S3 Turbo Chattering Under Acceleration..!?

Gaz-M

Gaz-M

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Ive just fitted a Revo intake to my S3 and now it lets you hear all the turbo noises i can hear what sounds like a wastegate chatter - but whilst im on full throttle!

Its almost as if the diverter valve is chattering open and closed allowing boost back to the intake pipe and giving me the noise. Anyone had this?

Ive also done Revo PCV delete and rev D diverter valve.

Going for a stage 1 Revo map tomorrow!

Ill see what its like after remap.
 
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Isn't that how boost pressure is regulated at full throttle? ie by opening/closing the DV to maintain around the requested pressure?
My pressure charts always show a climb then an up/down/up/down at peak pressure.

Not that I know anything about these things.
 
I have had exactly the same problem and am in a panic about it. I was wondering do you need a specific remap for the CAI?? My car almost feels a little under power as well. DV valve is fine on mine too.
 
Cheers, just weird that my Mk5 Golf never done it!
 
Sounds wrong though, sounds like its dumping boost which isnt what you want on full throttle!
 
Was your Golf an Ed30 or standard GTI?
If it was a standard Gti they never done it due to the different way the dv was setup.
My S3 does it and my previous Cupra R (same engine) done it.
Just boost being regulated by the dv.
 
My car has only done it since the CAI has been fitted. I replaced the old engine cover the other day and it made the same noise just not as loud. It didn't used it do it. Was yours the same Gaz?
 
I'm sure sound in the intake and back from the turbo is Amplified by the cai, the standard air box cuts all the noise out. You just notice it more now
 
Sounds like its mapped on the surge line.. Its normal apparently.. Mine does this as well.. Does it only happen WOT in higher gears around 3-4k revs?
 
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S3_Mat said:
Sounds like its mapped on the surge line.. Its normal apparently.. Mine does this as well.. Does it only happen WOT in higher gears around 3-4k revs?
Click to expand...

I'd agree with that.

On my old K04,the car would do that,and to an extent with the GT3071,but the current 3076,with it's anti-surge housing etc,doesn't have any issues.
 
happens to mine too, I run Revo CAI apparentley there is too much air trying to get into the engine which turbo cannot force in. It wont damage the engine and is fine to drive with it.
 
RedDejavu said:
happens to mine too, I run Revo CAI apparentley there is too much air trying to get into the engine which turbo cannot force in. It wont damage the engine and is fine to drive with it.
Click to expand...

I'm no expert but physics is driving this. I wouldn't say "too much air trying to get in". The turbo is the drive for the air, it will push as much as can it can force into the engine. The CAI removes the stock air box allowing the turbo to take as much air as it needs.
 
The noise only occurs 4th gear upwards and about 3500rpm and the last time I researched and enquirer about this I was told its the boost level reaching max allowed boost so is bled off by the diverter to maintain the requested boost level.
Noticeable on the k04 car as the diverter blends this pressure in to the intake system which is heard with an intake fitted, this noise is usually almost silent on stock engine cover.
This is the same as anything else once you hear it once you tune in to that noise and notice it all the time even if its done it for months unheard.
 
From memory I can only get it in 4th upwards when the engine load allows the boost level to reach specified target
 
mechanic69 said:
I'm no expert but physics is driving this. I wouldn't say "too much air trying to get in". The turbo is the drive for the air, it will push as much as can it can force into the engine. The CAI removes the stock air box allowing the turbo to take as much air as it needs.
Click to expand...

"too much air" is actually correct. Or more correctly the engine cannot flow enough air for a given pressure. The turbo can only flow what the engine is flowing and this flow level is on the surge line if the turbo.

Rick
 
Rick @ Unicorn Motor Dev. said:
"too much air" is actually correct. Or more correctly the engine cannot flow enough air for a given pressure. The turbo can only flow what the engine is flowing and this flow level is on the surge line if the turbo.

Rick
Click to expand...

OK so the restriction is the engine /exhaust, the turbo pushes what it can in and the CAI supplies the air required by the turbo?
 
