Restrictive air intake

[N54CoupeHP]

What's a good way to measure if an air intake is too restrictive for the turbos?

Thanks in advance.

 

[derekgates]

Hmm. You can dyno the intake lid open vs. closed?


BuraQ did some extensive testing on an aFe intake which eventually became https://afepower.com/afe-power-54-76306-momentum-gt-pro-5r-cold-air-intake-system

He shows the modifications he did and the results compared to stock

https://www.e90post.com/forums/showpost.php?p=11735900&postcount=1

A followup thread: https://www.e90post.com/forums/showthread.php?t=1245659 with FAR more detail


If you feel like the stock is restricted, consider the Mr.5 Intake:

• Updated Mr. 5 Intake - Mr.5 enlarges holes for the side intake to 3"
• 'Mr. 5 Intake'... Zasquatch style - Custom CNC flange and CAI filter in lower bumper
• DIY - SyndicateGT's Custom Intake
• Custom Cold Air Intake with K&N Apollo supplemental airbox - PPK (like 335is) PS relocation, K&N Apollo CAI fed from lower bumper, PS reservoir relocated to fit Apollo behind fan relay for PPK

If you are 'room limited' like my 335is consider extra airflow with a Z4 35is lid like I did on my car:

I went this route after being recommended by BuraQ (BQ Tuning) as it ensures the maximum airflow is being delivered to the inlets on the stock box. You can see the massive reduction in the stock box of the 335i/s compared to the Z4 35is...

I didn't want to suck in hot air from engine bay and also wanted the noise under control. My car uses the ram air system and maximizes flow now.


Otherwise without dyno, not sure how to test? Someone else will have to chime in...

 

[N54CoupeHP]

Hmm. You can dyno the intake lid open vs. closed?


BuraQ did some extensive testing on an aFe intake which eventually became https://afepower.com/afe-power-54-76306-momentum-gt-pro-5r-cold-air-intake-system

He shows the modifications he did and the results compared to stock

https://www.e90post.com/forums/showpost.php?p=11735900&postcount=1

A followup thread: https://www.e90post.com/forums/showthread.php?t=1245659 with FAR more detail


If you feel like the stock is restricted, consider the Mr.5 Intake:

• Updated Mr. 5 Intake - Mr.5 enlarges holes for the side intake to 3"
• 'Mr. 5 Intake'... Zasquatch style - Custom CNC flange and CAI filter in lower bumper
• DIY - SyndicateGT's Custom Intake
• Custom Cold Air Intake with K&N Apollo supplemental airbox - PPK (like 335is) PS relocation, K&N Apollo CAI fed from lower bumper, PS reservoir relocated to fit Apollo behind fan relay for PPK

If you are 'room limited' like my 335is consider extra airflow with a Z4 35is lid like I did on my car:


I went this route after being recommended by BuraQ (BQ Tuning) as it ensures the maximum airflow is being delivered to the inlets on the stock box. You can see the massive reduction in the stock box of the 335i/s compared to the Z4 35is...

I didn't want to suck in hot air from engine bay and also wanted the noise under control. My car uses the ram air system and maximizes flow now.


Otherwise without dyno, not sure how to test? Someone else will have to chime in...

Thanks for responding, I have the aFe Momentum GT intake, and I was curious if it would choke upgraded twin turbos.

 

[derekgates]

Thanks for responding, I have the aFe Momentum GT intake, and I was curious if it would choke upgraded twin turbos.

Oh well sheesh you are already ahead of the game. @BQTuning helped develop that intake and I hiiiiighly doubt you will run into restrictions. The stock box can flow quite a bit, Z4 lid even more, Mr.5 even more and then the aFe should be equal or greater than the Mr.5.

Dynos with opening the intake and comparing to closed would be the only way to answer your question objectively.

 

[RSL]

Thanks for responding, I have the aFe Momentum GT intake, and I was curious if it would choke upgraded twin turbos.

Virtual Dyno, but you need to be really careful with logging to be comparable.

Maybe depends how big on the hybrids, but I've not seen any difference in output or boost/WGDC between DCI, AFE SI, AFE Elite, ECS CF and stock airbox with scoops and inlets on all with 15Ts at 21-22psi. Tested the boxes opened and closed as well and intake swaps back to back same day, same map.

Open intake/lid show gains on the dyno because they shorten the intake tract, which is vacuum only, and reduce pressure drop accordingly. Hot side inlets take those physics about as far as it can go in these cars.

Scoops reduce pressure drop in a closed intake at speed, probably even more than cold side DCI, and no underhood air ingestion. The faster you go, the less the drop. No way a shop dyno fan can replicate that flow, which is why VD is good, but the logs have to be apple to apples.

I've had the stock airbox back over a year now, Elite and ECS box are collecting dust in the garage.

 

[N54CoupeHP]

Virtual Dyno, but you need to be really careful with logging to be comparable.

Maybe depends how big on the hybrids, but I've not seen any difference in output or boost/WGDC between DCI, AFE SI, AFE Elite, ECS CF and stock airbox with scoops and inlets on all with 15Ts at 21-22psi. Tested the boxes opened and closed as well and intake swaps back to back same day, same map.

Open intake/lid show gains on the dyno because they shorten the intake tract, which is vacuum only, and reduce pressure drop accordingly. Hot side inlets take those physics about as far as it can go in these cars.

Scoops reduce pressure drop in a closed intake at speed, probably even more than cold side DCI, and no underhood air ingestion. The faster you go, the less the drop. No way a shop dyno fan can replicate that flow, which is why VD is good, but the logs have to be apple to apples.

I've had the stock airbox back over a year now, Elite and ECS box are collecting dust in the garage.

Thanks for responding, they are not very big, they're TD04HL-19T.

 

[Torgus]

Thanks for responding, they are not very big, they're TD04HL-19T.

That is big for N54 hybrids. I don't think you can stuff much larger in. Stock is 10T.