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……
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.
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.
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.
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)
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.
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
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 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
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 Book on Turbocharging, Maximum Boost (love that name!):
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.
We’re going to compare this boost controller to the Dawes Hybrid, to see which is the best manual boost controller, FOR THE MONEY. Meaning, even if the Dawes is better, is it $30 better?
I came across a pretty good article on the future of turbocharging, by Larry Carley. Lists a lot of the vehicles you can buy with a turbo, in North America and the challenges involved. Worth reading!
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!
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 (firstname.lastname@example.org) and he’ll talk you to death about it (kidding again!).
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.
This time we will review what we see as the best boost controller, at any price (hint: we’ve mentioned it before and you can even follow the link, lol). Whether you need a WRX boost controller to hit 20 psi, or just more area under the boost curve for your Neon SRT-4, we think this is the best you can do. Watch for our review in the next week!
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.
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.
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.
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.
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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We are writing ups some general guidelines to help with the installation of your boost controller. Watch here for more information. The Boost controller installation guide should save you a lot of time and aggravation.
Here are a couple of quick tips and things to consider, when buying a boost controller, that we’ve learned from experience.
First, decide on whether you want a Manual Boost Controller, or an Electronic Boost Controller. Each has its own advantage, which you can read about in our earlier posts.
Second, decide on the variation of your boost controller. If you decide on a manual, you must pick from either a bleed type, or a ball-spring type. If you decide on an electronic controller, you have a gauge pod type (round, mounts like a gauge), or a control panel type. If all of this is confusing, sign up for our email list. We are working on a detailed document, to help clarify all of these details.
Third, decide on a vendor. You might think, “hey, I can buy the product I want from 15 different places”. Not so fast! We have found everything from counterfeit products, to suppliers in the far east, that ship OEM products, but with no support. Buying the cheapest price now, will often cost you more later on. Especially if you have a problem with the install or the product itself.
What we have found works best is to buy your boost controller DIRECTLY from the manufacturer, if possible. With some of the big guys, you will often be redirected to their retail dealers. If that happens, try to find one that deals ONLY in turbo accessories. However, with the smaller guys, especially in the manual boost controller arena, you can usually go directly to the manufacturer. An example of this is the company 3 Bar Racing Inc. at www.3barracing.com, or their sister site, dawes-devices.com. These guys are a small player volume wise, but they make a world class product. If you have issues with the install, you can actually talk to the owner and the people who build the product. Beware of the sites that carry 10 different product lines, or sell unrelated items like hoses and wheels. You are unlikely to find an expert when you need them.
Hopefully, these tips will help to keep you out of trouble when buying your first boost controller. Watch for our upcoming manual boost controller review.