injen vs k&n vs fujita CAI

[Entity]

Hi, i did a search but it seems the only compary doesn't include the fujita (but has the comptech icebox instead)

i was just wondering which of these were the best bang for buck?

i've heard good things about injen but to be honest the sp1430 is abit too loud for me.. it has a great sound but i think the noise will eventually peeve me off.

the k&n is also great, sounds pretty good but i've heard is not as good a performer.

the fujita seems the cheapest, but is there a reason for this? is it genereally a reputable brand or just is it lacking something?

[yfin]

Hi, i did a search but it seems the only compary doesn't include the fujita (but has the comptech icebox instead)

i was just wondering which of these were the best bang for buck?

i've heard good things about injen but to be honest the sp1430 is abit too loud for me.. it has a great sound but i think the noise will eventually peeve me off.

the k&n is also great, sounds pretty good but i've heard is not as good a performer.

the fujita seems the cheapest, but is there a reason for this? is it genereally a reputable brand or just is it lacking something?

The Injen, K&N and Fujita are going to be around the same noise level and performance. They are all loud at full throttle and above 4000rpm. Don't believe anyone who tells you the K&N is lacking in performance vs the Injen. It is not true. The only relatively quiet intakes on the market yet still improving performance use a panel filter like the Icebox and the Mugen (I haven't heard that yet).

[aaronng]

I agree with yfin.

Also, the fujita is cheaper, but is a 1 piece. Both the K&N and Injen are 2-piece and can have the lower hose removed to have the intake work as an SRI.

[TypeG]

K&N is one of the most famous intake/filter manufacturer man...

[akira]

so which one would be the best in terms of performance and noise level?

[aaronng]

so which one would be the best in terms of performance and noise level?

All 3 are very similar.

[TypeG]

it is all about your budget and target

CAI like injen give u a loud noise over 4000rpm and got great improve on high end but lag on low end.
Drop in filter like K&N gave you slightly more airflow but dont expect much
Airbox replacement like Mugen and Icebox give u improve on high,mid and low end but wont have so much high end like Injen

[Entity]

I agree with yfin.

Also, the fujita is cheaper, but is a 1 piece. Both the K&N and Injen are 2-piece and can have the lower hose removed to have the intake work as an SRI.

i'm aware of that but i don't like the idea of a SRI anyway so the one piece doesn't bother me much (you will need to remove that one bothering screw when you are removing the stock anyway so may aswell install the full CAI)

other than that, is there any reason not to get fujita? like a bad rep or anything? because it seems if they all put out a similar noise then i may aswell just get the one piece fujita

[sodaz]

it is all about your budget and target

CAI like injen give u a loud noise over 4000rpm and got great improve on high end but lag on low end.
Drop in filter like K&N gave you slightly more airflow but dont expect much
Airbox replacement like Mugen and Icebox give u improve on high,mid and low end but wont have so much high end like Injen

Spot on! :thumbsup:

[h1coupe]

it is all about your budget and target

CAI like injen give u a loud noise over 4000rpm and got great improve on high end but lag on low end.
Drop in filter like K&N gave you slightly more airflow but dont expect much
Airbox replacement like Mugen and Icebox give u improve on high,mid and low end but wont have so much high end like Injen


but it has been shown that the k&n cai does not seem to have the low end lag, propably because of the 2 1/2"inch tubing as opposed to the 3" tubing of the injen.

I have the K&N cai and I love it and would recommend it to anyone!
but I would not be afraid to test out the fujita, looks like a good product.

[yfin]

but it has been shown that the k&n cai does not seem to have the low end lag, propably because of the 2 1/2"inch tubing as opposed to the 3" tubing of the injen.

Can you back that up with something H1? Cheers. I know Euroaccord13 has that product and he noticed the drop in the low end.

