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Message started by batman on 05/25/16 at 21:03:08

Title: tuneing your intake
Post by batman on 05/25/16 at 21:03:08

I use oldfeller's home made air filter because it's inexpensive,and it doesn't call for removal of the air box or intake tube to the carb,which is engineered for proper intake length. does anyone think their bike runs better with a 50 dollar air cleaner or is it because they look pretty.

Title: Re: tuneing your intake
Post by gizzo on 05/25/16 at 22:46:24

+1 for look pretty.

Title: Re: tuneing your intake
Post by justin_o_guy2 on 05/26/16 at 00:24:10

We haven't seen a bike dynoed with the air box, then ditch it and stick a cone on, but I Think the airbox will be better.

Title: Re: tuneing your intake
Post by gizzo on 05/26/16 at 00:53:13

A couple of the Enfield guys made a replacement airbox lid for the Continental GT. The old element sat inside the airbox and was only about 1/2" from the injector inlet. The new lid situates the element outside the airbox, in the new lid. So we end up with an empty airbox (apart from a velocity stack). It makes a noticeable difference. No one has dyno'd it to see how much. Another guy put a massive K&N pod on his and reported similar results.

Title: Re: tuneing your intake
Post by zipidachimp on 05/26/16 at 01:10:52

Mine's scary fast with a cone. and 152.5 main 8-)

Title: Re: tuneing your intake
Post by Yoshi on 05/26/16 at 18:17:20

I like the sound of the cone air intake

Title: Re: tuneing your intake
Post by batman on 05/26/16 at 19:27:14

I brought this up because I read a long while back, intake info that said the total area inside the intake path (from the intake valve seats to the entrance at the air box),should be equal to the piston displacement. A wave is present in the intake and exhaust to enhance removal of exhaust gases and to inject air/fuel ,(intake and exhaust are both open at the same time, valve overlap). If you use a cone filter ,and you have the room ,you might able to reuse the hose that ran between the carb and air box and mount your cone filter on the end and enhance your bikes performance.

Title: Re: tuneing your intake
Post by Witchdoctor on 05/27/16 at 03:21:55

Yeah my K&N is much better than that snorkel. lol

If you want performance velocity stack is the way to go, and the more surface area on your filter.. the easier it flows. Common sense I guess :-?
Some of the craziest tuning Ive seen on included CNC intakes, CNC polished carb inlet, custom billet CNC velocity stack, dial a jet, and massive oversized foam filters. Velocity length influences the power band on thumpers. short for top end power I think :-/ and longer for bottom end.. someplace in between for a balance is what you want.
Ive always thought 2 layer foam filters are the best for high end performance but I don't really have any proof.. only weak anecdotal evidence.

Some engines also like a "step" inside the intake I don't know why but it works well with some thumpers. Rough intake ports help with fuel atomization so even if you port it out leaving it rough keeps things flowing and prevents drip.

For 2 stroke foam filters are amazing.. especially if they get a little wet with gas.

For the savage I think the airbox is a pile of crap lol. A tuned velocity stack and oversized filter would be much better than that rubber intake boot with a cone filter. I see some dudes on here with those chinchongyoulicklongdingdong china fleabay filters.. dear god those are crap.. you can see right through the filer mesh.. Ive used one on a small engine and it only filters out birds and small babys.. Also you can throw on one of those mesh covers to help prevent water/rain from pulling dirt into the filter. Pretty sweet I think lol

I'm just rambling.. :-X

Title: Re: tuneing your intake
Post by Chase on 05/27/16 at 04:10:38

what about converting to the cone k&N with keeping the distance of the tube to the airflow box?

such as using a U bend like here

http://www.hps-siliconehoses.com/180-degree-u-bend-aluminum-tubing-pipe.html?___store=default

Title: Re: tuneing your intake
Post by Dave on 05/27/16 at 05:15:11

Well....I kinda' believe that "tuning" an intake scientifically is most likely a bit beyond what most of us are capable of doing.

That doesn't mean that we can't avoid things that hurt performance, and attempt to do the things that help to improve it.

This air filter stuck on the back of the carb - has to limit the performance. The air flow into the carb is not going to be efficient, as the air flow has to make a sudden 90 degree turn. At low throttle settings it most likely works just fine....at full throttle most likely is restrictive and disruptive to the air flow.

http://i67.tinypic.com/oaq5af.jpg

The small cone filters are also likely not to help much at high rpm. And as Witchdocter stated above.....don't buy a cheap Chinese knock off...especially the ones with the step in the rubber flange that blocks the vent at the top of the carb inlet. Several members have installed them and had all kind of trouble - and it turns out the filter is blocking that oval vent and making the carb do really weird things.

http://i65.tinypic.com/xkzvad.jpg

If you want a cone filter....buy a good one that is as large and long as you can fit on the bike. And if you can fit a tube between the carb and filter....that will help to stabilize the air flow as well - the length of the tube is the "tuning" part this thread is about, and you could try different lengths and see how it affects the performance.

http://i67.tinypic.com/aworia.jpg

I used a large foam filter, and I used as much of the stock intake tube as I could fit.

http://i50.tinypic.com/fxw3up.jpg

Title: Re: tuneing your intake
Post by batman on 05/27/16 at 06:23:38

If memory serves me right the length of the stock intake is 246mm. or about 9 7/8 inches ,I believe the wave moving back through the intake is called revision ,the velocity of wave when it enters the air box is converted into pressure due to expansion,this pressure helps move the air back threw the carb into the cylinder.I think the timing of the wave and the volume of the intake channel to be critical to completely filling the cylinder ,and might be causing a lean condition.(Are your header pipes turning blue?)in motors running shorter filters. I don't think RPM comes into play here.

