Author Topic: Airbox (Read 3544 times)

rappz7 · « **on:** February 21, 2014, 06:04:51 PM »

Anyone have experience with removing the stock airbox and replacing it with individual air filters directly on the carbs. I attached a picture to get a better idea as to what im talking about. Anyway, does swapping the air box for individual air filters effect the bikes performance? Does it effect how the bike runs, how it performs?

dave500 · « **Reply #1 on:** February 21, 2014, 06:10:17 PM »

couldnt you have just started an oil thread?

rappz7 · « **Reply #2 on:** February 21, 2014, 06:22:50 PM »

I could not. I don't know what you mean by "oil thread"

dave500 · « **Reply #3 on:** February 21, 2014, 06:44:09 PM »

have you used the search function here yet?
http://forums.sohc4.net/index.php?topic=81719.0

http://forums.sohc4.net/index.php?topic=71000.0

http://forums.sohc4.net/index.php?topic=77983.0

Powderman · « **Reply #4 on:** February 21, 2014, 07:19:40 PM »

99.9% of the time you will never get pod filters to run as well as the stock air box. The only time I have seen a bike make more power than stock with pods is when other major performance improvements went along with them so the gain can't really be attributed to the pods. The inside of the air box has velocity stack type venture's that aide in the flow of air into the carbs. Pods don't have this same design and often cover important venture's in the mouth of the carb (depending on the carb). IMHO pods should never be used for any other purpose than cosmetics at the sacrifice of performance. No one has ever posted a dyno sheet showing pods alone make more power than stock air box.

http://www.caferacer.net/forum/technical/19639-pod-filter-thread-geeto.html

alacrity · « **Reply #5 on:** February 21, 2014, 07:59:35 PM »

Lol. I think he was kidding. He HAD to be kidding....

Sent from my iPhone using Tapatalk

flybox1 · « **Reply #6 on:** February 21, 2014, 08:11:35 PM »

Quote from: rappz7 on February 21, 2014, 06:04:51 PM

Anyone have experience with removing the stock airbox and replacing it with individual air filters directly on the carbs. I attached a picture to get a better idea as to what im talking about. Anyway, does swapping the air box for individual air filters effect the bikes performance? Does it effect how the bike runs, how it performs?

Hey new guy. You've just been hazed because you brought up a controversial subject that has need discussing just as much as oil threads.

thousands of threads on the subject.
Take your lumps and stick around.
There is a search bar at the upper left of the page. Learn to use it.
Pods can be made to work, but often take too many hours and the benefit is minimal. mostly cosmetic.
If Honda thought they'd work better with these bikes, they'd have added them from the start.
Welcome to the forum.

goldarrow · « **Reply #7 on:** February 21, 2014, 08:46:08 PM »

Oh boy...Pods. Then pipes...then oil...

Pop corn please

skidooextreme · « **Reply #8 on:** February 21, 2014, 08:51:20 PM »

And he is gone to find another forum......

Powderman · « **Reply #9 on:** February 21, 2014, 10:37:09 PM »

Quote from: flybox1 on February 21, 2014, 08:11:35 PM

Quote from: rappz7 on February 21, 2014, 06:04:51 PM
Anyone have experience with removing the stock airbox and replacing it with individual air filters directly on the carbs. I attached a picture to get a better idea as to what im talking about. Anyway, does swapping the air box for individual air filters effect the bikes performance? Does it effect how the bike runs, how it performs?
Hey new guy. You've just been hazed because you brought up a controversial subject that has need discussing just as much as oil threads. thousands of threads on the subject.
Take your lumps and stick around.
There is a search bar at the upper left of the page. Learn to use it.
Pods can be made to work, but often take too many hours and the benefit is minimal. mostly cosmetic.
If Honda thought they'd work better with these bikes, they'd have added them from the start.
Welcome to the forum.

