Cold Air Intake HP Debate - Is it worth it ?
 

Picked up my new 370z on the weekend. I'm waiting arrival of my Stillen Cat Back ( stock exhaust really does suck ) and contemplating ordering the G3 Cold Air Intake to bolt on as well. Been searching the forums but still I'm hesitating for a couple of reasons. First - Installation: not sure I like the idea of having to remove the front bumper to clean the filters. That just seems to be a PITA and I'm concerned over time the bumper "fit" will be compromised.

Second - and most important is, from what I've read there is no performance advantage until 5K RPM or more - and low end performance ( torque ) is compromised. I don't drive at 5000 RPM and have no intentions of running this car on a track - I do that on a two wheels...

Should I pass on this upgrade ?

I am wondering the same.

I had the Stillen CAI on my G-37 (exhaust too) - and noticed less low-rpm power. But she ran like a scalded cat at, ahem, highway speeds.

Picking up my 370Z NISMO later this afternoon... :)

If those are your concerns, then just order the Gen II CAI from Stillen. It has all the benefits of the Gen II in terms of style and sound, yet sits in the factory airbox location (new boxes) and is easy to service. HP Gains are less, but I don't race my car either... it's more for the look and sound under acceleration!

http://www.the370z.com/members/wheee...race-place.jpg

I thought it was worth it.. Lossing lowend, I still a good punch down low,, and HEEMM HW for the win. :)

K&N filter's & HPS Post-MAF hoses...negligible difference in gains from CAI, at half the cost and installs in no time.

http://www.the370z.com/intake-exhaus...installed.html

The stock intake system actually has "cold air" built in. A more freely flowing intake pipe and filter are really all that is needed if you're after just performance. If you want a pretty engine bay and more sound then go with a CAI

lol, drop ins and maf hoses should not come near the gains made from the gen 3s. And with an exhaust, HFC, and the intake you should see more HP across the whole powerband... not just up top. Yes i understand diminishing returns happens as well.

Congratulations on your new purchase Hedly and welcome to the forum. There are two main groups in the forum: those who go for the CAI (Stillen Gen3 being the most popular CAI) and those who go for the Stock Catback with Performance Drop ins & Post MAF tubes. I personally belong to the second group.

The Stillen Gen3 CAI gives you a boost around 8hp-10hp (give or take), gains in power & sound will be most noticeable in higher RPMs range (don't know how often & how long you'll be driving at those RPMs during street driving). With the CAI, you'll lose low end torque and of course the cost, installation and warranty issues are to be considered in your final decision. Still, those who have the Gen3 love it.

The stock intake is pretty well designed and is actually a CAI. From changing the stock filters and replacing them with the K&N ones, I gained 3mpg within a few days, have better throttle and *feel* that the car is breathing better thus running smoother. With the addition of better Post MAF tubes, you should be able to get somewhere around 6hp, plus the advertised 1-2hp from the K&N filters. The combo above will give you gains very close to the ones from the CAI without loss of low end torque, no warranty issues and cost is a fraction of the CAI. This *to me* is a DUH WINNING situation :tup: Those who have this combo love it as well.

Check Out This Thread

I'm sorry but this is incorrect. Jordo! has dyno's showing 6 whp from just the drop-ins. Others have shown 10-12 whp from the combo. And the first breather mod always gains the most power. If yousee the Intake TV video, a stock 370z had a stillen G3 CAI, HFC, and CBE installed with an UpRev dyno tune. They reported the stillen G3 as only 6-7 whp, because it was installed last, and the exhaust system at 27 whp because it was installed first (and 10 whp from the tune). Stillen's site claims 18 whp from the G3 CAI, that is against a bone stock Z. I have seen dyno's of an otherwise stock Z with JUST a test pipe gaining 15-20 whp.

It's a matter of preference, but to say that the gains from the Stillen or any CAI are noticeably different from the drop-ins and HPS hoses is not correct.

OEM intakes are just fine.

this is true...i'm one of the ones that gain 10rwhp from the combo, my dyno are on here also...somewhere dynojet SAE corrected

Stokers are good but I have seen Dynos where the Gen 3's gave more than 18+.. Something like 23 WHP,, There was a thread on MyG37, Where he compared the R2C( Stockish intakes) and the Gen 3's.

Commentary based on review of numerous dynos here: http://www.the370z.com/985191-post25.html

And here, An these are numbers on a 7sd AT AWD sedan.

Stillen Gen3: 294whp/238tq
R2c: 272whp/226tq

My Stillen Gen3/R2c dyno comparisons - MyG37

Yeah sorry... you wont be convincing me that your drop ins and maf tubes equal the gen3 HP gains.. Just isnt happening. Call me ignorant, cause often i am!

wow all that thread proved was that r2c has better more useable power and g3 has higher peak numbers

under the curve > peak

The VQ37HR is not some magical engine. It has always been a small difference between a short ram vs a cold air anyway. In the end, forced induction is the key. (All motor setups are usually dominated by American cars, Hondas, and rotary engines)

I'm sorry but this makes no sense to me. Are you trying to say a Honda, an American motor or a rotary are superior NA builds?

A: name a Honda motor that is superior to any other motor for making power, hondas rely on weight and high revving motors but in reality compared to any other choice are a horrible option for power.
B: point me at a rotary NA build that makes power... The wankel was and is a failure. Don't mistake the brilliance of the handling of rx7s and rx8s and their power potential.
C: you don't mean American, you mean displacement (which is the typical route for American muscle cars) which will always make more power on an NA build

According to the available dyno data, the G3's make about 1.5% more whp on the average (i.e., about 4-5 whp on a dynojet) than the OEM airbox plus high flow panel filters plus smooth intake tubes.

