TheSamba.com :: View topic - Turbo Whistle

Thu Jun 29, 2017 12:35 am

Hi,

I recently installed an AAZ engine in my vanagon and decided to give a VNT install a go. So far i'm very happy with its performance and fast spool and the mechanical vane control seems to be working well.
The max boost is about 15 psi, JX boost pin, VNT15

My biggest worry at the minute is the turbo whistle I'm hearing as the turbo spools up. Not that the sound is a bad thing but it does sound a bit excessive.
The noise fades as the revs increase and the turbo makes boost.

Just wondering if anybody has similar results.
Would the addition of an intercooler add to the noise?

The turbo is a used turbo so am worried the noise could be symptoms of the turbo on the way out but the VNT route was only a bit of an experiment so didn't want to splash out on a new turbo until I had some experience with the setup.

Any advice appreciated.
Cheers,

Thu Jun 29, 2017 8:52 am

Mine does it too, not to worry. I have the AAZ with K14. It was rebuilt from the start and is in excellent condition. I hit 14PSI max and no intercooler, but I live in the thin air. AAZ pump with modified fueling by Giles.

It does whistle and warble on spool-up, but even more so on spool-down. Its obviously a turbo diesel to anyone that knows the sound. Everyone thinks it sounds pretty cool. To me it says its working normally.

Take the intake hose off for a drive and you can really hear it whistle.

Thu Jun 29, 2017 9:13 am

On the old Jx you could bearly hear the turbo do anything but with he new setup and window down its all I can hear until I get up through the gears and get to cruising speed. Once I leave my foot off the accelerator it seems to stop as the boost drops.
i'll give another look around it tonight, just to be sure I don't have a leak. Maybe bypass the intercooler just to be sure.
It doesn't really bother me but headding on a roadtrip to france in three weeks so a bit paranoid if it's on the way out that it'll go then.
Got a price for a new unit there and it's about €600 new or about 480 for a refurbished one by garrett. Wonder if theres any difference in quality seeming there both by garrett?
A Giles pump would be the way to go alright. Still haven't fiddled with the fuel screw so suspect a bit more Hp to come. Just playing with the boost pin a bit. You recon it's possible to get enough fuel from the boost pin alone or will I have to add fuel with the fuel screw? From what I've read the lda on the aaz isn't great in comparison to the 1.6 so I assume I'll be limited with adjustment.

Thu Jun 29, 2017 11:14 am

Double checked my intake pipework and intercooler and definitely no leaks however I did a bit of an experiment by blocking the drivers side air vent and this seemed to quieten it a good bit. My cone air filter is located directly behind the light on that side so maybe this is amplifying the sound.

Thu Jun 29, 2017 11:21 am

I’m not much of an expert, but living at 7,200ft elevation (2200m) has forced me to experiment with my engine to find the good settings. I am running the K14 turbo off a 1.6 JX because I figured it would run the 1.9 better in thin air. My wastegate is totally closed for all the boost I can get. My fueling is turned down to just below the smoke level. My aneroid pushes fuel a little late, I could probably adjust it for more fuel at lower RPM. I have a JX aneroid on the AAZ pump so it fits under the engine cover, but I hear the AAZ aneroid performs better than JX. I get no black smoke through the power curve, and no carbon on my chrome bumper. When adjusted right the AAZ is a clean running engine.

I don’t know anything about the VNT turbo but it sounds like it is working good. Turbo technology has come a long ways since the first JX, so its not too surprising it didn’t come with a whistle. I assume the whistle is normal for the AAZ with my turbo. It runs great, gets excellent mileage and has good power.

One warning if you go with a performance pump you are going to see excessive engine heat when pushing it hard. The AAZ runs hot anyway, I had to put in a newer aluminum radiator with cooler fan control sensor. An EGT gauge is highly recommended if you are going to charge up long hills.

Thu Jun 29, 2017 11:27 am

jpcos wrote: I did a bit of an experiment by blocking the drivers side air vent and this seemed to quieten it a good bit. My cone air filter is located directly behind the light on that side so maybe this is amplifying the sound.
That’s very possible. My original 1.6 NA diesel had a decomposing intake hose and the grill in the D piller transmitted a LOT of intake noise. I lined the inside of the tube with Rubatex®, a soft rubber foam that wirked really well to dampen the noise. It seems likely your cone filter is acting like a horn to transmit noise.

Fri Jun 30, 2017 5:41 am

Might try a bit of sound proofing myself and see how it goes. The turbo seems to be doing its job so I might leave it be until I get the road trip done. Might just have a spare used one in the van just in case. :lol:
The trip is what will determine the success of the install so if all goes well i'll probably splash out on a new turbo anyway.

I have a EGT gauge installed but to be honest I don’t really thrust it as I bought several of the same make gauges cheap from ebay and am not yet convinced of their accuracy. Oil pressure drops when you turn on the lights :lol: . I guess you get what you pay for. So that’s why I’m a bit slow adjusting the fuel screw yet. Need to sort some proper gauges.

A clean running engine is what I’m after so would rather sacrifice a few HP over a trail of black smoke following me everywhere. :P
Still plenty tinkering to be done especially with the aneroid. Need to spend a bit of time figuring out its travel and maybe cut a pin to suit. This is all completely new to me so learning as I go.

Cheers for the advice and nice van, exact same colour scheme as myself :D . Must get a pic uploaded over the weekend.