Title: Re: tuneing your intake
Post by Dave on 05/27/16 at 06:39:59

67647168646B313D050 wrote:

I don't believe the stock intake is nearly that long....I cut the stock rubber tube just about in half. As a guess, I believe the stock rubber boot/tube is about 5" long.

I also wonder if any of the length of the foam filter acts as a part of the plenum?

My pipe has never turned. I jetted by bike with a fuel/air meter installed, and I the fuel/air meter allowed me to adjust the jets more precisely than I could have done by ear/feel. I am confident my bike runs well, and does not have any bad habits (unlike the rider).

Title: Re: tuneing your intake
Post by justin_o_guy2 on 05/27/16 at 09:11:50

I didn't have the numbers To run them against the stock airbox.
I don't have any experience with tuning, but studied the design and saw a way to increase the volume and did it.
I don't think a box of air is nearly as likely to provide a pressure wave to the carb as the intake opens as a tube would, but, where is That gonna go?
So, without a Dyno comparison to see what a cone filter versus the stock airbox does, I think what I did helped, of course, the rubber inlet was removed, and I probably increased the volume by fifty to 100cc,
But, having a box of air, already sucked through filter, and, at some RPM even that box begins to resonate and develop a pressure wave, it's just not aimed down the throat of the carb.

Title: Re: tuneing your intake
Post by batman on 05/27/16 at 13:53:19

That number ,9 7/8 is the total length of the intake from the valves to filter box ,which includes the carb.Another measurement that I failed to speak about was that the filter should stand off the end of the tube 40mm,Gizzo said the Enfields ran better when the filter was moved from1/2 inch to outside their new custom air boxes ,leaving a much larger space between the filter and intake tube,you can't do this with a cone , the Enfield guys knew what they were doing.They did a better job than the factory. JOG,velocity and pressure are inversely proportional ,that means the wave hits the end of tube the wave spreads out in the box(loss of velocity)and therefore does pressurize the air box.As the exhaust valves close and the piston moves downward ,the pressure wave helping to send air through the carb.The carb being smaller further increases velocity (causing a pressure drop, or vacuum)which pulls fuel from the jets. We might then look at the piston it's moving down,where is the air under going?Through the huff tube to further pressurize the air box,but not with a cone filter.

Title: Re: tuneing your intake
Post by Witchdoctor on 05/27/16 at 18:38:26

I love these.. probably because when it rains here ..IT FRIGGEN RAINS :o you just get caught in a downpour sometimes.

We may not scientifically be able to tune them but we can use our intuition and commonsense/logic. A bit of bro-science never hurt haha.

http://https://images.duckduckgo.com/iu/?u=http%3A%2F%2Fwww.qrckarts.com%2Fstore%2Fimages%2Fproducts%2Fk-n-ru1240pk-lg.jpg&f=1

Title: Re: tuneing your intake
Post by VortecCPI on 06/04/16 at 10:20:23

A tuned intake system can have a significant impact on performance. With proper tuning you can have a VE as high as 130%, which translates to 4.4 PSIG at the intake side. That is the equivalent of a 1.25 point increase in CR.

I recently fabricated a tuned intake system for my 1986 Yamaha SRX600 and the difference was nothing short of amazing. The primary runner is smaller/longer and the secondary runner is bigger/shorter. This gives me overlapping areas of tuning that compliment each other. Edelbrock used to make headers using the same concept.

The primary side uses a 1-1/4" NPS PVC elbow and the secondary side uses 1-1/2" NPS PVC pipe and flexible elbow. I did lose some power just before redline at 7,000 RPM but I could care less as I never ride up there.

I was lucky with the old SRX because my father already gutted the airbox and I had plenty of space between the swingarm and seat to construct a new airbox area. Total length of primary is 20.5" and total length of secondary is 18.0". Total length is length from end of intake runner to face of valve.

Downsides? None except the exhaust is a lot louder and now has a very distinct CRACK. I believe this is due to the increased cylinder pressure.

I would love to try this on my wife's LS650 but space on that bike is very tight.

Below are the results of the work I did:

Title: Re: tuneing your intake
Post by VortecCPI on 06/04/16 at 10:35:24

View of filters from right side cover:

Title: Re: tuneing your intake
Post by justin_o_guy2 on 06/04/16 at 10:48:57

Primary runner, secondary, no mental image for me.
Tell me where and I'll go back and look.

With proper tuning you can have a VE as high as 130%, which translates to 4.4 PSIG at the intake side. That is the equivalent of a 1.25 point increase in CR

VE, volumetric efficiency?
I don't understand how the 130% translate s to 4.4PSIG..
Is that Gain in pressure?

