Lowering boost pressure.

[Wortho91]

Hi all, I've been looking for ways to quieten down the intake on my zd30 and short of taking off the snorkel the only option I can think of is dropping the boost pressure. I realise it still won't be quiet but it should be a lot better then standard. The other possible benefit to this is the turbo might last a bit longer not having to work as hard. If anybody has done this already or has any thoughts on it I'd appreciate any feedback.

 

[mike1303]

....

 

[Malicious]

Make an intake baffle for it,

 

[Rumpig]

Turn the radio up.
Or try one of those prefilter socks that go over the snorkel head.

 

[dylan the villian]

What did I just read?

 

[bods]

Chuck a rag in the snorkel, that will quieten it down....

 

[Wortho91]

From what I can tell these engines suffer from premature turbo failure regularly and are known for breathing fairly heavy. I may be wrong but it seems as though they run rather lean and the 15psi is overkill and for egr purposes more then anything. If that is the case then provided the egt temps didn't rise excessively from the richer mixture the end result would be less chance of turbo failure, less oil through the intake and less noise alround.

 

[Wortho91]

Not much fun towing in 4th all day with a car as noisy as one of these things.

 

[bods]

Have you tried it with the snorkel head removed to see if that makes any difference? I agree, I have a yd25 and at around 3000rpm it really howls. Doesn't take long to give you a headache....

 

[tweak'e]

first thing is check what boost your running. with mods they sometimes do go over 15psi.
the other thing i would do is check air pressure just after the air filter and also see what the drop is over the filter/housing. if air pressure is low due to restriction that can make the turbo a bit noisy.

other than that all i can think of at the mo is to fit a resonator box in. it will be a lot of mucking around.

last thought, if the noise is only coming from the head of the snorkel, change the snorkel head.

 

[Wortho91]

It's running 14psi. I've had 3 different air filters in it the last one new and yeah I tried without the snorkel head it made no difference. I'll look into a sock for it for now. Just didn't want to introduce any more restrictions if I could help it.

 

[benchrisfennell]

The louder the better

 

[mike1303]

Mine sounds like a mack truck!
My exhaust is louder then the intake

 

[benchrisfennell]

Mine sounds like a mack truck!
My exhaust is louder then the intake

Tuff.... Straight through is it.

 

[mike1303]

Tuff.... Straight through is it.

Yes 3"still have the cat but no muffler

 

[Old.Tony]

A baffle is the answer to the sound issue. Yes it's a restriction, but the air will still flow. The idea behind it is that air will speed up until sound can't flow back out = quiet intake.

Don't reduce boost. Premature turbo failure is often a consequence of early engine shutdown after getting the turbo hot. Use a turbo timer, or just let the engine idle for a little while before shutting down. Duration depends on how hard you've been driving.

An intercooler - if you don't have one - is excellent insurance against failed turbochargers. They not only cool the air down, they reduce sound AND catch broken turbocharger impellers.

 

[benchrisfennell]

Yes 3"still have the cat but no muffler

Love it!!!!!

 

[BIG GUS]

Turbo diesel's love a gutful of good cool air ,why the hell would you want to restrict it, put some earplugs you goose or buy a petrol engine fair dinkum

 

[Wortho91]

Thanks to everyone who answered my question and particularly the ones that didn't need to be smart. I've got the turbo timer and a forefront intercooler. I'll look into getting a sock now. The next noisy part is the intercooler. Works great with keeping the egts under control but the noise is ridiculous. It sounds like running your finger over a wine glass only high pitched and 10 times as loud. Anybody else had this with the forefront winch kit?

 

[bods]

Sounds like you have a boost leak in that case. Check all your intercooler piping especially the silicon joiners for leaks