[Hotter]

Hi, I have just received my TURNER silicone intake boot for N52, but its quality does not look amazing. It has some groves/scratches inside of it. Is it acceptable and should I use it?

[Skoidat69]

You'll be fine but it wouldn't hurt to send then an email about the condition it was received n..

[Hotter]

Intake seems to have few bigger groves/scratches, and a lot of micro groves (air bubbles when making it?).

Should the silicone boot have completely smooth inside surface? Is it still better then OEM plastic one?

[E92_William]

What part of the intake are you talking about? The manifold behind the throttle body often isn't perfect because of the way the plastic parts of it are joined together, some are worse than others.

[Hotter]

Originally Posted by E92_William

What part of the intake are you talking about? The manifold behind the throttle body often isn't perfect because of the way the plastic parts of it are joined together, some are worse than others.

I am talking about this OEM part:


VS

Silicone part (which I bought):


I am wondering does all silicone intake boots have such imperfect surface inside?
Intake seems to have few bigger groves/scratches, and a lot of micro groves (air bubbles when making it?).
Is it normal or I got some kind of used one or badly made?

[The Nightman]

Looks like a manufacturing defect - the silicone hose should be completely smooth.

The stock hose contains a Helmholtz resonator and it isn't just for sound reduction. I notice more low-mid range torque at partial throttle with the stock hose (which is what the resonator should be tuned to do) while the silicone hose might've had more power at WOT.

[hassmaschine]

yeah, I don't buy that it does anything for power or torque. it's before the throttle plate for one, which would mess up an resonance effects. it's meant for sound reduction.

I wouldn't worry about that tiny defect. There's not much flow happening on the surface of that tube, and the stock one isn't exactly perfect either.

[The Nightman]

Originally Posted by hassmaschine

yeah, I don't buy that it does anything for power or torque. it's before the throttle plate for one, which would mess up an resonance effects. it's meant for sound reduction.

I think all resonator chambers are before the throttle body. It's possible the primary resonator is for torque tuning while additional chambers are for sound tuning. For example, the 530i has an additional resonator, likely to reduce induction noise on a more luxurious platform. Meanwhile, the Z4 has an additional branch identified as a "sound generator" for more noise on a roadster? Anyway, it's all speculation without any information from BMW, but I like to believe there is some power tuning involved.

E60 530i:

https://www.realoem.com/bmw/enUS/sho...diagId=13_1029

E86 Z4 3.0si:

https://www.realoem.com/bmw/enUS/sho...diagId=13_1173

Here's an Alfa Romeo employee explaining how they use resonators: https://physics.stackexchange.com/a/411272

I also attached a page from a Mazda training manual showing how a Helmholtz resonator pre-throttle body (No.2) is tuned to increase mid-RPM torque. The first resonator (No.1) is pre-filter and identified as a silencer.

[Biginboca]

It’s seems possible to me a helmholtz resonator on an intake could increase power and torque.

https://www.dundonmotorsports.com/

These guys produce headers for the Porsche 781 GT4 that add like 40whp which is way more than other companies and they have a helmholtz resonator on their headers which they claim does exactly that, adds more power and torque than any other headers for the platform.






If the resonator can add power in the exhaust side then I think it might add on the intake side also if properly implemented.

[Hotter]

We need that someone would dyno it. Maybe someone did the dyno already for OEM and this Silicone intake boot?

[hassmaschine]

Yes, people already dynod it. the increases were small but the hoses are also cheap. there was no loss of torque. I just like the sound better personally.

[neilvan]

Originally Posted by Guy Fieri;27707434

I think all resonator chambers are before the throttle body. It's possible the primary resonator is for torque tuning while additional chambers are for sound tuning. For example, the 530i has an additional resonator, likely to reduce induction noise on a more luxurious platform. Meanwhile, the Z4 has an additional branch identified as a "sound generator" for more noise on a roadster? Anyway, it's all speculation without any information from BMW, but I like to believe there is some power tuning involved.

E60 530i:
[img

https://file.euroauto.ru/v2/file/parts/used/1035/60/21/51602121/6.jpg[/img]
https://www.realoem.com/bmw/enUS/sho...diagId=13_1029

PS My 530 N52 does not have the extra resonance chamber; Its just on the top side instead of the bottom where the E90's is

[CTinline-six]

I doubt there are any power gains from this that could be seen on a dyno, maybe 1 or 2 hp.

With that said, I have the Mishimoto silicone tube on my car, along with the Euro intake box and each of those mods helped reduce the "dead spot" when first pressing the gas to accelerate from a stop while in 'D' on my automatic car.

A friend added the silicone tube and deleted the charcoal filter on her E91 and noticed the same gain. The car doesn't seem to have any more power, just a bit more response off the line, which to me is worth it for the low cost to improve the drivability.

[Hotter]

Originally Posted by CTinline-six

With that said, I have the Mishimoto silicone tube on my car, along with the Euro intake box and each of those mods helped reduce the "dead spot" when first pressing the gas to accelerate from a stop while in 'D' on my automatic car.

Did your Mishimoto silicone tube have completely smooth inside?

[E92_William]

The stock tube looks like a vacuum cleaner hose with a hole and a box attached to it so there's no way it can get any worse. Also the intake itself will have more ridges and flow restrictions due to the way it's molded together than that small imperfection

[CTinline-six]

Originally Posted by Hotter

Did your Mishimoto silicone tube have completely smooth inside?

It is completely smooth inside, although I doubt the small imperfection inside yours will cause any issues or get worse over time.

[The Nightman]

Originally Posted by E92_William

The stock tube looks like a vacuum cleaner hose with a hole and a box attached to it so there's no way it can get any worse. Also the intake itself will have more ridges and flow restrictions due to the way it's molded together than that small imperfection

It's possible that removing the resonator could actually do more harm than good. Here's something from Porsche that explains how the resonator helps reduce air fluctuation and pulsation after the MAF sensor (yellow box):


Mercedes using a resonator to reduce intake noise and improve air flow between 3500-4500 rpm:


Mishimoto testing also found that the resonator decreased pressure drop:
https://www.mishimoto.com/engineerin...e-2018-rd-pt7/
https://www.mishimoto.com/engineerin...e-2018-rd-pt8/

Testing on an MR2 found smoother MAF readings with the resonator:
https://www.mr2oc.com/threads/intake...esting.683305/


tl;dr: it's likely that engineers smarter than us used the resonator for a reason other than sound

[desertman123]

Time to load up the CFD software.

[Hotter]

Not sure who I should believe now

[The Nightman]

Originally Posted by Hotter

Not sure who I should believe now

Smooth toob go brrrrrrrrrr

[hassmaschine]

You keep posting that but it's already been dyno proven. this isn't a porsche and that box isn't for torque. We already have a system for that - it's the 3-stage intake manifold.