Jump to content
SAU Community

Rb25Det Or Rb30/25Det

Emmanuel1992

By Emmanuel1992,
in Engines & Forced Induction

 Share

Recommended Posts

niZmO_Man Grand Master

niZmO_Man

Posted
Posted

Put a V8 in it.

Or, you can turbo your RB30E, it's been done plenty of times. Have a search, look on the R31 Skyline Club as well.

If you want twin cam, drop an RB25DET in and do the wiring. Worry about 3L bottom end later.

But since you want a fast reliable car, spend $20k on a 25/30 + all other things required to make it reliable.

GTScotT Grand Master

GTScotT

Posted
Posted

For a VL commodore :-) street use but powerful to make pretty good times on the 1/4 mile, so I want a fast realiable car

Cheap, reliable, fast,

You can only have two.

Actually he can have all 3, turbo the RB30E.

If it blows a replacement motor costs a case of beer, and we all know you don't need a DOHC head to make an RB30 perform.

Do the following:

high mount manifold (ask hypergear if BRAE make one and he can get you a discount)

50mm gate from hypergear

hypergear G3 turbo

fmic

tbe

adaptronic ecu (order from hypergear with your turbo and gate) + tune

decent injectors around 1kcc

regrind cam to a decent turbo profile (must be done to make decent power)

Totals about $6,000 if you shop smart.

Add another 2k if you plan to run an RB25 box. Another 1k for a clutch that will hold the power.

It may seem cheaper to slap in a stock RB25 but then you will only need to spend the above 6k on that to make it go fast once you are bored of 150rwkw.

I reckon that answers all your questions in one hit. Thread closed.

Dose Pipe Sutututu Grand Master

Dose Pipe Sutututu

Posted
Posted

OP, before even considering anything why don't you just get that RB25DET running in the first place?

I saw in another post you were asking about "turbo pipe"... get the car running first, then build your knowledge by reading up 10000000000000000000000 other threads about power.

discopotato03 Grand Master

discopotato03

Posted
Posted

Cheap dirty 30 because as far as the authorities are concerned it has a 30 from the factory .

Anyone who's anyone would be less concerned about a twin cam VL than an RB30 in a Skyline 33 or 34 .

Build it up the std cheap way (rods/NA pistons) and with a Neo turbo head , smaller chambers , the CR should be manageable .

More part throttle torque in a 30 than a 25 and being 20% larger is in theory doing everything the 25 does at 7000 from under 6 . VLs have tall gearing

Lastly you lose the dinosaur distributor / cap / leads with twin cam heads .

A .

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
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • Zoidian
      What's this Foreign Object?

      By Zoidian · Posted

      Forgot to update. I ended up removing it and found out that it's dead. The car seems to run better than it did, although I haven't driven it hard yet. Literally just a flow restriction.
    • joshuaho96
      R33 general questions

      By joshuaho96 · Posted

      Sounds like the rack seals blew.
    • GTSBoy
      BCNR33 Blower Motor Resistor - Testing

      By GTSBoy · Posted

      ^ This is all good advice. I can imagine that there's some passive components in the HVAC controller that run that PWM output that could die, or suffer bad solder joints. It can be worth opening it up, taking a schmooze around looking for swollen electro caps, evidence of liquid escape anywhere, tracks that have been hot, lifted, cracked, etc. A DMM might not be suitable for seeing if the PWM output is pulsing. Might be too fast and too low voltage for a DMM to keep up. An analogue voltmeter might give a better hope. I use a handheld oscilloscope (<$100 from Aliexpress if you want something cheap). A DMM might see the voltage across the motor flicker. Otherwise, as above. If you can successfully see PWM action, then the control side should be good. If you can't see it with what you have, you might need to step up the instrumentation used, as above. Beyond that, and dbm7's advice on testing the motor directly, you're down to looking for broken wires, corroded connector pins, etc.
    • ChrisGtt
      R34 Gtt RB25det neo Issue After Modifications

      By ChrisGtt · Posted

      So Thanks for the comments etc. To follow up on this, we went down the path of fitting a divider down the middle of the external pipe that was added to the exhaust manifold and the divider went from very close to the external wastegate all the way up to the "V" part where the pipes from each side of the manifold joined. After this modification it was finally in a position to do the dyno-tune with some degree of success. Top end power was down about 10kw (250rwkw down to 240rwkw) I believe from previous but it seems to be more responsive lower down and at least it is now driveable and fun and back on the road to be enjoyed. Apparently the timing couldn't be run the same as it was running into knock and boost was down about 1psi. For all we know this could have been from the fuel being a bit older, or perhaps some slight complication from the new head gasket as we didn't have compression figures from before that mod to compare. I'm no mechanic and this is second hand info but I just wanted to follow-up to those that commented or read the original post with interest. After so many months of stuffing around this is a big win. The interesting part was most of the info around this was gained from information around Barra motors and not GTR as the manifold setup on the Barra with single turbo was more similar.  Thanks for those that helped with info. Regards Rob 
    • dbm7
      BCNR33 Blower Motor Resistor - Testing

      By dbm7 · Posted

      G'day ... first up, I very much doubt that's a resistor network (as used also for this job), but the part# looks right. The description of 'power module assembly' looks to be nissanese for 'PWM driven, ground switched, DC motor speed controller'.... the circuit in the schematic kinda infers that's the case... ...with the transistor symbol appearing in the unit described here as 'Fan Control Amp(lifier)'....being driven by pin20 on the HVAC unit,  and a feedback signal on pin19 from the motor negative terminal for some reason (might be motor fault detection, maybe they detect commutator switching to determine motor revs as well, I dunno)... but if they are  counting commutator spikes, a bad segment (or really worn brushes) will throw a spanner in the works... The motor itself will as said be brushed DC with segmented commutator, rated at 12VDC nominally ~ now-a-days I just unplug them, determine the positive wire, and hook them up to a variable power supply and find out how much current they draw, if they work etc etc ...you can also check for bad segments...ie; set the power supply up to feed 1volt @ 2amp max, then watch the wattage count as you slowly rotate the fan blower motor through a complete revolution ; any bad/dead segments will be clearly evident...some folks would just say determine the positive wire, and feed it battery voltage, and if fan spin, you've got a win...<grin>... well, at least that infers it should do something when plugged back in, and the HVAC unit commands it to run... and if it doesn't, you suspect the module, but you should check the PWM signal on pin20 is actually present, and if it is, blame the module ...  
×
×
  • Create New...