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Old 02-24-2003, 12:17 PM
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3.9LTwinTurbo
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Default Cold Air Intake gains

Hi all,

My name is Budi and I work for a very respectable tuner in North America (To see our creations, please refer to the cover of the current issue of Sports Compact Car).

There has been a lot of talk about a cold air intake being one of the first modifications to the 350Z. This makes sense since they are relatively cheap and easy to install. There were even dyno charts to prove the incredible claims. One in particular caught my eye, an eye-popping 18lb/ft of torque was gained just by installing a cold air intake. I am as much a sucker for bang for the buck products as the next person but after studying the intake system utilized by Nissan on the 350Z, I have serious doubts a huge improvement like 18lb/ft of torque can be realized just by a cold air intake.

To go about investigating this claim, I had to use one of the member's before and after dyno charts (I apologize beforehand if this offends anyone; it is not my intention to belittle anybody).



Here is the claimed 18lb/ft torque gain from a CAI. Notice that only the peak numbers are quoted and the before and after graph's axis scales do not match. I had to alter the graph so that i can normalize both scales. Looking at the torque curve (horsepower curve is useless as we all know that horsepower is merely a function of torque over time), we see that the shape of both curves are very similar. The difference in torque overall is about 2 - 3lb/ft, which imho, is statistically negligible. The spike happens at 2500RPM where the motor inexplicably displays it's maximum peak. This does not correspond to how a naturally aspirated motor develops it's power. My best guess is that the dyno operator may have started the test early and if that's the case, data gathered before 3000RPM should be thrown out the window as outlying data. This would explain why horsepower numbers did not increase as drastically as the torque numbers.

This dynochart proves to me that just changing the intake does not dramatically improve power. I believe that the factory airbox and intake tract is already very optimal. Also, car manufacturers typically build their motors tight from the factory, needing a relatively long break in period before they are considered broken in and in optimal operating condition. On the cars we work on, it takes about 5000 miles before we would consider the motor broken in. That fact is proved on the dyno where a brand new car will be 15 - 20 Hp down compared to a car with over 5000 miles.

After a long-winded message, I guess the bottom line is a). let your motor completely and totally break in and b). do not look at a dyno chart just for it's peak numbers. A dyno is a powerful tuning tool and it can divulge a lot of information about the health and performance of your car/motor. But it can also be used for marketing purposes. I can be reached through my email if you guys promise not to sell it to those bulk email address collectors.

budi
budi@fisherspeed.com
Old 02-24-2003, 12:32 PM
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jeffw
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I believe the car in question was an auto tranny. The strange torque gains were probably just from the torque converter. If the 350z's auto has a locking torque converter (I don't know b/c I have the manual, but I think most modern torque converters do) then the first run might have had the torque converter locked and for some reason on the second dyno, the torque converter did not lock. Just a theory, but I seriously doubt that gain was from the intake.

--
Jeff
Old 02-24-2003, 12:37 PM
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3.9LTwinTurbo
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I believe it's the way the car is driven on the dyno, or conversely, how the dyno is loaded. I won't stipulate what exactly happened, but after that initial spike, the curve settled down and conforms to the stock curve. All in all, I do not believe it has anything to do with the car itself. For what it's worth, I believe that the intake contributed increases in the range of 2 - 3 and that, in my books, is within run to run window of error.


budi
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Old 02-24-2003, 01:23 PM
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fdao
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Budi,

Thanks for your contribution to this topic. I, too, share your views about the CAI pertaining to the Z. I also question the validity of the dyno runs as the Z's intake tract is arguably one of the best/optimal design on a production car. It is essentially a CAI/Ram air type of design. The only fault that I can see is the usage of a flat air filter vs a cone type of filter (ie more surface area with the cone filter). This may explain the nominal increase in the aftermarket CAI vs the stock filter.

Your thoughts.
Old 02-24-2003, 02:52 PM
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menehune
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fdao, I notice that you're from Hawaii and your Z is red, anyway there was a discussion on the SpeedHawaii forum of a red Z "lining it up" with a crotch rocket, by any chance was that you?
Old 02-24-2003, 04:04 PM
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fdao
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Originally posted by menehune
fdao, I notice that you're from Hawaii and your Z is red, anyway there was a discussion on the SpeedHawaii forum of a red Z "lining it up" with a crotch rocket, by any chance was that you?
Menehune,

Hahaha, what's a "crotch rocket"? I was there, but after seeing the burn outs in the parking lot, the Z group decided to have our own cruise instead. Did not want to be associated with Speedhawaii due to the cop magnet "stunts".