Alright I'm thinking I'm beginning to grok some of it.
While I'm pretty sure I'm not gonna be Doing anything like this, I Am still interested in understanding it. Everyone seems to focus on exhaust, and while there are good gains there, at least there's a piston to Shove it out. Intake efficiency just seems like that Getting the Rest of the goody out of an engine.

Title: Re: tuneing your intake
Post by striknein on 06/04/16 at 15:38:29

0F362B2D3C3A1A0910590 wrote:

Where would you start on our bikes?

Title: Re: tuneing your intake
Post by KennyG on 06/04/16 at 16:54:46

Here is how I would start if I was clever enough to do the job. Curve the manifold so the carb sticks out the side of the bike and then you can add as much pipe to the carb to move the air filter as far from the engine as you want.

I had a 600cc AJS Scrambler in 1959 with tuned intake and exhaust. The carb mounted on a piece of rubber hose about a foot long. I won a lot of races until someone came up with the $100.00 to protest. I took the hundred bucks and pulled the head and some spoil sport knew how to calculate CCs That was the end of racing a 600cc engine in the 500cc class. All was not wasted I did well in the 650cc class.

The 600cc engine was powerful with the factory intake and exhaust, but it flew with the tuned intake and exhaust.

This would be a job for Lancer because that is where we go for carburetor stuff.

Kenny G

Title: Re: tuneing your intake
Post by Ed L. on 06/04/16 at 17:10:02

I've always wanted to turn the right side cover into an air scoop which pushes air into the stock airbox while riding. It would be pretty simple, just remove or drill out the air box door and hammer the front edge of the cover out into a scoop, a little heat and some light hammer work should do it :D. Could probably bend and hammer one out of some thick aluminum sheeting. Bet it would really help with a drop in K+N filter.
The biggest advantage of a cone filter is less weight and a cool look 8-).

Title: Re: tuneing your intake
Post by verslagen1 on 06/04/16 at 17:10:41

How long?
http://www.savageriders.com/verslagen/Beast/beast%20mode.jpg

Title: Re: tuneing your intake
Post by KennyG on 06/04/16 at 17:26:47

Verslagen,

How long?

It will take someone like you or Lancer to answer that question.

I wish I could.

I would like to see more pictures of the arrangement in your photograph.

Kenny G

Title: Re: tuneing your intake
Post by batman on 06/04/16 at 20:28:39

Like I said when I started this thread, If you dump the stock air box and just toss on a cone filter your passing on performance.Vortec and Kenny G. seem to have a handle on this ,I wonder if they know the math or if it was trial and error? come on I'm all ears!

Title: Re: tuneing your intake
Post by Ruttly on 06/04/16 at 20:50:08

I had a teacher in junior college Dima Elgin of Elgin Cams he taught that you select the proper cam for the application then build the engine to match the cam. Every thing you change you will need to correct something else and so on( the butterfly effect ). So knowledge is key or monkey see monkey do. Here's where I learned and I still refer back to when needed. This book has been in print for over 30 years one of the best books for understanding a four stroke engine , building , tuning. Hope your good at math , I'm not I have a calulator. In the book the Yamaha SR500 is used, not all that different from the Suzuki .
Four Stroke Performance Tuning by A.Graham Bell
In Dima's 12 week course I was in week seven and on the verge of failing,he said go back and read the book and read it again if you have to. Week 12 scored A- in the class, tough course, tough teacher,great education,that was 20 years ago and still have that book !

Title: Re: tuneing your intake
Post by Ruttly on 06/04/16 at 20:55:10

Batman you wanted the math, here's all the math needed !

Title: Re: tuneing your intake
Post by Ruttly on 06/04/16 at 20:58:56

Versey's set up is as good as it gets. Does it ever suck up your pant legs?

Title: Re: tuneing your intake
Post by KennyG on 06/04/16 at 21:08:33

Batman,

I am not clever enough to develop a tuned intake or exhaust.

I have had two guys in my life that could make a motorcycle fly.

One was my brother William and the other was Marion Cameron who sold me my AJS Scrambler and tuned it. On the AJS he also heated and bent the exhaust header up in the air right about where the muffler connected. It was about the same angle as a Norton.

I have no clue why his tuning worked, but you could feel the results, and see the results in 1/4 mile times. In those days the only place to test a motorcycle for acceleration was the local drag strip. I can remember hearing the announcer on the PA system saying "Listen to that Thumper go"...... All of the noise was behind me I could hear him like he was inside my helmet.....

Kenny G

Title: Re: tuneing your intake
Post by verslagen1 on 06/04/16 at 21:32:46

486F6E6E76631A0 wrote:

found it for $5 +$4 8-)

Title: Re: tuneing your intake
Post by Ruttly on 06/04/16 at 21:54:12

Think I paid about 20 bucks 20 years ago. Good deal.

Title: Re: tuneing your intake
Post by KennyG on 06/04/16 at 22:11:11

I want to see more pics of Verslagen's Intake System.

Kenny G

Title: Re: tuneing your intake
Post by Ruttly on 06/04/16 at 22:22:37

I think that's all your goin to see. I want to see how fast his bike is !