[EuroAccord13]

No drop in low end? Are you talking about the Typhoon system?:wave:

CAI will almost definitely cause a slight drop in the low end.. I have seen it for myself in multiple tests performed with my car on SRI and CAI mode, I even took it to the strip and my 60ft time confirmed that I lost abit of power on my lower end of the RPM band... :) :)

[ginganggooly]

No drop in low end? Are you talking about the Typhoon system?:wave:

CAI will almost definitely cause a slight drop in the low end.. I have seen it for myself in multiple tests performed with my car on SRI and CAI mode, I even took it to the strip and my 60ft time confirmed that I lost abit of power on my lower end of the RPM band... :) :)

When i did the back to back dyno CAI vs Stock, I gained power from 3000rpm to cutout.

http://www.imagehosting.com/out.php/i292969_StockvsIntake.jpg

If you have a look at the above graph, it is of a system which is very similar to the k&n typhoon system. While it's not of the exact same dimensions as the typhoon system, it indicates that you lose almost no low end with a cai (on WOT).

[TypeG]

that's all we know
CAI always drop in low end and it quite noticable

[BusterSonic12]

i say box~!! comptech or mugen! looks stock, good gain over a range of rpm, hear vtec. ALL GOOD!! quiet when not full throttling.

[yfin]

If you have a look at the above graph, it is of a system which is very similar to the k&n typhoon system. While it's not of the exact same dimensions as the typhoon system, it indicates that you lose almost no low end with a cai (on WOT).

Your chart shows the base line ahead of the CAI down low. It also doesn't show you the differences in torque. So there is a loss down low with a CAI.

It is the main reason I prefer the boxed intakes like Icebox for street driving - unless you are prepared to spend money on ECU tuning out the losses down low.

[ginganggooly]

Your chart shows the base line ahead of the CAI down low. It also doesn't show you the differences in torque. So there is a loss down low with a CAI.

It is the main reason I prefer the boxed intakes like Icebox for street driving - unless you are prepared to spend money on ECU tuning out the losses down low.

No, it shows the baseline BELOW the CAI down low.

The CAI yielded small gains until ~2700rpm on the displayed graph. There is a ~400rpm area with slightly less power (difference of less than 2.5kw), at about 3000rpm they cross over and the CAI has a clear advantage from there on.

You don't need a tractive effort line to see that the car is making more torque everywhere except for that 400rpm space.

[aaronng]

Enclosed short ram ftw! :)

[TypeG]

but that 400rpm less than stock is a lot when u going up hill with a heavy car like Euro. I got stock air box, injen and mugen airbox. There is a HUGE different in low end as on the street, u usually rev up to 3000rpm unless u drive like a race car all the time. Actually CAI only work when the pod start to WOT.


No, it shows the baseline BELOW the CAI down low.

The CAI yielded small gains until ~2700rpm on the displayed graph. There is a ~400rpm area with slightly less power (difference of less than 2.5kw), at about 3000rpm they cross over and the CAI has a clear advantage from there on.

You don't need a tractive effort line to see that the car is making more torque everywhere except for that 400rpm space.

[ginganggooly]

Enclosed short ram ftw! :)

The enclosed short ram setups had interesting results in my car... I spent a whole day at the dyno (with the DC2) testing out various intakes.

I changed from the modified stock airbox to a shortram with no shielding and lost 6kw peak, and a bundle down low- not sure how much it was, but the whole graph was moved down.

I thought it may have been heat soak, so I bolted in the partition I made for short ram and tried it out again. Still had the same result. Thinking that maybe the heat shield wasn't working properly, we lifted the bonnet and ran the car up like that... same result yet again.

After trying out various configurations with pipe diameters and lengths, we worked out that the issue of powerloss (on the dyno) wasn't heat-soak, but due to having incorrect pipe lengths. It seems to hold true, as the modified stock airbox made almost as much top end as the optimumly sized cold air intake. As it turned out, the total pipe length of the stock intake arm, stock airbox with pvc pipe extension had an almost identical diameter and total length to the best tested CAI...

