Dawes Devices Manual Boost Controller Review Part 2

Time to return to the Dawes Devices MKII Hybrid Boost Controller and see how it did with our test vehicle, a 2012 Subaru WRX STI

Online Graphing

graph and chart

As I mentioned in the past, we have used Dawes Devices products many times over the years, for everything from a Shelby Dodge, to an SRT-4 Neon, to a Subaru WRX.  Each time, the experience has been positive, with more area under the boost curve and quicker throttle response.  It is clear from our experience with the electronic factory boost control solenoids, that they need to open the wastegate early, in order to prevent overshooting the target boost level.  That makes them slower to achieve peak boost, the net result being a lazy boost curve and lost mid-range torque.  To give you some real-world numbers, we were going to review the Dawes Devices MK Hybrid on a Mitsubishi EVO.  However, it was taking too long to hook up with that guy and he was in the middle of re-calibrating his ECU to make use of the fatter boost curve.  So, we found another guy with a stock 2012 WRX STI, to use as a guinea pig (thanks Jerry, and you ARE a pig!).

Darren Dawes supplied us with a length of hose for the install, shown in the picture below.  If you need silicone hose, I’d suggest getting some from www.dawes-devices.com.  This stuff has a 4mm id, but stretches to much larger and the wall thickness will hold over 60 psi.  That should be good enough for most of you……

Dawes Devices Silicone Hose

Dawes Devices Silicone Hose

We were going to show an actual install video, but decided to focus on the results and the boost controller itself.  Reason being, there are about 3000 install videos for a manual boost controller in a WRX out there and this is a “BOOST CONTROLLER REVIEW” site, so we don’t want to go off on a tangent.  But, about those results:

In the graph at the top of the page, you can see the results of adding JUST the boost controller, to a WRX.  Note that we recorded boost for various RPMs, using the digital output of the boost gauge.  We then plotted this to make the curve, since we didn’t have access to the software needed to record to a graph (like on a dyno).  You can see that the boost comes in earlier AND hits a higher level at that same RPM.  We also bumped the maximum boost on the WRX STI up a couple psi, which is well within the capabilities of the factory ECU to fuel.  As you know, boost without fuel equals heat….and detonation.  However, the stock ECU programming on the WRX and WRX STI is mapped to provide a 20% + margin of safety.  Why would that be?  Well, with the crappy factory solenoid boost control, you often get boost spikes.  They have to put in enough fuel to protect against detonation when those spikes occur.  By improving the boost control and eliminating the spikes with the Dawes, we can safely exploit the margins for added power.

And the power is there…..everywhere.  I would compare it to driving your turbo car  on an 80 degree day (stock) to driving it on a sub-zero day (Dawes Device Installed).  The mid range pull is AMAZING and the added boost at the upper end is definitely adding horsepower.  We would guess a conservative 15-20hp, but it doesn’t really matter what the peak power is, as this is about mid-range pull.  From a rolling start, the boost appears instantly.  It’s like a switch (actually, a LOT like hitting the nitrous at low RPM….incidentally, not something we’d recommend).  I’d say this is the best performance modification for the money (Net cost $50 on Amazon) and the best thing is that you can do it on a stock vehicle, or one that is heavily modded.  It’s amazing how many cone filters and K&Ns we see out there that really add nothing to a turbocharged  engine.  Cold air induction can add something, but it costs more than double this mod and you are never really sure it is helping, unless you dyno it.  With the Dawes manual boost controller, it’s night and day.  There will be no doubt that it is working, dyno or no dyno!


OK, so back to the “boost controller review”.  We thought it would be interesting to disassemble this Manual Boost Controller, to look at what’s inside and what separates it from the DIY boost controllers out there.

Dawes Devices Hybrid in broken down to components.

Dawes Devices Hybrid in broken down to components.

