Air Intake Mod Questions

[Unified]

Hello, I've had my Y2K VFR for a couple of years now and decided to try and squeeze some extra performance out of the stock engine. I've been reading through different posts over the subject and decided I wanted to go with a custom ram air intake setup. I went to my local Honda dealership shop to see if they had any experience with something like this and they told me that it would be more trouble than it's worth, saying I'd have to get custom fuel maps and get it on a dyno or else it would run terribly. Which makes sense to me but because of how ram air intakes function, I wouldn't think a dyno test could be used to accurately tune a fuel map. So I was wondering if anyone else has much experience with ram air intakes as far as tuning and performance goes. Also, would a PCV with an Auto Tune kit remedy such problems?

[Beesting]

The problem with a Ram air setup is you cannot duplicate the ram air effect on a dyno because the bike is stationary. Not saying it isnt possible but probably more than the average joe wants to tinker with.

[Rush2112]

Mohawk has a ram air set-up on his 5th gen... that in conjunction with his other mods has netted him ~120 HP at the rear wheel.

http://www.vfrdiscussion.com/forum/index.php/topic/80640-yoshi-style-velocity-stacks/

A RapidBike Race module with a MyTuningBike module can adjust fueling for different speeds and air flow...

http://www.vfrdiscussion.com/forum/index.php/topic/79234-rapidbike-evo-and-racing-related-questions/

also, some higher end Dynos have the ability to blow air up over 100 mph into the intakes to replicate ram-air setup in the real world...

[Mohawk]

Thanks Rush. The simple answer is yes it can be done & next winter I intend to improve my design & maybe build a custom air intake.

I just bought a gadget & will test later this week to see what if any ram effect my intake makes, it's not 100% sealed all round, but should still produce a higher inlet pressure at speed.

My advice, do some research on ramair, then read my 10 year refresh threads which show how I did it. A PCV or RBR with the relative O2 autotune will adjust fuelling for ramair because they analyse the burnt gas, so lean as in ram working equals more fuel required & rich means less regardless of what's happening in the intake.

You can't replicate the effect on a dyno & blowing air is NOT the same as collecting static air at speed. Imagine if you will a still day with atmospheric pressure at 1000milibars, riding into that still air will produce a pressure on the front of the bike parts exposed to it, it's that pressure you are trying to capture in your intake which is why a front mounted ram intake is best.

All fluid have a 3 way linked relationship. Air is a fluid, thus, speed, pressure & temperature are linked permanently in a static ratio change anyone & the other two have to adjust the ratios to compensate. So compressing air increases its pressure obviously, but to compensate for that change, it's temperature has to increase, whilst it's speed decreases to keep the balance.

So if a dyno blows air at the intake, that is moving air that means it's already at a lower pressure than the static air around the bike, so is less efficient. The only way to make it work is to seal the intake & use a massive blower, one of the online mags did a great write up on this. But you have to have measured the pressure first to work out what pressure to supply, so chicken or egg !

Ramair scoops air at static pressure, forcing it into an area larger than the intake & that slows the air as it enters which further increases the pressure. If the engine consumes air at a rate less than its supplied, then pressure will built marginally in the intake & airbox, but any boost is welcome especially at speed as its free !

Read this & the associated articles http://www.sportrider.com/ram-air-whats-it-worth

Have fun.

[Beck]

For the amount of extra power you might get ONLY at much elevated speeds, I don't think it's worth the effort trying to design a costume RAM air setup that works properly for your bike....

It's just way too hard to get it right. If it were any easier, we'd have half the people in this forum already doing it. Better bang for the buck and time would be a forced induction system like a supercharger or a turbo, but those would take deep pockets and even more time and knowhow to do....

[Unified]

Thanks for all the input! Actually, I got the idea from one of Mohawk's threads and that article he shared is what got me interested in trying it myself.

As far as other people doing it, from what I could tell, many don't do it because either they don't think of it, there's no pre manufactured kits for the 5th gen, or the gains from it aren't easily measured. I figure since a lot of sport bikes are doing it, it's got to be worth something.

[NCY2K]

Careful of ram water, too!

[Mohawk]

Careful of ram water, too!

Well I've ridden mine through some truely biblical rain & no ingestion issues. Your engine can quite happilly consume water mist, only silly amounts of water like sticking a hose in the airbox will stop it.

[RazorWing]

Careful of ram water, too!

Well I've ridden mine through some truely biblical rain & no ingestion issues. Your engine can quite happilly consume water mist, only silly amounts of water like sticking a hose in the airbox will stop it.

The "water mist" is actually something I have used and is even reccomended by some auto manufacturers for engine cleaning. You have a bottle with a controlled drip full of water and a little cleaning agent, on a warm engine, drip the water in a vaccume line (on cars its normally the PCV or power brake). I have done this many times before and it works great.

Only other concern is soaking the air filter too, but that would have to be a lot of rain for a long time, even then I think the rider would give up before the bike did.