A&Q about 350Z
Q:
I've read the K&N website very thoroughly and I'm curious why they indicate a 10.1 horsepower increase for the 350Z and most everyone else indicates an increase of 3 - 6 horsepower. Is the K&N claim just marketing rhetoric or do they have such a better design CIA that it can yield more horsepower? Also I didn't get my manual with my Z, but the dealer promised to send it to me. What is the function of the button type gizmo that has a short horizontal line engraved into it and is below the other button on the right side of the dash that controls the various functions of the gage that displays tire pressure, outside temp, speed, etc.
Thanks in advance for any info you can provide.
A:
I think you mean CAI. And yes - 10HP from an intake alone is a little high.
This should tide you over till your manual arrives:
Post Edited (Dec 19, 2:47pm)
A:
im thinking 10 is a little too high, maybe and thats a big maybe around 5-6
93 z32 convertible=pearl white, 5 speed
jwt pop-charger, hks hypers, asp underdrive pulley
86 z31 na=super white, 5 speed
A:
just an overstatement by the manufacturer...you most certainly will not get 10hp
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03 CS Touring
VIN #189
A:
The 10 hp gain is due to the "c" in the cai.
Cold air my friend is denser than hot air and more can be packed into the same space. K&N's is a true cai because it uses cold air from the outside as opposed to hot air from the engine compartment from , for example,
jwt pop charger. So yes theoretically you could double the hp gain with a K&N type cai as opposed to a popcharger. 10 hp? prolly.
A:
alright well i tried to find a real world dyno of it other than on the K&N site but i couldnt. However if you look at their dyno it stays pretty close to the stock curve until about 5700 rpm and theyre claiming that 10.1 at 6300rpm. redline is 6500... if you look at a JWT dyno after 4800rpm the JWT breaks from the stock curve, and doesnt dip back down. So you have to ask how useful the power is all the way up there, if someone tells you their feeling 10hp and theyre not shifting at redline theyre lying. Not to mention i read a couple reviews from knowledgeable people and it seems that the box gets pretty hot so while it isnt taking engine air it isnt as efficient as it cracked up to be. Also if it were producing 10hp everyone would have one, cause your real lucky if you can find a $1000 exhaust for the Z that makes that much. With that said im not knocking it, i know a few people on here have it and like it alot, but it may not be as great as K&N's website makes it out to be.
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03 CS Touring
VIN #189
Post Edited (Dec 19, 5:22pm)
A:
i was going to ask or say this too. doesnt the z33 have coolant lines that run to the throttle body like all the other z's. if so doesnt that really deceit sp? the purpose of a cai?
93 z32 convertible=pearl white, 5 speed
jwt pop-charger, hks hypers, asp underdrive pulley
86 z31 na=super white, 5 speed
A:
Hey DrivenZ, how much power do you think that Invidia exhaust actually added to my Z?
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guns and guitars, bikinis and fast cars - slide behind the wheel and GO!!
A:
Cold Air Intake doesn't do much of anything. Yes, colder air is denser, but It won't make much difference anyway for two reasons:
1) most (not all, but most) CAI systems just put a small deflector around the filter but still pull hot engine air from the engine compartment. Even ones that do pull from external air, the air gets heated up again because the intake manifold is really hot and the throttle body is heated by the engine.
2) the 350Z's intake system is designed to have such good flow that there is barely any room for improvement.
Even $200 plenum spacers and even more expensive higer volume upper plenum replacements can only hope to get 10HP max until you switch over to forced induction.
One other thing to remember is that you really don't want COLD air going into the engine because can actually hurt performance. That is why there are coolant lines on the throttle body, because you want WARM air going into the engine.
HOT air isn't good either, because its too thin (or in extreme cases [forced induction] can cause detonation). COLD air can hurt performance because it can lead to incomplete combustion. (thats why a lot of cars loose significant gas mileage in extremely cold climates)
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1985 300ZX n/a
Post Edited (Dec 19, 7:21pm)
A:
Wow, you guys are surely a wealth of information! It appears that while there are a few different opinions the overall consensus is that it is unlikely the K&N CAI will produce anywhere near the 10.1 horsepower increase. i also saw that the 10.1 increase was at the almost redline rpm and thought what good would it really be for me as I'd seldom, if ever, wind it up tighter than 6000 rpm.
As the one fellow said if it really was getting 10 horsepower everybody and their uncle would be putting one on.
A special "Thank you" to Zazupilot for sending me the pages out of a Z manual to explain the usage of the dash mounted trip computer buttons.
