Nissan Murano Forum banner

1 - 19 of 19 Posts

·
Registered
Joined
·
177 Posts
Discussion Starter #1

·
Premium Member
Joined
·
2,065 Posts
uhhhh.....

Unless I am not seeing a point correctly in their tests.....

If you put an oven mitt over the end of the pipe instead of the magic air filter, I bet the gauge would jump up into the 20's, if it were mechanical it would wind the needle like a clock spring.
LMAO
It is measuring vacuum isn't it---not velocity by venturi effect. Yes, the venturi effect increases with velocity, that's how a carburetor works. But, it seems to me, he is measuring vacuum. We need for him to put a turbine in between the magic filter and the vacuum source--that would show velocity.
I suppose in his setup, if it were supplied a turbocharger upstream of the filter it would show a positive air pressure---and in his test, that would show it inferior to his vacuum cleaner/magic air filter holder test.
It would take a much more sophisticated flow bench than a 7th grade plexiglas project they had going to show venturi vacuum increases due to a velocity increase. Using an analogy of ground effects in race cars is amusing. My bro inlaw who is an aeronautical engineer would get quite a chuckle off this one.

Bent science in my opinion.

To increase velocity via his route would entail a huge air cleaner with a monumentally huge funnel shaped ram air intake be bolted to the front of his car, and drive 120 mph to see significant velocity increases.
442 Oldsmobiles used something like that. They had two large funnels under the front bumper with twin 4 inch hoses going to the air cleaner. I think it was more for cool air induction than ram air velocity increases though.




:rolleyes:
 

·
Registered
Joined
·
177 Posts
Discussion Starter #3
Mgthe3,
That's why I like this forum, one can find something, ask or ponder and there is someone here who can usually come up w/ a good response or has tried it. I was though wondering about the Ram Air Duct/Kit they have. It does attach to the front of vehicle and connects into the "Special Filter". Do you think that has any better merit?
 

·
Premium Member
Joined
·
2,065 Posts
Currently your Mo gets it's air from over pressure in front of your radiatior. It makes its way up through one tiny hole at the left end of the fresh air scoop and one large hole beside your hood latch.
I can't see where you could snake a hose to a special air filter, there isn't any room. Also, the hose looks like a drier hose with internal ridges, any zig or zag would cause extreme turbulance and may negate any velocity gained at the front. You would have to have a very smooth walled tube to make it work. And, you would also have to make sure your entrance scoop has a large area and smoothly funnel it to the smooth bore piping.

If you want the "waaaa" of the intake, go with the cheapest asthetically pleasing pop charger.
If you want more velocity of cool air, get a K&N filter.
:D
 

·
Registered
Joined
·
177 Posts
Discussion Starter #5
Well, noise is not what I'm after, better performance always is!
I have a K&N FIPK2 on my Xterra now w/ a Blitz filter and believe it or not it actually runs quieter (except when I step on it) than the stock EVER did! I don't know the physics behind all of this, but thanx for explaining it and saving me $$$$
 

·
Registered
Joined
·
834 Posts
When desiding if I should install the JWT pop-charger I read the following:

As you can see, it seems to offer some HP gains.

On a Z

"Not wanting to mess around we put the car on the dyno immediately and recorded the biggest gains we.ve seen on any 350Z yet: 6.5 hp at the wheels! The driving difference was noticeable, springing a welcomed quickness to redline. To say we were amazed is an understatement. It.s not that we.ve ever been let down by the POP-Charger but it usually gets out-gunned by the fully piped Cold Air Intake. What a welcomed discovery: the most affordable intake modification we.ve tested makes the most power."

On a Altima

"After installation of the Jim Wolf Technology's POP charger. JWT's design is one of extreme quality and it showed on the dyno. The peak hp gain was 8 hp (208.8) and 3 lb-ft of torque (230.3). These gains stayed fairly consistent past 4,000 RPMs with max hp gain of 10 hp at 6000 RPMs and max torque gain of 10 at 5500 RPMs (blue lines on dyno chart)."

