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

    • I don't like "actual computers" for in car use. They take time to boot up, have OS annoyances, and so on. Arduinos etc are ready to go a few seconds after power on, don't mind being agressively powere cycled, because everything is non-volatile, don't mind being shaken and stirred.
    • As Fred would tell us, it's all about interpreting the rules. It's not a water sprayer, it's a water mister... But everything else you've said, 100%! Even a raspberry Pi would be great, use HDMI out for a display, and add a raspberry Pi CANBus hat to read values out from the ECU.
    • Being a race car, and being in the era of the Arduino, one would think it would take little effort to build a controller to do the spraying based on a real physical measurment. Waaaaay back in the dim dark AS days, JE "designed" (as in, he had help) a microcontroller based intercooler spray system. It watched the difference between a temp sensor stuck on the core and one in the free air in front of the cooler, and if the temperature difference exceeded a (settable) threshold, it would activate the sprays. Thus, it only ran water when there was an actual need for water. If you stop to think about the actual physical things that are going on in that stack of coolers, there's probably at least a couple of triggering conditions one could come up with, and one could probably even run one pump with more than one solenoid valve, to allow water to be placed where it is needed, or at all points at once (if it is needed at all points). We're in the age of science baby. But.... I suspect that intercooler water sprays are on the forbidden list in most circuit classes, no? So only good for Targa type stuff?
    • I'll just leave this with, holy shit, those cars at work are awesome, and this will look wicked!
    • Could you modify this duct so instead it pushes the extra air through the radiator too and not down and out? For temps, I know it's not the greatest idea, but as a bit of a last resort, you could use a very intermittent misting spray onto the front of the coolers/rad. You don't want to be soaking them such that water is dripping off, but a small most on/off so that the water evaporates. That point of it constantly evaporating, rather than being soaked in water, will pull a LOT of heat out of the cooler. I'm literally thinking just the little mist sprayers for a garden from Bunnings. Being in a low humidity climate it will help even more! The other trick if you want to be ghetto is some shade cloth hung in the opening, and keep it wet. Pretty much now it's acting like an evap cooler on a house, but cooling the air you need to use to cool the radiator...   On a topic to think about too though, when air enters through the bumper, is it all nicely ducted from the edges of that opening back at a nice angle, or is it like most cars, and the edge of the opening just stops, and suddenly it's wayyy wider behind that? If it does the later, get it shrouded out at nice angles. When that opening changes too rapidly, it can actually cause a high pressure zone between the front bar and radiator, and limit air flow into that area, which means less air for cooling, as it effectively stalls the air, AND adds to drag...
×
×
  • Create New...