1.2TSI Resonator Delete Info

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Jay-Jay
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Re: 1.2TSI Resonator Delete Info

Post by Jay-Jay »

It's not that easy to say.
It depends on the engine compression, on the engine timing, on the exhaust/intake valves diameter, on the turbo dimensions, on the turbo pressures, on the intake hose diameter, etc.
There so many factors...

I can just hope that I will not have a loss of torque at low rpm.
Considering my ECU is remapped and my turbo pressures are higher than stock (1,25bar of peak and 1,1bar of costant), maybe a less restricted exhaust will allow my (little) turbo to spin easier at any rpm.

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Re: 1.2TSI Resonator Delete Info

Post by iichel »

interesting write-up. I'm not an engineer, but I guess most of the backpressure is coming from the turbo and the 4-1 log-style exhaust manifold is also not optimised for low-end performance (little exhaust scavenging) but more for maintaining mass flow to the turbo at higher RPM. but correct me if I'm wrong.
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Jay-Jay
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Re: 1.2TSI Resonator Delete Info

Post by Jay-Jay »

Yes, the turbo (more precisely, the exhaut side, a.k.a. "hot" side) certainly is an obstacle to the exhaust gases.
But maybe what gives the most of the backpressure is the OEM catalytic converter (800 cells?).
I know that, after removing the cat and doing a complete cat-back exhaust on my engine, the tuners can increase the turbo pressure at 1,35/1,4bar of peak and 1,3bar of costant, with a power output of 145-150hp (search for JayWan's polo on YouTube).
The torque figure would extremely change, of course, with a peak at higher rpm (which I don't want).
And that would make the exhaust sound too loud and aggressive for my taste [emoji38]

Obtaining a decent exhaust sound from this engine without changing the torque figure seems to be pretty tricky, because backpressure is necessary to allow the little turbo to kick-in at low rpm (around 2000rpm) like when all it's stock (tell me if I'm wrong on this!).
So, in order to not loose torque at low rpm, I guess I need to maintain the proper level of backpressure in the exhaust.
This consideration makes me exlude:
- deleting the downpipe;
- doing a cat-back exhaust;
- installing larger pipe (Ø60mm or Ø70mm).

Considering I've already installed a less restrictive muffler (6R GTI muffler), but I would like a bit more of exhaust sound, the only remaining thing is to delete the resonator, replacing it with a straight pipe (Ø45-50mm), hoping it will not affect the torque figure or that it will be unnoticable.

If someone has done this mod before, I would be very grateful if he/she could share his/her experience. :)
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Jay-Jay
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Re: 1.2TSI Resonator Delete Info

Post by Jay-Jay »

Thi is an example of how it could be done:
Image
Image
Image


Now, let's talk about pipe's diameter!
The pipe coming from my resonator to the muffler is Ø50mm.
The pipe coming from the 6R GTI muffler is Ø55mm.
The Ø50mm resonator's pipe perfectly fits into the Ø55mm muffler's pipe. Then they are welded together.

So, I could buy a 6Q0253201 (or A/E/F) straight pipe, which is Ø50mm, the same as my resonator's pipe.

But...
On the other resonator's side, the pipe that goes to the cat is Ø45mm.
Infact, ETKA indicates that the dual clip is Ø45mm.
Image

So I'd need a reduction from Ø50mm to Ø45mm.

Alternatively, I could buy a Ø45mm straight pipe, which will fit into the dual clip with no problems, and I could link it to the GTI muffler with an adaptor (from Ø45mm to Ø50mm).
In this second case, will a Ø45mm straight pipe give more backpressure than a Ø50mm straight pipe? :)
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Jay-Jay
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Re: 1.2TSI Resonator Delete Info

Post by Jay-Jay »

Resonator delete done with a Ø50mm straight pipe!
Image
Image
Image



I don't feel any loss of torque at low rpm. Turbo kicks-in exactly like before. Only more sound!
I'm very satisfied.
Last edited by Jay-Jay on Sat Jun 16, 2018 2:07 am, edited 1 time in total.
Ricmondo
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Re: 1.2TSI Resonator Delete Info

Post by Ricmondo »

Yes and no.

Some Turbocharged intalations are tuned to a predetermined level of back pressure to fine tune power delivery. The difference might be apparent on a sensitive dynometer but I doubt if it would be apparent in road use where throttle settings are dictated by traffic, speed limits and hopefully common sense. A well used engine will probably not derive any benefit from such micro management.