We did some rough testing on a few different motors (b16, b20, 4age, sr20de) and they all had similar results.

The lesson learnt from the whole exercise was how important pipe length is to overall breathing efficiency of the motor.

[TypeG]

heat never be a problem on dyno i guess as u should have open up your bonnet plus you wont have a lot of runs before you sway to another setup

[aaronng]

but that 400rpm less than stock is a lot when u going up hill with a heavy car like Euro. I got stock air box, injen and mugen airbox. There is a HUGE different in low end as on the street, u usually rev up to 3000rpm unless u drive like a race car all the time. Actually CAI only work when the pod start to WOT.

You're splitting hairs.

[ginganggooly]

heat never be a problem on dyno i guess as u should have open up your bonnet plus you wont have a lot of runs before you sway to another setup

Why should we have the bonnet up?
We had enough consistancy in our results, from run to run, to convince myself and the tuner that the results were reasonably accurate.

[TypeG]

You're splitting hairs.

what does that mean?

[TypeG]

u never explain where and how u dyno your car.. I did dyno with bonnet up, some put dyno with fans in front which does make some different.
but for the fact, CAI is LAG at the low end

[EuroAccord13]

Low Down = <3000RPM so we both stand corrected except ginganggooly may have intepreted the what I think is low RPM wrongly...

Everything is cleared up now although there is an obvious flat spot... :)

[ginganggooly]

u never explain where and how u dyno your car.. I did dyno with bonnet up, some put dyno with fans in front which does make some different.
but for the fact, CAI is LAG at the low end

che?? wtf does the bonnet have to do with this situation?

EuroAccord13 hit the nail on the head... it comes down to how you define low end. I'd class anything below 4k as low end, in which case, the CAI -at WOT- is clearly much better than stock, as indicated on the displayed graph. Below 3000 it's much of a muchness, as there is a crossover.

Case closed :thumbsup:

[EuroAccord13]

Nail on your head or mine? LOL.... :D :D

Euro have around 8000RPM to play with (7400 for you anal measuring kids :D)

So to 3K is low end, 3K to 5K is mid range... 5K up is high end.. Although we cannot really classify our cars to have high end RPM because we don't! Anyway.. ALL CLEARED UP!!!!

[ginganggooly]

I'm used to a 9200rpm ceiling :P

[TypeG]

che?? wtf does the bonnet have to do with this situation?

EuroAccord13 hit the nail on the head... it comes down to how you define low end. I'd class anything below 4k as low end, in which case, the CAI -at WOT- is clearly much better than stock, as indicated on the displayed graph. Below 3000 it's much of a muchness, as there is a crossover.

Case closed :thumbsup:


release some hot air from the engine i guess

i do hope a CAI is much better than stock or why we want to pay extra which dont gain anything.
that range of 400rpm loss below 3000 is what we used it most of the time as unless u WOT your car all the time

[Tobster]

wtf does the bonnet have to do with this situation?


It's part of the whole reason many argue that dynos cannot represent real world driving situations, and hence measuring power/torque changes from air intakes is difficult.

With the bonnet down, you don't get the airflow (to the filter as well as through the engine bay) that you when driving the car. The in-drawn air also gets heated more which affects engine performance.

Hence, many leave the bonnet up and blow fans -- but that also adds extra cool air and doesn't allow for the under-bonnet heat that happens when you drive on the road.

Some argue that only real way to check things is to plug in the computer and plot things while you drive...

"Dyno-proven" doesn't necessarily mean much in real world driving -- unless your only real concern is winning dyno shoot-outs.

EDIT: Plus, anyone thinking about a Comptech icebox had better move quickly as Comptech is shutting its doors according to the US forums...

[yfin]

No, it shows the baseline BELOW the CAI down low.

