Vris Mod under boost

[BATTOSAI]

Reading again the "Vris heaven" page but now with the forced induction mentality I came up with a good and easy mod to take it´s benefits when N/a and to not close the air path at boost. I picked a small pressure sensitive switch wich I will use to ground both solenoids as soon as boost appears, causing the butterflies to open, thus having them operating them under the boosted range. I picked two of this switches, as they are adjustable, and in conjunction with a solenoid I will try to build an electronic boost controller, that will allow boost reach the wastegate at a preset boost level, which will help avoiding turbine speed loses caused by partially open wastegate. Those switches range from 2 psi to 15, just a good range for F/i application!

[boostedmx]

i recently had this discussion with jademx3. he had a nasty drop off in power at a certain rpm-(3500 i believe?). it is due to the butterflies opening. you loose all velocity in the intake at the moment the butterflies open untill you can build up pressure again to fill the secondary chamber. the smart thing to do would be to keep them shut for more velocity and better atomization. or you could keep them open too if you wanna test it.<p>[ February 26, 2003: Message edited by: boostedmx ]</p>

[BATTOSAI]

As the switch is adjustable, I can test at what boost level is better to have them opened. I will tell you anything as soon as I have it solved

[boostedmx]

what i am saying is that you will loose velocity at any level. you will get a drop off in torque and horsepower. velocity is one of the main factors in flow testing and atomization. if you open a secondary chamber pressure will drop to fill that space and all velocity will be lost. this will happen at any rpm or boost. if you do it at low rpm and low boost a hesitation will be felt feeling almost like more lag. if you are aiming for the upper rpm and higher boost, it will cause a drop off in power at the time you would want peak power output.

[atila]

Where did you get those switches i'm searching for something similar and the only thing i found where pressure switches that i could not adjust

[jonathanj]

boosted is right. when those plates open the car falls on its face. then it takes a few moments before its back up to par.

[David Coleman]

Ok, you guys are talking about two totally different things. B6's have VICS, which affects intake velocity. K series have VRIS, which does not directly affect velocity as VICS does.<p>Thank you, and have a nice day.

[BATTOSAI]

Atila, I founded them on my local pressure parts store. They can function both as open or short circuits when under boost, you just put the wires in different locations. They cost me 20€ each. I threw a vacuum line from the manifold to the pressure receiving port that they have and mounted one of them where my lighter was, so I can adjust it on the fly. The part number is Ps14 , I´m sorry but I can´t remember the manufacturer. I´ll post it if you´re interested.

[boostedmx]

<blockquote><font size="1" face="Verdana, Arial">quote:</font><hr> Ok, you guys are talking about two totally different things. B6's have VICS, which affects intake velocity. K series have VRIS, which does not directly affect velocity as VICS does.
Thank you, and have a nice day <hr></blockquote><p>Yeah, i wasnt quite sure what they were called. I havent delt with them much except for the flow testing on my own. thanks for the correction!!

[mazdamaniac]

<blockquote><font size="1" face="Verdana, Arial">quote:</font><hr>Originally posted by BATTOSAI:
Reading again the "Vris heaven" page but now with the forced induction mentality I came up with a good and easy mod to take it´s benefits when N/a and to not close the air path at boost. I picked a small pressure sensitive switch wich I will use to ground both solenoids as soon as boost appears, causing the butterflies to open, thus having them operating them under the boosted range. I picked two of this switches, as they are adjustable, and in conjunction with a solenoid I will try to build an electronic boost controller, that will allow boost reach the wastegate at a preset boost level, which will help avoiding turbine speed loses caused by partially open wastegate. Those switches range from 2 psi to 15, just a good range for F/i application!<hr></blockquote><p>Sick minds think alike.
I recently built a boost controller that matches what you are describing EXACTLY.
The pictures are in the second to last row here:
http://www.mazdamaniac.com/boost/turbo/turbo.htm<p>I like the VRIS idea.
I would leave the VRIS alone until you get above the 6300 RPM cutoff and then force them to stay open if under boost.
One of these days, I will get some real dyno data about the function of the VRIS while under boost.

[atila]

If you could find me the fabricant i would apprexiate a lot thanks

[BATTOSAI]

Jeff, what kind of solenoid are you using? I planned on using the Fpr one, as I won´t use it anymore, but if I can found anything with larger ports I´ll go for it!

[rmcg5]

the reason the cars falls flat on it's face is simply because the intake manifold has 2 chambers. a small, low rpm chamber and a large, high rpm chamber. when you close the solinoids you would technically loose pressure in the second chamber. when the vris re-opens it will have to re-pressureize the second chamber... which will cause a drop in pressure in the first chamber.... also when this happens your pressure sensors will sense the drop and possibly close again....

[mrspanky79]

hey jeff are you still using the Simple Digital Systems?

[992mmx3]

Huh? Jeff is using simple digital systems too? I just bought the system about 3-4 weeks ago, haven't had it installed yet.