Title: Re: tuneing your intake
Post by Ruttly on 06/04/16 at 22:34:50

What is that ? A headlight off a train ?

Title: Re: tuneing your intake
Post by verslagen1 on 06/04/16 at 22:55:11

the cable isn't cooperating.

The light is from a victory vegas.

In WFO, it definitely has a power band.

Title: Re: tuneing your intake
Post by Ruttly on 06/04/16 at 23:14:25

Still jetting mine, but it's fast,not used to that counter balancer,so smooth,but it's very fast,still haven't got to fifth gear. Sunday do some more tuning!

Title: Re: tuneing your intake
Post by VortecCPI on 06/05/16 at 05:49:35

Start here: http://www.bgsoflex.com/intakeln.html

You can also use the posted chart as a good starting point. Length is dependent upon cam timing but with short/small stock cams this will get you close enough.

Intake length is the ENTIRE length form valve to atmosphere so you need to know the intake port length and carb length.

Trust me in that this will make a huge difference, especially right in the middle.

On the 130% VE question... 1.30 x 14.7 PSIA - 14.7 PSIA = 4.4 PSIG

That is obviously a Best-Case scenario but I have seen dyno tests where they measured 3+ PSIG on the intake side with tuned runners.

My inspiration was here: http://www.phaedrus.me/id158.html

Title: Re: tuneing your intake
Post by VortecCPI on 06/05/16 at 05:55:56

More here:

Title: Re: tuneing your intake
Post by VortecCPI on 06/05/16 at 05:56:19

More here:

Title: Re: tuneing your intake
Post by batman on 06/05/16 at 06:55:30

vortec/Kenny G., thanks for the info ,you must have had lots of room on your srx vortec,I don't know how I can find 15-18 inches on a my 650.It does show that longer is better ,so there's no cone filter in my future!Maybe Verslagen 's setup is about the best so far.

Title: Re: tuneing your intake
Post by VortecCPI on 06/05/16 at 09:06:36

3437223B3738626E560 wrote:

Yes. I had LOTS of room. In fact, the new airbox volume is more than needed for 600cc.

One option might be to run the intake in a semi-circle with the pod filter pointing forward. Bends and elbows don't have much of an impact on air flow and tuning.

Ram-Tuned Hemi: http://www.hotrod.com/cars/featured/113-0704-ram-rod/#photo-03

Title: Re: tuneing your intake
Post by Kris01 on 06/05/16 at 11:13:03

Vortex, Bruce Bowling has had a lot of formulas on several sites for lotsa years. Most of his formula predictions are best case scenarios but they do work.

Title: Re: tuneing your intake
Post by Ruttly on 06/05/16 at 14:51:07

Is there some basic equations to figure out runner length by displacement & carb bore diameter ? You know ball park calculations for dummies or child's version!

Title: Re: tuneing your intake
Post by Kris01 on 06/05/16 at 16:49:07

Not really. Any simple basic calculation will be way off. Wave tuning has too many variables. Just use the online calculators and you will be close. You'll probably only see a difference if you actually dyno the bike and tune from that info.

Title: Re: tuneing your intake
Post by justin_o_guy2 on 06/05/16 at 18:58:17

Even then, if you don't really know what you are doing, it's just
Dyno might..

Title: Re: tuneing your intake
Post by Kris01 on 06/05/16 at 19:02:16

This is pretty simple math. Try this link:
http://www.chrysler300club.com/uniq/allaboutrams/ramtheory.htm

Title: Re: tuneing your intake
Post by Kris01 on 06/05/16 at 20:06:26

Here's a decent formula that's fairly simple:
http://www.rx7club.com/general-rotary-tech-support-11/heres-how-figure-out-intake-runner-length-199788/

I've run across this formula several times.

Title: Re: tuneing your intake
Post by Ruttly on 06/05/16 at 20:26:50

So it's kinda like trying to balance a single cylinder engine I need to know at what rpm I want it to be balanced but in this case I need to know at what rpm I want peak power/ram induction being I can't change my timing or valve timing. Is that correct ?
Whoops thanks kris01 for that link good stuff always fun learning new stuff and this is going to be fun , engines=math !

Title: Re: tuneing your intake
Post by verslagen1 on 06/06/16 at 13:49:11

http://www.savageriders.com/verslagen/Beast/beast-intake-side.jpg

http://www.savageriders.com/verslagen/Beast/beast-intake-top.jpg

Title: Re: tuneing your intake
Post by KennyG on 06/06/16 at 14:11:25

Verslagen,

Thanks for the pictures.

I think I could do something similar if I had a parts list and written instruction, but on my own I guess I will just drool.

Did you notice an increase in performance?

Kenny G

Title: Re: tuneing your intake
Post by verslagen1 on 06/06/16 at 14:24:58

That's a edelbrock quicksilver 40mm carb.

That and a stock airbox with a K&N drop in will get you from 70 to 95 in a third of the distance a stock carb will get you 85.
After that the limitations of the stock petcock play in.

I was quite surprised that I was running even with MMR on mpg last year at the dragon. She really likes eastern gas over western barfenated stuff.

Quote:

if I had a parts list and written instruction

;D
It's like cooking, a pinch of this and a smidgen of that.
The seat of the pants says its right or the ear says change that.

