R33 Rb30 Conversion

[Skyrine-Dave]

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.....

no sales pitch there

[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.

[[SweN]]

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?

[alkaline]

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%).

[[SweN]]

yeah thats what i figured. was going to set it to like 3-5 psi when i finish the transplant. just for the run in till i get something bigger

[Cubes]

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.

[Cubes]

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...

[[SweN]]

if this is true, it might be a good idea to get some other head work done at the same time, when you are aiming for high KW. porting and cams if not done + valves will be expensive, but would shoot your max KW output up a fair bit

[alkaline]

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?

[JNR24]

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...

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

Cheers,

Trev

[Bl4cK32]

the end bit that "opens and shuts" melts or snaps, & drops off the stem. make sense?

[GiJOr33]

hmmm... i've never heard of that happening before!

I've heard of valves stretching, but mainly on LPG converted cars.

[JNR24]

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

[Bl4cK32]

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......?

[JNR24]

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.

[alkaline]

lol @ "write" >> right?

But yeah bad timing puts more stress on the engine.

LPG raises fuel burn temp, to run efficiently needs high 12:1CR as its raited at 108RON (not MON) or maybe forced induction . Although this would raise temp even more.

[Cubes]

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?!?

[Cubes]

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.

[Steve]

Isnt Matlowth running around 340rwkw with stock head?

I still cant get my head around a vavle dropping because of a particular hp - how so??????

[[SweN]]

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