Equalizing Vacuum

vmax626 · Jul 25, 2009

Re: equalizing vacumn

richwrench said:
I used 3/16" ( 4.8mm ) fuel/emission hose from Goodyear - perfect fit ! It's the same stuff I used when making my manometer. Tight, secure fit, but you don't have to force it, and no clamp needed.

Hey Rich,
What size hose did you use on the board of your manometer ??
<<Dave>>

unk:

vmax626 · Jul 25, 2009

Re: equalizing vacumn

$c:\users\david\documents\myscans\2009-07\scan0001.jpg$

Here are some pics of how mine is hooked up, I used 5/16 O.D. 3/16 I.D. tubing with 3 3/16 O.D. "T"`s and one 3/16 plastic elbow to the vacume sensor.
<<Dave>>

unk:

dannymax · Jul 26, 2009

Re: equalizing vacumn

Nice neat job Dave. :thumbs up:

vmax626 · Jul 26, 2009

Re: equalizing vacumn

dannymax said:
Nice neat job Dave. :thumbs up:

Thanx Dan,
Those smaller hoses make a world of difference, I screwed up when I used that 1/4" hose, boy that was a mess the covers wouldn`t fit and the line got pinched.:bang head:
Did you do yours the same as mine ??
<<Dave>>

dannymax · Jul 26, 2009

Re: equalizing vacumn

vmax626 said:
Thanx Dan,
Those smaller hoses make a world of difference, I screwed up when I used that 1/4" hose, boy that was a mess the covers wouldn`t fit and the line got pinched.:bang head:
Did you do yours the same as mine ??
<<Dave>>

Yes, on the '06, except I came across in front of the carbs instead of between them. Your job is neater than mine, I was more concerned with the outcome and didn't even take the air box off. Now that I'm convinced this is a worthwhile mod I'll go back and do it right.

unk:

vmax626 · Jul 26, 2009

Re: equalizing vacumn

dannymax said:
Yes, on the '06, except I came across in front of the carbs instead of between them. Your job is neater than mine, I was more concerned with the outcome and didn't even take the air box off. Now that I'm convinced this is a worthwhile mod I'll go back and do it right. unk:

When I used the big 1/4" hose i had to go underneath the carbs and, that turned out to be a real mess and thats when i kinda new that the whole thing was wrong , I guess I learned my lesson about doing things hastefuly
LOL. I just hope that the pics will help someone who wants to do it to their bike so they wont make the same mistake that I did.
<<Dave>>

unk:

richwrench · Jul 27, 2009

Re: equalizing vacumn

vmax626 said:
Hey Rich,
What size hose did you use on the board of your manometer ??
<<Dave>>unk:

On the board I used 3/8" OD by 1/4" ID clear plastic tubing. From the restrictors to the carbs I use about a 6" piece of 3/8" fuel hose.

vmax626 · Jul 27, 2009

Re: equalizing vacumn

richwrench said:
On the board I used 3/8" OD by 1/4" ID clear plastic tubing. From the restrictors to the carbs I use about a 6" piece of 3/8" fuel hose.

How much tranny fluid did you put into the tubes ??
David

unk:

richwrench · Jul 27, 2009

Re: equalizing vacumn

vmax626 said:
How much tranny fluid did you put into the tubes ??
Davidunk:

About 15". Here's the link so I don't get too off topic.:biglaugh:http://www.vmaxforum.net/showthread.php?t=2369&highlight=manometer&page=5

Birdoprey · Jul 27, 2009

Re: equalizing vacumn

The benifits of this mod are from having a steady vac at the map sensor, which inturn provides a steadier supplamental ignition advance. If you hook a vac guage to a single port, you will see how erratic the vac is. The map sensor follows this by adding and removing supplamental ignition advance. I suspect this causes some cyl to have more advance than others.
Connecting all 4 together allows the map to see a steadier vac source and inturn provides a steadier supplamental ignition advance.
If you've ever advanced your timing on your pickup or car with a distributer, i'm sure you noticed a higher and smoother idle when adding advance? Of course, this only works up to a point. Too much is WAY bad.

I suspect that Yamaha intentially reads vac off the #2 port. Prolly more for idle sound. They were really going for a hot rod look/sound. I wonder if the idle quality/sound changes if referenced off different ports?

WOT would be unaffected by this mod as there is no vac at these ports at WOT, and therefore no additional ignition advance is being added by the map/tci.

Wanna make an EFI bike run bad? Just hook the map sensor port to just ONE intake manifold port instead of all 4 like they normally use. Idle quality/low speed drivability and even midrange drivability gets crummy.

naughtyG · Jul 27, 2009

Re: equalizing vacumn

yo birdoprey that sounds just right - makes complete sense!

You rocket scientist you

2stangs69-91 · Aug 10, 2009

Re: equalizing vacumn

Damm it I thought I could take a little time off from moding the bike lol. So did you all decide this mod was worth your time?

bobzdar · Aug 10, 2009

Re: equalizing vacumn

I wonder how many people seeing an improvement are seeing it at least partially due to the old fittings having small leaks due to age? If you've got a couple of small vacuum leaks (in particular on the vac advance line), could be doing this mod just fixes the leaks. I'd be interested to know the condition of the vac advance line and caps before this mod...

vmax626 · Aug 10, 2009

My caps were ok no leaks and the vacume line was replaced so everything was ok when I did it.
The idle went from a lopey sound to a steady rumble and the throttle response is alot smoother through the cycle up to red line.
It pulls better in high gear range also so, I think it was well worth the $6.00 it cost to do it and, the spark plugs seem to like it.
<<Dave>>:cheers:

vmax626 · Aug 10, 2009

Re: equalizing vacumn

2stangs69-91 said:
Damm it I thought I could take a little time off from moding the bike lol. So did you all decide this mod was worth your time?

You should go for it,
Although you might miss the lopey big cam sound but the rumble says "don`t mess with tihs one"" It`s still deep and mean sounding.
<<Dave>>

unk:

naughtyG · Aug 10, 2009

Re: equalizing vacumn

I've done it too but I'm not sure I notice an improvement. Idle sounds just about the same, and throttle response is very much as before.

Maybe I'm using the wrong hose, I think it's a little soft and prone to getting squished under heavy vacuum..

44 magnum · Aug 12, 2009

Low end is noticeably smoother which is why I think it feels more responsive. My instinct tells me it?s just a seat-o-the-pants feel, but nonetheless, smoother low end is a welcome thing for me.

Now I just need to figure out how to clean up the vac line. It?s pretty thick (3/16 fuel line) so I couldn?t get my H covers back on. I may get some thinner hose to make it all fit in there better.

All in all, I'm glad I did this one.

-

spyder13 · Aug 13, 2009

Ok so just how many have tried this mod? Have any with open vboost tried it? What affect did it have on those? Just curious my is running great. I love this mod.

dannymax · Aug 13, 2009

spyder13 said:
Ok so just how many have tried this mod? Have any with open vboost tried it? What affect did it have on those? Just curious my is running great. I love this mod.

Stock boost here on both bikes, like your's they're running terrific. Biggest things I noticed were smoother idle and very quick starting.

It's a great mod...thanks for passing it on!! :clapping:

danny

COP RUNNER · Aug 13, 2009

**** ! .....THIS MEANS I'M GOING TO HAVE TO DO IT !:bang head:

Equalizing Vacuum

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