Title: Re: tuneing your intake
Post by KennyG on 06/06/16 at 14:33:28

Verslagen,

I have thought about switching to a Lectron carburetor, but the factory carburetor, with Lancer's help, is working without anything that I can think to improve at the moment.

Additional acceleration is always the improvement that makes us feel good. Maybe once the hot summer weather here in Texas is over I will try Windsor's kit.

Thanks again for the pictures. That setup is badass looking.

Kenny G

Title: Re: tuneing your intake
Post by Ruttly on 06/06/16 at 15:11:43

Versy , What piston and cam are you using ?

Title: Re: tuneing your intake
Post by verslagen1 on 06/06/16 at 17:39:04

She sips premium and has lotsa torque. 8-)

Title: Re: tuneing your intake
Post by Kris01 on 06/06/16 at 18:54:21

06212020382D540 wrote:

For a stock (or roughly stock) engine, 3500ish RPMs is a good compromise. Peak torque occurs somewhere around that point. This dyno chart is not dead-on accurate but it's pretty close. You want the ram effect to influence torque usually. I would tune around 3500-3800 RPMs.

Title: Re: tuneing your intake
Post by Kruzader on 06/06/16 at 23:02:46

Quote:

Hello Dave, what is and where can i get a fuel/air meter? I need to rejet my carb an will like to be as precise as possible.

Title: Re: tuneing your intake
Post by VortecCPI on 06/07/16 at 04:01:25

Length is from atmosphere (filter flange) to valve face. While the filter aids with signal due to pressure drop it is not in the length equation.

Good read here: https://forums.neons.org/viewtopic.php?t=294784

And here: http://www.emeraldm3d.com/articles/emr-adj-length-intake

This is how much space I had in the SRX600:

Title: Re: tuneing your intake
Post by Dave on 06/07/16 at 14:23:13

71484F405B5E5F483A0 wrote:

Hello Dave, what is and where can i get a fuel/air meter? I need to rejet my carb an will like to be as precise as possible.

http://suzukisavage.com/cgi-bin/YaBB.pl?num=1348491882

Title: Re: tuneing your intake
Post by Kris01 on 06/07/16 at 19:24:19

744D5056474161726B220 wrote:

Very interesting read. So where would a velocity stack fit - before or after the air filter? I assume you'd need the air to enter the vel. stack and then the filter but wouldn't that dilute the wave?

http://www.35pickup.com/tbucketa.jpg

Title: Re: tuneing your intake
Post by KennyG on 06/07/16 at 20:44:28

I have always been curious about what modifications are possible with the stock air box to make the engine breath a little better.

Kenny G

Title: Re: tuneing your intake
Post by LANCER on 06/08/16 at 02:29:28

[quote ]
So where would a velocity stack fit - before or after the air filter?
[/quote]

With a velocity stack there is typically no standard filter used.
Some stacks have a screen or micro-screen covering the intake end though.

SCREEN
http://cdn6.bigcommerce.com/s-jsy4pd/products/17657/images/17408/a20791d144bda1837ff55a_m__33223.1405674590.168.168.JPG?c=2

MICRO-SCREEN
http://https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcRXKln0COr8nBD-ljekZ6DkXuQG8iYq9fgcYrQDQL2dwmbi_yGi

http://https://encrypted-tbn1.gstatic.com/images?q=tbn:ANd9GcQTtLyv-CqI6uUkPfOKWS0mKuIfJ7R4fal5jFO1VQrnxFzeB6BZ

Title: Re: tuneing your intake
Post by VortecCPI on 06/08/16 at 06:31:57

08312A307372430 wrote:

No. Filter is at end of velocity stack. As Lancer stated most race applications have no need for a filter. Since we are on the street we basically have a velocity stack with a filter at the end. Ideally we would like to have the runner between the carb and port.

Title: Re: tuneing your intake
Post by Dave on 06/08/16 at 06:56:38

It is possible to have a filter prior to the velocity stack. The stock air filter on the Porsche 911/914-6 engine has a canister that fits around the top of the carb/velocity stacks.....and then a large air filter housing fits on top of the carbs. This provides both the performance advantages of a velocity stack - and the benefits of a filter....and it makes the intake weatherproof!

http://i63.tinypic.com/s1mfk5.jpg

http://i64.tinypic.com/az6wqp.jpg

And for those who want something a bit lighter.....they do have aftermarket paper, gauze of foam filters that can fit over the velocity stacks.

http://i63.tinypic.com/309111y.jpg

http://i66.tinypic.com/10xak29.jpg

And you can get them with rainshields that keep water from dropping into the filter.

http://i66.tinypic.com/1zebabo.jpg

Is this as efficient as an open velocity stack? Probably not - but it deals better with the dirty air and water that a street driven car or bike has to endure. Grit in the air can drastically shorten the life of the piston/rings/cylinder.

Title: Re: tuneing your intake
Post by Kris01 on 06/08/16 at 19:31:26

Forget about total intake duct length for a second. Does the length of the velocity stack mean anything? Or does it only matter if you are looking for a specific total length for the entire intake duct? For instance, is a 7" stack better than a 5"?

