Is it really worth putting a Cold Air Intake on 370z and what HP gains

PaulZ370 · 02-14-2012, 10:23 PM

Try this at home with your vacuum cleaner:

Turn it on, then use the attachments on the hose. You will notice that the more restrictive the attachment, the more "whine" the motor makes as it strains to pull the air through the attachment's opening. The more the motor strains, the more HP is being used to Pull the air into the attachment. In the case of a car, this means there is less HP to drive your wheels.

Same principle applies on the intakes and exhausts of cars as I've noted above.

Give the engine a larger "attachment", and it doesn't have to work as hard on "sucking" the air into the chambers. Free-er air flow = less work the engine has to do just to breathe, the more HP is now left over for the drivetrain.

Why do I know this? I am an engineer - and as such, I have dealt with calculating useable HP for Generator Engines considering pressure drops due to intake and exhaust piping. Piping (both intake and exhaust) have a tremendous effect on useable HP from the engine. This was a major factor in my choosing the FI exhaust system by the way - it has the least bends with the least angles (no 90's) which I know for a fact translates to less back pressure and more useable HP at the engine as a result. Intakes work the same way. The less bends and less pipes, the easier the engine breathes, the more useable HP is available for the drivetrain...

This is not hearsay, nor conjecture, nor abstract theory. This is something I have done as a matter of practical engineering - I make my living this way by the way, with 22 years experience in the industry, if that means anything to anyone out there...

Speedy · 02-14-2012, 10:29 PM

Quote:

Originally Posted by sfearl1

i believe my car had a noticeable improvement in throttle response after adding the drop in filters.

This is simple enough to test. I can just pull the filters out of my air boxes. If you had a noticeable improvement with drop ins, then I should REALLY notice something with no filter at all. I'll check it out this weekend and report back.

Quote:

Originally Posted by PaulZ370

Try this at home with your vacuum cleaner:

Turn it on, then use the attachments on the hose. You will notice that the more restrictive the attachment, the more "whine" the motor makes as it strains to pull the air through the attachment's opening. The more the motor strains, the more HP is being used to Pull the air into the attachment. In the case of a car, this means there is less HP to drive your wheels.

Same principle applies on the intakes and exhausts of cars as I've noted above.

Give the engine a larger "attachment", and it doesn't have to work as hard on "sucking" the air into the chambers. Free-er air flow = less work the engine has to do just to breathe, the more HP is now left over for the drivetrain.

Why do I know this? I am an engineer - and as such, I have dealt with calculating useable HP for Generator Engines considering pressure drops due to intake and exhaust piping. Piping (both intake and exhaust) have a tremendous effect on useable HP from the engine. This was a major factor in my choosing the FI exhaust system by the way - it has the least bends with the least angles (no 90's) which I know for a fact translates to less back pressure and more useable HP at the engine as a result. Intakes work the same way. The less bends and less pipes, the easier the engine breathes, the more useable HP is available for the drivetrain...

This is not hearsay, nor conjecture, nor abstract theory. This is something I have done as a matter of practical engineering - I make my living this way by the way, with 22 years experience in the industry, if that means anything to anyone out there...

I'm also an engineer and have been messing with cars since I was old enough to hold a wrench. Comparing a 332HP motor to a vacuum cleaner...meehhhhhhh.

The question becomes if the intake restriction creates vacuum at the area just behind the throttle body when at WOT. If so, then a larger air filter is warranted, if not....well not so much.

PaulZ370 · 02-15-2012, 08:41 AM

Quote:

Originally Posted by Speedy

I'm also an engineer and have been messing with cars since I was old enough to hold a wrench. Comparing a 332HP motor to a vacuum cleaner...meehhhhhhh.

The question becomes if the intake restriction creates vacuum at the area just behind the throttle body when at WOT. If so, then a larger air filter is warranted, if not....well not so much.

No where in my post did I say an internal combustion engine is the same as a vacuum cleaner. The point was the principle of doing a lot of work just to suck the air into the plenum vs not working as hard to do the same. The HP difference is what you use to do the suctioning, or divert to the wheels.

I hope that clarifies it a little?

Speedy · 02-15-2012, 11:23 AM

Quote:

Originally Posted by ZMan8

A couple threads regarding how much people get with a tune:

Uprev Tuned at Z1, results inside :)

My dyno results

Went to Uprev. Here's my results

There are many more like that if you search in the tuning section. My point is people don't get much hp out of a tune on this car. What a tune helps with is better usable power, corrects the afr, and gives it better feedback when you mash in the pedal. IF you go to an uprev tuner, they will most likely say you will gain between 6-15 hp. That number will depend on multiple factors of course.

That was some interesting reading, thanks for the links. To me it looks like most of those cars make over 300RWHP after a tune and a couple of bolt ons. Not too shabby for how light this thing is.

I've been browsing the tuning section of the forum but I'm not really finding any good nuggets of information that would help me know what's capable in these cars from a tune perspective. I may post a thread and see if anyone can chime in, but in my experience most end users have no idea how tuning works and think it's some kind of black magic. In reality it's no different than the old carb and timing light days, but since it's computer controlled people are spooked by it.

What I'd like to see is someone with a stock Z do a data log and see what the AFR is as well as the timing at WOT. It "could" be that Nissan already squeezed most of the available power out of this motor from the factory. OEMs don't normally do that, but it is possible. The fact that it's tuned for 91 tells me there is some on the table. We don't even have 91 in my area...it's all 93 and that'd be worth a bit right there. Normally you tweak the timing adding a bit at a time until the knock sensors show some retard, then you back it off just a tick. Then you start setting up the AFR and find the sweet spot of AFR and timing to avoid any knock retard on the fuel available.

