Jump to content
SAU Community

Recommended Posts

What is it about the stock turbo's on RB20/25's that make the induction sound so loud.

even with the stock air box in.?

I'm sick of it already.

Is it something with the design in the wheels or maybe the compressor inlet?

my SR was never this loud.

neither was the 4G63.

and no, there is no leaks or gasket issues.

it's just the standard skyline turbo sucking sound.

Link to comment
https://www.sau.com.au/forums/topic/101348-rb-turbos-induction-noise/
Share on other sites

The VG30DEt turbo is much quieter... No loud whooshing as it comes on boost yet it runs the same core (comp and turbine wheels) as the rb20det turbo only larger turbine and compressor housing. The other difference is the compressor housing snout is smooth in to the compressor, the rb20 and rb25 turbo's have a slight step in front of the compressor wheel. I assume this causes a little turbulence causing the loud whoosh noise as its building boost. :unsure:

fit an airbox with a panel filter, that will shut it up

This is true,just make sure the sponge stuff on the lid is on if you want to reduce induction noise take it off and it increases the sound surprisingly.

GTST,

The VG30DET turbo and the Rb25 turbo run the same sized comp cover, the only differece once again being the vg30 is smooth where as the rb25 has a step up. The Rb25 turbo is a noisy bugger like the rb20 turbo. I am 99% sure its this little step in front of the comp wheel that causes the noise.

Do you have the stock BOV fitted?

For some reason on both mine and a mates GTS-T, when we had the Stock BOV working it makes a much different and louder aray of sounds when its spooling.

When the aftermarket item went back on and the stock one was blocked off, less sound during spool up...

I run the stock bov.

The VG30DET turbo is so much damn quieter than the rb20 and rb25 turbo's. It HAs to be the step in the turbo's intake. :unsure:

If you block off the little bleed hole in the stock bov it also makes spool rather quiet, I experienced roughly part throttle acceleration through the hills so I removed screw I used to block the bov's bleed hole.

I blocked off the bleed hole on my last skyline.

but like you said, it's not a smooth transition between on and off throttle or part throttle.

so I'm leaving this one as is.

I'll have to put up with it for a while as is.

once I settle in to QLD, and everything is back to normal and bank account is a little beefier, THEN, I can build the RB30 that I want and stick the gt30 to the side of it.

I hate having it all planned out and no funds to make it happen.

NOTE TO MEN: Don't pay for your own wedding.

oh and don't have your UNINSURED car stolen.

oh oh.. and don't do all of the above when paying a MORTGAGE.

Lets hope 2006 brings better luck than 2005.

:unsure:

the only new part to this engine build will be bearings, turbo, sump adapter, idler pulleys and timing belt and ECU

bottom end will be stock.

just checked and tested.

and I will use the pistons it came with.

head will be stock with second hand 25det springs to be sure.

oil pump, second hand.

injectors I will get GTR ones.

B

U

D

G

E

T

We'll see how long the gts4 box holds up.

and I will only have it tuned with 14-17psi... don't want to really go over 1bar.

what ever power that yields is cool with me.

yep.. new rings, bearings, and new gaskets.

all parts will be OEM nissan/holden bits.

I just want it to be reliable.

so I will replace parts that are required.

nothing forged though.

I don't think it will be required for my needs.

I should also add oil cooler kit to my list of NEW things to buy.

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

    • Add to this... What blew the fuse too? If a circuit feeding power to the coils was blown, how were the coils even functioning to let the car start?   There is some seriously wrong wiring in that car for certain, and I'm betting there is some melted cables somewhere, but I can't explain the 30v either, unless there is something back feeding on that power line that has a dodgy power system and the electronics are giving it hell.
    • This is typically the case with such threads. What I cannot quite get my head around is where a reading above 12V (or 13.8 or 14.x or whatever the maximum achievable voltage might actually be in that specific car) comes from. 25V or 30V should be completely impossible. There's no way to create it. Hard to answer that question. It will literally depend on whether the current tune relies on the values as set. I'd guess it probably does. ie, the real base pressure being 49 means that the flowrate through the injectors will be higher than if it was 43.5. The Haltech's modelling should be handling that, but because it thinks the pressure is only 43.5, then..... I dunno. It should be thinking that it will be injecting less fuel with each pulse duration than is actually happening. So, something is definitely not-as-it-should-be, but specifically what that is is beyond my abilities to imagine. Someone like Dose who spends more time with Haltechs might have a better thought.
    • Bit of a late reply here as me and my wife have been really busy with new born twins. I finally got these issues fixed and it was something really stupid that caused all of this 🤦‍♂️... After alot of mucking around with trying to figure out what is causing these issues, I back probed one of the R35 coils on the power 12v supply, with the engine running it got 25v! And I thought, hang on..., this isn't normal. Measured my battery with the engine running to check for over charge from the alternator and it wasn't that. So then I dissconnected the R35 PRP coil harness and backprobed the power supply on the engine loom where the ignition coil harness connects, with the key on ignition (engine off) it measured 30v! So then I had to trace where that high voltage was coming from and it lead me to the brown relay "ECM & IGN coil relay" inside the cabin next to the ECU on the passanger wall. This relay feeds power to the ECM and ignition coils. Tried swapping it with another same relay. nah still 30v.. coming from the 2 green/white wires in the brown relay. So then I set my multi meter to the beep continuity mode and probed every fuse on the fuse box inside the cabin to try and find this high voltage power source. Wasn't any of the fuses inside the cabin. Then probed all the fuses in the engine bay and BAM, got my power source that was a 10AMP fuse called "ENG CONT". Pulled the fuse out, and what do you know... it was blown. 🤦‍♂️  So then I quickly replaced it with a new 10AMP fuse, started the car and yeah haha [insert extreme face palm]... The RPM blimping thing went away, car idles smoothly now like what it was before. I swear! I checked all my fuses with my test light twice before I created this forum thread. I think, maybe because one side of that faulty 10A fuse lit up on my test light, I must have thought it was still ok and not blown. But now I know to have both sides light up on the test light when checking fuses... I hate diagnosing electricals.... I'd take mechanical problems over electrical problems any day🤣. Drove the car around my suburb with the engine up to operating temp and it runs fine like before. However, I notice that my fuel pressure is still at 49psi. So I'm thinking this must be normal for my system as I've upgraded the stock fuel pump to a Walbro 255L/h with a constant 12v mod.  But anyway, I'm just glad to have my daily back on the road! Thanks everyone for the replies on this thread, all sorted now! One thing I want to ask you tuner guys, my base fuel pressure on the haltech main settings are set to 43.5psi from default (my tuner must have not checked the fuel pressure maybe when tuning my car?). Do I set it to what it actually is idling on at 49psi? Or just leave it ("if it aint broke, don't fix it/leave it")?  
    • The max they would go for me is 50.
    • That cannot have been a fun set of drilling. The stock "baffle" looks identical to rb26, I just cut fuel cell foam to fit the full length under the baffle.
×
×
  • Create New...