Title: Re: tuneing your intake
Post by VortecCPI on 06/09/16 at 05:37:27

615843591A1B2A0 wrote:

Absolutely. The length must be matched to cam timing and harmonic(s). The total length (atmosphere to valve) is what must be taken into consideration. Very generally speaking longer promotes low-speed TQ and shorter promotes high-speed TQ.

For a great test on stack lengths see here: http://www.phaedrus.me/id158.html

As you can see the impact can be dramatic and substantial. In my case it was both and the change to midrange TQ was just crazy.

Title: Re: tuneing your intake
Post by Kris01 on 06/09/16 at 16:14:07

Thanks! This is a very interesting discussion. I did a search the other day and found a Dodge Neon site where the guy had used individual throttle bodies and used PVC pipes as test velocity stacks. He picked up (I think) 18 ft/lbs in the mid-range with a certain size stack. Very cool!

Title: Re: tuneing your intake
Post by justin_o_guy2 on 06/09/16 at 21:33:34

My doctor told me to reduce my intake.

I said

Phhhhhhht!

Title: Re: tuneing your intake
Post by mastercarstech on 06/22/16 at 21:04:09

Interesting discussion. I'm planning a setup similar to verslagens. Any thoughts/ideas on the effect of the inside diameter of the intake tube? Right now I'm running a straight tube about 2 1/4 inch diameter that matches the size of the carburetor inlet (outside diameter). Over all length is about 8 to 9 inches long with a cheapo ebay cone filter that came with the bike.

Title: Re: tuneing your intake
Post by gizzo on 06/23/16 at 02:22:16

Here's a pic of the velocity stack inside my Enfield's airbox. It replaces a paper filter that used to fit inside the airbox (lousy design) and the filter is relocated to the outside of the box in a custom made lid. It makes a worthwhile improvement over the stock setup.

Title: Re: tuneing your intake
Post by gizzo on 06/23/16 at 02:27:24

Filter lid

Title: Re: tuneing your intake
Post by justin_o_guy2 on 06/23/16 at 03:45:15

Is that a purchased bit of hop up stuff or did you do that all by yourself? If you did it, take more than one bow to the well deserved
Standing O

Because it looks Mahvelous, simply Mahvelous.

Title: Re: tuneing your intake
Post by gizzo on 06/23/16 at 05:22:19

No, I can't take credit for it. A couple of very talented guys on the Enfield forum made them and did a small production run for us. Looks nice, huh? One of those guys is doing a billet cnc cylinder head and rockers for the bullet engine, as well.

Title: Re: tuneing your intake
Post by Kris01 on 06/23/16 at 05:34:09

373B292E3F28393B28292E3F39325A0 wrote:

A bell mouth opening flows much better than a straight pipe. You'd do well to curve the entrance to the intake.

Title: Re: tuneing your intake
Post by mastercarstech on 06/23/16 at 18:15:57

Question for Verslagen, is your intake setup a rubber hose or steel/plastic?if it is rubber have you had any issues with it sucking in or clasping with it being a bit longer than normal?

Title: Re: tuneing your intake
Post by verslagen1 on 06/23/16 at 19:30:08

http://www.savageriders.com/verslagen/Beast/beast-intake-top.jpg

From the carb to the tee is heavy reinforced rubber.
The tee is steel.
And I'm a little busy at WFO to notice.

Title: Re: tuneing your intake
Post by VortecCPI on 06/24/16 at 10:07:47

7F465D470405340 wrote:

A bell mouth opening flows much better than a straight pipe. You'd do well to curve the entrance to the intake.

CFD work and dyno work has shown this is not true for small airflows like what we are dealing with here. A 10,000 HP dragster engine pulling 3,000 CFM, yes, but not our puny engines. Twice the flow or velocity equates to four times the pressure drop so it will become a problem with very large air flow/velocity. That being said the inside corner should definitely be chamfered/radiused.

See here for HD XR1200 dyno work: http://www.phaedrus.me/id158.html

"In back-to-back dyno tests with and without the flare on the end of a tube, there was no noticeable difference in power output or torque produced. The flared end did not appear to make any difference in the dyno runs. So, all of the following test runs were conducted without the flare."

Title: Re: tuneing your intake
Post by verslagen1 on 06/24/16 at 10:28:46

11283533222404170E470 wrote:

Aside from actual study and dyno work, safer to include a bell mouth of some sort. Similar to our bike, people put pod filters on the cb750 and they perform terribly... until they separate the carb and filter with a small bell mouth.

Title: Re: tuneing your intake
Post by Ruttly on 06/24/16 at 12:44:01

Those tiny cone pod filters were only designed for small spaces and not for performance. In most cases the bigger the air filter the better. Look at the giant air filters used on flat trackers and not just the Harley's , all of them. For the best performance use the biggest filter you have space for, Versy's set up most likely has possibility of more flow than his giant carb can use. All that ram induction stuff is fun to calculate & play with but I don't think its any more efficient than just going as big a flow as you can get! And even so it's only going to improve performance for a specific rpm range.