The Dawes Hybrid is made up of a ball (ceramic), spring (rate is a secret), adjustable knob/tip, lock nut, and body.  The body is one piece of solid brass, to eliminate the possibility of leaking boost on the input end.  Darren suggests opening the controller and flushing it out with brake cleaner, about every 50,000 miles.

Assembled Dawes with lock nut loosened for adjustment

Assembled Dawes with lock nut loosened for adjustment

Here you can see it assembled, with the locking nut loosened for adjustment.  Once you get the peak boost you want, you lock it down to prevent any changing of the peak boost level.


Inside of the Dawes, you can see the polished ball seat.  This is why it costs more than the crap DIY boost controllers you see on Ebay.....

Inside of the Dawes, you can see the polished ball seat. This precise machining is why it costs more than the crap DIY boost controllers you see on Ebay…..but not MUCH more.

The MKII Hybrid Manual Boost Controller has a polished seat, for better sealing.  Darren says that elimination of burrs is key to reliable operation.  Brass is chosen because it is soft enough for the ball to peen into a perfect seal, yet tough enough to handle turbo heat.  Brass also has a natural lubricity that prevents the components from seizing and you can’t scratch the finish off of it (like anodized aluminum)

Here you can see the industrial ceramic ball in place.  Darren Dawes was the one who pioneered its use in a manual boost controller.

Here you can see the industrial ceramic ball in place. Darren Dawes was the one who pioneered its use in a manual boost controller.

Darren tested various industrial ceramics to find what held up the best.  He states that he has sourced the ball from a Canadian company with the best mix of mass, hardness, and longevity.  He also states that some of the bigger companies that copied the ceramic ball are using an inferior Chinese sourced compound that tends to flake off.  That means the ball will no longer seal and the boost controller loses performance.


Here you can see the breather hole.  Darren says this is the critical feature that lets this type of boost controller eliminate spikes.  The actual size and shape is "classified".....

Here you can see the breather hole. Darren says this is the critical feature that lets this type of boost controller eliminate spikes. The actual size and shape is “classified”…..

A breather hole allows boost trapped between the ball and the wastegate to vent out, slowly, when the ball goes back on the seat.  Without the right sized hole, you will shoot up to the boost level you want and then the boost will slowly roll off.  This is because pressure gets trapped in the line and the wastgate stays open.  Darren says it will “work” without the hole, IF you have a leaky homade boost controller.  But, performance is inconsistent.  This feature is one of the things that is missing from cheap Ebay controllers.

Note that you can buy the Dawes Devices MKII Hybrid from our Amazon link:
Dawes Devices MKII Hybrid Boost Controller

It does not cost you any more to buy it there, but we receive a small part of the sale, to help keep our site running.  Or, you can buy it straight from Darren at www.dawes-devices.com or www.3barracing.com

Cocked, Locked (for 20 psi) and Ready to Rock!  The best $50 you have ever spent!

Cocked, Locked (for 20 psi) and Ready to Rock! The best $50 you have ever spent!

So if you are looking for a manual boost controller for your WRX, SRT-4, EVO, or even a turbodiesel, you can do worse (a LOT worse) than the Dawes Devices manual boost controller, the MKII Hybrid.  If you don’t like it, Darren will take it back  and refund your money.  How can you go wrong?!

Thanks for reading!


Special Thanks to Jerry, for letting us pound on his car and then refusing to post his crappy iPhone pictures ;-)



Review: NXS Manual Boost Controller for WRX

 The NXS, a Cheap Boost Controller…..

Cheap NXS Boost Controler

……if cheap is what you are looking for.


For some time, we’ve been seeing the NXS boost controllers popping up in our search for the best performing manual boost controller.  There seems to be an NXS for every application (but more on that, later).  It ain’t the prettiest thing out there and looks like it is assembled from plumbing parts (because it is).  Still, we’re all about performance and wanted to see if this is worth your money.  As one of the cost leading DIY boost controllers, we wanted to know if it was equal to, or better than, the Dawes Device.  We’ll talk about performance, but first I’m going to say that we found one reason why you should never buy an NXS.  If you want to skip to that part, go right to the end of the article.  Otherwise, read on.