Source (search pop-charger)

http://www.nissanperformancemag.com
 

·
Registered
Joined
·
177 Posts
Discussion Starter #8
I read somewhere that with the INJEN CAI for the Altima 3.5, that someone dyno'd, it got a max of 14hp at the wheels. I see if I put it in Favorites.
 

·
Registered
Joined
·
834 Posts
Ijen seemed very nice, I even got the rep on this board for awhile.
But cost too much for me.

Plus the pop-charger is a easy in on/off setup.


grfg8r said:
I read somewhere that with the INJEN CAI for the Altima 3.5, that someone dyno'd, it got a max of 14hp at the wheels. I see if I put it in Favorites.
 

·
Registered
Joined
·
177 Posts
Discussion Starter #10
Did you guys remove the entire 2 pieces of the box?

Also, I read somewhere else, I'm alwyz doing that, someone put one of those turbonators (sp?) in the air tube, but didn't dyno it.
 

·
Registered
Joined
·
834 Posts
I left the bottom box in place and only removed the main air box.

grfg8r said:
Did you guys remove the entire 2 pieces of the box?

Also, I read somewhere else, I'm alwyz doing that, someone put one of those turbonators (sp?) in the air tube, but didn't dyno it.
 

·
Moderator
Joined
·
4,664 Posts
dmako said:
"Not wanting to mess around we put the car on the dyno immediately and recorded the biggest gains we.ve seen on any 350Z yet: 6.5 hp at the wheels! The driving difference was noticeable, springing a welcomed quickness to redline. To say we were amazed is an understatement.
I'm not saying this didn't happen (don't you hate double negatives!) but I look at this and think, 6.5 HP at the rear wheels... So what's that, 10 HP at the engine? 8 HP? Let's go with the 10 HP... So on an engine that's putting out 250 HP (or thereabouts), they felt a noticable change in the driving...

That's a 4% difference in HP. Do you think your rear end could truly detect a 4% difference? Or is it the sound that really makes it feel like you're going faster?

When I first got in the Murano, I didn't think it was fast, due to the CVT. Then I looked at the speedometer and all the people behind me.

So how much of this is a real, in the pants difference and how much is perception?

I'd really like to know from those that have done it.

I would also expect the change to impact low end torque, which could make it feel faster as it regains it in the powerband.

Just questions, as I'm wondering about doing this myself....:D
 

·
Registered
Joined
·
1,373 Posts
if someone on here has a murano S they could easyly make a cold are intake since it dosn't come with fog lights. someone can just run sometubing from a hole were the fog light should be and connect it to a pop charger. but you all probably already new that.
 

·
Registered
Joined
·
177 Posts
Discussion Starter #14
Someone did just that on the Xterra site.
 

·
SHIFT_FASTER
Joined
·
1,437 Posts
jaak said:


I'm not saying this didn't happen (don't you hate double negatives!) but I look at this and think, 6.5 HP at the rear wheels... So what's that, 10 HP at the engine? 8 HP? Let's go with the 10 HP... So on an engine that's putting out 250 HP (or thereabouts), they felt a noticable change in the driving...

That's a 4% difference in HP. Do you think your rear end could truly detect a 4% difference? Or is it the sound that really makes it feel like you're going faster?

When I first got in the Murano, I didn't think it was fast, due to the CVT. Then I looked at the speedometer and all the people behind me.

So how much of this is a real, in the pants difference and how much is perception?

I'd really like to know from those that have done it.

I would also expect the change to impact low end torque, which could make it feel faster as it regains it in the powerband.

Just questions, as I'm wondering about doing this myself....:D
I can't even remember what the original intake felt like it's been so long, but I recall noticing a difference.

I think another part of it is improved throttle response.
 

·
Moderator
Joined
·
4,664 Posts
Tyler_Canada said:
I think another part of it is improved throttle response.
I suspect much of that would come with the shorter intake length.
 

