vmapper

iTrader: (8)

Please, more input and discussion the better...

I however, can not find adequate information on using a BOV for this type of boost control...

Wastegates are designed to modulate airflow. BOV's just pop open dump air and then close, they are on/off valves.

The only viable solutions I have read are:
restrictor plate on inlet side of procharger. some use electronic throttles and a simple cockpit voltage (resistor dial).
or a wastegate setup.

I dont see how a BOV will work.
And many say the same.. BOV WILL NOT WORK:
Post #206
https://ls1tech.com/forums/forced-in...ollers-11.html
https://ls1tech.com/forums/forced-in...dding-bov.html

tim99ws6

iTrader: (31)

A JGS BOV will work.

vmapper

iTrader: (8)

Im sorry, going to need a better explanation of why a BOV (which many threads on both the corvette and here state) will not work with this proposed idea. A brand name of a BOV is not a sufficient reason. Perhaps you meant a JGS Wastegate?

Do you have dyno boost session to show a steady limited boost using a BOV? Or use one in this manner? I have yet to come across someone successfully using a BOV for this 'boost limiting' purpose. And to go further to allow ADjustable boost levels. (e.g. controller)

ChrisWTX, who has been quite successful wrote this:

BOV are not wastegates. They are designed to stay closed until you see a vaccum in the intake in a turbo car. They release pressure between shifts and rapid throttle closure to prevent excess pressure on the turbo impellers..They have nothing to do with controlling the boost pressure..you need a wastegate..

tim99ws6

iTrader: (31)

Sorry I didnt appease. The JGS is a valve type BOV, not a diaphragm like alot of it's competitors. Secondly, the BOV has a two port refrence specifically for use in a SC application. One side for engine vac one side for boost feedback. The basic "idea" of the JGS is extremely similiar to that of a wastegate in a Turbo application. It works.


PS-->Who ever said you have to spend $500 on a boost controller?! there are numerous cheap but effective manual controllers for this, as well as simple spring changes within the BOV possible to regulate boost before stepping up to an electronic boost controller.


here's a link to help you see the BOV itself:

http://jgsturbo.com/jgsbovinst.pdf

tim99ws6

iTrader: (31)

Easy with your close-mindedness. Just because you didn't find it in your searches on a internet forum doesnt mean it doesn't exist.

vmapper

iTrader: (8)

Not closed minded, just with present understanding of how a typcial Blow off valves work doesnt mean I go out and try to make it work when there are other proven methods found on the internet. I am fully aware not finding during searches doesnt mean it doesnt exist.. but its odd, that a well knitted community such as LS1Tech and Corvetteforms and Hptuners would keep this such a deep secret, no one posts about it. thanks for the direction, i will look into this..

vmapper

iTrader: (8)

?? Never said I had to.

tim99ws6

iTrader: (31)

That's cool, no worries! I honestly think the high hp LS SC world is the black hole IMO. There's just not alot of data on the forums when it comes to pushing the limits from a LS/SC setup yet. The car we tested it on was a YSi/5.3 setup. So far it's worked out well, just time to pulley the thing up and see where how much the belt configuration can handle at this point.


If i was you, I'd call JGS and speak to them directly. They are good people!

tim99ws6

iTrader: (31)

I was more refrencing the above post about eboost controllers.

vmapper

iTrader: (8)

Thank you, I will call them!

Are you using the JGS600 BOV?

vmapper

iTrader: (8)

So with this BOV
Upper port uses pressure to keep the bov closed.
Bottom uses pressure to open.

By running a single line to the bov, add a tee (upper and lower).
Run full pressure to the bottom post (valve lift)
Add a regulator to the top port and limit the max pressure to bov.
This will create an adjustable pressure by pass. ?

vmapper

iTrader: (8)

has anyone used this?
http://www.928m.com/parts/boostlimitervalve.php

pianoprodigy

iTrader: (1)

That thing would never vent enough volume of air to make a significant difference on the blower moving the amount of CFM on typical V8 setups.

There is another discussion about this going on on CF:

http://forums.corvetteforum.com/c5-f...p-is-done.html

And my comment from that thread:

This really doesn't seem like a difficult concept to me, but perhaps that is because I have pondered it quite a bit prior to this discussion. Let me try to give my thoughts in the most concise way possible. Initially, I’ll speak generally and then address OP directly.