NXS made of pipe fittings

“Cheap”, Definition: 1) costing very little; of low price 2) of small value; shoddy. So which “Cheap” do we have here?


The NXS Boost Controller is a ball and spring type design and should have performance similar to other ball and spring controllers.  It should…….but here is what we found.  First, adjusting the boost is a bitch.  A slight turn of the adjustment screw results in a BIG change in boost pressure on our WRX.  The adjustment is very sensitive.  Like, giver er’ a couple cranks and you might blow your engine, sensitive.  But, in the end we were able to get it adjusted to within .5 psi of what we wanted.  In this respect, the NXS does control boost.  However, we noticed that the boost would rise quickly, to about 8 psi and then it would climb slower to the target 16psi, then overshoot by a couple psi, before coming back down.  At first, we thought we had knocked a hose loose or something.  So, we re-installed the Dawes Devices Hybrid Boost Controller, that we were using previously.  The Dawes Device gave its characteristic fast boost climb, with no hesitation, stopping at a rock solid 17 psi (We had the Dawes set higher, because it is trusted.  But when we test a new boost controller, we always set it a little low until we are confident in it).  We put the NXS back in and it gave the same “meh” performance.  OK, let’s try to figure out why, by looking at the design.



As we noted previously, the NXS is made mostly of plumbing parts and a big screw.  The first thing we did after testing, was a complete tear down.  It’s possible some dirt or something got left in there and was interfering with the ball, or maybe there was an air leak.  Upon dis-assembly, we noticed something odd.  None of the pipe fittings had sealant on the threads.  That is not always a problem, but we thought that maybe a leak was causing the problems.  So, we wrapped pipe tape on and re-installed.  No difference.  We also noticed that the fittings have no chamfer for the ball to sit against.  It’s just a hose nipple/pipe fitting.



The next thing we noticed was that the breather hole was about 5x the size of the one in the Dawes Devices/3 Bar Racing manual boost controller.  Hmmm.  The hole is supposed to release any boost pressure that gets trapped between the closed ball valve and the wastegate.  Without this hole, the boost will rise but once the ball closes, the wastegate will stay open and boost will drop off.  However, if you make the hole too big, it just acts like a bleed.  A slow, lethargic, overboosting bleed.  So, we wrapped electrical tape around the valve and then poked a tiny hole through it with a big pin.   Boost rise was vastly improved  and overboost reduced.  So, problem solved.  Sort of.  There is still a big difference between the Dawes Hybrid and the NXS boost controller, with the NXS falling behind.  The NXS wins on price, but like we said, what kind of “cheap” are you looking for.  Our advice: get on grainger.com and throw some fittings together.  You can’t do any worse and you can seal up the fittings, drill a smaller hole (This one is like .080 on the NXS.  Try .034″) and use a better spring.  Oh yeah, the spring:



The spring appears to be a cut down version of a longer spring, that has the loose end bent over with a pair of pliers.  Also, it is different at each end, which could mean a problem if you put it in wrong, because one of the two ends is not going to seat properly on the ball.  The other end sits against the adjustment screw (literally a SCREW! ) and is free to migrate around on the surface.  To adjust the NXS, you will need an Allen wrench and a box wrench, should you ever tighten it more than finger tight.  Better keep em in your glovebox. Last, the spring is a very stiff unit (lol, stiff unit!) and short.  So, that explains why it is so hard to adjust (a little bit of compression equals a big change).  Well, that and the coarse adjustment screw.  Now the weird thing is that we bought the NXS on Amazon and we bought the unit specifically for a WRX.  But there is nothing that seems to make it specific to a WRX, or any Subaru.  So, we went to Ebay and ordered an NXS for “DODGE FORD DIESEL TURBO MAX”.  Looks like they are spamming the keywords there, but you would think that the diesel unit would have a stronger spring.  Nope, it is exactly the same as the WRX unit.  Which means, it looks like they are all universal fit units.  That’s why the spring is so heavy; so it can fit different applications.  Apparently the descriptions are just an internet marketing trick to target search keywords.  On the 3 Bar Racing Boost Controllers (aka Dawes Device) the automotive application and diesel applications use different springs.  Nothing wrong with universal fit products, but in this case it is useful to have two ranges of spring pressure, for the two ranges of turbo boost pressure.  This makes the Dawes unit a hell of a lot easier to adjust!