Were you there? BTW, I didn't "line up" with anyone .
Old 02-24-2003, 11:59 PM
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menehune
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Originally posted by fdao
Menehune,

Hahaha, what's a "crotch rocket"? I was there, but after seeing the burn outs in the parking lot, the Z group decided to have our own cruise instead. Did not want to be associated with Speedhawaii due to the cop magnet "stunts".

Were you there? BTW, I didn't "line up" with anyone .
"crotch rocket" = street bike. I'm over on Kauai. I read on the speedhawaii forum of someone with a red Z taking on a street bike in the middle of the freeway. Said that they stopped in the middle of the freeway just to race(during the day!). Honest mistake
Old 02-25-2003, 02:14 AM
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12SecZ
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Default To fdao

Double post

Last edited by 12SecZ; 02-25-2003 at 02:33 AM.
Old 02-25-2003, 02:32 AM
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12SecZ
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Thumbs down To 3.9LTwinTurbo and fdao

That was my Dyno you posted. Common courtesy would be to have asked me first via Email or PM before posting that. I would have agreed as it is on my web page but you still should of asked just to be nice. Apparently you don't give a crap about "nice." I guess.

To me that doesn't give you much credit or integrity where I come from, but that is just me.

That being said (that you are rude and inconsiderate of others)
the Dyno Jet in question was new and the operator was also new to using it. That was all explained.

It is an A5T and he went through the gears manually using steptronic and stopped in 3rd not 4th. I think I clearly explained all of this in several posts and I have also clearly explained that my next Dyno will be done at 5k miles (as you mentioned.)

Next time I am going to have him go through all the gears in just D instead of stepping through them. I wanted the results to be exactly as my first Dyno so I made him do Dyno #2 the *exact* same way. This is how we do thing here , consistenly....

Since you posted the name of the Dyno Jet owner (Marco's Automotive) perhaps you can give him a call about your amazing new find and how he did it wrong. He is a pretty nice guy and I'm sure he will be happy to learn lessons on how to properly Dyno from you.

I will be happy to post the number for you to call.

This is why I quite going to Usenet and came here to forums. To escape this type of magazine racer attitude from know it alls.

Might I suggest that next time you PM me or email me and explain that you want to post one of my Dyno's?
It's called common courtesy here in California.

I had planned on posting a series of Dyno's and time slips with my Zex Kit after headers and pullies but people like you make me tend to not want to anymore. They cost 60 bucks each ya know?

I go to the track here and *real* people/friends have seen my car and can't wait to see it at the track. I still fail to see the point of your post using *MY* Dyno as an example, certainly you can obtain others elsewhere couldn't you (considering your contacts) before calling BS on someone you don't even know?

From now on people I have dealt with in PM's in the past can email/pm me for my upcoming Dyno's with Zex and headers/pullies and my April Time Slips, so they are not publicly mocked by the likes of you. I take offense to your post in it's current state. Should have contatced me first, bottom line.
I reiterate, call Marco's Automotive with your comments next time before picking apart a Dyno somone posted for the benefit of other viewers without even asking them.

Last edited by 12SecZ; 02-25-2003 at 02:40 AM.
Old 02-25-2003, 02:38 AM
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12SecZ
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Here is the claimed 18lb/ft torque gain from a CAI. Notice that only the peak numbers are quoted and the before and after graph's axis scales do not match. I had to alter the graph so that i can normalize both scales.
"Claimed" and "altered"???

I think I need to make a COUPLE phone calls on you today bud. Nothing was altered or falsely claimed, the Dyno was scanned as is untouched and no one gave you the right to "alter" anything.

END RANT.
Old 02-25-2003, 03:57 AM
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Dr Bonz
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CHILL OUT MAX! Man, the guy seems pretty reasonable to me. I agree that maybe he should have asked you first, but he started off stating that he didn't mean to offend anybody. His post didn't seem derogatory nor did he "call BS" on you either. He basically tried to refute what he felt was an innaccurate dyno. You yourself just said that the guy who did it was new to it and was still learning! Based on that alone, couldn't you cut this guy some slack? Finally, he never said that YOU "altered" anything. He said in order to interpret the dyno HE had to alter the graph.

Calm down man!
Old 02-25-2003, 04:16 AM
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12SecZ
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Default I'm calm, just burned out from work

I will add though, before everyone starts disagreeing with me.

It wasn't your Dyno, taken from your web page and posted here without the consideration of asking. As I said, everything he *reposted* were things I had already mentioned in prior posts on this subject.

I am not claiming ownership of the Dyno Chart because I openly posted here at *others* requests.

Please try and keep in mind that if it was *your* info (and I say this to all not just you) you may feel like I do. Reading the thread as a 3rd party is allot easier.

1. He could have asked or even notified me
2. He could have mentioned the things I stated in prior posts
in relation to this chart to keep things in context.
3. If he wants to claim that the stock intake is = to an aftermarket intake that is his *opinion* and I (and I am sure Injen, AEM etc would agree) that I have the right to dispute said post.

