Turbo `drone` on Jap Spec Twins

Has anyone experienced a hum/drone noise from jap spec turbos before?

When I am accelerating gradually and the turbos are spinning up (say 40+ MPH) i`m getting a hum/drone noise that quickly dies off when the turbos eventually pick up more speed?

It sounds similar but not the same as the dreaded `death whine` on UK spec turbos and only lasts for a few seconds (if that) when the turbos start to boost.

This is further to my inital thread http://www.mkivsupra.net/vbb/showthread.php?t=46929

for which part of the problems I had was down to a split hose.

Are you sure the noise is coming from the turbos? Could it be somethings as simple as a bolt loose or something similar resonating at a certain rpm, eg, exhaust, heat shield, etc.?

Death Whine?

The noise does come in at the same time and only when the turbos are starting to spool up. Once they are up and spinning no more noise.

I was still hoping for a pipe leak or something similar and the noise is some sort of air escape/draw.

The odd thing is that it does not do it every time, sometimes no noise, other times quite distinctive?

If it was a `death whine` would it not make the same noise each time and continue through spool up to full power?

Am I not right in thinking the `death whine` only occurs on UK/US metal fan turbos and the ceramic jap specs dont whine they just detonate!!!

Noticed your Auto are you sure its not the box droning mine does now and again

MMmmmm....

I dont think so as it seems to be directly connected to the turbos spooling up.

I have the same thing. Sounds like a blowing gasket or pipe, as you say. Hoping to take the turbos out for a look around in there soonish, so will let ya know

Bob, would be very interested to know what you find. Have you got any idea as to when you will be taking a look at yours?

I only ask as I need to book mine back in with `Phoenix` as the boys need the car longer to see what the problem might be. If you find out anything then it may help me to steer them in the right direction! (and save me a bit of cash) !!!

Noticed this noise today. Don't think it's turbo related. I'm an Auto too so it could well be the box droning.

`Red` thanks for your comment `Ian` also mentioned the same thing earlier in the thread.

I cant recall ever hearing this before and directly connected it to another issue I had with a split pipe causing a wastegate `chatter`.

As you both have experienced this then perhaps I need to look at the possibility of the box.

What noise do you both get, how often, what sort of speed/rev range etc

Any help you can offer is much appreciated.

Note, if it does turn out to be the box is this something to be worried about as it seems to be doing it more often than not?

I noticed mine at about 60mph, hardly any pressure on the acc. I was cruising along through the country side. I thought it sounded like a boomy exhaust. Like when you have a hole in it.

Heard it a couple of times but once on the motorway it never came back.

`Red` thanks for the response. Mines sounds more like a `yawl`, sounds a bit like your humming through a pipe (for want of a better description)!!

I dunno, I`m coming round to the idea that it could be any one of a number of things and only a trip to Mr Mechanic is going to solve it...... better call the bank manager and prepare him !!!!

Also sounds like a constant note played on a digeridoo!

Mine sounds more of a 'toot' sound, (almost) definitely coming from the turbo side of the engine bay. May be taking out the turbos to check them over this week, as I've got a whole week off to fiddle

Mine has always done this - around the 3000rpm mark. The first turbo is up and running and the second one is getting ready to. I always thought it was pre-spool on the second turbo. I think someone humming down the pipe is a good description - I always likened it to a jet engine starting up, a sort of 'whooooooooooooo'. By the time the second turbo is online it's gone.

I think it might just be a resonance sound because of your aftermarket air filter setup

-Ian

I think it might just be a resonance sound because of your aftermarket air filter setup

 

-Ian

Not on mine it's not! I'll make a recording of it.

It does sound a bit like something resonating. I will also try and get it recorded as it could be useful to other club members in the future.

Ian, I do get a lot of `amplified` noise through the aftermarket filter (lots of induction noise etc) but its only recently that I have started to hear this and the filter set up has been the same for years!

Evenin' VIL.

I've got the same sound... it used to worry me . Judging by its inconsistence I would think that it's a result of resonance - I can't make it happen on purpose, it only appears at certain level of lead-footedness and RPM. Sometimes, you can hold it until you make a change in revs or speed.

Have you read about 'wolfing'? Oh and just to eliminate something from the discussion: it happened to me when I was running the stock airbox, and it still happens with an apex'i intake.

Keep us posted buddy.

Ben

Cheers for the post Ben

Yep, that sounds like the bugger!!!

You cant always make it happen, sometimes its very noticeable other times nothing! What do you think it is?

As a few people have now experienced this it must be more of a common occurance than I thought?

You mentioned `wolfing`? Dont know what this is?

It is a common occurance for the J spec cars, we only have J specs in AU, to whine as the first turbo spools up.

The whine gets louder if the intake is a non standard pod or similar.

Mine whines on light accelaration below 2500 rpm and only on number 1 turbo.

I thinks it's a cool sound in the background telling me all is right in the world.

That's how we view the whine in AU.

Steve

Hey Steve, welcome over from in AU.

Mine use to resonate at a certain rpm when accelarating when I first got it, thought it was normal until first service when garage found one of the exhaust hangers had broken. The vibration caused the thin titanium exhaust to resonate quite loudly, once hander was replaced no more noise.

`Nurzo` Thanks for your post.... its nice to hear that there are some Supras stuck to the underside of the planet !!!!!!! ;0)

Mine is not so much of a whine, but a `low noise howl` but could be the same thing!

My only real concern (as others seem to experience something similar) is that it never used to do it and nothing has been changed or messed with! Why is it doing it now?

My car did the exact same thing today,

so is this a problem that can be sorted or not?

Hi Simon

To be honest I dont know whats causing it, but it seems as with yourself and others that it is a common issue.

I`m supprised non of the technical guys have ever experienced this and looked into it before.

I was hoping `Bob` was going to come back after taking a look at his turbos with some idea of whats going on?

My concern is that its the start of a turbo issue and I dont fancy the thought of having them detonate unexpectedly!