Jump to content
SAU Community

Recommended Posts

First time posting, i would just like to thank you in advance for any help you have to offer. I purchased a rb20de Neo from a 1998 R34, I have had a difficult time finding any info on the US forums, seems i have a very odd engine. From what I have read, it looks like the engine never really made it to Australia either, but you guys seem way more informed when it comes to anything RB and would be my best bet for finding info.

I'm trying to build a high comp rb20de Neo engine and wanted to know a few things to calculate compression, like connecting rod length, deck clearance, cylinder head chamber volume...etc.

Does anyone have specs for the lift and duration of the cams?

Motor was in great condition when i received it, however the Crankshaft position sensor mounted in the transmission bellhousing was damaged, does anyone know a part number for this or what other motor would have an interchangeable sensor.

thanks

Link to comment
https://www.sau.com.au/forums/topic/428044-r34-rb20de-neo-need-specs/
Share on other sites

I'm building one of these for competition use at the moment, to replace my previous R32 RB20DE. I'm in New Zealand and it seems the 2.0 Neo engine made it out here in a few auto R34's.

The Neo is really quite different to the earlier version, with much lighter crank, rods and pistons. The pistons also run just one compression ring, so things look good for a high revving well ballanced engine once we are done. I am not sure on the factory specs of the motor because we are modifying everything to suit my R32 head, so stock measurements in this area are not critical.

Similar to my previous engine the block will be decked and a little more taken off the head. Due to the way the valves sit in the cumbustion chamber hopes to get mega compression are out the window, but hopefully the torque I will miss out on can be made up with rev's -I like that kind of comprimise!

Instead of trying to bash out some calc's on this, we decided to give the parts to the machine shop and get them to go as far as practable with what we have considering the car won't do high mileage. I'm picking the single compression ring will need to be replaced fairly regulary to keep it on song, but it's not a bad thing to get in there every now and then to check how it is all going.

What are your plans for the Neo? Street car?

Well i want a street car, but my definition of street car seems to differ from most of my friends. I'm running it in my 280z, stripped down to 952kg(2100lbs), with a subaru 4.44 final drive. The motor was inexpensive, revs high for stock application, and was almost a bolt in swap. I like n/a high rev motors; simply wanted to see what i could get out of it with light machine work. Raise compression, make some extractors(headers), maybe loose the old intake manifold and port match a greddy style intake if at all possible.

Was hoping to take advantage of the cam phasing to make up for some drivability, especially if i were to upgrade the cams.

Not looking to make the worlds most powerful rb20de, just wanted a responsive and rev happy motor with decent power.

Had no idea the pistons only had one compression ring, pretty interesting.

Sounds like fun! If you are really keen, consider some side draft Webbers or independent throttle bodies. I run itb's and some big cams, and oh the sound! More mild cams and itb's would be great street cred emitting sound from an early Zed.

The Neo has the right turning mass for rev's, so I'm keen to see what it will pull if my old RB20DE managed 8,600rpm for six years of rallying.

With a car as light as a 280 I would just look at taking some off the head, induction and exhaust mods, a tune and see how it goes. From there decide if you want to part with a lot more cash for a little more gain.

IMHO

For constant high revs, I'd recommend an upgrade of oil and water pumps to N1 items as a start before even thinking about performance tuning. I'd also say an oil cooler will be of benefit.

For such a light car under 1000kg, I'd keep the mods minor to start with. Headers, high flow cat and a K&N type high flow panel filter. Run full syn 10w30 engine oil. Don't run an exhaust bigger than 2.5"

Stock RB (both na and turbo) engines sound great at high RPMs with the right exhaust.

GReddy style manifold will be useless on such an application, as you don't have a turbo. Better wth sticking with stock manifold with the variable length intake manifold or go all the way to ITBs.

From memory (somewhere on these forums) someone mentioned the RB20DE NEO/25DE NEO have smaller CC in the heads.

Budget permitting, shave the head slightly to increase the compression, upgrade injectors from an RB25DE NEO and run an aftermarket ECU.