Assuming a blower is not vastly undersized for the application, a good rule of thumb to use is that a centrifugal blower will flow half of its pullied volume of air (and consequently realize half of peak boost) at 2/3 of the RPM for which it is pullied. In other words, if your pulley makes 10 PSI at a redline of 6,000 RPM, it will make 5 psi at 4,000 RPM. If your redline is 6500 and you are pullied for 12 PSI peak, then you would make 6 psi at 4,333 RPM. Here are a few dyno charts for example that actually logged boost: http://i226.photobucket.com/albums/d...008C6dyno1.jpg http://shop.brutespeed.com/media/dyno%20graph.jpg http://i176.photobucket.com/albums/w...ildDynoSAE.jpg

The goal of using a "wastegate" to bleed off boost from the charge piping in the upper RPM range is to use a pulley that has a substantially higher peak boost number so that you would get to whatever max boost you want to achieve as early as possible in the rev range to create cylinder pressure resulting in torque and horsepower.

If you do not want to exceed 12 psi on a particular setup, it would not make sense to only slightly increase potential max boost to 13 or 14 psi because the effort involved would not be worth the gains potentially realized. It would make far more sense to change your pulley ratio to something much closer to the max RPM of the blower (which is likely where it is most efficient anyways). This might result in 24 psi at redline (or more if you had a capable blower) if left unchecked which may not be desirable; however, using the above-captioned rule of thumb, if 24 psi occurs at 6,000 RPM, then 12 psi will occur at 4,000 RPM. After 4,000 RPM, the wastegate (as controlled by some type of boost controller, more on that below) will begin to gradually open and bleed boost from the charge pipe and maintain 12 psi all the way to redline.

It should be clearly evident that making 12 psi from 4,000-6,000 and consequently an average of 12 psi will result in far more average horsepower than making 6-12 psi over the same rev range (and consequently an average of 9 psi). Of course, the gains beneath 4,000 also cannot be ignored and would also be dramatic since the ramp rate of the boost will be roughly twice as fast using my example.

The blower will undoubtedly require more horsepower to be spun and will surely generate more heat, but not as much as if 24 psi were actually held in the charge tubing rather than being vented to achieve a max boost of 12 psi. I would plan on using an Alkycontrol kit anyways, so the charge temps would not particularly bother me either way as they would be easily corrected.

OP: I would strongly recommend at least getting a manual boost controller which will prevent if not eliminate the wastegate from creeping open early since a 12 psi spring will usually begin to open about half of the max pressure resulting in a loss of response. How dramatic? Perhaps not much, but a decent manual boost controller is $40 and takes all of 2 minutes to install.

When I get around to implementing this strategy, I will likely use an electronic boost controller (EBC) to keep the wastegate shut until the last possible minute without creating too much of a boost spike. This should result in maximum response from a given pulley setup.

My other purpose in using an EBC rather than an MBC is using the failsafe trigger on my new AEM Wideband Failsafe Gauge that has yet to arrive since it was just recently released. If it senses an AFR that you have defined as being “unsafe” at a particular boost level, it can send a signal which can trigger the boost controller to revert to spring pressure, dumping boost, going pig rich, and potentially saving the motor. I am running an F1R on an SBC than I’m only turning to 6,000, so I have more than enough cfm (2,000 max) to play with this and benefit from it.

vmapper

iTrader: (8)

very well explained. I am sure the OP will enjoy the read, I have.
The idea of having a boost safeguard off of a wideband, fantastic.

what are your thoughts on a restriction throttle inlet side vs W.G. vs adjustable BOV?

Marty Staggs

The OP was asking about the E-Boost2, so let me explain further -

Wastegate, BOV, diaphragm, or no diaphragm, does not really matter for the functionality, what matters is how you control it.

Yes, as has been pointed out, a typical BOV just opens and closes to vent the intake.

The EB2 controls by pulsing the solenoid via the programmed duty cycle in it.
The built-in MAP sensor adjusts the pulse width in response to the manifold pressure.

Using a BOV as I had suggested, you can modulate the manifold reference to the top of the BOV and turn it into a regulated "leak".
The manifold reference is regulated via the solenoid inversely to manifold pressure. More manifold pressure = less manifold reference to the top of the BOV. The manifold pressure acting on the face of the BOV piston lifts it to vent the manifold pressure.

