[Biginboca]

So I tested 2 intakes systems on my car today. This isn’t science in a lab but it’s the closest I can get at home and reflects use on the road with air flowing into the intakes. One intake is the stock airbox/K&N Drop In/Charcoal Delete/Rev Motoring Silicone Elbow that many of us use. The other is the AFE Magnum Stage 2 with the Oiled Filter P/N 54-81012-B. Both tests done today, same stretch of road, same car with no other changes. The battery was disconnected for 30 mins after AFE install. Also all throttle adaptations were reset.

Here’s what I measured with my new Dragy GPS timer.

20-60mph WOT Pull in 2nd Gear

Stock Combo - 4.39”
AFE Stage 2 - 4.39”

60-90mph WOT Pull in 3rd Gear

Stock Combo - 5.31”
AFE Stage 2 - 5.30”

60-70mph WOT Pull 3rd Gear

Stock Combo - 1.53”
AFE Stage 2 - 1.51”

70-80mph WOT Pull 3rd Gear

Stock Combo - 1.66”
AFE Stage 2 - 1.67”

80-90 WOT Pull 3rd Gear

Stock Combo - 2.12”
AFR Stage 2 - 2.11”


The only footnote I want to add is that although it appears to be a tie there’s one thing to consider. The second test was done 2 hours later (9:00am vs 11:00am). So conditions were as close as I could make them except the ambient temperature had risen to 5 degrees warmer (70* vs 75*) by the time the install was done.

I did some research and found that a 5* temperature difference equals just over 1% difference in power.**

My conclusion is I would say on my car the ~$500 AFE is making between 2.5 and 2.75 more than the Stock US Airbox/K&N Drop In/Charcoal Delete/Rev Silicone combo that costs approx $100. My opinion is, that’s not really a great value unless you are chasing the very last HP.

** Here’s a great article I found that explains how Temperature affects Horsepower:

https://www.reddit.com/r/cars/commen...ts_horsepower/

[Biginboca]

One other comment to add. The AFE is substantially louder than the Modded Stock Combo. Almost too loud IMO but if you like added sound there’s that. The modded stock combo actually sounds better and more refined to me. It’s loud when you rev above 5k but quiet otherwise, even at full throttle under 5k. The AFE is loud every time you pass above 3k rpms no matter Throttle input.

[avocet]

Is there any difference in throttle response? I think if it makes if feel snappier and more responsive, there might be some justification. And is there any difference in sound?

Thanks for the work! Like you said, it might not be an exact scientific method, but for a garage tweaker it's all we got! And it does give tangible results!

edit:
P.S. LOL your comment about sound beat me to the post!

[Biginboca]

Originally Posted by avocet

Is there any difference in throttle response? I think if it makes if feel snappier and more responsive, there might be some justification. And is there any difference in sound?

Thanks for the work! Like you said, it might not be an exact scientific method, but for a garage tweaker it's all we got! And it does give tangible results!

edit:
P.S. LOL your comment about sound beat me to the post!

I can’t say there’s any difference in throttle response. I have no way to measure that and the AFE is so loud it “feels” stronger but I believe that’s almost all noise and slight power difference. If AFE is making the advertised 15hp or whatever then the modded stock is making at least 12hp in my opinion.

[Taskmaster]

Dyno tested them a few years back, AFE made about 2whp more than a debaffled box - but that was without the Rev Motoring hose.

http://www.e90post.com/forums/showth...=918378&page=6

The Injen actually made more torque, but peak power was lower. I want another one to take advantage of the larger diameter piping put a box around it.

[rjahl]

Originally Posted by TheAxiom

Dyno tested them a few years back, AFE made about 2whp more than a debaffled box - but that was without the Rev Motoring hose.

http://www.e90post.com/forums/showth...=918378&page=6

The Injen actually made more torque, but peak power was lower. I want another one to take advantage of the larger diameter piping put a box around it.

