R33 Rb30 Conversion

[Spoolup]

I wish it was that easy - as Id just shoot the mother f--ker :-)

[Cubes]

Spoolup,

Fiddled with cam timing yet?

[Spoolup]

yeah spent 3 hours on the dyno doing that. I dialled both cams in to zero an then we played around on 10 psi until we made the most power.

I guess I should wait until I pump some serious boost in and see what happens

[shanef]

wasnt there a theory that the T04Z wouldnt start to make decent power until u fed the boost into it? (20psi+) i'm sure it was the T04Z, just cant quite remember

[sky30]

The tuners still have our car...been there all week. Car wont make more power then about 290rwkws and it keeps overboosting once it reaches its target boost. They have been playing with timing, and wastegate springs....they think the problem is a faulty gate, which is sticking or something...so another is coming from turbosmart which will hopefully clear it up.

Initial thought after playing with wg springs was that the timing was out a few degrees, as in piston was not tdc when we set it up...But now the blame has been shifted back to the wastegate. Hopefully it gets sorted cause races are next weekend. Car still needs a wheel alignment.

R33 Racer- What size wastegate you using?

[r33_racer]

48mm turbosmart progate....the exact one we used previously on the old motor before it died.

The only different things on this new motor is the dry sump system, gt3540 0.82a/r, 4" exhaust system, oh and not that it matters but argo rods(previously ran rev)....so it went from making 370rwkws to 290rwkws.

[Spoolup]

Im hoping thats the case.

wasnt there a theory that the T04Z wouldnt start to make decent power until u fed the boost into it? (20psi+) i'm sure it was the T04Z, just cant quite remember

[Guilt-Toy]

with 8.5 to 1 what does a compression test come out at? mine has 120 in each cyl and i was wondering what it was.

comp ratio is 8.5:1

had several bolt on probs previously to this run, which I ve recently sorted, bent plenum, fuel pump issues.

But fixed all those, new 044 pump etc. No leaks, A/F ratios all good now.

I agree cubes, I told Matt that this Friday to boost it until it pings :-) , as the engine will handle near enough what ever we put into it.

Ill be running 100 octane and I wont be happy if it doesnt make some serious power.

And if it doesnt Im not sure where to look as Ive pretty much sorted every other issue that has come along.

Feel free to suggest anything - because at 10 psi I really thought it would be making more power, I guess if I pump 25 psi in on a proper tune it might make what Im looking for....but who knows until Ive done it

[Spoolup]

I dont think compression ratio and compression pressure have a direct relationship. As there are many variables that effect compression pressure, ring end gap, bore wear, ring wear, valve to seat seal etc.

So you can have two engines with 8.5:1 but both have different compression pressures.

[Gts-t]

This might be a silly place to ask i dont know, but what motor would best suit a r32 gtst with standard diff ratio (4.3)

I have a standard bore rb30 bottom end waiting to be built into a 3.1 but always wonder if i would be better off with a 2.6,7 or 8.

Both motors would be fully built with 9.0:1 comp ratios

Thanks guys

r33 racer what diff ratio are u running and how do u find it etc.

[r33_racer]

I have no idea what our diff ratio is actually...whatever std r33 manual is? 3.11 i guess...that sound right?

[snbr2]

just after some info

want to run forged pistons with approx 9:1 comp ratio

and fit oil squirters

can i buy rb30 pistons or will i have to use rb25 with oil squirter cut outs

[shanef]

just after some info

want to run forged pistons with approx 9:1 comp ratio

and fit oil squirters

can i buy rb30 pistons or will i have to use rb25 with oil squirter cut outs

why bother with the oil squirters when people in the know ahve said u dont need them?

to quote a very repuitable shop, RIPS, taken from ww.gtr.co.uk:

Originally Posted by Sayajin

How difficult is it to put the RB26 oil squirters into the RIPPS RB30 block? Is it even necessary with forged internals?

Originally Posted by RIPS

Not required. No piston failiers, ever.

[Spoolup]

I installed the new wastegate springs in the HKS gate on Sunday. Hooked all back up and went for a drive and it was still only making .7 bar. So I turned off the AVCR, still only .7 bar. Then I plumbed the wastegate up straight to a boost source, so it had nothing to do with the AVCR, still only .7 bar. Getting a little annoyed by this time, so I totally disconnected everything to the gate. Thought I would go for a very cautious drive to see if this gate was working at all. Full revs still only .7 bar, so Im guessing ( havent had a chance to remove it ) that the valve is either not seating on the seat, or its stuck open.

There are no leaks in the intake side as I pressure tested it again yesterday.

Any thoughts on other reasons for no boost ?

[paulr33]

gate stuck open

or leaking gate (leaking out backpressure)

is it mega laggy? (it should be if the gate is stuck open)

[Spoolup]

yes laggy as all hell

Thanks for the confirmation - now to figure out why.

[paulr33]

do a search for hiflow and bassjunky

he had a similar problem with his gcg hiflow

he had to bend the actuator rod to make it work

not sure on the exact details

[Sydneykid]

T04Z compressor map, note the lack of airflow at 0.75 bar, lucky to make 450 bhp.

Get it up to 1.5 bar and then you are talking, 700 bhp teritory.

cheers

[paulr33]

yeah they finally released it, actually useful data for once

pitty it needs to much damn turbine speed to get anything useful from it

whats a realistic rpm we are talking to get a 0.70 a/r housing fast enough to make the compressor flow 1.5 bar. is there a way to mathematically work this out?

given that we know required turbine speed and pressure ratio ?

[Spoolup]

Paulr33 - Its an external gate - so Ill have to see if its seating on the seat on the manifold, or getting stuck after it opens ??

Thanks Gary - its all starting to make sense now :-) I couldnt find a map for the T04Z so thanks again