Now, using a BOV will require special softer springs and some tuning to provide the target boost you are looking for. Also, the solenoid pluming scheme is different than using a wastegate.


Now if you want to use a wastegate or a two-port style of BOV, the plumbing and configuration will be the same as using it for turbo boost control and only the spring will need some adjusting to get the response you are after.

BOV's seal better on cold side applications than wastegates do and that is why I prefer a BOV whenever possible.

Important things to note about the EB2 when used in this manner -

YES, you can still have multiple stages just like a turbo car.

Overboost safety will not work as programmed in the unit and must be turned all of the way up so as to not interfere with EB2 operation.
If you would like to still have an Overboost safety strategy, you can use an additional solenoid and the AUX output function to remove the manifold reference from the BOV at a set pressure and just vent the intake at that pressure.

Gate pressure setting should be turned to 0

All of this is "out of the box" thinking and using the EB2 in an application that it was never intended for, so some tuning and testing will be required to get it to function to your liking.
The EB2 does not know or care what its hooked up to. It sees a pressure and responds as programmed - thats it. It runs a solenoid and chases a target.
Simple

vmapper

iTrader: (8)

Perhaps I should have started my own thread... I have never heard of using a BOV (but also wasnt aware, some have two ports) for regulating boost on a centrifugal setup (to simulate a wastegate). I get how this all works now and I would like to do this on my setup. for myself, I am not asking about EB2.

Does one have to run a electronic boost controller on this top port? If manual controllers work, which one? BOV, how do you know which spring? manual controller?

I guess im all over the place on asking these questions, and have pushed this thread discussion somewhere else... I apologize to all including the O.P.

pianoprodigy

iTrader: (1)

The assumption in using a traditional BOV to accomplish the topic of this thread is that the pressure in the charge pipe is greater than the spring pressure. Ordinarily, vacuum is required to open the valve (if you start your car with your BOV hooked to manifold vacuum it opens, remove vacuum source, it closes), though, of course, enough boost pressure might be present on the face of the valve to open it and vent boost. This method as opposed to the wastegate relies on the absence of pressure (which allows valve to open) as opposed to allowing pressure to force open the wastegate.

I8UR4RD

iTrader: (16)

yeah but with a Blow off valve, would it not have compressor surge due to the fact that the set spring rate would not allow it to open under low RPM conditions which puts stress on the blower? id just get a pulley capable of doing 10-11lbs and just drop the rpm down. make the motor last longer and still be a wild ride. course I would miss those 6600-6750 sounds!

vmapper

iTrader: (8)

a bypass or surge valve is still being used. this thread is to discuss running a pulley combo which would provide huge boost, but limited by either a wastegate, restrictor or bov. check out some of the links and pointers to some magazines to understand better. If I run with a bov, which is new to me, I would have BOTH my bypass valve as normally AND a wastegate or BOV to cotrol the boost.


Posted from LS1Tech.com App for Android

allout06

iTrader: (11)

I just liked the idea of being able to control everything on one device. Since i would be running a meth kit with this setup, the EB2 can control meth so itd all work out. and i have 0 problem spending $470 on a boost controller, im not really worried about the cash lol...

Like i said previously, if i did this, id definitely go with an EBC, like an EB2. Along with an alkycontrol kit. Do they make a 16lb spring so i can make 8psi? Im not really concerned with making more redline horsepower, as i am with lower rpm torque/hp obviously. My main concern is previously mentioned cylinder pressure at lower RPM. Its obvioulsy going to be higher with boost coming in a lot faster, but is it at an unsafe level? Turbo guys running stock bottom ends, run large amounts of torque on the lower rpm range and do ok, would it be the same thing for what im wanting to do? Is it a good idea on a stock bottom. I plan on buying a forged shortblock either this fall or next spring, in which i would not need this wastegate setup, id just max the D1 and call it a day, but for as right now, i need more umph down low. And i figured running a 3.4" from my 4.38" pulley and adding a wastegate/EBC would get me the results i would want. I will have to speak with my tuner (Mike Norris) and see what he recommends. Thanks for the input. very well explained.

I see this setup benefiting in 2 types of setups.

1.Someone like me on a stock shortblock and wants the power to come on more quickly.

2.Someone with making high hp for the track but wants to be able to tone it down a bit for street use.

I dont see how this would benefit someone with a built motor that is capable of maxing their blower and ok with the power level on the street. Make sense?
.