Title: Re: tuneing your intake
Post by VortecCPI on 06/25/16 at 04:32:54

63706766797472707B24150 wrote:

I can not disagree on "safer" but it is not necessary and space makes it very difficult.

Poor performance with pod filters is almost always because the pod filter flange covers CV air bleeds at the carb bell. This is a huge issue with cheap/junk pod filters.

Examples below:

http://www.choppercharles.com/2013/12/jetting-made-easy.html

http://www.xs500forum.com/index.php?topic=1357.0

Title: Re: tuneing your intake
Post by Ruttly on 06/25/16 at 10:14:03

Versy is correct as well as his posted links. It's not so much it's shape but surface size, find surface size of stock filter then you want more not less or your new filter. Then increasing spacing between carb and filter gives air time to stabilize/straighten out and speed up going into carb. If we had room I would also be increasing distance between carb and intake port for the same reason.

Title: Re: tuneing your intake
Post by Ruttly on 06/25/16 at 11:55:26

Versy , I'm curious have you ever dynoed your beast? Your kinda tight lipped with your engine mods. The rest of us would like to know. Give us a HP goal or what's in that top end. When I'm done testntune mine is going to see the dyno guy across town!

Title: Re: tuneing your intake
Post by mastercarstech on 06/25/16 at 13:58:28

Verslagen and a couple others turned me onto the problem with cheapo cone filters covering the carb idle ports a while ago. Mine came with one attached directly to the carb so I got a piece of pipe and moved it out about 5 inches. Seemed to run okay but obviously running rich, puffed black smoke a little at idle and a lot when you goosed the throttle. Pulled the spark plug and it was solid black with only about 50 miles on it!
Tried adjusting the pilot screw and could turn it all the way in with no change. So today I decided to install the Jets I got from Lancer. Found the pilot jet in it was a 57! Stock should have been a 47.5 so I'm guessing someone was doing their best to get the thing to idle with that pod filter on it and the idle passes blocked. Lol! I switched it out for a 52.5 which should get me in the ballpark for the new intake/filter setup I'm making.
Again, beware who's been playing with your machine if it's new to you. :o

Title: Re: tuneing your intake
Post by LANCER on 06/26/16 at 03:16:32

I think it is a good idea, when you get a bike that is new to you, to pull the carb and check to see what jets are installed and if everything is clean inside. If you are going to tune the bike/adjust the carburetor, then you need to know what the condition of it is before you start.
That just makes sense.

Title: Re: tuneing your intake
Post by VortecCPI on 06/26/16 at 04:46:19

Lots of HD XR1200 dyno work here: http://www.phaedrus.me/id158.html

Almost any additional length will result in better performance. The least-efficient configuration is filter pods directly on carbs.

Title: Re: tuneing your intake
Post by Ruttly on 06/26/16 at 10:18:31

Lancer , What about you ever dynoed your bike? Or will you tell us what's in your top end ?

Title: Re: tuneing your intake
Post by LANCER on 06/26/16 at 13:12:09

4D6A6B6B73661F0 wrote:

Lancer , What about you ever dynoed your bike? Or will you tell us what's in your top end ?

The last time REX was dyno'd it indicated he was producing 43 hp.
0-60 time was 4.9 sec
1/4 mile was 11.9 sec. @ 89 or 90 mph.

That was done with the original Stage 1 cam, the outer ring on the exhaust port opened, 36mm VM carb, stock piston/compression ratio, cylinder had Silicone Carbide Treatment, 1.75" OD header with good flowing muffler, Barnett HD clutch springs.
12.5" Progressive shocks, heavy weight oil in the forks

Since then the exhaust ports have been smoothed slightly, a 97mm Wiseco high compression piston added (10.5:1 CR vs the stock 8.5:1), and in the process of doing the fork mod using the Gold Emulators, and the front disc brake mod, both which have been described on this forum in the past.

When this work is all complete we shall see if I gained anything by it.

Title: Re: tuneing your intake
Post by LANCER on 06/26/16 at 13:20:11

I will likely mount the velocity stack I have for the performance runs.
In the book that was discussed in another thread, about 4-stroke performance, the charts on motorcycle speeds/times a velocity stack in the 4-6" range out performed every other type of intake.
There is some interesting stuff in that book.

"Performance Tuning in Theory & Practice" by A. Graham Bell

Title: Re: tuneing your intake
Post by justin_o_guy2 on 06/26/16 at 13:37:06

he charts on motorcycle speeds/times a velocity stack in the 4-6" range out performed every other type of intake.

Does that include a filter?

Title: Re: tuneing your intake
Post by Ruttly on 06/26/16 at 15:04:17

Thanks for all that info Michael that gives me an idea where mine will be. My teacher Dima Elgin made us design a engine around a cam, the megacycle cam I won from a friend in a drinking contest , boy did I pay for that hungover for days. Graph the cam,bore & stroke,comp ratio,carb cfm, exhaust length all came together as one fast SR500 but never was put on a dyno. All from math from that book. But with the Ryca I did none of that , I just got together some parts & built it. As follows a Web cam STD has alittle more lift & duration than stock & hard faced the rockers, ported the head myself and removed all sharp edges in combustion chamber, 10:5 97mm wiesco & Boretech coated , 36vm mikuni with UFO,quad Wingy thingy,dialajet with a heat shield between head & carb,2" header 1 7/8 ID
With a muffler I built, repackable, Barnett clutch & springs , Versy's tensioner & plug. So far so good, guess the gearing is higher than I thought, should pull right past 100 mph easy. On One real hard run it barked rear tire & carried front tire for 30 feet on a first to second shift , she's got some big nuts that's for sure,seat & paint and she'll look as sexy as she is fast !

