1st gen ram air?

I was looking at my air box and thought maybe I could change the ducting to pull air in from above the rad. would this work? I always thought that the ducts facing each other was strange and why they didnt put them in front like the newer bikes.

 

advice. Abandon this effort, unless you plan to invest time and cash into replacing or retuning your carbs, possibly your combustion chamber. The way most carburetors work, the air gets sucked into the chamber from the previous explosion via the vacuum it creates. Forcing in the air, will over presurize the combustion chamber (un modified), and cause fuel to air ration differential. This will then cause the bike to run very poorly, and potentially miss on occasion. The engine will also run hotter, and potentially run the risk of warping the heads if its left to run hot over 30 mins.

To counter this problem, as you may have already guessed, you need to add more fuel, and increase your spark. To do so, you need to rejet the carburetor, and change the spark units. (Assuming there is an aftermarket spark converter for these bikes, which I know there isn't, so you will be making this yourself). Though this sounds rather simple, keep in mind, if you increase the volumetric amounts of the explosion, and do not increase the area, you run the risk of blowing your piston rings, and potentially blowing the heads off your bike.... not good. Hence you may need to bore open the cylinder walls, replace the pistons, and rings to a larger size, change the piston stems to produce a longer stroke, and cut the heads to allow for the increase in stroke.

*ahem* I repeat. probably a better idea to abandon this effort. If you have the know how, and perform this engine modification, please take lots of pictures, and provide the data. I'm positive MANY other first and second gen riders would be very interested to see how you turned out for HP increases.

Good luck!

 

wait wait wait ghost, there is no after market for these bikes period! what rare item's that you would find are on ebay or craigslist, but a ram air system would fuction rather well ofcourse rejetting will be Required but it's the same as running pods on it, as for the spark hell if i can get 05 gixxer coil pack to work on one then anything is possible, i've never heard of "over pressureizing " the cylinders before! and making ram air setup isnt going to send the piston shooting out of the cylinder or " blowing the rings" what do you think they did when they raced these bikes shit i doubt if they ran filters at all....not trying to be rude to you ghost..but dude do some more research about these bikes

 

so how do you intend to make a carborated ram-air setup run stoich at say 30 mph seeing no added pressure, and also stay in a stoich air/fuel ratio at say 120 mph plus with the added pressure of the ram-air effect?
IMO ram air is only going to work on a fuel injested bike.
in order to avoid leaning out at 120 mph you would need fairly larger jetting.
and the same jetting that would allow clean running at a buck twenty would be overly rich at low speeds with less ram air effect...

 

Agreed.

Again, I agree.

There is a specific ratio of combustion in each cylinder, and a compression % that is required to properly maintain the seal, Ring seal, head seal, and head bolts. too much pressure, aka over pressurizing, can result in a "blown head"... Which is a very common term, usually refering to the result of too much pressure during the combustion of the air, fuel, spark mixture, which then allows the pressure to go somewhere... typicall the head gasket. Matter of fact, it happens a lot. As for shooting pistons out of the cylinder, well, lets just not be silly. I have indeed seen piston heads pop on engines, and I am well aware of the amount of force and distruction it can cause. When we test parts and engines here where I work, we run them through several heat and time aging tests. One of which is called "DV testing". This stands for Design Verification. My point in the previous posting was to illistrate there is a lot more mathematics and calculation into the combustion than just adding more forced air. I test engines and new designed parts nearly every week.

So, since I am boasting on about "RAM air" or "Forced Air" lets get down and dirty. Simply opening up the Air box, I.e. (the anology, removing the air filter), will not affect the engines combustion ratio to any great degree. Forced air is only produced through a vacuum and pump system. Again, specific formula's and calculations must be applied in order to see any benefit what so ever. Scoop design, along with speed achieved will determine how much PRESSURE of air is applied to the air intake... course this is only relative to the area of accumulation and usage. Ram Air is a cheap, low cost, but highly mathematical option. Forced air, utilizes a pump system... usually called superchargers. No need to discuss this, cause its just stupid for a bike. Forced air, is a higher cost, medium mechanical modification, and agin highy mathematical option.

Yes you were. its ok though. I take no offence. Rather, I'll further educate.
I have posted many times, I own an 87 VFR700F2. I purchased two of them, one bent frame, and one with the engine already modified some, for wheelie competitions, but the bike caught fire and the rear was trash. I disassembled both bikes, down to the bottom engine casing. And reassembled the components into one bike. Wiring was shot, so I rewired the bike myself. Including the addition of a central grounding system. I found two flaws with the bikes design, and reported both to Honda. I got a response on one of them, which admited the find, yet kindly thanked me for my time, as they no longer support that modle bike. meh. I am an automotive engineer working for a Tier one supplier to global automotive manufacturers, such as Ford, GM, Chrysler, Honda, Toyota, BMW, Visteon, Borg Warner, and so on and so on. I work in the new design and development department responsible for engine and transmission designs, and electrical systems. I was one of 29 people who concepted, designed, prototyped, developed, and now manufacturing the "Shiftless Transmission" , Yes, I am on the patten listing.

I have two degrees specific to my field in Mechanical Engineering, and have applied already for my PE License. I do not think its too bold to state... I know what I'm talking about.

