AEM CAI vs Stk Airbox w/AVO Panel Filter.....

I have reformatted, and updated this post. I have included additional data sets, and conclusive proof, that the AEM CAI added considerable horsepower to my car. Granted, I am not lightly modded, but at least we know for sure that the stock airbox, regardless of filter media, IS indeed a RESTRICTION after 400hp at the crank. I felt this intake was worth roughly 30-35whp, if not more. Review the data below to see for yourselves:

MODS:

AEM CAI

AVO450(Sti style)

STI TMIC

STI Intake manifold

UP+TBE(Cobb HFC DP, MR CBE)

AVO FP

Deatchwerks 740cc Inj.

SMC Alky

Initial Impressions: Wow, this intake is pretty quiet! Barely louder than a panel filter.(I believe it is due to the MR drowning out the intake:icon_wink .) With a quieter CBE, it would likely be a bit noisier, but I can't imagine much more. Turbo definitely seems to breathe better. Kind of like it had a cold with the stock airbox, and now its nasal passages are cleared up:icon_bigg .

Those intial impressions still hold true! Even more so, now that I have data to backup my butt dyno.(which isn't all that accurate!)

Testing Data:

Boost Target = 21psi(With the lower duty %, the turbo is not working nearly as hard. Allowing it to stay in a more efficient island on the comp map.)

----------------Stock Airbox----AEM CAI

---WG duty %-------77%-----------55%

Boost @6.9k rpm's - Note:(The Avo can easily hold more psi, I just hadn't adjusted the WG duty from the pump gas tune. I'll do that soon, and we should see some more gains in power as well:icon_wink .)

----------------Stock Airbox----AEM CAI

---Boost (PSI)-------18.14-----------19.5

MAF (V) & Grams/sec(Here, the higher the volts/grams, the more air the engine is ingesting, hence more power.)

----------------Stock Airbox----AEM CAI

--(V)&G/sec---4.86/291.08------4.90/336.14

Fuel Injector Duty Cycle (%)(Again, the more fuel that is consumed, the more power is being made. The afr's between the tunes are all within .1-.2 afr's.)

----------------Stock Airbox----AEM CAI

---FI Duty(%)-------66.48-----------75.19

40-120mph Acceleration(Straight up math here, less time, more powerful, period!)

----------------Stock Airbox----AEM CAI

---Times----------11.37------------10.48 - Updated!

The above 40-120mph #'s, surpass or come within spitting distance of some pretty impressive vehicles, like:

-----Vehicle-------------------Times

BMW M6 V10--------------------10.3

BMW M5 V10--------------------10.9

RUF RK Coupe-------------------11.0

OLD SR40 Combo--------------11.6

C5 ZO6---------------------------11.8

911S Coupe---------------------12.4

OLD VF39 Combo--------------13.37

(I use the 40-120 benchmark, cause it tests both low & high speed acceleration. Thus reducing any advantages power/weight may play. Once you start going above 100mph, the differences begin to get magnified. It is also alot more repeatable, and less abusive to the drivetrain.)

Tuning Notes:

I have had to make pretty significant map changes(telltale sign of increased airflow). I have had to rescale the tables for higher load, as the volumetric efficiency of the engine has increased significantly:icon_bigg ! Oh, and the boost holds now no problem! In fact, I have tapered it down to 19.5psi past 6k, as the 93oct. pump isn't enough, or the STI tmic doesn't have enough cooling capacity. My inj duty cycles are hitting 90%, and this is with 740cc injector's, and 11.1 afr's. That's a good amount of fuel burned, indicating the engine is ingesting roughly 46lb/min of air. Eyeballing the AVO450's comp map says there is a bit more left, but it'll take alky to see how much more.

And W/Alky, I have been able to put back 5 degrees of advance(and I think I can put a bit more.), leaned out the afr's to 12.4 tapering to 12.05 at redline. (7.2k) These gains are all at roughly the same boost psi, and since it is only about 20.5 psi, I will be upping the boost to 22psi, as well as adding more timing. I think there is a few more whp left to be had from the setup, so I very well may further improve the already impressive gains!

Conclusion

The car pulls astonishingly hard now! I know when the power comes on, and it still catches me by surprise just how seemlessly it shoves me into the seatback. And then keeps me there til I grab another gear:icon_mrgr !

It's weird, but this turbo doesn't hit as violently as the vf40/vf39 setup's did. Even the Sr40 felt like it came on boil more explosively. With this Avo450, it kind of smoothly, but quickly mushrooms out, resulting in more power being made, and it's velvety smooth & sneaky about it:icon_mrgr .

No question about it, I am making alot more power than what I had in my last dragstrip visit. In which I trapped 112mph, with very poor launches, and little bit of heatsoak. Looking at the number's, tells it all! Clearly there was an intake restriction!

(Thanks to Paul@Avo & Jon@TDC, I suspected it, and they both said so as well, with Jon being very convincing with the Avo400 dyno on noam's car)

Edit: I love this intake:icon_mrgr !

