Intake Scoops

[Beau254]

Anybody ever try to make their Air Intake scoops functional, or is there a kit ava.?

 

[one2dmax]

Many years ago we had flipper doors in them. And another guy was making ram air conversions. Don't expect any real power gains.

 

[Poolio]

I’m trying to build my own right now for a set of vgas carbs. I hope they work. You never know till you try. Plus I’ve never seen a vmax with four pods sticking out of the front. I know it would look badass. I’ll get back to you on the function part

 

[MaxMidnight]

Yes there was someone who produced a kit - have a look here.
I have to Gen II style outer parts on mine but didn't thin the cost v. benefit of the full kit could be justified.

 

[02GF74]

Firstly I commend you on doing something different and looking purposeful, but in my opinion I expect you to be disappointed for any expected performance gains.

I am not an aerodynamycist (spelling?) but know a bit about physics and ofcourse am more than happy to be proven wrong.

Moving through air, air is going top hit the front of the filter and be deflected around it. This will cause a low pressure around the filter element that has the effect of wanting to suck air out of the filter, the opposite of what you want. Disagree? For prove of this, if you have ever driven a convertible with the roof up, the low pressure pulls up the roof. Likewise observe a motorcyclist's clothing when moving at speed - jackets bellow out to be like the Michelin man due to the same effect.

If you want ram air, the air intake arrangement needs to be a funnel with air going into the large open end.

Black lines are the scoop, red is filter element.
Top CAD drawing shows how I expect air to be have and just breeze past the filter.

Lower CAD drawing shows air being funnelled into the scoop.

 

[SpareHimps]

Yes there was someone who produced a kit - have a look here.
I have to Gen II style outer parts on mine but didn't thin the cost v. benefit of the full kit could be justified.

After reading that guy's story, sounds like he spent a ton of time and energy for and estimated 4 or 5 horsepower at the maximum. It's something but probably not the best for the money.

 

[Beau254]

I’m trying to build my own right now for a set of vgas carbs. I hope they work. You never know till you try. Plus I’ve never seen a vmax with four pods sticking out of the front. I know it would look badass. I’ll get back to you on the function part

Cool! Ya, let me know. But I’m not running individual pods. Mine has the 1 large main K&N air filter in the box. Is there an advantage to running individual filter pods?

 

[Beau254]

Firstly I commend you on doing something different and looking purposeful, but in my opinion I expect you to be disappointed for any expected performance gains.

I am not an aerodynamycist (spelling?) but know a bit about physics and ofcourse am more than happy to be proven wrong.

Moving through air, air is going top hit the front of the filter and be deflected around it. This will cause a low pressure around the filter element that has the effect of wanting to suck air out of the filter, the opposite of what you want. Disagree? For prove of this, if you have ever driven a convertible with the roof up, the low pressure pulls up the roof. Likewise observe a motorcyclist's clothing when moving at speed - jackets bellow out to be like the Michelin man due to the same effect.

If you want ram air, the air intake arrangement needs to be a funnel with air going into the large open end.

Black lines are the scoop, red is filter element.
Top CAD drawing shows how I expect air to be have and just breeze past the filter.

Lower CAD drawing shows air being funnelled into the scoop.

View attachment 77537

Ok, but what if you don’t have individual filter pods? Instead, I have the 1 large K&N round filter in the air box.

 

[Fire-medic]

Cool! Ya, let me know. But I’m not running individual pods. Mine has the 1 large main K&N air filter in the box. Is there an advantage to running individual filter pods?

That's what is in the Dynojet Stage 7 kit. Properly tuned with a proper full exhaust, you can get ~a 10% gain over OEM.

Don't bother with any other # of Dynojet kit. Sean Morley sells a Morley's Muscle kit, which is tuned for more midrange, since that's where you ride most of the time.

 

[Beau254]

Sorry, I should have originally noted that I’m not running individual filter pods. Running the large round K&N filter in the air box. Also, another thing, when I bought the bike it came with aftermarket fiberglass air scoops that are more of a Gen-II style. It has 2 individual ports on the scoop vs 1 on the Gen-I style. That’s what gave me the idea that it may be easier to convert to a functional Ram Air. See pics. Thanks.

 

[Beau254]

That's what is in the Dynojet Stage 7 kit. Properly tuned with a proper full exhaust, you can get ~a 10% gain over OEM.

Don't bother with any other # of Dynojet kit. Sean Morley sells a Morley's Muscle kit, which is tuned for more midrange, since that's where you ride most of the time.