Let’s compare the NXS components to the Dawes:

Dawes Devices Hybrid in broken down to components.

Dawes Devices Hybrid in broken down to components.

Notice how the spring is the same at both ends of the Dawes Hybrid?  So, it doesn’t matter which way you install it.  Also, note the length, which gives a longer range of adjustment.  This light spring is for gasoline applications (generally under 25 psi), but Dawes-Devices.com also offers a heavy spring for high boost (i.e. diesel) applications.  The adjustment threads are very fine, which makes it easier to adjust.  Last, there is a captivating ring inside the adjustment knob, that keeps the spring in alignment.  All adjustments can be made and locked down, without an allen wrench or other tools.  Our verdict; you can buy something cheaper, but you can’t buy anything better than the Dawes Devices Hybrid Boost Controller.  But, if you have your mind set on the NXS manual boost controller, read this:

Why You Should Not Buy an NXS Boost Controller:

So in the course of doing this review, we noticed something interesting about the NXS instructions.  Namely, the majority of the information was copied from the Dawes Devices web pages.  We can prove this by using the Internet Archive (wayback machine) and looking at the original dawesdevices.com website (now dawes-devices.com).  Here is a link to a shot of the Dawes Devices website in Feb 2001:


Take a look at the FAQ and then look at the FAQ in the NXS instructions, below.  Better yet, have a look at the Dawes Devices Super Duty Boost Controller instructions from 2002.


Notice how the pictures and instructions linked on the Dawes site are strikingly similar to the NXS pictures.  Well, if you look again on the Internet Archive (https://archive.org/web/) for www.nxsmotorsports.com, you can see that the site didn’t even exist for another 8 years after Darren Dawes wrote the original instructions.  Conclusion: whoever runs NXS is a douchebag and we are sorry we ever gave him a dollar for his shitty NXS boost controller.  I guess if he has a problem with our review, we can always tell 3 Bar Racing Inc., so they can sue him out of existence.  We recommend you buy something else and not support NXS!



NXS Boost Controller Instructions (plagiarized from Dawes Devices and 3 Bar Racing Inc.)



Dawes Devices Manual Boost Controller Review Part 1

A Review of what our team sees at the Best Manual Boost Controller, the Dawes Devices MK II Hybrid.

Dawes Hybrid

Dawes Devices Mark II Hybrid Boost Controller

OK, we’ve done something a bit unusual with our reviews.  We are reviewing our favorite electronic boost controller (below) and the best manual boost controller, first.  That kinda takes some of the surprise out of it, but here’s why we are doing it that way:  We don’t want you to spend your hard-earned money on something, only to find out later that there is something better.  So, we are putting the biggest bang-for-the-buck items first.  Keep reading our reviews though!  You may find something that fits YOU better, in an upcoming review.  Alrighty, here we go:

In the interest of full disclosure, we are acquainted with Darren Dawes over at Dawes-Devices.com and www.3 Bar Racing.com.  We first read about his products in Sport Compact Car (this is linked to the article) and then one of our local club members bought his air/fuel meter and the old “MK I” boost controller.  Darren is one of those guys that has been doing this for 15+ years and stands behind his products.  The design has evolved over time, but still uses the same internal components, for consistent performance.  Since we’ve talked to Darren on a number of ocassions, we got him on Skype, to tell us his story.  To hear Darren tell it, the original g-valve boost controller was the invention of Gus Mahon, who at one time had the fastest mini-van in the country.  We asked Darren to tell the rest of the story, for this review:

