Jump to content
SAU Community

Recommended Posts

yep that sounds about right

if you wanna start building it now

give me $800 and you can have a Series 2 block with AC compressor, RB25det head with DE cams and for $100 you can have full wiring loom and R33 ECU.....

:D no sales pitch there :(

Originally posted by alkaline

The RB25 turbo is too small (not enough flow) for the RB30 bottem end, same with the T03 that comes off the RB30ET. A hybrid T04/T03 or a GT25 / 30 is a better combination, with quicker spool times, although more expensive.

thats true, but you can use it for running in on low boost can't you?

I guess so, just don't boost too much as it would surely explode, maybe even damage the engine. Fragments can fly back into the engine causing big problems. These turbo's can explode even on 12psi if pushed vigorously enough. So stick below 8psi for the time being, remember that this engine is 3L, which efectively raises flow considerably (20%).

It all depends on what power you are making.. Keep the power levels within the turbo's specs and all will be ok.. i.e max 190-200rwkw. + it also depends on your current turbo's condition and if its got a plastic compressor. BUT on that note every one says the plastic compressor will shatter and go through the motor. Has any one heard of this actually happening or is it just a 'It might happen but I don't really know as its what john doe said can happen' type comment.

Also remember what Sydneykid stated earlier on in the thread.

In my words... :D

Over 450hp you have to spend big $$.. I've recently discovered that at around 300rwkw apparently the standard valves in the RB's tend to drop off. So if you want it reliable you have to spend $80 per valve on the exhaust side which adds up to around $960 for a complete set of exhaust valves.

So really Sydneykid was spot on. 250rwkw is good with standard pistons, rods etc. If you want over that then you are going to have to spend $1600 on pistons then another $600 or so on rod prep. then $960 on valves.

I could be way off on the valves but that is what my engine builder has told me. Apparently now that more and more RB25DET's are making 300rwkw or so they are having issues with the exhaust valves.

Please Sydneykid correct me if I am wrong as I didn't want to really hear that it was going to cost an extra 1k if I wanted a reliable 300rwkw.

I do remember you stating if you want over 450hp then you may as well go 600hp as anything over 450hp is going to cost roughly the same as 600hp in regards to engine build, injectors etc.

Its finally sinking in... :D

Joel then you should state this in your RB30DET diy guide.

So for instance, mr blogs wants 300 to 450 hp then this (list) needs to be done and with 450 to 600 then this, etc... Like in stages, say about 3 stages such as the ones listed on the rotorworx website. Just get someone experianced like Sydneykid to check up on it. =)

Also, what are peoples opinions on using water injection, such as the Aquamist? I have heared of one VL running high advance and gaining reasonable power increases though the high rpm range. Needs to be injected after the turbo, not before the compressor, as not to sandblast the hell out of it. Also, can be mixed with methanol (half burnt methane) to give more impressive results? Any supliers in Aus citys such as Perth?

Originally posted by -Joel-

Also remember what Sydneykid stated earlier on in the thread.

In my words... :(

Over 450hp you have to spend big $$.. I've recently discovered that at around 300rwkw apparently the standard valves in the RB's tend to drop off. So if you want it reliable you have to spend $80 per valve on the exhaust side which adds up to around $960 for a complete set of exhaust valves.

So really Sydneykid was spot on. 250rwkw is good with standard pistons, rods etc. If you want over that then you are going to have to spend $1600 on pistons then another $600 or so on rod prep. then $960 on valves.

I could be way off on the valves but that is what my engine builder has told me. Apparently now that more and more RB25DET's are making 300rwkw or so they are having issues with the exhaust valves.

Please Sydneykid correct me if I am wrong as I didn't want to really hear that it was going to cost an extra 1k if I wanted a reliable 300rwkw.

I do remember you stating if you want over 450hp then you may as well go 600hp as anything over 450hp is going to cost roughly the same as 600hp in regards to engine build, injectors etc.

Its finally sinking in... :D

What do you mean by "Valves drop off"?.

Cheers,

Trev

Neither have i!??

i can understand that the factory standard cam & valve setup may only be good for 300RWKW... but i couldnt imagine a solid single piece constructed valve, snapping or dropping off into the combustion chamber.

my 2cs

The std. valves are what -Joel- is talking about. "It happened to MattR's white r32 with the rb25 in it i think. He was over 300 and dropped a valve. It does become more of a problem though if u also use toluene etc. (as it raises exh. temps.)"

