toddk911

So what style is the best?

I know most use and/or have used LBE, or Reliabost, Accuboost, which are all spring/ball type with bleeder hole.

Although, IIRC, John and ST mentioned that the air compressor(home depot) style are much better then the ball/spring type??

I have been trying some air compressor in comparison to my Reliaboost and the relief style seems ok, but when full boost is reached, it "relieves" too much and then dips a 1-2 psi. (I have Tial and Bigger turbo so it has to be the controller)

How is the Accuboost different?

Is an air compressor regulator much different in design then air compressor relief valve???

I know some have used both of those in conjuction and got good results as well; i.e. the relief valve first to help spool up then the actual controler as being the regulator.

Anyone???

Oddjob

From a function standpoint, a pressure relief valve and a pressure regulator work differently and for different applications.

A relief valve holds pressure until the setpoint is reached, then the pressure is released through the valve. A regulator limits pressure through the valve to the set maximum.

So with a relief valve set at 10psi (for example), the waste gate diaphram would see no pressure at all until the intake pressure reaches 10 psi, then the valve would open sending pressure to the WG,which would then push the waste gate wide open. This would slow the turbo, dropping the intake pressure which would close the relief valve, closing the waste gate - so the boost should make small spikes and dips as the relief valve opens and closes, causing the WG to open and close. My guess is that the system response is quick enough that you would not see the flutter on the boost gage, or feel it in the power band.

With a regulator set to 10 psi, it would allow all intake pressure to go to the waste gate up to 10 psi, and would limit any intake pressure above that. Now keep in mind that a stock waste gate starts to open around 2.5 psi and is fully open around 8-9 psi. So I am curious how/if a pressure regulator is supposed to work on a single port waste gate (Lindsey states that they do, Boost Sciences state that they do not).

Are you using a single port or dual port WG?

I am curious to see what kind of response you get to your questions, since I am also wondering about the best manual control setups.

Chas

the Lindsey MBC I guess would be considered a bleeder type, correct? As in, it's like a controllable "leak" in the line, alowing a control over the wg?

David Floyd

I have used all 4 with a Tial, Accuboost was the last used of that type, switched to the "Home Depot" black **** style in dual port mode and spool up dropped 200 rpm.

hally

i've got my tial hooked up this way, reliaboost set to ~12psi and the MBC (bleed) adjusted for desired max boost. No air gets past the reliaboost until u are close to needing to regulate boost.

---> reliaboost -------------------> port A
XXXXXXXXXXXXX |
XXXXXXXXXXXXX ---- MBC ---> port B

Waterguy

Boost Sciences, the manufacturer of the Accuboost ball-and-spring type controller, has this to say:

and
http://www.boostsciences.com/mbc.html

I figure that these guys should know what they are talking about, since they make both types and have no axe to grind.

jasoncoker

Hello,

I emailed back and forth with BoostSciences a while back when I had the same questions. I was told that my Accuboost would give quicker spoolup, be more stable, and have less temperature-related boost changes. I was told that if I wanted to use my Tial in DP mode, then I should use a bleeder-type controller. I then asked how that would compare to the Accuboost in single port mode and was told again that I would get slower reponse and more variation. I have not tried a Black **** on my car, so I cannot speak to that. I would be interested to find out.

Sincerely,
j

sweanders

I have a Reliaboost, an Accuboost, a Home Depot black ****.. I could try and do some testing once spring is here and my car is back together.

toddk911

Well, I am glad I asked as it seems I am not the only one that has been told varying info about MBC's.

I had a GURU WG and used Reliaboost and alwasy worked fine and held rock solid, although I am not sure how spool up was affected one way or the other. I also tried the relief/regulator combo with that set up and did not see much difference. I was looking for quicker spool up, as many MBC can hold a constant boost without problems.

I also tried that "Audi boost controler" that was a thread here a while back that used a relief, then regulator and had a check valve T'd in to help as well. Some in here posted seeing noticable results. I really did not see any.