“At the time, I was driving an 88 Dodge Daytona T1.  I used a “g-valve boost controller” which was a design that Gus Mahon came up with, using off the shelf parts.  Gus was a great source of information to the Turbo Dodge crowd and a very generous guy.  Unfortunately, he was killed a few years later, in a motorcyle accident.  Anyway, his initial design used a plastic barb pushed into the end of the g-valve and that was how I built mine.  Then, I suggested that we could improve it by threading the barb into the valve, in addition to the epoxy that we were already using.  Gus didn’t think it was necessary and looking at it 15 years later, I’d have to agree.  I’ll get back to this in a bit.”

“At the time, everyone was tuning Air/Fuel ratios using  Cyberdyne or Autometer gauges.  Really, you weren’t tuning, just making sure you had enough fuel to support the boost.  So you were running rich.  Anyway, I had trouble reading the meter on the fly and so, I had my 6 year old counting LED segments while I hit 15 psi in third gear.  Not the best approach (by the way, he survived and is currently in college.)  So, I made my own A/F meter, using the same chip, but different electronic components and display.  You can still see them if you go to the internet archive wayback machine and look up www.dawesdevices.com.  Unfortunately, a Japanese company caught me sleeping and stole the domain.  So now I am at www.dawes-devices.com and www.3barracing.com.  My meters were made with discrete LEDs that would let you tune by color, without looking directly at the display.  In fact, they caused retina burns if you did (laughing).  Those were some f’ing bright LEDs and I ended up adding a dimmer circuit.  The meters could also be tuned internally, to match specific applications.  Sold a lot to the DSM crowd.  So, I put one in the Daytona and showed some of the guys in the local Shelby Dodge Club.  More than a few people asked if I could build one for them.  I then thought, “hey, I can make a business out of this, to support my car habit”.  I figured that if I could get one of my A/F meters talked up on the Shelby Dodge Mailing List, then I could sell more, so I approached Gus.  I offered to make him one in his custom tune (he was running BIG boost), to try out.  He liked it and posted it on the mailing list, which launched the business.  Around this time, people started referring to them as Dawes Devices.  Oh yeah, you were wondering about boost controllers……”

“So, I went back to Gus and said, hey, do you mind if I sell your G-valves along side the A/F meters, since a lot of people don’t want to build their own.  He said, “go for it”.  Well, I couldn’t in good conscience sell something with a plastic barb that could melt, so I started fitting a brass barb and soldering it in place.  That made it kind of a bitch to drill the breather hole that is really the key to these g-valves working correctly.  Gus came back with an elbow that could be pressed into the end, eliminating the soldering, and showing his superior genius.  We stuck with that design for awhile and later added a special ceramic ball, replacing the stainless steel one.  I called this the Hybrid and developed it because my 1.8T Jetta’s boost would oscillate with the steel ball controller.  That seems to happen if you run a very big or in this case, undersized, turbo.  The Hybrid reacted faster and stabilized the boost.  By the way, we were first with the ceramic ball innovation.  I made the mistake of talking about it at SEMA and then everyone copied it (laughing).  That story would take up another 10 min, so let’s skip it.  OK.  After that, we started polishing the internal ball seat and have now developed our own boost controller from scratch.  I’m making air quotes over “scratch” because the internal dimensions are exactly the same as the g-valve.  But, we machined the input barb into the valve itself, reducing the weight and size and reducing the “fill” dimensions.  This is called, “the Mark II Hybrid Boost Controller”.  It is the fastest responding controller, due to a number of internal specs, that I don’t want to give away.  So, although its heritage can be traced to the original G-valve design, it is really a different beast and trumps the ol’ g-valve performance, in every way. ”

OK Darren, thanks for that rambling story ;-)  We are kidding, Darren!