My guess is that the small difference is due in part to the marginally better flow dynamics of cone filters; the rest may simply be due to leaning out the mixture via a small, but stable, misread on the MAF sensors, for example due to a variation in the diameter or orientation of the piping.

With tuning, the difference between them should be even less if that's the case, as you would simply set the mixture where you want it on both types of set-ups, rather than relying on mechancially induced effects.

Explain to me your theory of why the G3 should be vastly superior.

My statements are all based on after market parts and builds that have been done over the years. I am not sure about the rotary though, since all I have seen are 4 rotor builds and a naturally aspirated build done by RE Amemiya that output 400whp. I know that the Nismo 380RS is rated at 380hp naturally aspirated but I am not sure if many people go with the n/a route.

honda s2000k over 100hp per liter n/a . nissan cant touch this. period

Yes hp/liter s2000 and even them rotary potaoes are some of the top contenders, but I wouldnt consider them the top NA cars. No matter, we're derailing.

Based on all that I've read, it seems that you get the biggest boost from your first intake/exhaust mod. After that, the gains are in smaller increments. So, since you have the Stillen CBE (which is a very nice sounding exhaust, BTW, with proven gains), you won't as much in the way of gains from intake (unless you get a tune).

I agree with other comments that the OEM intake is well designed. I went with K&N drop-ins, and like the combo with my aftermarket exhaust.

:iagree:

For the most part that does indeed seem to be true -- probably sucessive changes result in diminishing returns as you get closer to maximum VE for the engine NA.

Actually, with an exhaust swap and a tune you'd be pretty close to 370 bhp and though the 120 HP/liter is impressive on the s2k you sacrifice a lot in terms of low-mid range power with a high revving motor like that.

I've heard the F20 and F22C are pretty solid at making power (only through rumors of course) and the K series is also pretty beastly as well. I've seen plenty of guys laying 250whp+ out of a 2.0 with just bolt-ons.

Yep. A fully bolted on tuned Z will definitely be there at the crank, espcially if we use ps units, which are a few % higher than hp units.

VVEL tuning, I predict, will be the key to really getting a NA motor to wake up tho'.

Intake placement should take full advantage of cold air INTAKE. In real world situations "not dyno fans" you should see colder intake temps with the placement of the gen3s. If someone can prove me wrong then so be it.

The OEM airboxes duct air from exactly the same place as the G3's... :ughdance:

A unducted/shielded SRI will perform more poorly than both.

Interesting, my filters are pulling air from in front of my bumper core suport, completely outside the engine. Factory boxes are inside the core support/ partially inside the engine bay?

I'm no expert on this but I have to agree with Nitex

The boxes are in the engine bay, but I think the air is drawn from the same area. Hp wise, both mod gains are hardly impressive on their own. I think it's a matter of personal preference.

I hardly find myself revving to 7k on the road (although it sounds awesome). I just don't find a need for it. One I get this baby on the track, things may change, but I just can't see spending the money on G3s for a slight gain up top in the power band. I would rather spend money to get low to midrange response. Henc the reason for my long wait and deliberation regarding TT and SC.

Not knocking the s2k its a great car and all I considered buying one but the comment about Nissan not being able to touch 100hp per liter is just retarded nismo 370z 350hp/3.7 is about 95 so it'd very very close. And the comment about bolt on mods give more power on Hondas than Nissan is just plain false. As a matter of fact bolt ons with the 370 will gain more power. I have very close friends with s2ks and know the car quite well. The usual bolt ons intake test pipe exhaust will net you around 225whp on a dynojet. Most of which is all from the test pipe and couple HP from intake and exhaust. Other than that your spending big money to increase HP anymore than that on your s2k.

the S puts out 120 hp per liter.

His argument was that Nissan can't come close to 100. So thats what I'm basing my argument on. But regardless the 2.2 at supposedly 238 HP dyno more to the wheels than the 2.0 at supposedly 240 HP. Either way I'm sure Nissan can improve HP per liter but at what cost? Lower rpm power and shifting the power band way up top like the s2k

Lol wow, sparked up some heat here. All I wanted to state was the aftermarket support. Lots of naturally aspirated built engines out there in the Honda world. I do not consider bolt ons (i.e. on a Nissan) as a naturally aspirated build (part of it, yes, but I am talking about internals).

I am not a honda or nissan fanboy, name 1 box stock nissan or and " normal" car that comes close to 120 hp/liter? So it not a false statment, it a fact. At 120 hp/ liter the z needs to make around 450 hp. Yes the s2k makes no tq and yes it is tiresome to have to rev it to go anywhere. I can't think of 1 nissan the hit 100 hp/ liter.

They have ducts that pull air from in front of the radiator. The location of the filter itself is irrelevant.

If the ducts weren't there (as they aren't for a SRI) you would be right.

As to the airbox being under the hood, the pipes are under your hood too... the air will warm up once it is in there...

Actually, metal pipes will heat it up more than plastic -- considered that?

In any case, the difference appears to be less than 5 whp on the average.

I'm still betting the Gen III is really making power by leaning out the MAF signal using a (slightly) larger diameter tube at the sensor. That sorta explains why the first two versions did very little in terms or performance. It really doesn't have to be much bigger. A millimeter or two would likely be all that's needed.

It would be great of someone could measure the diameter of the MAF tube on the Gen 3 vs the OEM pipe.