Speed Density airflow difference
Oct 20, 2009, 02:47 PM
#1
Speed Density airflow difference
I couldnt find the thread where I talked about this car before, so I decided to make one and show the power difference. I am also going to add the logs from tuning this car at the time to show what we were running into.
June/July-
At 26psi with a custom cold air 3" MAF setup the car made 480.39 and this was at the edge of timing (intermittent 1s and 2s). Taking the filter off with no changes to the tune (open turbo) it immediately picked up power and went to 493.09. It was late so we left, came back the next morning early and made some pulls. We installed a 4" filter pipe assembly and were able to get 2 more degrees into it and ended up at 512.
Logs to follow.
June/July-
At 26psi with a custom cold air 3" MAF setup the car made 480.39 and this was at the edge of timing (intermittent 1s and 2s). Taking the filter off with no changes to the tune (open turbo) it immediately picked up power and went to 493.09. It was late so we left, came back the next morning early and made some pulls. We installed a 4" filter pipe assembly and were able to get 2 more degrees into it and ended up at 512.
Logs to follow.
Oct 20, 2009, 03:10 PM
#3
Account Disabled
iTrader: (3)
Join Date: Jun 2009
Location: central pa
Posts: 312
Likes: 0
Received 0 Likes
on
0 Posts
Interesting. My gains were much smaller but I am also on a stock turbo and unfortunately I added a downpipe between track visits. With similar air going from MAF to SD and from stock downpipe to a 3" downpipe I gained 2.4mph in the quarter mile. I would guess 5-10 hp on a stock turbo style car.
Oct 20, 2009, 03:19 PM
#4
Dave posted earlier about 55whp from removing a MAF and fixing/replacing a BOV, so I wanted to share that we have seen very similar gains (well MAF removal) to back him up.
On the stock turbo we have seen a best of 11whp from switching to SD without cams, and one car that really seems to have picked up about 15whp over where an S2'd VIII would normally otherwise be.
0x, your 2.4 would be about 25whp going by the old rule of thumb so your guess of 5-10whp seems about right to me.
On the stock turbo we have seen a best of 11whp from switching to SD without cams, and one car that really seems to have picked up about 15whp over where an S2'd VIII would normally otherwise be.
0x, your 2.4 would be about 25whp going by the old rule of thumb so your guess of 5-10whp seems about right to me.
Oct 20, 2009, 03:24 PM
#5
Evolving Member
iTrader: (5)
Join Date: Sep 2005
Location: Near water
Posts: 481
Likes: 0
Received 0 Likes
on
0 Posts
^ John, the 55 HP David gained were not from the switch to SD as he had already switched to the AEm and documented those gains. He said (once the AEM was in) once he switched the BOV and intake pipe he then realized another 55 HP.
Oct 20, 2009, 03:37 PM
#6
Oh, so you added a 4" intake and picked up power over the open turbo?
In David's thread, I thought you were saying just some extra tuning on the open turbo got you up to 510 WHP.
I'd still like to see an AEM vs. a Speed Density patched stock ECU shootout.
All out power...
And driveability/fuel economy...
In David's thread, I thought you were saying just some extra tuning on the open turbo got you up to 510 WHP.
I'd still like to see an AEM vs. a Speed Density patched stock ECU shootout.
All out power...
And driveability/fuel economy...
Trending Topics
Oct 20, 2009, 04:07 PM
#9
Oh, so you added a 4" intake and picked up power over the open turbo?
In David's thread, I thought you were saying just some extra tuning on the open turbo got you up to 510 WHP.
I'd still like to see an AEM vs. a Speed Density patched stock ECU shootout.
All out power...
And driveability/fuel economy...
In David's thread, I thought you were saying just some extra tuning on the open turbo got you up to 510 WHP.
I'd still like to see an AEM vs. a Speed Density patched stock ECU shootout.
All out power...
And driveability/fuel economy...
Intake-
Vs the 3" it had-
Oct 20, 2009, 05:24 PM
#10
Account Disabled
iTrader: (3)
Join Date: Jun 2009
Location: central pa
Posts: 312
Likes: 0
Received 0 Likes
on
0 Posts
I should note that I'm still using the stock rubber intake snorkel. I just bought a PVC reducer from Lowes to replace the MAF, it is a $3 part, works great.
My BOV isn't leaking to 28psi during a boost leak test. Are you seeing a power gain just switching out a seemingly non leaking BOV? I'm running the stock metal evo IX BOV, not crushed, no gus mod, doesn't seem to need it.
My BOV isn't leaking to 28psi during a boost leak test. Are you seeing a power gain just switching out a seemingly non leaking BOV? I'm running the stock metal evo IX BOV, not crushed, no gus mod, doesn't seem to need it.
Oct 20, 2009, 07:02 PM
#11
Registered User
I should note that I'm still using the stock rubber intake snorkel. I just bought a PVC reducer from Lowes to replace the MAF, it is a $3 part, works great.
My BOV isn't leaking to 28psi during a boost leak test. Are you seeing a power gain just switching out a seemingly non leaking BOV? I'm running the stock metal evo IX BOV, not crushed, no gus mod, doesn't seem to need it.
My BOV isn't leaking to 28psi during a boost leak test. Are you seeing a power gain just switching out a seemingly non leaking BOV? I'm running the stock metal evo IX BOV, not crushed, no gus mod, doesn't seem to need it.
i replaced it and it was an instant improvement. to justify it on my DD map i could only get 10/11 psi on WG boost, when i changed BOVs i got 12 psi. NOTE: i tightened some IC piping as well, but the BOV was leaking badly as per my test.
nice thread Aaron, i am currently looking for a neat MAFless intake setup for the stock turbo. if you got one let me know.
-Ravaal
