Actually Griceiv, that's exactly the first design that was done.

Have a throttled (by a ball valve) vent governed by a half inch brass viton solenoid.

Some deficencies are:
1) at different air temps/elevations (winter/summer/mountains etc) the system does not compensate. Would u like to have to go in your engine bay in freezing conditions to 'adjust' the ball valve?

2) You still have to weld in new 1/2" plumbing nipples, twice over for a recirc. MAF system

3) The valve still weighs 2 lbs, which requires some secure mounting, and weight is a factor in all perf. vehicles.

4) The valve/ball valve ain't pretty, which does matter for a commercial item.

There's no need to make extra mechanical items when the problem can be solved by intelligent, configurable, easy to install, gauge/controllers. Remember, when u make mechanical items, u require fittings for each model vehicle and series etc. The solution in this thread will work with the majority of preinstalled wastegates or BOV. When you think in commerical solution terms a one off or one model solution is not the best option, esp. when custom fabrication work is required as an added cost.

 

The stock BOV opens partially under part throttle. The Synapse BOV is supposed to work the same way but at higher boost values, but there are many posts about it also causing surge and not being able to "dial it out" as the advertisements say you should be able to do.

If the Synapse valved functioned 100% as advertised in all applications that would be an answer - but so far I think it has not. That is why I am interested in the new advancements undergoing testing in this thread. . .

 

This sounds like a great idea, but I would like to know what mechanism specifically you are going to utilize to gain this much control.

-Acree

 

see next post

 

Ok, take a deep breath, here we go......

This is based on the application of a 3 way boost control solenoid driven simultaneously by a hybrid boostcontrol/ BOV control PID PWM algorithm. The BOV control is enhanced by the use of a small vacuum canister to support BOV actuation (under boost) based on the DELTA Pressure manifold rate of change . The normal BOV response is operated in a digital ON/off manner with no partial openings for best throttle-release transition venting and best on-throttle holding pressure. The Boost controller operates the BOV valve partially to provide both low pressure antisurge control and regular cold side boost control.
The system permits programmable over boost 'POP off' via the BOV with user set latencies for transitionary spikes eg. under 2 seconds. Risk free boost control tweaking results.

There are 3 RPM/TPS maps for both Closed loop boost control and open loop boost control. There are 2 one touch settings for Performance/Urban BOV driving sensitivities .

The custom PID algorithm achieves sophisticated control by going to the 2nd derivative of the map absolute pressure changes, which is more advanced than the standard single derivative PID algorithms in general use. This 2nd order derivative permits advanced predictive phase lead compensation from the points of inflection derived from the PID control changes.


Any more specifics and I willl have to get an NDA from u. Or shoot u.!

 

Which island in the Caribbean are you from? I used to live in Antigua and that's where I first saw an Evo III.

 

By reducing spring rate meaning adjust it to soft?

 

I am in Trinidad, lot's of Evo's and STi's.

Yes, reduce spring rate means soften the spring tension. .

As you mention it I indicated that shortening a spring is an option. That actually increases the spring rate, but will reduce the overall spring force if the amount of spring deflection is significantly reduced.

 

FWIW, all the "new" 2.0 audi/vw turbo engines use electronic BOV's bolted right to the turbo. Pretty cool stuff.

 

So in other what you are talking about is a complicated EBC, nothing more.

I follow what you're saying about lowering the BOV reactive pressure to 2-3 psi, but what I don't get is how you plan on "partially" controlling the BOV to hold a certain pressure. Wouldn't it make more sense to use the PWM to fully open and close the BOV a number of times to bleed off a certain amount of air to maintain the desired boost level?

Here's my analogy: LED tail lights. If you've ever taken a look at say, a newer Cadillac with the tail lights where you can see the individual LEDs, you might notice that when you glance from side to side the LEDs appear to blink. When an LED tail light appears dim, and then someone hits the brakes, and they brighten up, they're not actually dimming. They utilize a PWM circuit that simply "blinks" the leds very rapidly. It's so rapid that most observers simply see a dim LED. Once the brake is pressed, the LED stops blinking, and just stays constantly lit. To relate this to the BOV, consider the amount of light the LED emits proportional to the amount of air you to want to bleed off. For this purpose I'll consider the BOV in the "ON" position if it is open, and off if it is closed. If you want to emit a small amount of light, or bleed a couple of psi, you would turn on the led, or open blow off valve for a small amount of time, and then turn off the led or BOV for a larger amount of time. If you wanted more light, or want to bleed 10psi, then you would turn the BOV on, open it up, for a longer amount of time, and turn it OFF, or close it for a very small amount of time between openings. It seems to me this would be a much more accurate way of bleeding pressure out of the BOV. The only potential hurdle here is how fast your BOV can react.

Another problem with "partially" opening a BOV is there's no way to know how much PSI is being bled out at what percentage of total opening. Each make and model would be different. BOV A would bleed 5psi at 25% open and BOV B might bleed 7psi at 25% open. I see a lot of issues here. On top of that, how would you know what percentage the BOV is open?

Just some thoughts.

-Acree

 

Closed loop control.

 

Or why not simply connect your PWM controller to something like an electronic BOV?

-Acree

 

They are not widely available nor easy to come by. That link u included requires additional plumbing and custom fab work. It also does not offer any kind of control other than on for a sec and off. That's stone age compared to the TPS/RPM/MAP and PID control.

However, the direction of your comments about electronic BOV are spot on. They ARE the future. Just not for a couple years at least.

A true electric BOV is what is best, like those on the VW/AUDi and the 2010 Ford ECOTEC TAurus driven by this same controller for lower latency and tighter controls.

When u consider the mass market u must realise that the installed base of vehicles are 99% pneumatic wastegates and BOV. It's poor business planning to make a solution for 1% of the market when u can make a solution for 100% of the market.

Those vehicles with electric BOV will realise better control than those with pneumatics. However, the intelligent control of pneumatics still has a fair life cycle and isn't going away anytime soon.


A DIY guy CAN install an electric solenoid valve IF he is willing to do the custom fab work and bear with the 2lb brass valve. He will realise somewhat better perf. Whether it is measurably better economically is part of the testing going on.

Remember that an electric solenoid shuts Tight, and will encourage partial throttle surge, so u will need the controller to run it.

FYI, I am actually still running version 1 of this product with the same 2lb brass valve on my turbo engine. That version does not attempt to handle boost control though, just BOV control for throttle response. It's interesting to note the same pattern of dev. in this thread as took place with the product dev. I'll share this workshop pic with u, BUT, IT IS NOT what V2 is looking like.

http://img199.imageshack.us/i/gauge0psi.jpg/

Version 1 will eventually be released to the DIY market as an electronic kit with housing/faceplate etc. It has been road tested already.

 

interested in a solution to the surging/bucking issue as i have dealt with it for over a year now and have reasearched and fount a few threads but no1 with a solid fix....

 

Bump....