The CAI yielded small gains until ~2700rpm on the displayed graph. There is a ~400rpm area with slightly less power (difference of less than 2.5kw), at about 3000rpm they cross over and the CAI has a clear advantage from there on.

You don't need a tractive effort line to see that the car is making more torque everywhere except for that 400rpm space.

Slightly less power is less power than stock which no one wants. And I don't see a torque graph so how can you comment on torque? The other graph is air fuel ratio.

[TypeG]

Slightly less power is less power. And I don't see a torque graph so how can you comment on torque? The other graph is air fuel ratio.

very true

i feel the damn lag man
dun tell me i am BSing

[cdjhitman]

so which is better out of the three again? lol....

[TypeG]

i will go injen or K&N
more famous

[Omotesando]

Just thought I'll mention that Torque is in fact a derivative of Power, so the power curve's gradient at any one point, when plotted, will become the torque curve. So you can mentally picture how the torque distribution and performance of the car from the power curve. :D

To me anyway, reading a power curve and torque curve has little difference, you can tell instinctively what effects any change in both will have on drive ability, I think!

[yfin]

Just thought I'll mention that Torque is in fact a derivative of Power, so the power curve's gradient at any one point, when plotted, will become the torque curve. So you can mentally picture how the torque distribution and performance of the car from the power curve. :D

To me anyway, reading a power curve and torque curve has little difference, you can tell instinctively what effects any change in both will have on drive ability, I think!

I don't find it easy. If I showed you only the power chart on the right could you predict what the torque curve on the left would look like?

http://blkcrx.hondata.com.au/blkcrx/hondatech/compair.jpg

[yfin]

I found some charts for the Injen for the TSX on their website. Have a look at the torque graph between 2000 and 3000rpm. The base line shoots up. Sorry for pic size. In day to day driving you spend a lot of time at that RPM.

http://www.injen.com/galleries/products/SP1431_charts.jpg

[TypeG]

I found some charts for the Injen for the TSX on their website. Have a look at the torque graph between 2000 and 3000rpm. The base line shoots up. Sorry for pic size. In day to day driving you spend a lot of time at that RPM.

http://www.injen.com/galleries/products/SP1431_charts.jpg

nice find
that's the fact

[aaronng]

I don't find it easy. If I showed you only the power chart on the right could you predict what the torque curve on the left would look like?
[/IMG]

I can. :)
Power (hp) = torque (lbf.ft) x RPM/5252

Given a power curve, choose various points on the chart (the more the smoother). The higher the RPM, the lower the respective torque of that point.

[yfin]

I can. :)
Power (hp) = torque (lbf.ft) x RPM/5252

Given a power curve, choose various points on the chart (the more the smoother). The higher the RPM, the lower the respective torque of that point.

You need to be an engineering geek to do that calculation in your head!

[aaronng]

You need to be an engineering geek to do that calculation in your head!

What do you think I am? :p
Ask EuroAccord13. Hhahaha

[ginganggooly]

Slightly less power is less power than stock which no one wants. And I don't see a torque graph so how can you comment on torque? The other graph is air fuel ratio.

Like most modifications, there is a compromise. I'm more than happy to sacrifice less than 2kw for a 400rpm piece of powerband, when the trade off is more torque thus power for the rest of the powerband in its entirety.

To answer your second question- If you understood the relationship between power and torque you'd understand my comment. Power is a derivative of torque and RPM.

[yfin]

What do you think I am? :p
Ask EuroAccord13. Hhahaha

Yeah I know you are an engineer - that is why you are so smart :D So am I right in saying that even a small drop in power at low RPM is going to correlate to an even bigger drop in torque at low RPM?

And the same would not necessarily hold true at high RPM?

The torque in that first Injen graph (without MR tech) is terrible. It dips below stock quite a few times in the curve - not just down low :eek: The revised Injen looks much better.

[ginganggooly]

It's part of the whole reason many argue that dynos cannot represent real world driving situations, and hence measuring power/torque changes from air intakes is difficult.