No the engine and exhaust can flow much more than the K04 could produce, but at a certain given time the turbo can be producing more boost pressure than the engine needs- and vents the excess boost off via the diverter valve, im presuming thats what Rick means although the wastegate is what really should be controlling the boost by diverting exhaust gasses away from the turbo to stop it continuing to build un-required pressure.
 
Hi there, this happens with my S3 too.

I'm running Revo 2+ with an ITG Maxogen CAI.

I was also concerned by the sound - that sounds like fluttering when you're flooring it - but was told that this is a standard feature of the setup I've got, and nothing to worry about...
 
KentKid said:
Hi there, this happens with my S3 too.

I'm running Revo 2+ with an ITG Maxogen CAI.

I was also concerned by the sound - that sounds like fluttering when you're flooring it - but was told that this is a standard feature of the setup I've got, and nothing to worry about...
Click to expand...


you should be worried that you need a bigger turbo :)
 
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I have the same problem , just had the actuator changed for a forge one did the diverter and n75 too .. got a CAI and turbo back decat and the noise on full boost is unreal in every gear.... got someone coming wed to take a look and plug it in to check all is ok
 
mine's stage 2+ (365hp) and does this between about 3000-4000rpm too (and in all gears). it's partial surge due to running close to the compressor surge line, which is where best efficiency is (compressor efficiency, not fuel efficiency).

i logged a couple of acceleration runs and sent the data to R-Tech who did my remap and they were not concerned at all.

It's pretty normal - the K04 can handle it pretty well and there has been very few failures
 
lincoln_dj said:
mine's stage 2+ (365hp) and does this between about 3000-4000rpm too (and in all gears). it's partial surge due to running close to the compressor surge line, which is where best efficiency is (compressor efficiency, not fuel efficiency).

i logged a couple of acceleration runs and sent the data to R-Tech who did my remap and they were not concerned at all.

It's pretty normal - the K04 can handle it pretty well and there has been very few failures
Click to expand...

Surge,partial or otherwise,isn't what you want to see,although to get close to it is fine....when surge begins to occur,you're getting flow limiting,as well as other problems,indicating the airflow is beyond optimal,and the time to get something bigger has arrived....
 
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Mine does it all the time any RPM/Gear etc - It's been descirbed as a "Horse" lol.
 
I've had my 8p mapped about a week and only just noticed it when u wot in 2nd and 3rd u can here it worse it sounds like you diverter is going off its nuts letting the air out while under load. Thought I'd broke the diverter valve as mines the old revision c still but from all your guys answers its common on a mapped s3.. I have a cdl with a stage 2 r tech map and I'd say it happens between 3 and 5 maybe? Under hard load. It's kind of the same noise as when u have the front windows down on the motorway at 70
 
I’m having a similar issue as you guys are describing. Mine just started doing it last week a few days after I put my apr intake on. 15 8v a3 2.0 with is38 map from apr. I thought my diverter had gone bad so I swapped a new revision c in to see if it made any difference and it didn’t only notice the flutter at wot in 3 and up definitely feels at loss for power when Its fluttering. Also noticed if I let out quickly then get back into it in 3rd it goes away and I can hear the turbo spool better. Haven’t had enough room to test in 4th or higher..
 
8va3is38 said:
I’m having a similar issue as you guys are describing. Mine just started doing it last week a few days after I put my apr intake on. 15 8v a3 2.0 with is38 map from apr. I thought my diverter had gone bad so I swapped a new revision c in to see if it made any difference and it didn’t only notice the flutter at wot in 3 and up definitely feels at loss for power when Its fluttering. Also noticed if I let out quickly then get back into it in 3rd it goes away and I can hear the turbo spool better. Haven’t had enough room to test in 4th or higher..
Click to expand...

Compressor surge - normal on mapped vehicles. Custom maps map around this, I’d suspect Apr do too but can’t confirm as it’s not ‘custom’. Possibly post in the 8V section as this is the 8P - they may be able to help too.
 
