Thread Starter
#1
Before getting into the topic I want to make clear that I have no intention to start an argument.
I am working with 5 different chassis dynos in the UK as well as other in other countries.
Additionally, me and my associates conduct real time testing on the track and drags trips as well as 1/4 mile tests on different public places. The public places used are not used as 1/4 mile references even when the average used of 2 opposing runs. The reference value is in so far that changes before and after can be evaluated on the absolute changes as well percentage changes.
All runs are repeated a number of times in order for the driver to get his best result before and after as well as the ECU adjusting to the ambient conditions.
When doing the testing before and after we try to do this in the shortest possible time frame to be able to lock out as many variables as possible.
When testing competitors product we have independent observers present. we do this in our own interest as we do not want any misrepresentation of facts and/or being accused of being biased or trying to fake figures.
All the above is general procedure in Europe.
Coming to the questions. The first question is whether air intake revisions and performance filter increase performance.
This question can't be answered with a straight 'yes' or a straight 'no'. Also the impression one might have after changing is subjective,which can be proven with acceleration metering equipment. And some of the before and after 'tests' made are of no relevance because they are made under different conditions.
It is also noteworthy that in the industries changes below 2% are not considered as improvements or losses due to tolerances that affect the reciprication.
Air intake revisions can be split generally into 5 different groups.
1. Replacement panel or cylindrical filter elements
2. Universal filters/air intakes
3. Model specific induction kits/CAIs/AIRs
4. Bespoke AIRs
5. Custom AIRs
1. Replacement panel or cylindrical filter elements
Depending on the make and material the replacement filters can improve overall performance. However this will be marginal.
Usually when people report about the improvement they have seen when replacing the original filter with the replacement filter is the fact that in virtually all cases the original filter was not new and therefore the flow rate was decreased. Changing a used original filter with a new original filter will also show an increase in performance.
Over the years we have conducted many tests with these filters and accept that they can improve performance by anything up to 1.5% (usually cotton gauze) on small engines, but less on bigger engines. Some of the foam filters or sponges have actually lost performance.
2. Universal filters/air intakes
They will work on some turbo air intakes, but will on normally aspirated engines reduce torque the further down the rpm range the more. This usually results in poor driveability and often an increased fuel consumption. Placing the universal filter on the throttle body or at the end of a pipe does not consider some of the important points to gain performance.
Near the throttle body usually the air is usually rather hot. Adding a cold air feed will in very few cases change this for reasons I am not discussing here as it would lead too far. One thing cold air feeds do adversly is helping to throw a lot of dirt at the filter.
Another aspect is the turbulent air. The faster the vehicle moves the more the turbulences affect air intake.
In case the universal filter is attached to some part of the factory air intake additional flow losses might be observed at the filter mouth and throat, which add to the system specific ones.
Here is 2 pictures of what a cold air feed can do when installed as BMC specified:
I am working with 5 different chassis dynos in the UK as well as other in other countries.
Additionally, me and my associates conduct real time testing on the track and drags trips as well as 1/4 mile tests on different public places. The public places used are not used as 1/4 mile references even when the average used of 2 opposing runs. The reference value is in so far that changes before and after can be evaluated on the absolute changes as well percentage changes.
All runs are repeated a number of times in order for the driver to get his best result before and after as well as the ECU adjusting to the ambient conditions.
When doing the testing before and after we try to do this in the shortest possible time frame to be able to lock out as many variables as possible.
When testing competitors product we have independent observers present. we do this in our own interest as we do not want any misrepresentation of facts and/or being accused of being biased or trying to fake figures.
All the above is general procedure in Europe.
Coming to the questions. The first question is whether air intake revisions and performance filter increase performance.
This question can't be answered with a straight 'yes' or a straight 'no'. Also the impression one might have after changing is subjective,which can be proven with acceleration metering equipment. And some of the before and after 'tests' made are of no relevance because they are made under different conditions.
It is also noteworthy that in the industries changes below 2% are not considered as improvements or losses due to tolerances that affect the reciprication.
Air intake revisions can be split generally into 5 different groups.
1. Replacement panel or cylindrical filter elements
2. Universal filters/air intakes
3. Model specific induction kits/CAIs/AIRs
4. Bespoke AIRs
5. Custom AIRs
1. Replacement panel or cylindrical filter elements
Depending on the make and material the replacement filters can improve overall performance. However this will be marginal.
Usually when people report about the improvement they have seen when replacing the original filter with the replacement filter is the fact that in virtually all cases the original filter was not new and therefore the flow rate was decreased. Changing a used original filter with a new original filter will also show an increase in performance.
Over the years we have conducted many tests with these filters and accept that they can improve performance by anything up to 1.5% (usually cotton gauze) on small engines, but less on bigger engines. Some of the foam filters or sponges have actually lost performance.
2. Universal filters/air intakes
They will work on some turbo air intakes, but will on normally aspirated engines reduce torque the further down the rpm range the more. This usually results in poor driveability and often an increased fuel consumption. Placing the universal filter on the throttle body or at the end of a pipe does not consider some of the important points to gain performance.
Near the throttle body usually the air is usually rather hot. Adding a cold air feed will in very few cases change this for reasons I am not discussing here as it would lead too far. One thing cold air feeds do adversly is helping to throw a lot of dirt at the filter.
Another aspect is the turbulent air. The faster the vehicle moves the more the turbulences affect air intake.
In case the universal filter is attached to some part of the factory air intake additional flow losses might be observed at the filter mouth and throat, which add to the system specific ones.
Here is 2 pictures of what a cold air feed can do when installed as BMC specified:
![[:)]](https://www.theautomotiveindia.com/forums/images/smilies/Smile.gif "Smile [:)]")
![[confused]](https://www.theautomotiveindia.com/forums/images/smilies/Confused.gif "Confused [confused]")
![[:D]](https://www.theautomotiveindia.com/forums/images/smilies/Big%20Smile.gif "Big Smile [:D]")