Now that you have the history, we’ll close out by talking about ball/spring boost controllers in general.  The next post will address the Dawes Devices, specifically.

When you look at the different types of boost controllers available, the manual style fall into two general categories.  Bleed, or ball and spring, aka “check valve”.  A bleed is what the DIY boost controller builder usually starts with.  They are cheap and easy (see earlier posts) and do raise the boost.  Unfortunately, they are not very quick to respond.  That is because at the wastegate opening event, they are letting boost pressure out at the same time they are trying to open the wastegate.  This causes overboost, or a situation where the boost spikes above a set point, then settles back down.  Also, they allow pressure to cause wastegate creep BEFORE you actually want the wastegate to open.  In other words, it starts opening the wastegate early, which slows the boost rise time.  All of this is similar to the factory electronics, except that you can get a higher boost setting, overall.  Performance is, meh……

With a ball and spring boost controller, the pressure builds behind the valve until the threshold is reached and then it opens all at once.  This allows for a VERY fast boost rise time, as the wastegate does not even begin to move until the boost peak is reached.  In fact, half of what you think of as turbo lag is the result of the crappy factory ECU control.  After all, if horsepower sells cars, they only need to worry about peak numbers, not the boost/torque curve).  Of course, YOU know that it is torque that wins races!  The quick boost rise of the ball/spring manual boost controller gives you more area under the curve, even if the boost peak is the same.  In fact, you can use it WITH the factory controls, to improve response at lower boost levels, then let the factory ECU control the peak.  Drop Darren a note (d@3barracing.com) and he’ll talk you to death about it (kidding again!).

The Dawes Devices MK II Hybrid Boost Controller

The Dawes Devices MK II Hybrid Boost Controller

At the opposite end of the boost curve, the ball/spring controller snaps the wastegate open at the last moment, dumping boost immediately to reduce spiking.   Some designs work better than others and they definitely are not all the same.  The reason for this is that you have to keep the fill volume (amount of space between the boost controller input and the wastegate actuator) small, to reduce spiking.  You also need a breather hole, or once the space is filled, the boost becomes trapped and the boost drops way below the threshold.  The result is boost oscillation.  It is the ratio of this breather hole to the fill volume that Darren says is critical.  Considering that some of those Ebay/Amazon pipe-fitting boost controllers (link here) don’t even have a breather hole, there is a good point for buying a Dawes Devices (also, by the way, available on Amazon, here).  Darren also had something to say about the DIY models people are selling on Ebay and Amazon:  “Look, if you want, I’ll show people how to properly build a DIY g-valve boost controller for less than they can get those pieces of crap.  It costs less than those POS pipe fittings they sell on Ebay.  The problem with those is that there is no proper seating of the spring, or seat for the ball.  Also, there is a lot of space around the spring, which can let it move out of position.  Everyone thinks they are great, because when they work the performance is better than their bleed valve.  It is, provided the spring doesn’t jam and overboost you.  Then you are f’d.  I guess they are at least pretty f’ing heavy and some people associate that with quality.  But, the g-valve works better and of course, our Hybrid is the best.  Sorry if that sounds conceited. ”

Well, when you have the best, you need to talk about it.  So no, it doesn’t sound conceited to us!  Watch for Part 2 of this series, where we really dig into the Dawes Device.




The Best Book about Turbocharging, Ever Written!

So I’m not sure why I didn’t think to put this link up before, but the other day the guys and I were having a few post race beers and someone asked, “where did you guys learn so much about turbo charging, intercoolers, boost controllers, and such”? Three of us said, “Corky Bell” (apparently the other 4 guys were born knowing this stuff). Who is Corky Bell, you ask? Well, he is the guy who literally wrote The Best Book about Turbocharging, Maximum Boost (love that name!):

Best Book on Turbo Systems, Ever Written!  Buy it and you will learn EVERYTHING there is to know, about Turbos!

Best Book on Turbo Systems, Ever Written! Buy it and you will learn EVERYTHING there is to know, about Turbos!

