I decided to check out the effects of different air filter set-ups last week and get some testing done. I had done this as like all mods you tend to get used to the effect quickly and then doubt whether the money was worth spending. The method was as follows:
All tests were done on the same rolling road at the same time with the same calibration.
All tests were done within a 3 hour timeframe. Also, the car was left on the rolling road whilst filters were swapped out. Each time a dyno was run the ECU was reset as the car quickly learns the new airflow readings. Each run was repeated twice to check variablility.
Additionally, the HKS was run both at the beginning (2 runs) and the end (2 runs) with an ECU reset. This showed the following results:

All results are at the rear wheels:

Run 1, HKS filter set-up: 180bhp, 181.5 bhp
Run 2, Standard filter assembly and inlet: 172, 173.5
Run 3, JR filter on standard assembly: 167, 169.5
Run 4, HKS re-run: 180, 183

These runs show a low variability between the first and last runs. The JR filter result may have been due to leaving the air filter 'open' rather than in the closed box which would have given a cleaner airflow. The standard set-up shows 237bhp at the engine which is the standard output.

It shows that the HKS filter seems to give between 7 - 10 bhp at the rear wheels. The dyno's are below:

Standard Test


HKS Test


The fitted article on the car:


It makes a good noise (like all HKS Kit) and looks great in alloy. It also fits very well. HKS have an FCON with harness for the S2000 now and I'll be checking that out soon! Thanks to 'Tuning Japanese' for their testing and excellent service.

Though I'd post as like others I was always looking around for some data before I bought. That said, everything performs differently, depending on the car...

 

Thanks for posting! First posted UK dyno I think! Was this on Tuning-Japanese's rolling road? And can you tell me if the bonnet was close during the tests or not.

-Brian.

 

Thanks for the info Maca -- can you please provide a link to the HKS website?

 

Note that the HKS filter flows EXTREMELY well - due to its internal bell mouth design.

Tests made in Australia in regards to different filters have shown it flows better than virtually all filters - even though it looks quite small

 

I was just at the HKS USA website and couldn't find anything about the 'Racing Suction Kit'...plus your setup is obviously more than just the filter (from your diagram).

Can you please provide a link to more info?

Thanks!

 

Here's a link to the main company in the UK that has been offering HKS kit for the S2000. They is some info here on the kit.

TDi-PLC

Note that they are claiming a 'Dyno proven 7bhp gain' from this setup. And list the HKS exhaust/headers as stage upgrades. Draw your own conclusions.

-Brian.

 

Thanks for the report.

There was a posting a few months back about the inverse relationship between airflow and filter capability. In a nutshell, that means that there "ain't no free lunch". In order to gain more airflow, the ability to filter out particles is compromised.

I'm all for performance enhancement, but I think it's important to acknowledge the tradeoffs. Is there any more data regarding this issue?

 

Some more information:

The bonnet was closed for all tests
Fans were used in the test bay to simulate speed
A temp sensor was used on the filter area for all tests and results were recorded on each test sheet (Varies from 16 - 18 degrees centrigrade)
On filter resistance - yes there is a trade-off. Breathing resitance, filter efficiency and pressure drop are all related. Each filter technology (pleated paper/ oiled cloth/ charged fibre) has strengths and weaknesses and is optimised.

For me the key result was that the Honda result was in line with spec which gave me confidence in other results.

Hope that this data is of interest

 

that's what i like to see...nice hard facts...posted charts and everything....now i might have to get one of those

 

Why are the hp numbers so low? The vast majority of the dyno runs that I have seen are 196 - 202hp, but your values are 20hp lower. Was the airbox lid left off in all cases?

In any case, it sounds like the HKS setup is on par with the AEM and Injen CAI gains.