Do you have any data to show there is even a minimal benefit other than cosmetic? It's amazing how many people think the Honda engineers are idiots. Even their failures (CX500, CM400,etc) are better than anyone has made them into customizing them.

dave500 · « **Reply #10 on:** February 22, 2014, 12:57:10 AM »

rappz7 wont go,he wont ask that question again though?stick with the airbox man,its the best way to enjoy the full range torque.

alacrity · « **Reply #11 on:** February 22, 2014, 02:16:10 AM »

I have found that four old gym socks held on with rubber bands work perfectly. You need 100 percent cotton though, the oily blends don't flow as well

Sent from my iPhone using Tapatalk

alacrity · « **Reply #12 on:** February 22, 2014, 02:16:38 AM »

I meant the poly blends

Sent from my iPhone using Tapatalk

jonda500 · « **Reply #13 on:** February 22, 2014, 03:05:33 AM »

How do you stop the gym socks getting sucked into the carbs? - do they have wires inside or large springs maybe?
What type of filter oil are you using to oil the gym socks?

dave500 · « **Reply #14 on:** February 22, 2014, 03:13:44 AM »

that post stinks jonda,hang on a minute,its just the gym socks,you have to use neatsfoot oil?

flybox1 · « **Reply #15 on:** February 22, 2014, 07:24:33 AM »

Quote from: Powderman on February 21, 2014, 10:37:09 PM

Quote from: flybox1 on February 21, 2014, 08:11:35 PM
Quote from: rappz7 on February 21, 2014, 06:04:51 PM
Anyone have experience with removing the stock airbox and replacing it with individual air filters directly on the carbs. I attached a picture to get a better idea as to what im talking about. Anyway, does swapping the air box for individual air filters effect the bikes performance? Does it effect how the bike runs, how it performs?
Hey new guy. You've just been hazed because you brought up a controversial subject that has need discussing just as much as oil threads. thousands of threads on the subject.
Take your lumps and stick around.
There is a search bar at the upper left of the page. Learn to use it.
Pods can be made to work, but often take too many hours and the benefit is minimal. mostly cosmetic.
If Honda thought they'd work better with these bikes, they'd have added them from the start.
Welcome to the forum.

Do you have any data to show there is even a minimal benefit other than cosmetic? It's amazing how many people think the Honda engineers are idiots. Even their failures (CX500, CM400,etc) are better than anyone has made them into customizing them.

the benefit? You become familiar with all the parts of your carbs and how quickly you can get them off and back on before you start asking yourself if this was all really worth it.

Powderman · « **Reply #16 on:** February 22, 2014, 08:34:17 AM »

flybox, I'll certainly accept that explanation of a benefit and right you are.

Black 750K8 · « **Reply #17 on:** February 22, 2014, 10:14:53 AM »

Benefit #2 we all have a chance to buy the parts taken off to replace the ones the PO took off our bike.

rappz7 · « **Reply #18 on:** February 22, 2014, 05:03:54 PM »

What am I 8 years old. It'll take a bit more to send me away with my tail between my legs. Just remember none of you were pros from the "get go" Im sure plenty of "stupid" question fly around here.

vames · « **Reply #19 on:** February 22, 2014, 05:15:29 PM »

Quote from: rappz7 on February 22, 2014, 05:03:54 PM

What am I 8 years old. It'll take a bit more to send me away with my tail between my legs. Just remember none of you were pros from the "get go" Im sure plenty of "stupid" question fly around here.

Excellent attitude! People will give you a little #$%* around here, but it's an honor to get #$%* from them. As for the individual filters -- people call them "pods". It's a very polarizing issue. The one thing we do know is that you can't just swap out the box for some pods and expect to keep riding -- there is a lot of tuning needed to adjust to the different characteristics of the pods. The other thing we do know for sure is that the airbox supports smoother performance and more pull toward the lower end of the RPM spectrum. To the extent there are benefits to pods, they happen at higher throttle ranges, particularly in engines that have been modified with ported exhausts, sportier cams, free exhausts, etc.

