Justin@VMP
August 26th, 2007, 12:14 PM
I will be testing and documenting various GT500 induction system modifications. For the purposes of this article the "intake" can be thought of as the portion between the throttle body and air filter, consisting of some tubes, a mass air meter housing, and filter.
Part 1 will cover the stock airbox and changes to it.
GT500s are very sensitive to heat and weather conditions, so each time I do testing a new "baseline" is done. In this case, the baseline is a performance tune and completely stock intake, gains are then compared from there.
KN recently came out with a replacement filter for the stock airbox. A lot of guys that want to keep their car stock have asked me about it. A regular Mustang GT/V6 filter will not work in the GT500 airbox. From the factory the GT500 comes with a special high flow paper filter. The pleates are much larger and deeper than most panel filters, it looks to be a very nice piece.
The KN replacement filter is much shallower and has less pleates, so there is actually less surface area for air-flow. The only way it can flow more is if the material is less restrictive than stock. The pleats also run the opposite way of the stock filter.
http://www.vmptuning.com/GT500/1stockvsknpic.jpg
On the dyno I compared the stock air filter vs the KN filter. There was no increase in boost (boost graph not shown on this run). Air/Fuel ratio actually got richer with the KN filter, due to the different pleate design. I feel this is completely unacceptable. Air to Fuel ratio needs to be closely controlled, and a filter should not change it. With the stock airbox I would just run stock replacement filters. I know the KN is cleanable, but at nearly $50 for a KN you can buy several stock filters. Most guys will never drive their GT500 enough to need more than a few filter replacements. With a stock dry paper air filter you never have to worry about oil coming off the filter and migrating to the Mass Air Flow sensor, potentially causing it to read incorrectly (I recomend anyone with an oiled air filter clean their MAF sensor reguarly).
http://www.vmptuning.com/GT500/1stockvskndyno.jpg
KN also makes a full replacement intake system, more on that in part two.
Part 1 will cover the stock airbox and changes to it.
GT500s are very sensitive to heat and weather conditions, so each time I do testing a new "baseline" is done. In this case, the baseline is a performance tune and completely stock intake, gains are then compared from there.
KN recently came out with a replacement filter for the stock airbox. A lot of guys that want to keep their car stock have asked me about it. A regular Mustang GT/V6 filter will not work in the GT500 airbox. From the factory the GT500 comes with a special high flow paper filter. The pleates are much larger and deeper than most panel filters, it looks to be a very nice piece.
The KN replacement filter is much shallower and has less pleates, so there is actually less surface area for air-flow. The only way it can flow more is if the material is less restrictive than stock. The pleats also run the opposite way of the stock filter.
http://www.vmptuning.com/GT500/1stockvsknpic.jpg
On the dyno I compared the stock air filter vs the KN filter. There was no increase in boost (boost graph not shown on this run). Air/Fuel ratio actually got richer with the KN filter, due to the different pleate design. I feel this is completely unacceptable. Air to Fuel ratio needs to be closely controlled, and a filter should not change it. With the stock airbox I would just run stock replacement filters. I know the KN is cleanable, but at nearly $50 for a KN you can buy several stock filters. Most guys will never drive their GT500 enough to need more than a few filter replacements. With a stock dry paper air filter you never have to worry about oil coming off the filter and migrating to the Mass Air Flow sensor, potentially causing it to read incorrectly (I recomend anyone with an oiled air filter clean their MAF sensor reguarly).
http://www.vmptuning.com/GT500/1stockvskndyno.jpg
KN also makes a full replacement intake system, more on that in part two.