Did some air intake modifications and VAG testing - est. 15-20 hp gain (LONG)

DarinS4Turbo · 09-14-2002, 09:28 PM

I did some modifications to my air intake today and VAG tested MAF flow, and saw a peak increase of 15 grams/sec (that is almost 20 hp!). I have done lots of different airflow testing in the past so I typically know what to expect (little gain). I was quite surprised by these results.

For the starting point I am using a standard AWE S-flo intake. With temps approaching 80 deg I peaked at about 265 grams/sec today. This is completely consistent with prior testing I've done in these temps (and also pretty consistent with most reports from chipped cars out there). As ambient temps go down, I typically gain about 3 grams per 10 degrees (and I've seen as high as 280 grams/sec with temps around 40 deg).

I did 3 things to the intake:

1) Installed a wider (standard JC60/73) ITG maxogen cone filter than that in the AWE S-flo (which is a G60 spec). I measured and calculated that the larger filter has about 15-20% more surface area.

2) Sawed an inch or so off the end of the S-flo intake pipe, to shorten it such that the filter is situated a bit higher in the airbox. Otherwise the filter was crammed a bit by the sides of the lower airbox, so doing this created a better perimeter of air space around the filter.

3) Cut a small hole in the very bottom of the airbox to let in more air from the fenderwell.

Here are the before and after results from VAG:

As you can there was a solid 10 g/sec gain through most of the upper RPMs, finally peaking at about 15 g/sec. This represents a theoretical 15-20 hp gain, which was definitely more than I expected. Until now I had never peaked at 280 g/sec except in 40 degree weather. I can now foresee hitting at least 290-295 in that cold air.

So for any non-believers (I used to be one) that nothing can really be done to the stock intake to get any significant gains, take this data for what it's worth.

NYfinestS4 · 09-14-2002, 09:33 PM

DYOS4 · 09-14-2002, 09:37 PM

No More B5 S4 · 09-14-2002, 09:42 PM

Lightweight-USPowah · 09-14-2002, 09:44 PM

Milpitas2.7T · 09-14-2002, 09:45 PM

Since I don't have the correct oil to keep it clean, it has been sitting on my shelf for roughly a year.

would be interested in seeing what you have done.

J4SON · 09-14-2002, 09:45 PM

SlvrBullet Unloaded · 09-14-2002, 09:49 PM

part of the dirty factor comes from the hole cut in the bottom of the box but the ITG filters perfectly, AWE sells the oiling kits also! Now put the damn thing including the modded mass air meter back on it works.

ed@4induktion.com · 09-14-2002, 09:59 PM

Mirror|rorriM · 09-14-2002, 10:00 PM

09-14-2002, 09:28 PM	#1
DarinS4Turbo AudiWorld Senior Member Account #: 16111 Join Date: Feb 2001 Posts: 2,174	Did some air intake modifications and VAG testing - est. 15-20 hp gain (LONG) I did some modifications to my air intake today and VAG tested MAF flow, and saw a peak increase of 15 grams/sec (that is almost 20 hp!). I have done lots of different airflow testing in the past so I typically know what to expect (little gain). I was quite surprised by these results. For the starting point I am using a standard AWE S-flo intake. With temps approaching 80 deg I peaked at about 265 grams/sec today. This is completely consistent with prior testing I've done in these temps (and also pretty consistent with most reports from chipped cars out there). As ambient temps go down, I typically gain about 3 grams per 10 degrees (and I've seen as high as 280 grams/sec with temps around 40 deg). I did 3 things to the intake: 1) Installed a wider (standard JC60/73) ITG maxogen cone filter than that in the AWE S-flo (which is a G60 spec). I measured and calculated that the larger filter has about 15-20% more surface area. 2) Sawed an inch or so off the end of the S-flo intake pipe, to shorten it such that the filter is situated a bit higher in the airbox. Otherwise the filter was crammed a bit by the sides of the lower airbox, so doing this created a better perimeter of air space around the filter. 3) Cut a small hole in the very bottom of the airbox to let in more air from the fenderwell. Here are the before and after results from VAG: As you can there was a solid 10 g/sec gain through most of the upper RPMs, finally peaking at about 15 g/sec. This represents a theoretical 15-20 hp gain, which was definitely more than I expected. Until now I had never peaked at 280 g/sec except in 40 degree weather. I can now foresee hitting at least 290-295 in that cold air. So for any non-believers (I used to be one) that nothing can really be done to the stock intake to get any significant gains, take this data for what it's worth.

09-14-2002, 09:33 PM	#2
NYfinestS4 New Member Account #: 38078 Join Date: Jun 2002 Posts: 194	Photos? __________________

09-14-2002, 09:37 PM	#3
DYOS4 Elder Member Account #: 33816 Join Date: Mar 2002 Posts: 12,014	Hmm, interesting, would to see some pics if possible. Nice work ;- ) __________________ GIAC X, SLs, Borla, H&R+Bilsteins, Piggie SS. AIM - DYOS4

09-14-2002, 09:42 PM	#4
No More B5 S4 Elder Member Account #: 41217 Join Date: Aug 2002 Posts: 30,774	Very cool...first Piggie Pipes, now the DarIntake! :-) __________________ --------------------------------------------------------- "The Lord be with your spirit. Grace be with you." -2 Timothy 4:22 Click for Peer FATS Times. Updated: 03/15/05<a href="http://public.fotki.com/s4madman/scenerylandscape/wallpapers_1600x1200/"> Got Wallpapers? Updated: 10/29/04</a> The AW Database. Updated: 02/15/05

09-14-2002, 09:44 PM	#5
Lightweight-USPowah AudiWorld Super User Account #: 25882 Join Date: Sep 2001 Location: Manhattan, NY Posts: 11,261	what gear did you do your logging in ?? Pictures?? __________________ 5.7 Liters of Forced American Muscle: 2 + 8 = 715 6.0 Liters of American AWDrivin Muscle & 599ccs of Japanese Track Samurai (ninja style) http://public.fotki.com/johnjacobjingleheimer/

09-14-2002, 09:45 PM	#6
Milpitas2.7T Elder Member Account #: 6383 Join Date: Jun 2000 Posts: 25,962	More info about that filter? The one that comes with it is small and get's dirty really quickly. Since I don't have the correct oil to keep it clean, it has been sitting on my shelf for roughly a year. would be interested in seeing what you have done. __________________

09-14-2002, 09:45 PM	#7
J4SON Senior Member Account #: 21229 Join Date: Jun 2001 Posts: 8,780	Very nice, finally some proof. Can't wait to see the pictures. __________________ Jason Patel '96 BMW M3

09-14-2002, 09:49 PM	#8
SlvrBullet Unloaded Member Account #: 2711 Join Date: Mar 2000 Posts: 3,175	See Tory I wasn't crazy for my lower box modification after all... part of the dirty factor comes from the hole cut in the bottom of the box but the ITG filters perfectly, AWE sells the oiling kits also! Now put the damn thing including the modded mass air meter back on it works.

09-14-2002, 09:59 PM	#9
ed@4induktion.com Former Vendor Account #: 17991 Join Date: Mar 2001 Posts: 6,010	what happened to you today ? __________________

09-14-2002, 10:00 PM	#10
Mirror\|rorriM Elder Member Account #: 11167 Join Date: Oct 2000 Posts: 25,553	Or even...the DarIntake __________________ Mirror\|rorriM

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