Title: Re: tuneing your intake
Post by LANCER on 06/26/16 at 15:45:32

Yep, our 650/700 can pull pretty darn good when set up correctly.
Even with the crappy exhaust ports that Suzuki put in there purposely...to bad they did not see fit to give us a decent set like the DR has.
You have the Webcam cam ? Yea, it is just up slightly from the stock cam.
The UFO can really add some hp to the first half of the rpm range. Thunder Products says 1 hp for each 100cc of engine size, so that makes 6-7 extra hp for our engine, and that is quite a kick in the butt ! It can be a bit hard to deal with jetting/tuning wise, so I don't highlight it like I use to, there were just too many folks that had a lot of difficulty dealing with it. If someone asks me about it then ok, but otherwise I don't mention it.
Wow, a 2" OD/1 7/8" ID header ! That is pretty big. I use the 1.75"OD but would like to build a 1.65" OD/1.5"ID. I think it might be functionally a bit better for torque & power, but that is down the road a bit...many things to do before that.
I'm in the process of modifying the barn for better air flow. It is really freaking hot in there and I need some "flow through ventilation". Then a heavy duty work bench is needed. Then there is my dad's '75 Chevy C20 truck that needs to be rebuilt; yea, everything needs rebuilding since it has sat for 5-7 years minimum. 350 engine, 4 spd. on the floor with a granny 1st gear, the stock bed was removed a long time ago and a steel flat bed was built on it. He bought the truck brand new back then and it has been in the family ever since...now it is mine. I can tie down at least 6 Savages on its maybe 8. I love it.

Title: Re: tuneing your intake
Post by LANCER on 06/26/16 at 16:32:02

[quote author=283731362B2C1D2D1D25373B70420 link=1464235388/75#86 date=1466973426]he charts on motorcycle speeds/times a velocity stack in the 4-6" range out performed every other type of intake.

Does that include a filter ?

It seems I got a couple of charts mixed up together.
One was for cars in which an "air horn", or velocity stack I assume, was used. For the car the velocity stack did out perform all but one, and that was very close, like839 to 853 cfm. There were a total of 10 catagories
.
The other was a chart for an SR500.
The SR had 4 categories;
1. 34mm Mikuni carb with air filter & air box;
2. carb with 2 filters + mod. box;
3. carb + 2 filters;
4. 36mm Mikuni carb

** NO velocity stacks on these as I thought earlier.

In this case 2, 3 & 4 were nearly identical, with 1 being 1 hp ahead between 3-4500k rpm, all even at 5k, and from 5500-7500 from 1-3 hp behind.

Does anyone remember the SR500 having a redline of 7500 ? ?
I sure don't, but ...

My apology about the misinformation earlier.

Title: Re: tuneing your intake
Post by Ruttly on 06/26/16 at 16:32:14

Yes jetting is painful but when isn't it . Went back to a 10 pilot , went up & down with needle and back to middle groove, putting tail light on so I can go find a long farm road to dial in the main jet and then hook up the Dialajet. This carb rocks it's all sh*t n git. Can't thank you enough for all your help. You build your dads truck and don't ever even think about selling it, that's a great project. Thanks Michael

Title: Re: tuneing your intake
Post by Ruttly on 06/26/16 at 16:59:27

Redline for a stock SR500 is 7000 so with mods 7500 sounds about right. Always would bring mine to redline at 7 and it was still pulling. Going to try UFO / Wingy /dialajet on that 36vm & see what it can do!

Title: Re: tuneing your intake
Post by LANCER on 06/26/16 at 17:16:35

785F5E5E46532A0 wrote:

No worry about dad's truck, it will be with me until I die.

Title: Re: tuneing your intake
Post by LANCER on 06/26/16 at 17:20:36

Back up with me a little; what was done to your SR500 and what has been done to your LS650 ?
I think my mind has confused the 2 of them a bit.

Title: Re: tuneing your intake
Post by Ruttly on 06/26/16 at 18:40:50

Pretty much the same things except the sr doesn't have the UFO/Wingy/dialajet YET. I think cam used in SR is more a mid to top range cam and only about 520 cc or so.

Title: Re: tuneing your intake
Post by Kris01 on 06/26/16 at 22:33:06

303D323F392E6E6B5C0 wrote:

It seems I got a couple of charts mixed up together.
One was for cars in which an "air horn", or velocity stack I assume, was used. For the car the velocity stack did out perform all but one, and that was very close, like839 to 853 cfm. There were a total of 10 catagories

Title: Re: tuneing your intake
Post by mastercarstech on 06/30/16 at 15:51:16

Looking at the description of the K&N filter that's essentially a round filter on top of a velocity stack which would be similar in function to the design the Enfield guys came up with. Just thinking out loud. :o