Jump to content
SAU Community

Recommended Posts

Hey guys,

Let me introduce myself. My name is Brett and I have just become the proud owner of a '98 R34 Skyline. As this is my first Skyline (or for that fact my first Nissan), I have very little knowledge about Nissan technologies, so I need your help.

Can someone tell me the difference between the RB25DE and the RB25DET engine (besides the obvious). I am looking to turbocharge the NEO 6 and was wondering whether parts of the DET would bolt onto the DE.

Also, has anyone turbocharged their R34. I would like to get as much information as I could regarding the matter (prices, parts, problems etc).

Thanks in advance

Brett

  • Replies 48
  • Created
  • Last Reply

Top Posters In This Topic

or alternativly, you could just purchase a bolt on turbo, but along with that theres alot of associated bits and pieces you need to get, and you'll prob find that it would end up being a more stressful and expensive procedure than just getting another r34 with a turbo.

It has a lot to do with A) how much will you lose on your car if you sell it B) The car you've got is a good example...why sell it to buy a questionable GT-t C) are you crazy enough to do it :P and D) do you like seeing people question the lack of factory gauges and say "but I can hear a turbo"

Seriously though...if you check the specs on the RB25DE Neo compared to the RB25DET Neo...you won't find much that the 2 don't share, even cams are almost the same unit 2ms exhaust duration seperate them both!

The R33 RB25DE and RB25DET are a whole new ballgame...different parts completely.

I found the whole process to be worth it in my eyes :D Luckily I've done all the hard work...and found out the hard way what needs to be done...so I can make it a fairly easy process if you decide to do it.

Dan

  • 1 month later...

yes but you wont be able to go much higher due to compression etc...

im my eyes it owuld be better overall to get a new rb25det and use that instead of adding on bits to your stock rb25de and using that. give your brakes, ecu etc will be non turbo based

  • 5 weeks later...

Some help here would be good. I have an R32 GTS4. It has an RB20DET at the moment wiha VG30 roller turbo. I want to have a 2.5L though, if the $ work out.

I can only choose from two types of engines due to my car being 4WD. a. RB20DE form an R33 GTS4 ($1200) or an RB25DET from a Stagea ($2,800). Obviously the first looks better to me because of the price, but if it's a shit engine it won't be worth it.

Can anyone tell me the differnce in these two engines. Brakes etc are not a problem as I already have an brake upgrade (R32 GTR).

I undertsand that the injectors are different 270 vs. 370. What are the other differences?

There is word that the R32/33 RB25DE valve springs are slightly softer than the RB20/25 springs.

Apparently this causes valve bounce over 15psi which generally occures at 6500rpm.

17psi valve bounce begins to occur around 5500rpm.

The higher the boost the earlier the valve bounce.

This causes the lifters to pump up which then makes the car idle lumpy until the lifters bleed back down.

I am unsure if this is a rare occurance where the valve springs have started to go soft or another issue regarding the valve spring tension when the valve is fully closed.

I have also heard a roumer that some stocker CA18DET's running high boost have this issue also. Fitting heavier valve springs fix's the problem. Any 1 care to confirm that for me?

I will find out with my RB25DE head soon as it uses the stock valve springs BUT the head has been rebuilt and all tensions checked etc..

Another bloke Darren also bought the same head as I & had his head rebuilt at the same place/time as I. He had to have his valves shimmed due to the valve spring tension not being great enough when the valves are closed. Mine were fine. I'm not sure 100% the exact terminology so don get picky on me. :D

As I said i'm not 100% as i've onyl heard of a few people having this problem.

Any one else care to share any problems they have had with the 'possibility' of the NA valve springs being softer than the T springs?

Maybe you could buy a whole engine with ecu and everything. Take the head off the one you have and put in a new head gasket to lower the compression then add all the bits from the other engine. After this you can sell the 2nd engine as is to someone else who has blown theirs up and doesn't need all the bits and pieces that you have pilfered.

Doing it from scratch the way you are gives you the chance to go straight to after market computer, exhaust, bigger injectors and fuel pump maybe, etc.

Hi guys, been following this thread (and 666dan's conversion) with much interests as I am trying to find a 4 door R34 as well.

Currently I am trying to choose between a RB25DET neo and a RB25DE neo. The non-turboed car is newer (by a year), comes with tiptronic controls and costs substantially less than the turboed car. However, since ultimately I am interested in getting a truboed car, a turbo conversion on the RB25DE is guaranteed should I choose to purchase it.

666DAN's comment on the NEO engines nearly having the same internals had me very excited. The reason being I currently have in possession all the neccesary components for turbo charging the car (intercooler, turbo, exhaust manifold) and it would work out cheaper for me to turbo charge the N/A car than to purchase the RB25DET car.