Ghost was kind enough to post the following threads:
http://vfrworld.com/forums/mechanics-garage/22793-ghost-says-lets-learn-about-tires.html
http://vfrworld.com/forums/mechanics-garage/22592-ghost-says-let-s-learn-about-clutches.html

http://vfrworld.com/forums/mechanics-garage/22254-ghost-says-lets-learn-about-batteries.html

http://vfrworld.com/forums/first-second-generation-1983-1989/22187-86-87-does-your-head-wobble.html


For anyones consideration regarding the PRESSURE equations, please feel free to read up on the subject of gained HP, VS scoop design, VS Pressure at speed.

Sport Rider-ram air induction test for sport bike motorcycles

Sport Rider-Ram Air Test of sport bikes on the motorcycle dyno

Here is the Honda bike specifically listed. (CBR600F4) New bike. with a DESIGNED and CALCULATED wind air scoop... results

Bold lines are the relative HP, and the dashed lines are just torque for a second reference. Heavy bold is assisted air.




But I digress, if Ghosts postings are un informative, or preceived inaccurate, I will refrain.

Regards.

 

damn! i was'nt being rude im sorry it sounded that way ghost :frown: but man you went all out....hahahaha.....but what do i know i am just a lowly truck driver....sigh

 

well, all that aside...

If you were to get any benefit from relocating the intake hoses, it's more likely to be a result of slightly lower air intake temps than "ram air"...

Assuming you did drive the bike fast enough to take advantage of high pressure air built up on the leading edges of the bike, the carb rework required would be extensive (read: expensive) to utilize it properly.

Honestly, just leave it alone....there's better ways to make HP.

 

Wow I guess it wasnt as simple an idea as I thought .
I need to study how motorcycle carbs work then since they seem to bear no relation to the common four barrel Holley

 

Well, the principles are the same, the execution is different.

You're be getting into slide needle profiles and whatnot on top of jetting issues....

 

Instead of thinking of some sort of ram air setup, why not a cold air setup? Reading the original post, I think that is more what the OP was getting at. You could probably rig some sort of hose (clothes dryer flex hose?) to take air from somewhere other than right above the engine and dump it where the carbs could pick it up, without causing any issues with overpressure.

IIRC, when mfgs first started using ram-air systems it was with carbs. They had to make sure the float bowls were pressurized as well (one of Honda's models had a trick flapper in the airbox to change over above a certain speed), otherwise the jets would not have been able to pick up the fuel at higher speeds. So as has been stated, that scenario is not a simple one.

 

seriously, not a problem boss. I actually took fault in myself for being too generalistic. I should have given him some information to support my comment. I was a little misleading without it. Its cool. nothin but love for fellow riders.

Chiefmg has a good point. with carbs and CAI, you may be able to at least make the air intake more efficent with a well routed hose. I would suggest as a precaution to being caught in the rain or night riding with bugs around, positioning the opening just under the front cowl near the radiator. a good K&N air filter will help too.

heh, funny story, when I first got my bikes, one air box had 4 extra 1" holes drilled into the side, and a pair of womans pantyhose stretched across the air filter opening, and glued down with a full round rubber "push in place" seal. sort of like a screen door set up. I wondered why the bike had a fishy smell when I got it... and this proves my bike is female.

 

Ram Air Systems were implemented on production machines before the introduction of FI. Do a web search and you will find that you don't require FI to have ram air work correctly, yes it would take a little bit of effort, but it is doable and has been done in the past on production carbureted machines. The term I believe that most posters in this thread are looking for is called "reversion".

 

Reagrding post #5, that's all great - but people who speak of themselves in 3rd person and can't use a spellchecker still irk me.

LOL

 

Seconded!

Ghost tinks that is rghit on!

:biggrin:

I've learned long ago.. ya, got to laugh at yourself first, and often. And I admit, I get a kick out of talking about myself in third person. Makes me feel distinguished, or just crazy enough to others to give me enough space.

 

Sure makes you look like you think you're distinguished... :biggrin:

 

i would make a set of garden hoses go straight to each carb hanging in front of headlight. awesome............

 

The problem with something like this is trying to accurately document any gains/losses.

If you read the articles that Ghost put up, you will see that the gains to something like this is pretty small, especially considering the majority of the gains are gonna be >140 MPH.

your NOT gonna blow up your junk, with the HUGE power gains your gonna have. the bike is calibrated on the fat side to begin with, adding a little more air is not gonna hurt it.

Last I checked more air through the carb = more fuel, to a point its self compensating.

personalize your bike & have fun with it.

my2c........ FWIW.

Bob

 

Darkhorse, if you want to get a bit more air to the motor, you can remove the plastic plate that sits behind the steering neck, under the gas tank(in front of the airbox). You can also get a slightly longer bolt for the forward gas tank mount, and add a washer or two between the tank and the frame.

That'll let a little more air flow down there, so the motor can breathe a little easier. Adding an aftermarket air filter will help a lot too.

I don't think you'd run into any real problems like breaking anything by adding some air scoops, but you may have to do a bit of fine tuning. I don't think you'll be gaining much, so unless you have something in mind that'll make the bike look better to you, I wouldn't worry about it.

 

+1 :smile:

Ram air was introduced for race machines and the biggest gains are in the higher end of the RPM range in the higher gears. Unless you are typically close to redline in your upper two-three gears, it probably won't be of much use.

 

O.k. But I need to know these better ways, Besides the classics lines and looks the only big thing I can shove in my buddy's face about my bike is the it has a factory one way clutch and his super high end R6 dosnt haha!!