I tuned my supercharged 4Runner myself and it's not really a huge deal. I did it with a Split Second piggy back since there is no tuning available for the 4Runner directly. I tuned it on a dyno, then touched it up on the street. Gained about 120RWHP in that little truck

Being able to switch tunes on the fly with the cruise control is VERY slick. I wish my Challenger could do that. I have to carry a tuner with me and I have two tunes. A 93 octane street tune and a 109 octane race tune. The only differences between the two are the race tune has a bit leaner AFR, 4 more degrees of timing, and the adaptives for IAT are dialed back to not pull as much timing as the IAT increases. It was good for about 3/10 and 2MPH at the 1/4 mile track.

Quote:

Originally Posted by PaulZ370

No where in my post did I say an internal combustion engine is the same as a vacuum cleaner. The point was the principle of doing a lot of work just to suck the air into the plenum vs not working as hard to do the same. The HP difference is what you use to do the suctioning, or divert to the wheels.

I hope that clarifies it a little?

I hear what you're trying to say. I look at it differently, but probably comes to the same thought....my point of view isn't that it takes more horses to pull in the air, but allowing an engine to breath more easily makes it more efficient. Probably saying the same thing you are in the end. I'm just not sure a CAI will help this car that much, but I just got mine and have some research to do on the current system to form an educated opinion. On my Challenger, which had a similar stock CAI that pulled air from behind the head light, I only gained about 5RWHP. However once I added the supercharger it really needed it as that blower could use all the air I could give it.

PaulZ370 · 02-15-2012, 11:34 AM

Quote:

Originally Posted by Speedy

On my Challenger, which had a similar stock CAI that pulled air from behind the head light, I only gained about 5RWHP. .

5 Rear Wheel HP is a lot by just changing a simple Intake on the engine.

sfearl1 · 02-15-2012, 11:44 AM

Quote:

Originally Posted by Speedy

This is simple enough to test. I can just pull the filters out of my air boxes. If you had a noticeable improvement with drop ins, then I should REALLY notice something with no filter at all. I'll check it out this weekend and report back.

your ECU will need to relearn your new "setup", no? i'm not sure you're going to want to drive the amount of time/distance without filters to recalibrate

Speedy · 02-15-2012, 11:50 AM

Quote:

Originally Posted by PaulZ370

5 Rear Wheel HP is a lot by just changing a simple Intake on the engine.

That's not a lot to me. Standard dyno deviation between runs can be that much.

Quote:

Originally Posted by ZMan8

speedy if you wait until april/may I can get datalog for you afr and timing numbers.

Cool, what do you have going on in April/May? Mods planned or ?

Quote:

Originally Posted by sfearl1

your ECU will need to relearn your new "setup", no? i'm not sure you're going to want to drive the amount of time/distance without filters to recalibrate

Should take too long on a MAF based car. Not like I'm gonna drive around for a week without air filters.

Most of the time on these types of vehicles people clear the adaptives and realize a temporary performance improvement just from that alone, however it does revert back as it relearns how you drive.

I can test some of this stuff when the track opens in March and report back.

02-14-2012, 10:23 PM	#1 (permalink)
PaulZ370 Track Member Join Date: May 2011 Location: Covington, LA Posts: 956 Drives: 011 370 BSM/T/SP/6MT Rep Power: 18	Try this at home with your vacuum cleaner: Turn it on, then use the attachments on the hose. You will notice that the more restrictive the attachment, the more "whine" the motor makes as it strains to pull the air through the attachment's opening. The more the motor strains, the more HP is being used to Pull the air into the attachment. In the case of a car, this means there is less HP to drive your wheels. Same principle applies on the intakes and exhausts of cars as I've noted above. Give the engine a larger "attachment", and it doesn't have to work as hard on "sucking" the air into the chambers. Free-er air flow = less work the engine has to do just to breathe, the more HP is now left over for the drivetrain. Why do I know this? I am an engineer - and as such, I have dealt with calculating useable HP for Generator Engines considering pressure drops due to intake and exhaust piping. Piping (both intake and exhaust) have a tremendous effect on useable HP from the engine. This was a major factor in my choosing the FI exhaust system by the way - it has the least bends with the least angles (no 90's) which I know for a fact translates to less back pressure and more useable HP at the engine as a result. Intakes work the same way. The less bends and less pipes, the easier the engine breathes, the more useable HP is available for the drivetrain... This is not hearsay, nor conjecture, nor abstract theory. This is something I have done as a matter of practical engineering - I make my living this way by the way, with 22 years experience in the industry, if that means anything to anyone out there... Eagle, luigi90210, SterlingDrive and 1 others like this. __________________ *BD2ZBN :: 2011 BSM/TRG/SP/6MT/Stillen Oil Cooler/K&N CAI/Michelin PSS/Brake Light/EIBACH Sway Bars/FI Res. HFC+18" Res. CBE/Morimoto XB LED/DRLs/10mm Spacers*

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Cold Air Intake HP Debate - Is it worth it ?	hedly	Intake/Exhaust	77	11-02-2014 02:56 PM
AEM 370z Cold Air Intake System with ETI	370zNismo66	Parts for sale (Private Classifieds)	3	02-11-2011 10:54 PM
Worth putting my old ST40 332s on a new 370z?	mswc	Brakes & Suspension	2	12-09-2009 04:13 PM
370Z AEM cold air intake and Exhaust	KenAEM	Engine & Drivetrain	6	10-09-2009 10:51 PM