Well...

Following on from the threads about folks longing for that WRC stylee chatter / chirp / flutter noise (me being one ) I thought Id give it a go!

I had my HKS SSQV removed, plus some blanking plates made and fitted!

Would anyone like to know the result ??

 

yep, i would

did you get it remapped after you removed it ?
someone mentioned before that it may need to be, dont know if this is correct or not.

 

Hmm yes I'm intrigued, on my last Turbo it had a Forge Motorsport VTA but with a hefty spring in and I used to get both the Dump valve pssft and a small chatter through the Induction kit.

Sounded quite weird really as they are on different sides of the engine, bit like a 60's record when people started doing weird things in stereo

 

ka-boom

 

Nooo no ka-boom

Well firstly, the chirping / flutter noise is there, but its not very loud, you can hear it and you can hear it from down the road but its certainly not as loud compared to those heard on say RS Turbos or S15s etc...

Mine wasnt remapped or anything before I tried this, but Iam running on a Tek 3 map by AF putting out circa 320-330bhp.

Now for the funny part!!!! ...

Prior to the chirp, as you begin to lift off throttle it makes a noise as to which people described it sounding like a 'strangled pig' LOL its very funny indeed!

So all in all, it makes a fairly high pitched squeeling noise, the as you come off throttle completely the flutter happens.... and thats it

I should mention I dont have any induction kit fitted so it would probably be louder with one. Saying that its not all that loud, my friends noticed the difference instantly before I'd told them I'd changed anything and everyone preferred it to my HKS apart from the misses who just laughs everytime she heard it - you know what woman are like lol

Now onto the performance side of things....

There is a noticable difference when going through the gears, thats for definate!! The pickup between gears is faster... and you could definately get used to it, it really does feel slightely 'rapid'er'!

So the question you all want to know is am I keeping it like this???


.... tuffy but probably not

It was only ever a little experiment, and as good as it sounds, the flutter isnt quite prominent enough (certainly not from within the cabin - yet to hear it myself from outside) for me to justify keeping it this way at the possible detriment to my poor turbo

I'll see if I have time tonight and I might go for a run out with the digi cam and record what its like and post it up for those interested in running something similar!



Terence

 

Quite tempted to try this too.

What turbo is this on? VF series? I have a TD so should be fine.

Did you just block the intercooler hose or others as well? I see there is a big bore hose going back under the inlet manifold and a small bore going to the top of the manifold. Did you do anything with them?

 

Hi mate, mines a VF29, I did read its not the VF series arnt the strongest in this respect but it was only a quick experiment

As for the pipes im not too sure m8, I had it done for me, I do know only 2 pipes were blocked off tho if that sheds any light... I forgot which they were

 

Anyone else know if I can just blank the intercooler to DV hose and leave the rest or if i need to blank the lot?

 

You need to blank the lot, as the car will cut out if your dont!

Banny

 

The noise is called compressor stall.

The whole design of a dump valve it to avoid it as in extreme circumstances you can shatter a compressor wheel.

It may feel different, but on full boost situations you will be generating more lage, by not having a DV to keep the compressor spooling when the boost drops.

 

I bet if you replaced the standard recirc dump valve you would get the same pick up after gear changes, just without the noise. If you are replacing the HKS just give it a try before you do. Be interested to know how VTA/None/Recirc compare on same car back to back

 

Much easier to just pull the pipe off the dump valve no blanks needed then. lol

 

In most situations, the closer you can get to no dumpvalve at all, the less the lag will be between changes. With a Dump valve, and pressure built up in the system will be bled off, with an OE DV, nearly all the pressure is bled off. THe OE DV gets rid of nasty noises, and is designed to dump the air in a fashion that doesn't upset the MAF sensor, which would also coat it in oil as the breathers vent in to the inlet pipe. And of course the OE DV prevents pressure spikes that could damage the intercooler, or the compressor wheel.

Paul

 

That has just decided it for me, i am not going to buy an aftermarket BOV/Dump Valve!

 

I have a TD05 turbo and run with no dump valve with no problems. The car does feel sharper when changing gears. I can't hear much noise, although I am using the std air box/filter.

 

That makes sense actually, as much as I noticed it was quicker going through its gears, when in 3rd on full boost it did feel laggy but I was just wondering if it was me!

 

My car sounds like a horse on ' lift off '... get a really loud ' chatter ' now there is no dump valve fitted...