I know have a new Tial in single port, as I was told no need to run dual port unless yo uare running an EBC...I guess this is not true??

How do you run in dual port mode with MBC???

"I have used all 4 with a Tial, Accuboost was the last used of that type, switched to the "Home Depot" black **** style in dual port mode and spool up dropped 200 rpm."

Any details on this piece or directions on what parts are needed to build it?

toddk911

Ok, I just checked out Boost sciences "black ****" model and this is the same style that I used, and just tried again, although one is a relief valve and one is a regulator. but both are the "****" style that you can turn and push to lock.

Maybe in dual port mode I would see a difference??

It seems silly to have a Dual port Wg and not use it as such. So if others are using MBC's with dual port, then I guess I will try it.

My main concern is quicker spool up.

jimbo1111

With a dual port WG. Boost is maintain by 2 forces canceling each other out. Side port pressure and the top port pressure. The spring rate as the variable. For every psi that the side port sees. The top port has to equal it. Once the top port has a diff of 12 psi less than the side port the WG opens. An example would be a .8 bar spring = 12 psi roughly. The 2 forces from the top and side ports cancel each other out. If both top port and side port are equal your WG will stay shut. As soon as air is restricted by the pressure reg. valve. The opposing side port starts to overcome the spring pressure. 12 psi less on the top port will start to open the WG. A bleed type valve works best with a dual port because it controls the WG with more precision and makes the WG action smoother.

toddk911

"A bleed type valve works best with a dual port because it controls the WG with more precision and makes the WG action smoother."

So relief or ball/spring?

toddk911

So is the "black ****" from boostsciences a relief style or regulator?

Also, this is the same "black ****" unit that is available from Home Depot?

toddk911

Got this from boostcontroller.com:

So, getting back to the question of how a MBC opens the Wastegate when the desired boost level is obtained… When using the MBC, the user (that's you!) sets the MBC's adjustor to the desired setting. Then, when the car is accelerated, the boost pressure rises, and air pressure builds in the charged portion of the intake system. Because one of the MBC hoses is attached to this charged portion of the intake system, the rising boost pressure is also delivered to the MBC.

What the MBC does with the pressure that is delivered to it, and how it goes about causing the Wastegate to open, depends on what type of MBC is being used. There are two basic types of MBCs: ball-and-spring types, and bleeder types.

With ball-and-spring types, a spring-loaded ball is used to block this delivered boost "signal", until the desired boost level is attained. It is at this point, that the delivered boost pressure is strong enough to push the spring-loaded ball toward the spring and out of it's seat, allowing the signal to pass, and reach the Wastegate Actuator. The boost pressure then presses against the Wastegate Actuator's diaphragm, causing its arm to move, so that the Wastegate is opened. The opened Wastegate then allows the exhaust gases to divert away from the spinning turbine, thus preventing the turbo from boosting higher than the desired level.

The MBC is adjusted by turning a **** (or other adjustor), which varies the load on the spring inside the MBC. By adjusting it so there is more load on the spring, you are 'raising the boost" because more boost pressure is required to move the ball off its seat before the signal can pass to the Wastegate Actuator. By contrast, lessening the load on the spring allows the boost signal to more easily unseat the ball and continue on its voyage to the Wastegate Actuator, so by backing the adjustor away from the spring, you are "lowering the boost". The Joe P MBC, and all Hallman Manual Boost Controllers, are ball-and-spring type MBCs.