He also could have "altered" the Automotive Dyno Shop that did it rather than try and publicly embarrass them.

I am not going to get in a huge debate/flame war whatever over this issue. I am happy with my mods and I have a feeling my car will perform well at the track with what I have done to it.

He could have used a 3rd party Dyno graph rather than a board members and I as a member have a right to express my distaste in his post. If you beleive him then no one should by a CAI everyone just keep your car stock intake because it's "ram air and optimal"

For the record this is the paragraph I take offense too mainly

Here is the claimed 18lb/ft torque gain from a CAI. Notice that only the peak numbers are quoted and the before and after graph's axis scales do not match. I had to alter the graph so that i can normalize both scales. Looking at the torque curve (horsepower curve is useless as we all know that horsepower is merely a function of torque over time), we see that the shape of both curves are very similar. The difference in torque overall is about 2 - 3lb/ft, which imho, is statistically negligible.
It is not "claimed" if I did it, it's fact. If it is in error or innaccurate a more fitting word should be used. Also he says " only the peak numbers are quoted and the before and after graph's axis scales do not match"

I have no control over that. I paid for a Dyno, took the chart home, scanned it in as is and posted it. So if the Dyno Operator did something wrong he should now address it with said person (since he left their name on the chart after "altering" it.

"imho" In My Humble Opinion, in other words we all have opinions. So my opinion is even if it was only 4 pounds of torque that is *indeed* negligable. IMHO!

Dr. Bonz, do you have an aftermarket CAI? If so why? According to this poster they are a waste of money? Perhaps that is why you are so unsettled? You wasted your money too

P.S. Starting off a posT by saying I don't mean to offend anyone, does not give you the right to commence to offend them anyway just because you give a disclaimer, this specially applies to someone using your own personal data.

Example,

I don't mean to offend anyone but I saw a pitcure of so and so's girlfriend and she is not as pretty as this person "claimed" I "altered" her to make her look better. LOL, no offense of course but here is her new picture, oh by the way I didn't ask them if this was ok either, I took it upon myself to do so.

Last edited by 12SecZ; 02-25-2003 at 04:26 AM.
Old 02-25-2003, 06:50 AM
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3.9LTwinTurbo
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Wow,

MaxHax, I truly apologize. I never singled you out, even though the charts might be cleary labeled as being yours. I am not out to start any wars, just trying to start a discussion, in a civil manner, about real world gains.

I know that I started out on the wrong foot with you Max, and for everybody else, please note that I do not know Max, I have never seen him, nor talked to him before. I do not know the shop that performed the dyno testing. What I do know is real world testing on a dyno and what error/s might occur. After all, we're just looking to go fast and have fun. Again, I do not mean to belittle anybody. I have posted my email address openly and stated my name on a public forum. I do not feel like I have anything to hide.

Just take it with a grain of salt everybody; companies have to sell parts, hence the marketing department. If the claimed gains are not repeatable, then shouldn't we as a community stand up against it? I am not against you nor the shop that did the work. I don't know you nor the shop. I have no reason to badmouth either of you. If anybody feel my reasonings or methodology is flawed, feel free to correct me. We're all adults and we can have a discussion without going at each other's throats. I apologize for using your particular dyno chart, I did not name names nor did I say anything that is outside the scope of the discussion.

Please accept my apology, Max, and let's move on. I will not post anymore particulars about your car or it's modifications without notifying you first. By the way sir, you have mail.


budi
budi@fisherspeed.com
Old 02-25-2003, 07:17 AM
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2003z
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Default Re: I'm calm, just burned out from work

Originally posted by MaxHax
3. If he wants to claim that the stock intake is = to an aftermarket intake that is his *opinion* and I (and I am sure Injen, AEM etc would agree) that I have the right to dispute said post.
With regards to the above quote, I have been following phillip@injens posts, asking him to explain why other dyno's show little or no gain, and other than saying bad gas, he refuses to address the issue, so apparently only you and AEM would like reserve your rights to dispute, not Injen.
Old 02-25-2003, 07:38 AM
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12SecZ
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Take it off then, sell it, send it back. Smash it!

You have options, you are in control of what goes on your car not Injen.

This is why people shouldn't personalize threads.

As for "not naming names" it clearly shows Marco's Automotive with the phone number and I had a lenghty thread on this Dyno. You also say you live in the midst of somehere? Or some crap?
My name is Max and I live in Sacramento, CA and one click gives you my email and web page so exactly who is hiding?

If you don't want a CAI don't buy it, but don't shoot me down because I like mine. Thousands are installing them.

Oh and BTW, no I do *not* have mail, just checked. 0840 no mail.

