not, im asking what should i do? get a plenum off a rb25det to connect the crossover pipe with BOV or should i get a custom pipe made for mine. i appreciate the comments, but for now i just wanna turbo it and keep it less than 200rwkw.

Don't bother swapping the manifolds...

[Adriano]

Cant see how fitting a turbo to the stock motor would cost anywhere near that of fitting a turbo motor. 155,000k is not high km, dont be fooled into thinking import motors/cars have 50,000km on them. As said stock turbo/exhaust manifold aftermarket dump pipe, aftermarket front mount, a set of neo turbo injectors (i have a set for $150 if you want) and a nistune. Should see 200rwkw easy at about 9psi.

[Tangles]

Neo engines with turbo and ecu start at around $1600

http://cgi.ebay.com.au/NISSAN-SKYLINE-R34-GT-RB25DE-NEO-ENGINE-PACKAGE-/110631425857?pt=AU_Car_Parts_Accessories&hash=item19c2259741

Id be buying the det engine as above

drop it in

sell off old parts

underpants

profit

[tm_r33]

i didnt realise alot of people turbocharged factory DE motors. i just would of thought 10:1 cr would of been a prick to throw forced induction into. though i may very well be wrong by the sound of it. what sort of boost are people with de+T running? to be honest ive been working on rb20det, rb25det for about 5 years now but i still havnt had to work on any naturaly asperated rb engines lol. i imagine a 10:1 rb25de+T would be a pretty responsive unit even if limited up the top end.

[Samon]

i didnt realise alot of people turbocharged factory DE motors. i just would of thought 10:1 cr would of been a prick to throw forced induction into. though i may very well be wrong by the sound of it. what sort of boost are people with de+T running? to be honest ive been working on rb20det, rb25det for about 5 years now but i still havnt had to work on any naturaly asperated rb engines lol. i imagine a 10:1 rb25de+T would be a pretty responsive unit even if limited up the top end.

The higher CR of the DE+T certainly makes it feel more responsive than the equivalent DET, but it could also be a lot of placebo

9-10 PSI is where I hit the limit of detonation, but that's probably also a good thing to keep the stock turbo from exploding

[Hanaldo]

Cant see how fitting a turbo to the stock motor would cost anywhere near that of fitting a turbo motor. 155,000k is not high km, dont be fooled into thinking import motors/cars have 50,000km on them. As said stock turbo/exhaust manifold aftermarket dump pipe, aftermarket front mount, a set of neo turbo injectors (i have a set for $150 if you want) and a nistune. Should see 200rwkw easy at about 9psi.

You´re ignoring dyno time and labour required to turbocharge a DE. If you could do all the work yourself then it would work out cheaper, but then I´m sure you would have the know-how to swap in a DET motor and hence you wouldn´t really make it any cheaper.

You gotta keep in mind things like tapping the block for the turbo oil feeds. Not too mention you want the RB25DET gearbox to go with because the factory 20DET box is less reliable than the high CR engine, and all the custom work to make the driveshaft fit. Then you couldn´t simply NIStune your car because it isn´t compatible with the DE ecu (as I understand it anyway, correct me if I´m wrong), you would have to get either a full stand alone ecu or a DET ecu and a lot of work to NIStune the engine with that because even with the turbo there would be things the ecu expects that just aren´t there.

It´s not as simple as pulling the stuff off the DET motor and putting it on the DE motor.

i didnt realise alot of people turbocharged factory DE motors. i just would of thought 10:1 cr would of been a prick to throw forced induction into. though i may very well be wrong by the sound of it. what sort of boost are people with de+T running? to be honest ive been working on rb20det, rb25det for about 5 years now but i still havnt had to work on any naturaly asperated rb engines lol. i imagine a 10:1 rb25de+T would be a pretty responsive unit even if limited up the top end.

There is someone on this forum making ~285rwkw at around 20psi on a GT3076R if memory serves.

[WYTSKY]

i didnt realise alot of people turbocharged factory DE motors. i just would of thought 10:1 cr would of been a prick to throw forced induction into. though i may very well be wrong by the sound of it. what sort of boost are people with de+T running? to be honest ive been working on rb20det, rb25det for about 5 years now but i still havnt had to work on any naturaly asperated rb engines lol. i imagine a 10:1 rb25de+T would be a pretty responsive unit even if limited up the top end.

19-20psi rb25de+t

There is someone on this forum making ~285rwkw at around 20psi on a GT3076R if memory serves.

Me

look, my opinion on this is If the non turbo motor is healthy and you know it is - compression test etc, you should be fine.

The only reason I turboed mine was that it was a GTS4 and at the time i didn't know you can get turboed 25 4wd motors from stageas, but still, the amount of wiring looms and changeover stuff I believe would be a massive pain.

cost wise depends greatly on your mechanical skill but i would say with doing alot of the mechanical work yourself on a budget with a few unforseen headf*cks about $1500-2000 to +T the de, similar price for just buying a new motor.

The advantage of getting a turbo motor to put in is it is hopefully complete and ready to go, downside is you have no clue if it actually is a decent motor and how much time it would take to put in and wire up

the advantage of turboing your current de motor is you know how the motor drives, hopefully know a bit more history about it and you dont have to change much electronically, just ecu and afm.

oh and the end result of the higher compression that everyone thought was just going to blow my motor within a month means i have full boost (19-20psi) with the 3076r at 3000rpm is nice.

[R31Nismoid]

don't forget to mention a .63 rear

[WYTSKY]

don't forget to mention a .63 rear

yes yes, it has an ass the size of a super models...

[Nickzke]

I'm not looking for high power +200rwkw for the moment i just wanna turbo it, and keep it at 7psi see how it goes before i decided to do anthing. the history of the motor is pretty good, had the car for 3 yrs had nothing wrong with it apart from changing the coils.

any other opinions on what should i do about the plenum?

Nick

Edited January 10, 2011 by NicKzKe

[bubba]

Any chance you could take some more pics of that plenum for me please mate? didn't know Nissan made such a thing!

IMO, if you were to +T the DE, I would use as much of the DET stuff as possible.. try score the whole intake/exhaust setup that someone is selling cheap after they upgrade their own bits.