I have no idea what is going on here.

Is the AEM better??

I have no idea what is going on here.

 

Is the AEM better??

Well, whether it's better is subjective. Sure it flows more air than the stock airbox, but it is a bit louder. If perhaps you only plan on running a stock turbo, then the stock airbox will easily meet those airflow requirements. Also, if you value quiteness over power, then the stock box is better in that regard.

I was just posting what an intake has initially done for my setup, and yes in this case the AEM is leaps & bounds better:icon_bigg !

Nice...you are running a lil more than stock boost huh?!! 22psi!

Glad it looks promising..I wish I understood all that data logging info!

If perhaps you only plan on running a stock turbo, then the stock airbox will easily meet those airflow requirements

That's kinda what I was thinking. It should be fairly straight forward that the only real benefit for us going to a CAI system is if the stock airbox is restricting flow, which, it doesn't seem to do with the VF40.

Makes sense you might see a restriction with the AVO450, it's also interesting to see that big of a difference in the PSI!

Very interesting and makes me real glad I ordered an AEM CAI last week!

Nice to hear it is not too loud.

Another quick question:

Did you use the OEM turbo inlet hose, or did you buy an aftermarket one like Perrin's?

I'd be curious how intake temps compare between these setups as well.

Edmund do you happen to have that info as well? Is the low-end similiar?

Matt

Another quick question:

 

Did you use the OEM turbo inlet hose, or did you buy an aftermarket one like Perrin's?

I still have the OEM inlet. That's partly why I didn't immediately discover the intake restriction. The stocker is made of a thicker plastic, that will not collapse, but I have no doubts that if I had had a silicone inlet, it would have had the same results as Noam's car did!

I'm just waiting for when the stock inlet hose has a problem, then I'll upgrade. Most likely to at least a reinforced silicone(Samco), or an APS one.

I'd be curious how intake temps compare between these setups as well.

Edmund do you happen to have that info as well? Is the low-end similiar?

 

Matt

Well, it just so happens that I do...

---------------------------------Stock Airbox---------AEM CAI

--Normal Operation----------4-5*------------------2-3*------(above ambient)

--Idling 10min----------------119*------------------133*------(60* ambient)

--Idling 15min----------------143*------------------154*------(60* ambient)

In normal operation, I was pleasantly surprised to see that the IAT closely follows my onboard temp readout. And when sitting idling ,it would creep up a bit faster than stock, BUT, it cooled back down very quickly once moving!

With this CAI placing the filter in the fenderwell, plus a heatshield plate, it seems that the aluminum inlet pipe is mostly responsible for the added temps. At least it is thin walled/lightweight, hence why it cools rapidly:icon_bigg .

^^Intake wrap might help the idle heat soak

http://www.modernperformance.com/all/dei/dei_intake_wrap.jpg

^^Intake wrap might help the idle heat soak

http://www.modernperformance.com/all/dei/dei_intake_wrap.jpg

I thought about that, but once it gets heatsoaked, it'll tend to stay soaked...

Not to mention it would hide the pretty metallic Red AEM pipe.

With wrap, it shouldn't stay soak with the cool air running through it at speed.

Just in case it becomes an issue, gotta linky?

http://www.jscspeed.com/index.html?/univ/thermotec.htm

You can get the thing make directly for an intake you just get a blanket and slice up other parts/need like wrapping the turbo/dp.

There is also a tape from Thermotec, it's about an inch thick. I used it on my eclipse for the FMIC to TB pipe, which was chromed, and it made a big difference. Here ya go, page 14

http://www.thermotec.com/products/2006_catalog.pdf

Very interesting information.

I just updated the 1st post, with even more "interesting info":icon_wink

^update the first post with pics and part number/linky

I picked it up from one of our vendor's...Rob@Maryland Turbo Systems, great guy to deal with! Got the order processed uber fast, not to mention a great price too!

I'll take pics, when I can, and put them up...

I still have the OEM inlet. That's partly why I didn't immediately discover the intake restriction. The stocker is made of a thicker plastic, that will not collapse, but I have no doubts that if I had had a silicone inlet, it would have had the same results as Noam's car did!

 

I'm just waiting for when the stock inlet hose has a problem, then I'll upgrade. Most likely to at least a reinforced silicone(Samco), or an APS one.

are you running the LGT oem inlet? I'm looking at doing an 18G TMIC setup soon and the CAI seems like it would be a nice supporting mod.

are you running the LGT oem inlet? I'm looking at doing an 18G TMIC setup soon and the CAI seems like it would be a nice supporting mod.

Yes, stock inlet hose...if it goes, then I'll look into either the APS or Samco.

Yes, stock inlet hose...if it goes, then I'll look into either the APS or Samco.

Why not the PERRIN Turbo Inlet Hose? Are the APS & Samco better?

Why not the PERRIN Turbo Inlet Hose? Are the APS & Samco better?

I have had a couple of Perrin products, none of which exuded quality.... They also do not reinforce their silicone inlets, whereas Samco does, and the APS is made of metal.