The Amazon Link is HERE.  Buy it.  Buy it Now.  Become a Turbo Guru, Overnight!  Girls will throw themselves at you, guys will cower in fear of your ultimate turbo knowledge!

Before all the book stores started going belly-up, you could pick up this book in Barnes and Noble or Borders. Now, it is tougher to find, but you can still get it on Amazon, using the link above. It’s like $23 bucks and a quick read. But it should be considered Turbos 101 for ANYONE driving, building, or modifying a turbo system. The physics still apply, as do the formulas for turbo sizing, intercoolers, tubing bending, boost controllers, gauges, etc. Basically, everything you need to know about turbo systems or DIY turbo systems is IN THIS BOOK. In fact, go get it and read it before you look at anything else on this site. You’ll get more out of everything else, if you do. Oh, and it doesn’t come in an electronic format, but you wouldn’t want it that way. You want the paperback version so you can see the illustrations clearly. Besides, it’s a BIG paperback. OK, go buy; thank me later.


Sale Price for the Turbosmart e-Boost

We just got a tip that Amazon lowered their price on the Turbosmart e-boost to $282!

You can go right to the page, by clicking on the picture, or read our review of the e-boost, HERE.

We think that the Turbosmart e-boost is the best electronic boost controller, for the money!

e-Boost Street

e-Boost Street


Manual Boost Controller FAQ

So this is a starter Manual Boost Controller FAQ, based on questions received so far.  We will add to it as time goes on and republish occasionally.  Here’s what we have so far:

I’ve been told that I can’t use a manual boost controller with my vehicle. Is it true that they don’t work on computer controlled engines?  No and anyone that tells you this is full of BS. In almost every case, the modern turbo is controlled by the same vacuum actuator that was used in the 1960s. The only difference is a solenoid is employed to “bleed” off the boost pressure to the actuator, allowing a higher boost level. It is the solenoid that is controlled by the ECU, not the vacuum actuator. You CAN employ a manual boost controller in concert with, or as a replacement to, the factory electronic solenoid control. We’ve done so on vehicles from the 80s, 90s, 2000s, 2010s, and expect to in the 2020s.
Can I use a Manual Boost Controller with my performance “chip”? Yes, although the gains will probably be of a lower magnitude than those of unmodified cars. This is because many chip manufacturers have already raised the boost to the upper limit of what the factory fuel system can support. Additional gains can be found by using the Boost Controller if the chip manufacturer allows the boost signal to reach the wastegate before peak boost is achieved. This is usually the case, as the factory boost controller cannot respond fast enough to control “spiking”. The result will be more area under the boost curve and more torque.
Will I Void My Warranty? Um Yeah! However, one benefit of a Manual Boost Controller is that it is easily removed should a warranty issue arise. However, we do not endorse this action as it would be dishonest, LOL! Unfortunately, carelessly increasing the boost without monitoring air/fuel ratios or exhaust temperature may damage your engine. Most factory systems can take a 10-20% increase in boost without fuel problems. A good EGT gauge can help, to monitor your progress. Check the values at WOT at stock boost levels and then slowly increase the boost. When you notice a drop in O2 sensor voltage, or a rapid increase in EGT, you have reached the limits of your current fueling capabilities. You will need to add more fuel. There are too many ways to do this to cover here. This same risk is present with an electronic controller or a chip.
How high can I raise the boost?  Provided you have the fuel to accommodate the extra boost, as high as the boost controller will allow. That is usually in excess of anything the factory fuel system would support. Actual limits of the controller are dependent on variables, which include turbo size and wastegate actuator parameters. Keep in mind that some turbo systems will cut fuel delivery above a preset factory limit, usually 14.7psi.


Manual Boost Controller Install

This was written as a basic manual boost controller install guide.