Do your dyno look anything like this as everyone whos seen this has said something is wrong but unable to tell me what it is. Ive been trying ro find an answer for 3 months nkw after installing my revo intake but ive noticed i have a big difference in terms of bhp and whp which has me a little worried, i also get the fluttering after 4th after giving it the beans, but i bought the car assuming it was stock View attachment ov11jyw(1).pdf

Sent from my SM-N960F using Tapatalk
 
Readings look like a stock engine but I'm no Tuner. As the intake temps are rising the power is reducing. There is a bit of a torque spike @3000 RPM which doesn't look right but then I wouldn't know... Chatter is normal with this turbo, and now you have the Revo the sound is more pronounced
 
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samuelh_888 said:
Readings look like a stock engine but I'm no Tuner. As the intake temps are rising the power is reducing. There is a bit of a torque spike @3000 RPM which doesn't look right but then I wouldn't know... Chatter is normal with this turbo, and now you have the Revo the sound is more pronounced
Click to expand...
Cheers mate, yea i found an old post back from 2014 whoch sounded like the same thing as its probably tuned near the surge line as that where is most efficient and the revo is what is making it all.the more audible, my only concern now is the power spike as i can understand power drop after each run due to it having the ****** OE plastic shroud I/C known to have heat soak issues

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e9_mustii said:
Cheers mate, yea i found an old post back from 2014 whoch sounded like the same thing as its probably tuned near the surge line as that where is most efficient and the revo is what is making it all.the more audible, my only concern now is the power spike as i can understand power drop after each run due to it having the ****** OE plastic shroud I/C known to have heat soak issues

Sent from my SM-N960F using Tapatalk
Click to expand...

Na, the ic isn’t going to be that inefficient because it has the plastic caps.

The plastic end-caps are more prone to leaking but you don’t read too much about that issue here right, so how much of an issue is it?

When my S3 was mapped to Stg2 with the stock ic, all 6 dyno runs were working about 1 deg of each other. .
 
samuelh_888 said:
Na, the ic isn’t going to be that inefficient because it has the plastic caps.

The plastic end-caps are more prone to leaking but you don’t read too much about that issue here right, so how much of an issue is it?

When my S3 was mapped to Stg2 with the stock ic, all 6 dyno runs were working about 1 deg of each other. .
Click to expand...
Thats the thing day to day diving is fome but then again this is my first s3 kve droven and bought whoch was supposedly stock, when my first oil change i noticed it the mid red was deleted and thought id have it dyno'd for peace of mind, at sa tuning now i wasnt to keep cause he spoke like he knows it all plus the car was on a brand new dyno they had installed i basicly had the first run on it so there may be a factor or two in there which is throwing me off, which he also told.me my car was unhealthy but wouldn't be specific,
I just want peace of kind and if something is wrong then at least have an idea where to start

Sent from my SM-N960F using Tapatalk
 
samuelh_888 said:
Na, the ic isn’t going to be that inefficient because it has the plastic caps.

The plastic end-caps are more prone to leaking but you don’t read too much about that issue here right, so how much of an issue is it?

When my S3 was mapped to Stg2 with the stock ic, all 6 dyno runs were working about 1 deg of each other. .
Click to expand...
Yea but u can also see the big different in hp drop.from engine to wheel when its mostly 15% difference mine is much higher

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If the tuner himself says the readings may not be accurate then hard to know what the status is. When the summer temperatures drop get to RTech for a dyno session and map if needs be.

Don’t worry about chasing numbers and the difference between engine to wheel hp - you need to make sure it’s a safe map and all the fuel, boost, timing settings are correct.
 
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samuelh_888 said:
Did he have a fan in his dyno cell blowing cool air into the front of the car?
Click to expand...
No clue because the won't let see the car when on the dyno and they close it in a sound proof box which was the first thing i was suspicious about. But i was considering that when it gets cold again around Octoberish, abit of a drive but if he can sort it out on the day happy days assuming its nothing major

Sent from my SM-N960F using Tapatalk
 
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