In real life changing the middle components will change the noise, any other change will be slight and subjects to swings and roundabouts.

The downside is that the vehicle will no longer pass the toughened MoT requirements if the test centre is on the ball, the publicity may have been about the removal of cats and filters but be aware the regulations in their entirety go much further.

Things may be better or worse if you live outside the UK.
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Re: 1.2TSI Resonator Delete Info

Post by Jay-Jay »

I live in Rome (Italy) where the requirements for passing the MoT test could be different from UK.
I've seen many cars pass the test with a much, much (MUCH!) louder exhaust than mine! :)

Talking about performance, I can't feel any difference at all. A dyno could tell better, but I daily drive on the road, where (as you wrote) the conditions are different than on a dyno. :)

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Re: 1.2TSI Resonator Delete Info

Post by Ricmondo »

Hi Jay-Jay, having driven in Rome a few times and survived multiple death by motor scooters I think anybody who drives there on a day to day basis is a hero, you have my respect.

In the past I owned a series of MGBs, I always used to change the centre box for plain pipe, made no difference to noise or performance but was great for ground clearance.

I’m pleased it has worked well for you.
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Re: 1.2TSI Resonator Delete Info

Post by Jay-Jay »


Ricmondo wrote:[...]I think anybody who drives there on a day to day basis is a hero, you have my respect.[...]
Ahahah, thank you! :)
Ricmondo wrote:[...]
I’m pleased it has worked well for you.
Yeah! I am very satisfied. Performances are the same: maybe thanks to the ECU remap and the bigger intake hose with Pipercross air filter.
The sound is exactly what I was looking for! The 6R GTI muffler is the key of this sound.
I have a friend who owns a 6R 1.2TSI with resonator delete and standard single-pipe muffler and his sound is much more quiet and muffled than mine.
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Re: 1.2TSI Resonator Delete Info

Post by gtsportms »

Jay-Jay wrote: Sun Jun 10, 2018 11:11 pm
Ricmondo wrote:[...]I think anybody who drives there on a day to day basis is a hero, you have my respect.[...]
Ahahah, thank you! :)
Ricmondo wrote:[...]
I’m pleased it has worked well for you.
Yeah! I am very satisfied. Performances are the same: maybe thanks to the ECU remap and the bigger intake hose with Pipercross air filter.
The sound is exactly what I was looking for! The 6R GTI muffler is the key of this sound.
I have a friend who owns a 6R 1.2TSI with resonator delete and standard single-pipe muffler and his sound is much more quiet and muffled than mine.
You used the 6R GTI intake only or other parts too? The Funnel got so many holes..
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Jay-Jay
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Re: 1.2TSI Resonator Delete Info

Post by Jay-Jay »

I installed only these parts:
- 6R0 129 618 D;
- 6R0 129 621 B.

This is a new video I've just uploaded:
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Re: 1.2TSI Resonator Delete Info

Post by vis »

How about replacing resonator with straight pipe AND replacing muffler with salvaged resonator?
From UU>-R-M-
.....To UU>---R-
Could it be done without too much fiddling?
What kind of sound one should expect?
Would it work with a subsequent remap?
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Re: 1.2TSI Resonator Delete Info

Post by obiehakerman »

Hi @Jay-Jay .

You seemed really clued up or/and experienced with exhaust work on this so i had a few quesitons. I've got a 2017 polo 1.2tsi, I am looking at fitting an Electric Exhaust Cutout before the resonator but after the CAT. Most of the cutout kits come as 2.5" diameter and was wondering if you would know if that would fit and where i could do it. Don't have access to a lift until i actually begin the install so trying to gain all the knowledge before hand.

Cheers.
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Jay-Jay
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Re: 1.2TSI Resonator Delete Info

Post by Jay-Jay »

2,5" is 63,5mm of diameter.
As far as I know, the exhaust of the 1.2TSI EA211 engine has 55mm of diameter from the CAT to the resonator, so it is smaller than the cutout you want to install.
You'll need to put some adaptors.
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Jay-Jay
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Re: 1.2TSI Resonator Delete Info

Post by Jay-Jay »

A new video of the acceleration sound (with some pops and crackles).

When ASR activates (loosing traction), the exhaust produces a very loud crackle: unfortunately there was too much traffic when recording yesterday and I've not been able to make it do it.
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