Yes you're right- As has been said many times on these forums, dynos aren't meant for pissing contests, they're a tuning tool, and they're great for measuring gains and losses from various mods, provided you try to maintain some consitancy during the testing process.

The point i was making was that, during testing, the various setups were dyno'd bonnet up and bonnet down. The results were nigh on identical, they were consistant and very repeatable.

[040501912]

You need to be an engineering geek to do that calculation in your head!

google - ing ! lol

[Tobster]

Yes you're right- As has been said many times on these forums, dynos aren't meant for pissing contests, they're a tuning tool, and they're great for measuring gains and losses from various mods, provided you try to maintain some consitancy during the testing process.

The point i was making was that, during testing, the various setups were dyno'd bonnet up and bonnet down. The results were nigh on identical, they were consistant and very repeatable.

What I was trying to express was that just because a dyno shows a repeated improvement, the improvement is applicable under THOSE conditions. It doesn't necessarily mean that the improvement will happen on the road where the airflow conditions are different. SRIs are the prime example: they'll show a marked improvement on a dyno where there's lots of air, but tend to suck in lots of detrimental hot air on the road.

[ginganggooly]

What I was trying to express was that just because a dyno shows a repeated improvement, the improvement is applicable under THOSE conditions. It doesn't necessarily mean that the improvement will happen on the road where the airflow conditions are different. SRIs are the prime example: they'll show a marked improvement on a dyno where there's lots of air, but tend to suck in lots of detrimental hot air on the road.

The point I was making is that the SRI's showed a big loss on the dyno, which I'm guessing would have been amplified on the road due to heatsoak
There was no tangible gain anywhere on any of the graphs by running a SRI over a CAI on any of the cars we tested. (bolt on only)

What I was trying to get across was that in terms of output, regardless of heatsoak issues, CAI > SRI on the cars tested :)

[EuroAccord13]

That is why we have Dyno Days... Same dyno, same day... no arguments :D .... (Minus the fact the temperature changes throughout the day)

[aaronng]

Yeah I know you are an engineer - that is why you are so smart :D So am I right in saying that even a small drop in power at low RPM is going to correlate to an even bigger drop in torque at low RPM?

And the same would not necessarily hold true at high RPM?

The torque in that first Injen graph (without MR tech) is terrible. It dips below stock quite a few times in the curve - not just down low :eek: The revised Injen looks much better.

At low RPM, a small drop in power is equivalent ot a small drop in torque. At high RPM, the same small drop in power is equivalent to a larger drop in torque.

[ginganggooly]

At low RPM, a small drop in power is equivalent ot a small drop in torque. At high RPM, the same small drop in power is equivalent to a larger drop in torque.

Then you can chuck gearing into the equation and throw the torque graph out even further :)

[aaronng]

Then you can chuck gearing into the equation and throw the torque graph out even further :)

You're thinking about tractive force. That's the raw figure measured by the rollers.

Power at the wheels (hp) = Torque at the wheels (lbf.ft) (corrected for gear ratio) x RPM/5252

This is used to calculate power at the wheels on the dyno. A dyno can't measure power. It measures torque put down on the rollers (which have a known resistance) and then calculates the power from it using the engine RPM at each point.

[ginganggooly]

You're thinking about tractive force. That's the raw figure measured by the rollers.

Power at the wheels (hp) = Torque at the wheels (lbf.ft) (corrected for gear ratio) x RPM/5252

This is used to calculate power at the wheels on the dyno. A dyno can't measure power. It measures torque put down on the rollers (which have a known resistance) and then calculates the power from it using the engine RPM at each point.

I didn't realise that the dyno used engine rpm to calculate outputs, I assumed it was using roller speed vs tractive effort and whatever calculation is required to plot power.

So when the operator calibrates engine RPM vs Speed on the dyno, its going a little deeper than just changing values on the graph?