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

    • From there, it is really just test and assemble. Plug the adapter cables from the unit into the back of the screen, then the other side to the car harness. Don't forget all the other plugs too! Run the cables behind the unit and screw it back into place (4 screws) and you should now have 3 cables to run from the top screen to the android unit. I ran them along the DS of the other AV units in the gap between their backets and the console, and used some corrugated tubing on the sharp edges of the bracket so the wires were safe. Plug the centre console and lower screen in temporarily and turn the car to ACC, the AV should fire up as normal. Hold the back button for 3 sec and Android should appear on the top screen. You need to set the input to Aux for audio (more on that later). I put the unit under the AC duct in the centre console, with the wifi antenna on top of the AC duct near the shifter, the bluetooth antenna on the AC duct under the centre console The GPS unit on top of the DS to AC duct; they all seem to work OK there are are out of the way. Neat cable routing is a pain. For the drive recorder I mounted it near the rear view mirror and run the cable in the headlining, across the a pillar and then down the inside of the a pillar seal to the DS lower dash. From there it goes across and to one USB input for the unit. The second USB input is attached to the ECUtec OBD dongle and the 3rd goes to the USB bulkhead connected I added in the centre console. This is how the centre console looks "tidied" up Note I didn't install the provided speaker, didn't use the 2.5mm IPod in line or the piggyback loom for the Ipod or change any DIP switches; they seem to only be required if you need to use the Ipod input rather than the AUX input. That's it, install done, I'll follow up with a separate post on how the unit works, but in summary it retains all factory functions and inputs (so I still use my phone to the car for calls), reverse still works like factory etc.
    • Place the new daughterboard in the case and mount it using the 3 small black rivets provided, and reconnect the 3 factory ribbon cables to the new board Then, use the 3 piggyback cables from the daughterboard into the factory board on top (there are stand offs in the case to keep them apart. and remember to reconnect the antenna and rear cover fan wires. 1 screw to hold the motherboard in place. Before closing the case, make a hole in the sticker covering a hole in the case and run the cable for the android unit into the plug there. The video forgot this step, so did I, so will you probably. Then redo the 4 screws on back, 2 each top and bottom, 3 each side and put the 2 brackets back on.....all ready to go and not that tricky really.      
    • Onto the android unit. You need to remove the top screen because there is a daughterboard to put inside the case. Each side vent pops out from clips; start at the bottom and carefully remove upwards (use a trim remover tool to avoid breaking anything). Then the lower screen and controls come out, 4 screws, a couple of clips (including 3 flimsy ones at the top) and 3 plugs on the rear. Then the upper screen, 4 screws and a bunch of plugs and she is out. From there, remove the mounting brackets (2 screws each), 4 screws on the rear, 2 screws top and bottom and 3 screws holding in the small plates on each side. When you remove the back cover (tight fit), watch out for the power cable for the fan, I removed it so I could put the back aside. The mainboard is held in by 1 screw in the middle, 1 aerial at the top and 3 ribbon cables. If you've ever done any laptop stuff the ribbon cables are OK to work with, just pop up the retainer and they slide out. If you are not familiar just grab a 12 year old from an iphone factory, they will know how it works The case should now look like this:
    • Switching the console was tricky. First there were 6 screws to remove, and also the little adapter loom and its screws had to come out. Also don't forget to remove the 2 screws holding the central locking receiver. Then there are 4 clips on either side....these were very tight in this case and needed careful persuading with a long flat screw driver....some force required but not enough to break them...this was probably the fiddliest part of the whole job. In my case I needed both the wiring loom and the central locking receiver module to swap across to the new one. That was it for the console, so "assembly is the reverse of disassembly"
    • But first....while I was there, I also swapped across the centre console box for the other style where the AV inputs don't intrude into the (very limited !) space.  Part# was 96926-4GA0A, 284H3-4GA0B, 284H3-4GA0A. (I've already swapped the top 12v socket for a USB bulkhead in this pic, it fit the hole without modification:) Comparison of the 2: Basically to do the console you need to remove the DS and PS side console trim (they slide up and back, held in by clips only) Then remove the back half of the console top trim with the cupholders, pops up, all clips again but be careful at the front as it is pretty flimsy. Then slide the shifter boot down, remove the spring clip, loose it forever somewhere in the car the pull the shift knob off. Remove the tiny plastic piece on DS near "P" and use something thin and long (most screwdrivers won't fit) to push down the interlock and put the shifter down in D for space. There is one screw at the front, then the shifter surround and ashtray lift up. There are 3 or 4 plugs underneath and it is off. Next is the rear cover of the centre console; you need to open the console lid, pop off the trim covering the lid hinge and undo the 2rd screw from the driver's side (the rest all need to come out later so you can do them all now and remove the lid) Then the rear cover unclips (6 clips), start at the top with a trim tool pulling backwards. Once it is off there are 2 screws facing rearwards to remove (need a short phillips for these) and you are done with the rear of the console. There are 4 plugs at the A/V box to unclip Then there are 2 screws at the front of the console, and 2 clips (pull up and back) and the console will come out.
×
×
  • Create New...