With bleeder types, a valve simply "bleeds" off some of the boost pressure that it receives. It always allows some boost pressure to reach the Wastegate Actuator, but the boost pressure that the Wastegate Actuator receives is always less than the level of boost pressure in the charged portion of the intake system (or the boost level delivered to the bleeder-type valve) because this kind of MBC basically is a controllable boost leak. Since the Wastegate Actuator does not receive the "full boost signal", it only opens the Wastegate when the amount of boost that gets past the "leak" is sufficient to force it open. The bleeder-type MBC is adjusted by changing the size of the leak. Closing the leak down lowers boost level, because more of the boost signal then reaches the Wastegate Actuator, opening the Wastegate sooner. Opening the leak wider raises the boost level, as more boost is released to the atmosphere, as opposed to being delivered to the Wastegate Actuator as a boost signal; so the opening of the Wastegate is delayed.

The ball-and-spring type MBC is clearly superior over the bleeder type MBC. The ball-and-spring type does not leak any boost (at least prior to reaching the desired boost level), and then sends an immediate signal to the Wastegate Actuator to open the Wastegate upon reaching the set level. The bleeder type, by design, is actually a boost leak. Typically, for maximum performance, it is best if the charged portion of the intake system has no leaks while it is in a charged state (AKA "under boost") but the bleeder type valve is allowing boost pressure to be released before attaining the desired boost. So, like your Mom or Dad yelling, "We're not paying to heat the outdoors" when you left the door open as a kid, you are in a sense now "paying to boost the outdoors" with a bleeder type MBC. Boost leaks are counter-productive and you pay the price of using a bleeder type MBC by blowing out energy from your closed, charged-air system that would have been better used to cram more air into the intake manifold. Also, Wastegate operation is less efficient with a bleeder type MBC, as some boost pressure is always allowed to reach the Wastegate Actuator. This results in the Wastegate being partially opened at times before the desired boost level, and results in the Wastegate opening more slowly when the desired boost level is obtained.

You may notice that many ball-and-spring type MBCs have, by design, a small hole… either in the case, or in one of its "barbs" or "nipples". In the picture below, the red arrow is pointing to such a hole. This does not indicate that it is actually a bleeder type MBC. Near the start of the last paragraph, it was stated that ball-and-spring type MBCs do not leak boost, "at least prior to reaching the desired boost level". Such a hole is typically on the "Wastegate side", so when boost is building on the charged-air side of the MBC, no pressure can go out that hole until after the desired boost level is achieved and the spring-loaded ball is pushed out of its seat. Then the boost signal rushes past the ball on its way to the Wastegate Actuator. The reason for that hole is to allow the "column" of charged air, or "boost signal", to drain or "bleed" out of the hose that sent the signal to the Wastegate Actuator. Without that hole, the charged air in the hose to the Wastegate Actuator would tend to "get trapped" and would slow the proper closing of the Wastegate. Technically, it is an inefficiency to allow some boost to escape, but it is a very small inefficiency that has a good trade-off. The inefficiency is relatively small so it really is not even worth mentioning… but that hole is a source of curiosity to many, so an explanation was warranted. Some ball-and-spring type controllers may not have such a hole and in those cases, the manufacturer may advise a small diameter "T" fitting or some other means of providing release hole.

toddk911

Is the Home Depot one? Even has guage built in.

http://www.homedepot.com/prel80/HDUS...gmn.0&MID=9876


HUSKY
3/8 In. Regulator with Gauge

Model HDA70700AV

Price: $29.96/ea

Quantity:



This item cannot be gift boxed
- Usually arrives in 5 - 7 business days
- Local store prices may vary from those displayed.

Description Specifications Warranty Description
Four way regulator with 1/4 In. fittings.

• Provides regulated output pressure of 0 to 150 PSI for proper tool operation.
• Self-relieving design vents downstream air flow for easier adjustment.
• Locking pressure **** prevents accidental pressure changes.
• Include 0 to 160 PSI pressure gauge.
• 120 SCFM flow capacity @ 90 PSI.
• 3/8" NPT (F) ports.

Store SKU # 858404
Internet # 169687
Catalog # 100071386
Specifications

Internet ID 169687
Brand HUSKY
Model # HDA70700AV
UPC CODE 045564606732
Weight 1.77 Lb.