I have found the following information on the two engines while researching:

RB25DET NEO (GTT)

24-valve turbo EFI straight six

Capacity 2498

Bore x Stroke 86.0x71.7

Compression 9.0:1

Power 207kW @ 6400rpm

Torque 343Nm @ 3200rpm

(auto 333Nm)

Kerb Weight 1410kg (1440kg auto)

0-100 in 6.0 sec flat

0-400m in 14.2

(tested by reviewer)

RB25DE NEO (GT25)

24 valve EFI straight six

Capacity 2498

Bore x Stroke 86.0x71.7

Compression 10.0:1

Power 147kW @ 6000rpm

Torque 255Nm@ 4000rpm

Kerb Weight not stated

0-100 in 8.7 sec

0-400m covered in 16.3

Can someone clarify just exactly how "nearly the same" are the two engine internals? From the bore x stroke and the compression ratios its clear that the pistons between the two engines are not of the same size if both engine blocks are the same.

Are the engine block the same?

What about the crank, conrod (length and strength) and cams?

I'd say it the head design influencing the compression...as with the RB20DE Neo it's called a lean burn head, just an assumption there :)

Specs for most of the parts would be available in the Nissan parts CD...which has been mentioned for sale but no-one followed through on it.

There has been some info floating around, the NEOs are meant to have solid lifters...unlike the previous counterparts and actually have oil squirters in ALL models. I've been running the turbo on my engine now for 20,000k's with no related problems (the coil packs were just shite!) My engine has now done a total of 130,000ks and I'm confident of it making 200,000...we'll see cause I'm keeping her until she rusts away...or the trade-in price on a 350Z isn't too bad :D

I'm very keen to get to a dyno if anyone knows of any dyno days in the near future :)

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



  • Similar Content

  • Latest Posts

    • You just need to remove the compressor housing, not the entire turbo. I would not be drilling and tapping anything with the housing still on anyways. 
    • So, I put my boat on a boat. First of all, I'm going to come out and say it. Why is Tasmania not considered a holy goal, an apex that all road-legal modified cars go to, to experience? This place is an absolute wonderland of titanic proportions. If people are already getting club runs for once in a lifetime 30 person cruises to Tassy then I've never seemed to see it. It is like someone replaced the entire place with an idyllic wonderland for cars, and all of the people living there with paid actors who are kind, humble, and friendly. Dear god. After doing a lap of almost all of the place I've found that it's a great way to find out all of the little things that the car isn't doing quite right and a great way to figure it all out. All in all, I drove for 4 hours a day for a week and nothing broke. I didn't even need to open the engine bay. This is by all means a great success, but it has left me with a list of things to potentially address. I also now have a 3D printed wheel fitment tool which annoyingly hasn't got any threads in it to actually assemble it. I might be able to tape it together to check the sizing I actually want to use, but it'll likely involving pulling the shocks out to properly measure travel at least at the front, and probably raise the car while I'm at it, at least in the rear. I scraped on quite a few things and I'm not sure how else to go about it. I was taking anything with a bump at what felt like 89 degree angles. And address those 10 other tasks. And wash the car. God damn it is dirty. And somehow, the weather was perfect the entire time - And because I was on the top of Mt Wellington it turns out it was very much about to freeze up there. I did something I typically never do and took some photos up there in what must have been -10 and the foggy felt like suspended ice, rather than mere fog. If you own a car in Australia, you owe it to yourself to do it.
    • Damn that was hilarious, and a bit embarrassing for skylines in general 馃槀 vintage car life ey. That R33 really stomped. Pretty entertaining stuff
    • Hi, I have a r32 gtr transmission. Does any of you guys have an idea how much power it will hold with the billet center plate and stock gearset? At what power level and use did yours brake with or without billet plate? Thanks, Oystein Lovik
    • Saw this replica police car based on a Mitsubishi Starion XX parked next to a 'police box' (it's literally a box) in Hirohata, Himeji City in Hyogo prefecture the other day. It's owned by Morii-san who is a local Mitsubishi Starion enthusiast. According to a local radio station blog post, he always wanted to make a police car himself based on ones he saw in his favourite Manga comics.  As it's illegal to modify a car to look like a police car and drive on the road, Morii-san tried many times to get permission from Aboshi police station headquarters nearby. They refused initially by after they got tired of that they granted him permission. However, the car can only be displayed on private property and obviously can't be registered as long as the police livery is present. The car was completed at a cost of 1.5 million yen (US$ 10,000) in addition to the car cost. A location was chosen outside Hirohata Police box where the car can easily been seen from the street. Morii-san has two other Starion road cars, both widebody GSR-VRs.
  • Create New...