·
Registered
Joined
·
443 Posts
jaak said:




That's a 4% difference in HP. Do you think your rear end could truly detect a 4% difference? Or is it the sound that really makes it feel like you're going faster?

Absolutely correct. If you removed the added sound a CAI makes and did a blind test, I'd be surprised anyone could discriminate a 10 PEAK hp gain in a 250 crank hp car, much less a ~300 crank hp car. Keep in mind, that it is PEAK, when you look at the dynos of those CAIs, for 80% of the rev range the difference is within the 'noise' of just repeating the dyno run. Also, keep in mind that any dyno runs will be best case scenario with an open hood and a large fan blowing on the engine. Close that hood and the differences become even more negligible.

If anyone can give an objective measurement of "throttle response" I'd love to see it. I suppose it could be incorporated into your 60' time at a strip. Perhaps audible throttle response is a better descriptor.

Look, I don't want to rain on anyone's parade. Modding cars is a fun hobby. But, don't let marketing hype fool you, most bolt-on mods for normally aspirated cars these days yield about as much gains as removing a couple of sets of golf clubs from the back. True, a gain in hp is still a gain, even if it is only a few percent.

Notice I'm not talking about FI cars where a simply a smaller pulley or a boost controller can yield big gains.

Some interesting reading on lying with dynos:
http://www.caranddriver.com/article.asp?section_id=4&article_id=8020&page_nu
 

·
Premium Member
Joined
·
2,065 Posts
And....I think that if Nissan could have put one more cool thing on the Mo from the factory, especially if it were to increase any kind of performance not detrimental to the CVT, they would have done it. Surface area of the filter is how you gain velocity without sacrificing the efficiency of the filter.....I know, I designed and built a class 10 clean room myself. It actually was a class 5 according to my laser benches. It had to quickly go from a class 100 down to class 10 in 10 minutes. I did that with a dozen 3 inch input/output absolute filters. Flow plus filtration. One of these babies would flow MUCH better than any filter you could put on an auto...but cost $400 each--plus they were 4 inches thick and 18x24 inches---wouldn't fit in our engine compartment.
 

·
Registered
Joined
·
80 Posts
Halo said:


Absolutely correct. If you removed the added sound a CAI makes and did a blind test, I'd be surprised anyone could discriminate a 10 PEAK hp gain in a 250 crank hp car, much less a ~300 crank hp car. Keep in mind, that it is PEAK, when you look at the dynos of those CAIs, for 80% of the rev range the difference is within the 'noise' of just repeating the dyno run. Also, keep in mind that any dyno runs will be best case scenario with an open hood and a large fan blowing on the engine. Close that hood and the differences become even more negligible.

If anyone can give an objective measurement of "throttle response" I'd love to see it. I suppose it could be incorporated into your 60' time at a strip. Perhaps audible throttle response is a better descriptor.

Look, I don't want to rain on anyone's parade. Modding cars is a fun hobby. But, don't let marketing hype fool you, most bolt-on mods for normally aspirated cars these days yield about as much gains as removing a couple of sets of golf clubs from the back. True, a gain in hp is still a gain, even if it is only a few percent.

Notice I'm not talking about FI cars where a simply a smaller pulley or a boost controller can yield big gains.

Some interesting reading on lying with dynos:
http://www.caranddriver.com/article.asp?section_id=4&article_id=8020&page_nu
Another factor to consider is how much of any gain obtained from intake modification is still present after the computer "retrains" for any difference in airflow and makes the necessary "calibration" changes to get it's measured data back to anticipated margins..

A dyno run immediately after resetting the computer and making the change, compared to a dyno run after using the modification 300 to 400 miles would reveal that answer.

I'm not sure what the answer would be, but past experience with OBDII based computer control would suggest that any performance gain would likely be offset by the computer derating performance until it's measured data returned to anticipated ranges.
 
1 - 19 of 19 Posts
Top