[E90jacob]

Today I figured I'd set the point straight with wether the silicon intake elbow is legit or not.

I ran some test for temperature and flow.

Both tests were at operating temperature one reading per minute.

At idle the silicone elbow was 2.4F cooler on avg than the plastic oem elbow.

In addition to the cooler temperatures, I decided to do a flow test.
Flow test was at Cruise control 50mph 4th gear EAST on the same strip of road. I also did the same test at 25mph 2nd gear.

As shown in the paper. On avg the silicone elbow offered .43psi more flow at 50mph, and .48psi more flow at 25mph.

In conclusion, the silicone elbow is actually better for flow and intake temps. The oem plastic one is too thin and doesn't insulate as well as the silicone elbow does, this results in better intake temps. With lower intake temps, you get more oxygen molecules per psi. The oem plastic elbow also has corrugated plastic and a resonator box that both reduce flow, therefore the silicone elbow also offer almost .5psi more flow.

The horsepower: with .5psi more flow and 2.4F or more cooler temps. You're looking at about 5hp more. Of course once your 5hp goes through the trans,diff, and wheels. You maybe have 1 solid whp. Happy tracking

[E90jacob]

Originally Posted by E90jacob

Today I figured I'd set the point straight with wether the silicon intake elbow is legit or not.

I ran some test for temperature and flow.

Both tests were at operating temperature one reading per minute.

At idle the silicone elbow was 2.4F cooler on avg than the plastic oem elbow.

In addition to the cooler temperatures, I decided to do a flow test.
Flow test was at Cruise control 50mph 4th gear EAST on the same strip of road. I also did the same test at 25mph 2nd gear.

As shown in the paper. On avg the silicone elbow offered .43psi more flow at 50mph, and .48psi more flow at 25mph.

In conclusion, the silicone elbow is actually better for flow and intake temps. The oem plastic one is too thin and doesn't insulate as well as the silicone elbow does, this results in better intake temps. With lower intake temps, you get more oxygen molecules per psi. The oem plastic elbow also has corrugated plastic and a resonator box that both reduce flow, therefore the silicone elbow also offer almost .5psi more flow.

The horsepower: with .5psi more flow and 2.4F or more cooler temps. You're looking at about 5hp more. Of course once your 5hp goes through the trans,diff, and wheels. You maybe have 1 solid whp. Happy tracking

To back up my claims here's a user that did a dyno to prove the gains

[Phil325i]

You can also wrap the silicon and other parts of the intake with gold heat wrap to reduce intake temp further...

[The Nightman]

I don't believe the silicone intake hose is better than the stock hose. The Helmholtz resonator smooths airflow and yields better mid-range power at partial throttle. Unfortunately no proof of this from BMW, but lots of references from other manufacturers documenting the use of similar resonators for those purposes. It seems that BMW adds additional resonators for sound tuning. Eg the Z4 intake hose has an additional "sound generator" branch for more induction noise, while some E60 models have an extra resonator presumably for noise reduction.

I had both and went back to the stock hose after my butt dyno felt it was more responsive in daily driving conditions. People keep claiming the silicone hose is dyno proven but I've yet to see an actual dyno graph. 2 whp is noise and I would rather have more usable mid-range power than an insignificant increase in peak power.

https://www.e90post.com/forums/showp...34&postcount=8
https://www.e90post.com/forums/showp...5&postcount=17

[E90jacob]

Originally Posted by Guy Fieri

I don't believe the silicone intake hose is better than the stock hose. The Helmholtz resonator smooths airflow and yields better mid-range power at partial throttle. Unfortunately no proof of this from BMW, but lots of references from other manufacturers documenting the use of similar resonators for those purposes. It seems that BMW adds additional resonators for sound tuning. Eg the Z4 intake hose has an additional "sound generator" branch for more induction noise, while some E60 models have an extra resonator presumably for noise reduction.

I had both and went back to the stock hose after my butt dyno felt it was more responsive in daily driving conditions. People keep claiming the silicone hose is dyno proven but I've yet to see an actual dyno graph. 2 whp is noise and I would rather have more usable mid-range power than an insignificant increase in peak power.

https://www.e90post.com/forums/showp...34&postcount=8
https://www.e90post.com/forums/showp...5&postcount=17

Wrong. The test literally should that at mid rpms you're gaining more power and flow than the stock one. And please also remember that the silicone is a lot better at insulating the intake from the engine heat than that cheap thin plastic. And of course the corrugated tunnel way disrupts airflow along with the resonator which isn't even an empty box. If you cut it open you'll see there are plenty of walls to mess with airflow and trap air inside.

While you are correct about the "sound tuning" aspect, the only sound you're changing is wether or not the intake makes a sucky sucky noise. Please don't lie and tell me you hear a difference in the exhaust from a plastic pipe

[hassmaschine]

Originally Posted by Guy Fieri

I don't believe the silicone intake hose is better than the stock hose. The Helmholtz resonator smooths airflow and yields better mid-range power at partial throttle. Unfortunately no proof of this from BMW, but lots of references from other manufacturers documenting the use of similar resonators for those purposes. It seems that BMW adds additional resonators for sound tuning. Eg the Z4 intake hose has an additional "sound generator" branch for more induction noise, while some E60 models have an extra resonator presumably for noise reduction.

I had both and went back to the stock hose after my butt dyno felt it was more responsive in daily driving conditions. People keep claiming the silicone hose is dyno proven but I've yet to see an actual dyno graph. 2 whp is noise and I would rather have more usable mid-range power than an insignificant increase in peak power.

https://www.e90post.com/forums/showp...34&postcount=8
https://www.e90post.com/forums/showp...5&postcount=17

You say there's no proof, then you use your butt dyno as proof.. Okaaaay..

I'm not going to dig through 10 years of posts to find the dyno charts, but I know they exist and I have seen them.

[E90jacob]

Originally Posted by hassmaschine

You say there's no proof, then you use your butt dyno as proof.. Okaaaay..

I'm not going to dig through 10 years of posts to find the dyno charts, but I know they exist and I have seen them.

^
I even showed a screenshot from someone else's forum showing that there were proven gains from the elbow upgrade.