whistling on boost

[james walker]

okay guys, reversed n249 bypass today, id say it feels better oem than bypassed on mine..

anyway, i had a whistling noise on boost, to accompany the whine i have aswell on low revs, kinda hoped the re bypass would make it dissapear, but to no avail

any ideas on whistling on boost? quite high pitched aswell.

prefer the dv sound un bypassed and no more turbo stall kinda sound which was there on bypass. im gonna do some logs to see if theres any differences, but for now any ideas on the whistling.

while your here... went out for a razz after i did the re bypass, pulled over, checkd connections, all good.. noticed a crackling sound coming from behind the block, near the turbo/manifold.. like a open fire crackling sound as if something was mega mega hot?? what could this be and is it normal?

im thinking, exhaust downpipe gasket or turbo gasket? could this also be contributing to the whining noise...

from my vagcom logs, all seems ok, other than some slightly high timing pull, and running slightly lean aswell... pointing towards gasket failure??

sorry for the long winded post, just after this sorting asap.

 

[dippy4000]

okay guys, reversed n249 bypass today, id say it feels better oem than bypassed on mine..

prefer the dv sound un bypassed and no more turbo stall kinda sound which was there on bypass. im gonna do some logs to see if theres any differences,

exactly what i found, will be interested on what yours logs show, if anything like mine

 

[james walker]

anyone else fellas??

 

[LEE69]

Get a rag and put it over the exhaust tip, can you hear anything or get a mate to check under the bonnet whilst your doing that.

 

[james walker]

what im i hearing mate... back pressure?

 

[LEE69]

You should hear it blowing, as your blocking the exhaust tip.
You also might be getting movement when under load/boost so may blow then too.

 

[james walker]

just a thought, when i had my quaife fitted alex at backdraft dropped a new ths mount on the gearbox side, still oem on the engine side.. totally forgot to sort this.. could this have casued an issue, uneven load etc on the downpipe components

 

[LEE69]

could this have casued an issue, uneven load etc on the downpipe components

Hell yeah, but I'm sure it would have been supported when being changed.

 

[james walker]

yeah i mean now with running one uprated mount and one 90k oem mount!!! cant believe i forgot about this... knob.

 

[LEE69]

Yeah be different levels of "tightness" so will "twist"

 

[james walker]

so what will this have caused... the whining i have was there before the quaife was fitted.

 

[LEE69]

It could be causing the blow (that's if there is one) just depends how much flex you have in the exhaust system.

 

[james walker]

i do know the rearbox is goosed.. its louder than before, quite a bit.. hence looking into the scorpion.

ill try that pressure test then. also its running a little lean aswell on last vagcom logs.

 

[JamJay]

On an N249 note, I found my car performs much better on the road, yet made lower figures on the RR. May just be coincidence but it's the only thing that I changed between the 2 runs unless it was the heat in there (24degrees or something) or the MAF failing.

 

[james walker]

im finding its much better with n249 in place, spoke to will at p torque, he says its better on stage 2 with it conected.

 

[JamJay]

Quite possibly, I am on Stage 1. I found that disabling the N249 stopped that silly hesitation when you plant your foot where the ECU needs to think "do I have enough grip? yeah, I probably do but what if I am wrong? Oh well, lets see what happens" then the annoying "im losing traction, better dump all of this poor lads boost out so he looks like a fool" .