Yes, you’re correct. It has the Stage-7 Jet kit & UFO Quadzilla exhaust. Thing is a monster man. Beast!

 

[Beau254]

Pro

After reading that guy's story, sounds like he spent a ton of time and energy for and estimated 4 or 5 horsepower at the maximum. It's something but probably not the best for the money.

Probably so. But on a stock bike. But with Jet Kit & Exhaust, it Might be slightly more. However several horsepower doesn’t sound like much of an increase on a car. But is on a bike.

 

[Traumahawk]

Cool! Ya, let me know. But I’m not running individual pods. Mine has the 1 large main K&N air filter in the box. Is there an advantage to running individual filter pods?

The only advantage to running individual filter pods is LOSING midrange torque. Running the K&N filter in the top of the airbox (which is what Sean Morley sells....AKA One2dmax.....the muscle jet kit. ) you keep the velocity stacks that are in the airbox, so you keep your midrange torque.

 

[02GF74]

Ok, but what if you don’t have individual filter pods? Instead, I have the 1 large K&N round filter in the air box.

Any filter is going to restrict air flow to some extent.

The larger the surface area, the less restriction for the same type of filter. That's why filters are pleated.

If the surface of four individual stacks greater that that of the elongated oval original, the engine will breathe better.

I'd like to hear otherwise but no air filter has to be better than having an air filter fitted, downside is engine longevity is going to suffer.

I read a while back that the best performing filters were the paper type, better than the K&N type but get clogged quicker so the K&N win out after few hundred miles.

I'm sure there will be some dyno run data to confirm or not the above 2 statements

I believe there is a mod where the top and sides of the air box are replaced by filters, that gives larger area but that may be a Gen 2 mod.

Velocity stacks and their length improve power a certain rpms so removing them is likely to be detrimental. Again from memory, the shorter the stack the higher the rpm.

And there were tests done that show the best airflow is having a bell end shape (UK peeps stop sniggering!), I can't remember the formula for the curve, so having a flat face, as what the carb will present without the velocity stacks is not going to help.

There's a lot of **** going on with the carb induction so you can't make adhoc changes without researching the effect in order to squeeze the last few percent of power.

 

[Poolio]

These are not the filters I will be using. These were just $20 for mock up. I will be running k&n’s which have a hole in the middle. They do t have a cap. Also, they make these same ram air scoops for the carbs. You just can’t find them

 

[02GF74]

Yeah that sounds much better.

I'm not sure which is the better approach.
a. Scoops without air filters to gather as much air into the air box with a filter inside it (or individual filters over each velocity stack
b. Filters in scoops with no filter in the airbox.

 

[Beau254]

Yeah that sounds much better.

I'm not sure which is the better approach.
a. Scoops without air filters to gather as much air into the air box with a filter inside it (or individual filters over each velocity stack
b. Filters in scoops with no filter in the airbox.

I would think that filters inside the air box would be better than pods in the air intakes. It will allow more air to be funneled in the air box. Vs air deflection from sticking out the scoops.

 

[02GF74]

I would agree.

Do you intend to carry some before and after tests, such as putting it on a dyno?

There may be DIY ways of getting a comparison, dunno say ride at 30mph in 5th, WOT, then time taken to get to 70mph?

 

[MaxMidnight]

Pro

Probably so. But on a stock bike. But with Jet Kit & Exhaust, it Might be slightly more. However several horsepower doesn’t sound like much of an increase on a car. But is on a bike.

But together any increase from a ram effect you will (probably) need to be travelling at illegal speeds. OK on a drag strip but not on public roads.
As Mr 02GF74 says, to have any meaning you would need to measure engine output for every change you make. You would also need to establish at what rate the pressure at the mouth of the intake increases as your road speed rises. Next problem would be how to replicate the pressure increase when on the dyno.
I guess if you have the time and inclination then have a go and I wish you well.
That said I having just re-read the the original write-up I'm not convinced the time/ cost/ benefit ratio is that persuasive.

 

[Beau254]

Probably not. But wouldn’t it be nice next time a spectator asks about the scoops they you’re able to say they’re functional? Vs “Na, they’re just for looks.” I hate that. It’s kinda like what’s the point. Lol. I’m not so much concerned about how much gain in HP vs they actual work & are good for something besides just looks. It’s a performance bike. Although it is powerful, in my mind the scoops should do more than just make it look powerful. Just like on a ram air hot rod car. But that’s just my 2 cents.