Anyways, I like my car and that is all that matters, let this thread turn into I hate CAI's thread or whatever just leave me out of it.

Thank you for everyones consideration. I think I have said my peace in a quite lenghty and detailed fashion. Just because I am man enough to defend myself and my setup on a board does not mean I am overreacting. Don't by that (for the lurkers only.)

Max
Old 02-25-2003, 07:45 AM
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z327
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Right now I'm not sure any changes to intake or exhaust will result in appreciable HP gains. In the dyno runs I saw in Dallas there were no improvements and if the change was real time the HP actually went down. Until someone can crack the code on the ECM or get clear info on how long it takes for the ECM to learn, I would not spend big bucks. Buy a CAI if you like the sound or the looks. If you get it for performance you will not be happy if you dyno it.

I've started emailing performance company's asking how they got the increases in HP. So far only one has answered who had yet to publish horsepower increases for their new header and they were honest. They to did not see an increase that would justify the expence and had put 150 miles on the car so far.
Old 02-25-2003, 08:07 AM
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2003z
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Originally posted by MaxHax
Take it off then, sell it, send it back. Smash it!

You have options, you are in control of what goes on your car not Injen.

MaX,
I'm not attacking you!

I like it too, it looks good, and I have no intentions of removing it, I was just pointing out that aside from their one dyno graph, injen has no intention of backing up their claims, or refuting other dyno's. Phillips only response to me had been to ask why I am following him around asking the same question over and over. He finally chocked it up to bad gas, but I don't buy it.

Aside from your dyno chart, anyone who has claimed big gains hasn't posted the actual charts.

AEM may take a different approach, but injen has lost credibility with me.

Last edited by 2003z; 02-25-2003 at 08:10 AM.
Old 02-25-2003, 08:09 AM
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12SecZ
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Budi and I settled this offline. He seems like a caring , interesting and more importantly knowledgable individual.

I have advised him I am finished with this thread, so please feel free to contunue the CAI debate w/o my interuptions. I informed him I never put much stock in Dyno #'s and anyone doing a search of my old posts can confirm this. I am building my car for the track, not a machine that holds it in place with straps. I had posted the Dyno #'s at others requests not mine, and it cost 120 bucks. Now I know why I hate Dyno's (FireHawk Flashbacks.)

Sincerely,

Max

Edit add,

Phillips only response to me had been to ask why I am following him around asking the same question over and over. He finally chocked it up to bad gas, but I don't buy it.
Sorry to here that, I bought mine at a great price from wicked4u2 and I didn't buy it based on Dyno charts I bought it to bring in more cold air to complimet my exhaust, I have a road map plan for my mods and I am doing them in order. After I add the ECU it will all come together! I am in agreeance with the false Dyno claims, I just ignore them and do research on what works. Like 8RWHP for a BBK TB. Now that is BS! *But* it's a good mod. Ya Know what I mean?

Last edited by 12SecZ; 02-25-2003 at 08:13 AM.
Old 02-25-2003, 09:11 AM
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gfornal
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I don't mean to tread on anyone but i think we need to start a poll of how old everyone is and who is on this board. I would prefer to have just people who actually have the car or are a vendor posting. Thsi is the second thread I have ready that was horrible. I will not mention the other and I'm not choosing a side, but please lets think before we write. This isn't about who's is bigger. I have seen this happen to many message boards.

thanks,
Greg
Old 02-25-2003, 09:50 AM
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Andorion
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Greg, why shouldn't I be able to post just because I don't have the car? I'm considering one, I've done my research, I might be able to contribute something... I definitely agree, though, that this board isn't about "whos is bigger."

...

I'm so sick of everyone being so thin skinned. Get over it. MaxHat, you really flew off the handle and frankly it's a bit scary... it's like roadrage, but on a message board.

Noone else has congradulated Budi on a job really well done, and I don't know why. He saw something worth investigating and investigated it. All this talk about "opinions" is total BS - opinions don't make charts. Normalizing and lining up the two dynos was absolutely the RIGHT move, and identifying the anomalous peak was brilliant. He wasn't insulting the owners of the intake, he was analyzing its performance, and how anyone can take PERSONAL offense is just beyond me.

Stop being so defensive about everything - if you bought it and you're happy with it, then good for you. If you want to believe it gains you 15 lb/ft of torque under the entire curve, feel free, but don't start crying when someone questions the claim or actually proves otherwise.

One more thing - as far as I'm concerned, if you post something on the internet, in a public forum, it automatically goes up for review. If you don't want it scrutinized, don't post it - this goes for pictures, claims, comments, everything. And again - thicker skin, please.

Sorry for the ranting, but seeing someone get flamed for doing some scientific, honest and USEFUL work really bothers me.

~Berj


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