[The Nightman]

BDS claims that silicone intake boots are worse than the stock boot. Their dyno shows a loss of 6bhp and 2Nm with the Mishimoto silicone hose compared to stock. I suppose this supports the belief that the resonator on the stock boot is a tuned Helmholtz resonator and not a silencer.

"we also conducted a comparative analysis between the silicone hose solution and the stock intake system. Astonishingly, our findings revealed that the silicone alternative actually performed worse than the original resonated tube."

https://bdsmotorsport.co.uk/store-1/...52-intake-boot

Then they go on to push their own product (which seems to also delete the resonator) and unless I'm missing something, they share no evidence that their intake duct is superior other than a bunch of marketing wank that borders on a word salad.



tldr save your money

[MOD.Works]

They are right.
The silicone boot resonates and its shape changes, which slightly affects the air flow. Hard pipe is better, but I don't think the difference is big.

[Jros]

in my case it gave me negative LTFT, i guess the stock Helmholtz resonator kills some resonance / turbulence that affects MAF readings. Using euro airbox.

Switched back to stock resonated tube, noticed more refined intake sound and honestly no difference at all in power or response. But now normal fuel trims.

[Hotter]

So should I replace my silicone intake hose back to stock one?
Anyone else tested this on dyno?

[Tambohamilton]

Originally Posted by The Nightman

tldr save your money

100% agree

[AmuroRay]

Hmmm, I don't know if I agree. I'm sure it was dyno tested to increase power, and when it comes to intakes, I know Diameter of the tube (and length) play a key role. That tube looks to be smaller than the TB diameter.

When I dyno tested a few intakes (AFE, Stock and Injen) the INJEN made the most torque and was 1whp off from peak of the AFE airbox. I should have stuck with it.

[gunnerxq]

There were multiple old dynos that showed the silicone boot had increased power.

[ZimZimmmmer]

Originally Posted by gunnerxq

There were multiple old dynos that showed the silicone boot had increased power.

I was really close to getting the BDS Intake Boot because of it's material qualities (metal) but I chose a silicone because of the sheer amount of people that have. Basically, my decision was based on "well if silicone is that bad, then no one would advocate for it this much" also this video helped solidify this decision:

However, what I hardly see from any commenter is the mention of the maximum working temperatures that a silicone hose can operate at. I opted for a Mishimoto intake boot (which I have read is a popular brand) This intake boot works at a max temp of 330°F (approx 170 Celsius if you are over the water like myself - UK). We all know that the engine bay gets really hot, hotter than the max temp of many silicone variants. So why is metal intake boots with the possibility of using heat shielding coatings not more favourable? Am I missing something? Please point this out to me

My project car is a 330i N52 which is an naturally aspirated engine. Therefore I can't make major gains from tweaks here and there. But the little gains I do make, I want to make with my best take. So keeping air cold and dense as much a possible is super important to me.

Purpose of my project car: A little bit faster to give me a kick when driving on a daily but comfortable whilst doing so.

Current Mods:
B4 Coilovers
K&N Filter
EuroBox (currently working on a Dinan style adaptation to incorporate more air from the front bumper).
Awaiting to install the Silicone Intake Boot as per post.
Awaiting to install MILVS

Planned Mods:
Air scoops because they 100% work according to other commenters.
Exhaust headers though I can't find a supplier who sells RHD Exhaust headers. Recommendations welcome?
xHP Remap. Recommendations welcome?
Change Drivetrain to a 3.91 ratio for torque gains. Advice on this welcome.
10-20mm Wheel Spacers to not unstable the car

Any advice /recommendations welcome. I am newbie to mechanic work but not afraid to pick up a tool to get it done.