Equalizing Vacuum

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Re: equalizing vacumn

My guess would be 1/4" tubing? Buy some extra hose and fitting and make yourself a homemade manometer while your at it! I always wanted to compare a homemade unit to the carbtune. Sorry off topic.

 

[gamorg02]

Re: equalizing vacumn

diam.. diameter.. sorry guys! hah

 

[robsplatf4]

Re: equalizing vacumn

My guess would be 1/4" tubing? Buy some extra hose and fitting and make yourself a homemade manometer while your at it! I always wanted to compare a homemade unit to the carbtune. Sorry off topic.

+1 I used 1/4" OD (1/8" ID) tubing to hook up my homeade manometer.

 

[maleko89]

Re: equalizing vacumn

I'm assuming fuel line was used and not the clear stuff?

 

[dannymax]

Re: equalizing vacumn

I used 3/8" OD, 5/32" ID black flexible vacuum hose, and 3/16" vacuum barbs.

It fits tight, but will relax a bit over time.

 

[maleko89]

Re: equalizing vacumn

It fits tight, but will relax a bit over time.

Lol! I had to clean my monitor off after this line Dan-o. I don't care who you are...that's funny!

 

[naughtyG]

Re: equalizing vacumn

Lol! I had to clean my monitor off after this line Dan-o. I don't care who you are...that's funny!

Bwaaahahahha!!

classic, nice one :rofl_200::rofl_200:

 

[dannymax]

Re: equalizing vacumn

Lol! I had to clean my monitor off after this line Dan-o. I don't care who you are...that's funny!

Wondered if that would just float by unnoticed!! :biglaugh::biglaugh::biglaugh:

 

[vmax626]

Re: equalizing vacumn

Did I start all this ?:rofl_200::rofl_200::rofl_200:

 

[richwrench]

Re: equalizing vacumn

I did it with 3/16" fuel hose - perfect fit. :biglaugh:

 

[4gasem]

Re: equalizing vacumn

Everyone needs to post up there thoughts on this after you've thoroughly tested it. MPG and everything if possible.

It's hard to believe something this simple makes this much difference.

I'm thinking about doing it to my SV as well. It's easy with that one... Its a twin! lol

 

[dannymax]

Re: equalizing vacumn

Everyone needs to post up there thoughts on this after you've thoroughly tested it. MPG and everything if possible.

It's hard to believe something this simple makes this much difference.

I'm thinking about doing it to my SV as well. It's easy with that one... Its a twin! lol

I agree!! Just went out for a short ride to warm it up, see if that starting thing was some kind of illusion....nope, it started the same way....basically LOOK at the button and she's running!! :biglaugh:

Has anybody else had this happen too?

Just do one carb on the SV Chris....see what that does!! :rofl_200:

 

[4gasem]

Re: equalizing vacumn

I agree!! Just went out for a short ride to warm it up, see if that starting thing was some kind of illusion....nope, it started the same way....basically LOOK at the button and she's running!! :biglaugh:

Has anybody else had this happen too?

Just do one carb on the SV Chris....see what that does!! :rofl_200:

The SV is FI but that's some funny ****!

Wait... I think it's done then... :biglaugh:

 

[richwrench]

Re: equalizing vacumn

Just finished a road test with mine - no difference. I'm not implying it's not a valid mod - my bike had issues to start with - this just wasn't the fix for it. When my bike is at full operating temp. the idle goes to *****. I bumped it up to 1200 rpm to cover it up until I fix it. The last time I went through the carbs I didn't dis-assemble the jet blocks - I believe they are plugged. A proper cleaning should take care of it , but I'm putting it off because it runs so great everywhere but idle . It makes sense to me to link all the vacuum ports together - think about it - a V8 with a 4 barrel carb has the idle circuits shared among all cylinders - why not a V4 ? Obviously there are many other reasons why a V8 runs so smooth, but I will continue with this mod even after I repair the idle circuits to their normal state. I never heard of this mod before , but it makes mechanical sense to me - good call Spyder !!!

 

[RagingMain]

Re: equalizing vacumn

Maybe I am looking at this wrong but it seems to me it is NOT a mechanically sound idea and here is why.

First you really cant "equalize vacuum because only one cylinder at a time is on its intake stroke and normally it is only pulling on its carb (below 6k rpm). Now we are opening up that intake, which is below the carb, to all the other intakes and carbs???

On a carbuerated bike the only thing that moves air/fuel into the cylinder is the difference in pressure between the float chamber(atmospheric pressure) and the venturi affect at the throat. The fuel doesnt get sucked in, it gets pushed in by the air rushing through trying to fill the cylinder as the piston travels down.

Now opening that intake to more area (tubing and other intakes is going to allow that pressure through the carbs to travel to places other than the intakes valves and to the cylinders. It is going to take the path of least resistance. It will lower the VE of that carb.

Plus the only time any cylinders are on their intake stroke together is #1 & #4 during the last 70* of #4 intake stroke #1 is starting to open. You can see that here
http://vmaxguru.com/Tech/Gen1/Pages/Ignition/Ign_Sreadsheet.bmp

Now it might actually help with the timing because you are smoothing out the pulses seen by the vacuum advance. Instead of seeing vacuum once every 720* it will now see it once every 180*. Not going to give it any more or less timing but allow it to work more smoothly.

So in summary
1. You really cant "equalize" vacuum when the cylinders dont overlap except as noted above.
2. You are giving the pressure/vacuum other places to go other than into the cylinder lowering VE.

I appreciate any feedback on my thoughts
Cheers

 

[MAXXMAN93-4301]

Re: equalizing vacumn

So in summary
1. You really cant "equalize" vacuum when the cylinders dont overlap except as noted above.
2. You are giving the pressure/vacuum other places to go other than into the cylinder lowering VE.

I appreciate any feedback on my thoughts
Cheers

i understand your point and as i stated before the benefits are more even vac signal at the advance module and a smoother vac pulse through the carbs at low rpm. i agree with what you said, it wont equalize the vacuum but it possibly will even it out a little:confused2: and it should promote some swirl or tumble in the intake .

as for the intake stroke overlap, that is my point they are almost totally seperate so the vac in each cyl is high at seperate times so the slight equalization might lessen any reversersion in the off cylinders. just brainstorming so... its good brain exercise

also yamaha used a very similiar setup on the seca and maxim with small ports between intake ports. it was called yamaha induction control system
YICS

besides who couldnt use some nice even suction!!:biglaugh:

 

[06VMAXIMUS]

Re: equalizing vacumn

I'm not agreeing or disagreeing with this mod....it sounds like a great idea, BUT.... If yamaha put it on the seca and maxim (YICS), why didn't they do it on the VMAX???

 

[mr.maxx]

Re: equalizing vacumn

i think back in the day.....the YICS was a selling point for the seca and maxim. 'yamaha induction control system" i think suzuki had a similar one called TSCC "twin swirl combustion chambers" i think it was called?? the vmax has the v-boost for its extra special feature:rofl_200:

 

[naughtyG]

Re: equalizing vacumn

Still, such an easy mod, why don't a whole bunch of us do it then start a poll and vote for:

a - it really helped
b - it help a bit
c - it didn't do anything

 

[maxcruiser]

Re: equalizing vacumn

Still, such an easy mod, why don't a whole bunch of us do it then start a poll and vote for:

a - it really helped
b - it help a bit
c - it didn't do anything

Well G, I just tried this mod and I'll go with b

Mike