A starter guide, if you will.  A more complete version with detailed illustrations, will be coming in our E-Book.  It will work with a Hallman boost controller, a Turbo XS boost controller, or our favorite, the Dawes Devices Hybrid G-Valve.  We’ll be showing you how to make a DIY Boost Controller (the right way) in the coming weeks.  Your Boost Controller likely came with its own instructions, but you can use this to see what you are in for, or as a supplement to the included instructions. It will work with a ball-spring type controller, or a bleed. You installation may vary, so email us if you have any questions!  Sign up for updates on the right and be notified of our every post.
1) Never increase boost without the available fuel supply to support it. Please read our upcoming FAQ for details on monitoring your progress.
2) A controller is usally shipped at a low boost adjustment, to protect your engine. Follow the instructions below to adjust it.
3) When adjusting your manual boost controller, you will find it necessary to uncoil the vacuum hose leading from the boost source to the controller. Do this by rotating the vacuum hose about the end of the controller. A drop of oil on every nipple that gets a hose, will help in rotating the hose, later. However, DO be sure to secure the lines with a ty-rap or hose clamp.

Getting Started: Installing a Boost Controller:

1) Locate the wastgate on your turbo system. Most will have an integral design like the one in the illustration. Attached to the wastegate will be a vacuum line or hose. Remove the hose from the wastegate and plug the hose. A large, short, sheet metal screw works well for this purpose and will not work loose. DO NOT DRIVE THE VEHICLE WITH THE WASTEGATE DISCONNECTED. If you have an adjustable wastegate, set it to the lowest boost setting. Most factory wastegates are NOT adjustable. You’d know if you had one.
boost controller install 1
2) Attach a length of vacuum hose from the output end of the boost controller to the wastegate nipple. This is the nipple that you just removed the vacuum hose from. Ty wrap it in place, so it can’t fall off. Also tie wrap any intermediate fittings that you had to add. There are adapters available at your local hardware store, to match the inside diameter of the hose to the wastegate nipple, although vacuum hose will stretch considerably. However, be careful not to split it.
3) Locate a boost source using the diagrams as a guideline. You can use the intake manifold, or turbo, if it has a nipple. The shorter the hose runs, the better the resistance to spiking. The best place to use is a nipple on the turbocharger output, if you have one. Now run a piece vacuum hose between the boost source and the straight end of the controller. A drop of oil on the boost controller nipple will aid in adjusting the hose later. Do not use the original wastegate line as your boost source. If there is already a line attached, install a vacuum tee (as close to the nipple as possible). Alternate sources include the intake manifold, or the pipe between the turbo and throttle. Do not tie wrap this hose yet. You will need to rotate the hose about the nipples later.

boost controller installation 2
4) Check all connections to ensure that they will stay on during testing. Now start the vehicle and drive moderately for a few minutes. Notice the boost level while you drive. If you have followed the instructions, you will now have a peak boost that is the same or LOWER than the stock boost setting. If this is true, then proceed to step 5. If boost is higher, check your connections before adjusting the controller. If boost remains higher that stock BREIFLY accelerate in a higher gear (to avoid wheel spin) and note the boost. If boost exceeds your target limit, let off the accelerator immediately and adjust the controller to a lower setting.
5) If you are at this step, then the boost is currently at a stock or lower threshold. Adjust your boost controller upward, to a higher level, according to the instructions that came with it. Accelerate again in a higher gear and note the new boost setting. Repeat until you have reached your target boost level. Note: it may take a few turns of the adjustment knob, before you begin to see a change. Be patient, do it a turn at a time to avoid overboost. It only takes a half hour or so to complete the adjustments. After a turn or two, you might find that the line from the boost source to the controller becomes twisted. Turn it about the boost controller tip while holding the controller still. This will relieve the twisting.
6) When your adjustment is completed, tie wrap all connections, and tighten any lock nut.
7) Use caution when driving your newly adjusted vehicle. Control problems may appear during rapid acceleration that were not there at the lower, stock boost level. Yee Hah! Torque Steer!

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