"Over 450hp you have to spend big $$.. I've recently discovered that at around 300rwkw apparently the standard valves in the RB's tend to drop off."

Joel have i forgotten anything......?

Seems strange. Somehow i dont think MattR's Valve snaped becuase he is generating XXX Amount of RWKWs.

To snap a valve with ONLY combustion & cam pressure, without detenation and abnormal cylinder tempretures would be allmost impossable. ( know of 2 VLs running RB25s (Standard head) producing well over 330RWKWS.)

Once again it all comes down to tuning... Right computer, right timing, write air, write fuel = No probs.

Its only when one of these components are pushed to its limits, is where you start to run into problems.

JNR24..

couldnt imagine a solid single piece constructed valve

Valves arn't a solid piece of material. Do a quick search in google as there is a good explaination on the stages before a valve drops and where the valve seperates from the stem and why.

GiJOr33..

I've never heard of LPG causing valve stems to stretch, I have heard of the need for hardened valve seats in turn burning valves.

Who knows.. I know I want to know for sure if there is problems. SydneyKid?!?

Here's my post in regards to JNR's Post 733. My ISP dropped offline today and have only been able to get back online tonight.

The valve seperates from its stem where the two metals are joined. First it will generally start to run a little od as the metal stretches causing the valve not to seal properly and the valve will burn, if you keep driving it the valve will drop mashing your piston and head sending metal particles through the whole motor damaging every part of it. Basically if you drop a valve its time to buy a whole new complete motor and head as little if anything is salvageable.

I'm hoping Sydneykid see's the thread and states his opinion regarding the standard valves dropping.

It could be caused also due to an influx of peoples using totulene lately which raises the combustion temperatures dramatically causing the exhaust valves. I.e MattR's RB25DET making 316rwkw.

Why just exhaust valves? what is so special about the intake valves? i understand they are cooler (obviously) but wouldnt there be a high risk of intake valves dropping too? or are they really safe?

i think we need a few of the guys with high kw rb25/30 conversions to come back and give us a hand again :rofl:

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

    • My guesstimate, with no real numbers to back it up, is it won't effect it greatly at all.its not a huge change in position, and I can't see the air flow changing from in turbulence that much based on distance, and what's in front of it. Johnny and Brad may have some more numbers to share from experience though.
    • Which solenoid? Why was it changed? Again, why was this done? ...well, these wear..but ultimately, why was it changed? Did you reset the idle voltage level after fitment? I'm just a tad confused ~ the flash code doesn't allude to these items being faulty, so in my mind the only reason to change these things, would be some drive-ability issue....and if that's the case, what was the problem? Those questions aside, check if the dropping resistor is OK ...should be 11~14 ohms (TCU doesn't throw a flash code for this) ~ also, these TCU designs have full time power (to keep fault code RAM alive), and I think that'll throw a logic code (as opposed to the 10 hardware codes), if that power is missing (or the ram has gone bad in the TCU, which you can check..but that's another story here perhaps).
    • Question for people who "know stuff" I am looking at doing the new intake like the one in the picture (the pictured is designed for the OEM TB and intake plenum), this design has the filter behind the front bar, but, the filter sits where the OEM duct heads into the front bar, and the standard aperture when the OEM ducting is removed allows the filter to pulled back out of the front bar into the engine bay for servicing, a simple blanking plate is used to seal the aperture behind the filter This will require a 45° silicone hose from the TB, like the alloy pipe that is currently there, to another 45° silicone hose to get a straight run to the aperture in the front bar Question: how will it effect the tune if I move the MAF about 100-150mm forward, the red is around where my MAF is currently, and the green would be where it would end up Like this This is the hole the filter goes through  Ends up like this LOL..Cheers    
    • Despite the level up question, actually I do know what that is....it is a pressure sender wire.  So check out around the oil filter for an oil pressure sender, or maybe fuel pressure near the filter or on the engine. Possibly but less likely coolant pressure sensor because they tend to be combined temp/pressure senders if you have one. Could also be brake pressure (in a brake line somewhere pre ABS) but maybe I'm the only one that has that on a skyline.
    • Pull codes via the self-diagnosis procedure. As far as I can tell this is just a sign of transmission issues but not a code unto itself.
×
×
  • Create New...