Try logging MAS and MAP with TesTo. Best way to see what's really going on. Software is free and you probably already have a DCan cable.

[CobraMarty]

Drive it and give it a week and maybe retest it in the earlier morning. Adaptation and cooler temps might help.

I have the same setup.
First the stock with carbon delete, aFe dry filter, rev elbow and front scoops.
Then replaced with aFe. Yes it is louder. My interest has been measuring fuel mileage at steady cruise 70mph. I noticed a drop in mpg with the aFe. But after 2 weeks my mileage was actually more than the stock/deleted/aFe/Rev.

My theory is that there are 2 vents on the front of the aFe airbox and the mild 'RAM Effect' of the scoops is lost vs. the stock box which is sealed. So after 2 weeks and adaptation, the mileage went up.

I want to block the front vents and retest. Hopefully quieter and will stay pressurized and do even better.

IDK, just my thoughts. Don't give up on it yet.
Maybe just duct/masking tape over the front vents and retest for sheets and giggles.

We scrape for every +2hp increase on these engines.

[Phyrexia]

I don't know about you guys, but it'd be a lot more worthwhile to me to lose 30 pounds than to hunt for a hundredth of a second off a 60-90 pull.

[Biginboca]

Originally Posted by CobraMarty

Drive it and give it a week and maybe retest it in the earlier morning. Adaptation and cooler temps might help.

I have the same setup.
First the stock with carbon delete, aFe dry filter, rev elbow and front scoops.
Then replaced with aFe. Yes it is louder. My interest has been measuring fuel mileage at steady cruise 70mph. I noticed a drop in mpg with the aFe. But after 2 weeks my mileage was actually more than the stock/deleted/aFe/Rev.

My theory is that there are 2 vents on the front of the aFe airbox and the mild 'RAM Effect' of the scoops is lost vs. the stock box which is sealed. So after 2 weeks and adaptation, the mileage went up.

I want to block the front vents and retest. Hopefully quieter and will stay pressurized and do even better.

IDK, just my thoughts. Don't give up on it yet.
Maybe just duct/masking tape over the front vents and retest for sheets and giggles.

We scrape for every +2hp increase on these engines.

I’m going to retest again in a few days. I agree there may be some more adaptations still to come because I did a lot of resetting and did my “after” pulls after only like 10 mins of driving around.

[Biginboca]

Originally Posted by Phyrexia

I don't know about you guys, but it'd be a lot more worthwhile to me to lose 30 pounds than to hunt for a hundredth of a second off a 60-90 pull.

I know what you are saying, but losing 30lbs would also be exactly like gaining 2.5hp. (Which funny enough is coincidentally what I figure the AFE makes over the much cheaper modded stock airbox.). I know from a handling perspective the weight loss pays a dividend as well.

The point here was more to see how the 2 set ups compared because there has been debate about that.

[Phyrexia]

Originally Posted by Biginboca

I know what you are saying, but losing 30lbs would also be exactly like gaining 2.5hp. (Which funny enough is coincidentally what I figure the AFE makes over the much cheaper modded stock airbox.). I know from a handling perspective the weight loss pays a dividend as well.

The point here was more to see how the 2 set ups compared because there has been debate about that.

Don't get me wrong, I'm no stranger to chasing percentage points. And that was no coincidence, I played with the numbers to get them in the right range. Too bad I have a little more than 30 lbs I could lose

My only comparison here is the PI, which definitely felt like it did more a hundredth of a second in a 60-90 pull compared to stock, though admittedly I had the stock air filter and charcoal filter beforehand. The PI seems to do more at > 60MPH than it does at < 60 MPH, which leads me to believe either the intake through the grilles is more effective, or the high pressure cell on the fender is stronger than I thought.

[justpete]

Just an observation but it seems like the intake isn't going to make much difference until the exhaust scavenging is optimized.

[atmosphericM]

Thanks for doing this testing. The results are pretty inline with my expectations. OE is good or aFe if you want additional noise.