I'm pretty sure all those factors are known knowns, but someone will shoot me down. I'm ready.

05c50 · « **Reply #20 on:** February 22, 2014, 06:16:30 PM »

Quote from: rappz7 on February 22, 2014, 05:03:54 PM

What am I 8 years old. It'll take a bit more to send me away with my tail between my legs. Just remember none of you were pros from the "get go" Im sure plenty of "stupid" question fly around here.

As it's been said, "The only stupid question is the one that's never asked". You asked a question that has been asked many times before and will undoubtedly be asked many more times. Among the gear head world, there are many things that have been discussed (beaten to death) many times. Some of the popular ones are oil, tires, fuel additives, and on motorcycles, "pods". If it weren't for these kind of threads, some people would have no way to demonstrate their "expertise"(actual or imagined). Using the search feature will help, but will not always return the desired results. Especially if you're unfamiliar with the slang term for an item. Welcome, good luck, and now that you've been initiated, you can sit back and wait for the next person to ask "the question"

................Paul

LesterPiglet · « **Reply #21 on:** February 22, 2014, 06:17:35 PM »

Quote from: vames on February 22, 2014, 05:15:29 PM

I'm pretty sure all those factors are known knowns, but someone will shoot me down. I'm ready.

I fart in your general direction. Your mother was a hamster and your father smelt of elderberries.

AJK · « **Reply #22 on:** February 22, 2014, 06:20:47 PM »

Quote from: rappz7 on February 22, 2014, 05:03:54 PM

What am I 8 years old. It'll take a bit more to send me away with my tail between my legs. Just remember none of you were pros from the "get go" Im sure plenty of "stupid" question fly around here.

rappz7,

I'm encouraged to see young guys like yourself playing with the CB750. Its an awesome piece of machinery & you will come to understand this and appreciate more and more as you work on the bike. Its both a simple bike, yet precision made as well. Learn to understand it, look after it and it will look after you. Furthermore, learning this bike mechanically puts you in good stead for other bikes as well.

This forum is a great place. Just use the search tool first. As everyone has mentioned, having the airbox in place takes a lot of fuss out the equation. Just put it on and ride away. Or install the pods and give yourself time for more fun ahead.

In short, airboxes play a critical part of conditioning the air prior to getting pushed into the engine. Pods don't condition the air anywhere as good as an airbox, so adjustments are necessary in the carb to compensate for this.

PS: I can recommend you buying Hondamans book if you really want to get to know this bike properly.

rappz7 · « **Reply #23 on:** February 22, 2014, 07:27:54 PM »

Thanks for the input everyone

TwoTired · « **Reply #24 on:** February 22, 2014, 08:00:23 PM »

Regarding pods, it's really not about airflow until you rev the engine near or above red line.
The most significant effect of them is the change in pressure experienced in the carb throats. Since the carbs deliver fuel at a rate determined by the pressure differential between the carb throats and what exists outside the carbs. Changing to pods and shortening the inlet duct, greatly diminishes what fuel the carbs deliver, if they are still set to factory specifications. Honda adjusted the carbs to the parameters that the stock air box presented to the carbs (as well as the exhaust pressure reflections). So, changing the intake and exhaust parameters requires finding new settings/sizes for the carb fuel delivery internals, which are very unlikely to be equal to book values.

I expect the CB650 to be particularly sensitive to induction and exhaust changes as these bike were introduced during the EPA's initial crackdown period on motorcycle exhaust hydrocarbon emissions. So, Honda fine tuned the carbs to balance properly with the production induction and exhaust.

It's not impossible to make changes "work". But, "working well" is another matter, requiring proper test and measurement techniques and a pretty thorough understanding of how the whole system works. Alternately, you must be pretty darn lucky.

News:

Author Topic: Airbox (Read 3544 times)

Black 750K8

AJK