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Difference between RB25DE and RB25DET

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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


Posted 31 March 2004 - 09:09 PM

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talk to 666DAN he just did this conversion, search for it he did a huge write up in this section.

Posted 31 March 2004 - 09:11 PM

NEW PB!! 10.17 @ 132mph Saving for a Big Block Chevy!!
Read about it here....Here

Blacky Evolution:
15.8 @ 88mph RB25DE
[email protected] RB25DE Nitrous
[email protected] VH45DE
12.8 @ 109mph VH45DE Nitrous
10.38 @ 132mph

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sell it and buy the turbo charged model, probably work out cheaper. speak to dan666, he just converted his 34 N/A to turbo

Posted 31 March 2004 - 09:11 PM

Have considered an engine swap but as the engine only has 12k on it, seems pointless. Also I know the history of the engine and its condition, so why waste money buying an engine that has been flogged??

Posted 31 March 2004 - 09:36 PM

he means sell the car and buy a turbocharged model (car)

i think?

Posted 31 March 2004 - 10:37 PM

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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.

Posted 31 March 2004 - 11:05 PM

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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.


Posted 01 April 2004 - 01:14 PM

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sell it and buy a good gt-t.

Posted 01 April 2004 - 04:08 PM


Thanks 666Dan. Much appreciated

Posted 01 April 2004 - 09:52 PM

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hey bro. i have a R33 RB25DE and i added a R32 turbo. i only had to change the injectors. at the moment i run 7 pound boost. i went from 100kw to 140kw quite happly.

Posted 10 May 2004 - 08:34 PM

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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

Posted 13 May 2004 - 09:19 PM

  • Location:Petersham, Sydney
  • Car(s):1993 R32 GTS4
  • Real Name:Ben
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?

Posted 12 June 2004 - 12:44 PM

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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?

Posted 12 June 2004 - 01:58 PM

Still nothing like quite like a Jap Car.

im not really sure on the RB's

but my CA with stock internals runs out to 8500rpm & 16psi boost quite happily!

i havent run into any valve bounce problems

Posted 15 June 2004 - 02:00 PM

R34 GTT Daily

“Jetstar 6162, for noise abatement turn right heading 095 Degrees.”
“Centre, we are at 35,000 feet. How much noise can we make up here?”
“Sir, have you ever heard the noise a 747 makes when it hits a 737?”

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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.

Posted 15 June 2004 - 02:16 PM

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My high-compression weapon is going great-guns...hopefully will have some quarter mile times next Wednesday :P

Posted 15 June 2004 - 03:37 PM

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Posted 15 June 2004 - 03:44 PM

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Slap her on LPG and uppppp the boost.. :D

Posted 17 June 2004 - 07:29 PM

Still nothing like quite like a Jap Car.

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:

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)

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?

Posted 20 June 2004 - 11:55 PM

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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 :)

Posted 21 June 2004 - 01:47 PM

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