Honestly I'm surprised no one has cut holes in the side of their OE box yet, for the noise...

[Biginboca]

Originally Posted by justpete

Just an observation but it seems like the intake isn't going to make much difference until the exhaust scavenging is optimized.

Good point, I’m gong to work on that next!

[Biginboca]

Update:

As some of you know 2 weeks ago I changed from the AFE airbox back to the stock airbox but now added the Ram intake, a 2.5” corrugated intake pipe from the bumper to the bottom of the sealed stock airbox which is also still using the stock intakes as well.



This is the changes I documented:

AFE Stage 2 Sealed Intake:



Stock Airbox, Charcoal Delete, K&N Drop In, Ram Intake:


Both airbox set ups tested on same road, same amount of gas, multiple passes each way on the road to equalize wind variables. The only variable I couldn’t equalize for was weather and temperature. But I then corrected for the temperature and weather data using the Dragtimes D/A calculator.

This shows what experience has told me is a definite advantage (~3hp is my feeling based on my prior experience with this testing) using the stock airbox w/ram combo over the AFE.

Intersting side note: Dinan used to claim a 6-7hp increase when adding their ram intake to the stock airbox. Before I added the Ram I documented what I felt like was a 3hp advantage to the AFE and after adding the Ram what I felt was a 3hp advantage to the modded stock set up.

This also aligns with this data taken from this thread:

https://www.e90post.com/forums/showthread.php?t=1186611

And shown here AFE product page and a screen cap from that thread:



The bottom line is this...

Save your $$ fellas and mod your stock airboxes. It’s a win all around, you save hundreads while beating what is known to be the best aftermarket intake on the market.

[6ixSpd]

I'd be interested in trying out the RAM air intake mod, but the biggest thing I love about the AFE is the increase in induction sound and the ease of access to clean/change the filter. I suppose modding a Euro box would help with the latter.

How does your modded stock box sound compared to the AFE box?

[Biginboca]

Originally Posted by 6ixSpd

I'd be interested in trying out the RAM air intake mod, but the biggest thing I love about the AFE is the increase in induction sound and the ease of access to clean/change the filter. I suppose modding a Euro box would help with the latter.

How does your modded stock box sound compared to the AFE box?

The sound is comparable to my ears. Definitely close enough that I’d be hard pressed to tell the difference.

I agree on the euro intake. My plan is to pick one up next time I’m due for a filter change. Filter changes on the stock airbox are a pain and especially so now that I’ll have to disconnect that ram hose from the bottom each time as well.

[Noir]

Originally Posted by Biginboca

The sound is comparable to my ears. Definitely close enough that I’d be hard pressed to tell the difference.

I agree on the euro intake. My plan is to pick one up next time I’m due for a filter change. Filter changes on the stock airbox are a pain and especially so now that I’ll have to disconnect that ram hose from the bottom each time as well.

hindsight...

I wish I didnt sell mine so quickly.

[hassmaschine]

Delete the MAF. run whatever intake you want. AFE causes problems with headers, because the MAF screws everything up.

the N52 was *designed* to run without a MAF! It's only there for emissions reasons..

[Taskmaster]

Originally Posted by hassmaschine

Delete the MAF. run whatever intake you want. AFE causes problems with headers, because the MAF screws everything up.

the N52 was *designed* to run without a MAF! It's only there for emissions reasons..

That makes a lot of sense...

[Biginboca]

Originally Posted by hassmaschine

Delete the MAF. run whatever intake you want. AFE causes problems with headers, because the MAF screws everything up.

the N52 was *designed* to run without a MAF! It's only there for emissions reasons..

I’m definitely tempted to ditch the MAF. It seems that the only way to do so would be with a custom dyno tune though?

[hassmaschine]

BPC can do it, as can I - doesn't really need to be dyno tuned, although you might pick up a couple ponies. Works with both headers and stock manifolds now.