A:
i don't see any validity to your cold air vs. warm air phxz31. Colder air is always better than warm air. I don't think the coolant lines on the TB are for "warming the air" but more for possibly keeping the moving parts operable if running in freezing weather.
Intercoolers for turbos are designed to make the air cooler, resulting in more horsepower. Yes, I'm sure there is a temperature at which the colder air becomes so dense that it becomes less effective, but not in most climate zones on this planet!!
the reason for poorer gas mileage is because the air is denser, meaning more and (and concurrently more fuel) can be packed into the cylinders, creating more power.
My guardian angel has twin turbos. . .
1995 Cobalt Green NA
1988 Maroon 300ZX NA (sold)
A:
Well I've been told that unusually cold air into the intake can cause the temperature of combustion to become too low which leaves some fuel unburnt. I guess it could be wrong, don't really know for sure... but thats definitely what I heard.
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1985 300ZX n/a
Post Edited (Dec 22, 10:57pm)
A:
i'd honestly have to go with the HP increase explaination... because here in texas you can tell a bit of a difference in accel from winter to summer... the gas mileage on the other hand... is worse in the summer (why i don't know...maybe from less dense air mixture)... and better in the winter if you don't run around WOT everywhere...
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Chrome Silver '03 Touring -MT-
C.F. Nismo Wing
Shorty Antenna (Stolen!!! Thanks alot!)
Kicker Solo Baric L7 1200w
I don't think, I know...
Well, I don't think you know either
A:
Cooler air intake ALWAYS leads to denser air/fuel misture--more hp.
BUT. The general trend of this thread is about right.
Most "cold air" induction systems for the 350 Z are bogus. The pop-chargers are taking air from the (hot) engine compartment. The stock air intake at least takes air in from in front of the radiator bulkhead.
The true "cold" air intakes that swoop down to pavement level to suck up unsullied air are are also problematic. Never mind the water than comes in when it's raining, but in many climes, the temperature of the air just above the pavement is AT LEAST as hot as your engine compartment.
Zeero
2005 Daytona Blue 350Z
A:
i have a k&n and it takes in air from the grille, which to me makes much more sense than the stock intake that has no direct access to air at all.
i'm not sure how you can say the air by the pavement is anywhere near as hot as your engine. asphalt might get hot, but hot air rises and how many days in the year is it really hot enough outside where the temp of the road would be that hot anyway?
A:
yeah but it's not the hot air that we are concerned about... it's the suns gazed on the exposed asphalt that heats it up... as you may know if you drive around with the sun beaming down on you or at least one side of you... you will notice or at least i do that that side is hotter than my other side... usually my arm... now i may be traveling with the windows up and AC on but that does no good when you start talking about radiation... you know the Alpha, Beta, and Gamma rays??? what good is air going to do to block radiation? None...
One of my friends... obviously one with no social life... had the time to actually cook an egg on a cement sidewalk one year... and that was cement... not asphalt... which as everyone should know gets aLOT hotter than cement...
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Chrome Silver '03 Touring -MT-
C.F. Nismo Wing
Shorty Antenna (Stolen!!! Thanks alot!)
Kicker Solo Baric L7 1200w
I don't think, I know...
Well, I don't think you know either
Post Edited (Dec 26, 4:31pm)
A:
i thought it was the hot air we're concerned with??
the air 10 inches above the cement (or asphalt) still isn't going to be hotter than your engine compartment.
scrambled eggs are good with ketchup.
A:
yeah it is hot air that we're concerned with... but it's not hot air that heats pavement is my point... and no... it's probably not going to be and hotter than an engine compartment... i would say that the best bet for an intake would to be behind the front bumper high enough that it doesn't catch any hot air from the pavement... with some sort of ducting from the front grille... that way you get more direct air, i guess...
i mentioned to a friend, who asked me "why are they called "cold air intakes?"..." that simply because they relocate the filter to a cooler part of the engine compartment... i added that i really don't think that a simple bent piece of tubing is going to actively "cool" the air that passes through it...
he said "then they should call them, COOLER air intakes..." heh, yeah slightly cooler than your exhaust fumes...lol...
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Chrome Silver '03 Touring -MT-
C.F. Nismo Wing
Shorty Antenna (Stolen!!! Thanks alot!)
Kicker Solo Baric L7 1200w
I don't think, I know...
Well, I don't think you know either
A:
In phx in the summer there is no such thing as "cold air intake"
When the ambient air is 110 and your engine is running at about 230 or so, any air is pretty damn hot by the time it gets to the cylinders.
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1985 300ZX n/a