bump, just think of all the noobs we could redirect to the faq for info on boost controllers if ppl can come up with some good info here
Anyone running them? I like the turbosmart dual stage mbc with the toggle switch in the cabin and it looks like a simple install. But how complicated are gear based mbc's?
This guy made his own gear based and from what it sounds like it, it's not too bad to make. Any input or experience?
I think it's too many moving parts for my liking..
I'd prefer to do a gear based DIY EBC instead. I bet you could do the electronics for <$100, a good solenoid for <$50, and then the wiring.
Honestly, most EBC's are grossly overpriced in my opinion.
Gear-based MBCs could be dead simple or really complicated... depends on the technique employed for determining the gear. It could be as simple as a microswitch on the gears you want to control all the way up to logging directly from the ECU to figure it out. I personally fall somewhere in the middle... I'd prefer to monitor the VSS and engine RPM myself to map to a gear table.
At any rate... as grossly overpriced as they may be, going with a pre-rolled solution is usually the best for 99% of people. Honestly, hardly anyone here is going to invest all the time to roll a gear-based boost control solution unless they have a reallllll important need for one.
science: it's for real.
The turbosmart dual stage mbc actually attracted me because I found it relatively simple-2 mbc's with an electronic switch to go between the 2. I'll probably end up doing the homebrew though for something to keep me busy after school lets out. I'd like to make a diy if this-I was originally planning on a gear based mbc, do you think most guys on here would prefer a diy for an ebc though? Perhaps I could do both if they didn't differ too much.
Yeah, I was thinking of using the vss since its already there, but I'd prefer to keep it simple as possible. I run unitronics for a reason, and when I want the fine tuning done I let someone who knows what they're doing dyno it. Clearly, I'm no electric guru, so can you dumb down how a microswitch works and how it would be utilized in this scenario?
A microswitch is placed in just the right spot so that when you're in first gear, the switch is engaged. Thus, when you're in 1st gear, the switch is on... and when you're in any other gear, the switch is off. If you wire the switch up to your multi-stage boost controller in the right way, you can have it trigger one stage of the controller (in this case, the low boost stage) and then when its off, have the other stage kick in giving you full boost.
This could be achieved pretty simply. If we operate on the idea that the "stage" with the lowest boost will always "win" (as in the lowest boost stage will always trigger the WG first) then we can use a manual boost controller to limit our maximum boost and use a simple solenoid valve to control the low stage, or even multiple stages.
Picture it as such:
The solenoid, "max boost" MBC and N75 valve all get the boost source from a tee. Their output is also merged with a tee and goes back to the wastegate.Code:N75 valve Boost Source ---> MBC (max boost) ---> wastegate solenoid (with another MBC inline)
The solenoid has a MBC inline with its output. This MBC is how you set your "low boost" stage. The microswitch, when you were in first, would trigger the solenoid "on" and let the boost pressure hit the MBC, which once it exceeded the low boost setting, would feed the full boost pressure to the WG and thus opening it and limiting boost.
In all cases, the "max boost" MBC will always feed pressure to the WG when hit. If you're under max boost, though, your boost level will then only be able to be limited by the MBC behind the solenoid... and only if the solenoid is energized (on).
You get the benefit of part throttle control via N75 and the benefits of the a hard cap on boost (overboost protection) along with your 1st-gear-limited boost control via the microswitch/solenoid.
science: it's for real.
Ok, I get it. Although, I don't think I would use the n75, I've been fine without it. But here's the question-what if I wanted the microswitch to be on thru 1st & 2nd gear? Or making things alot more complicated I imagine, what if I wanted more than one microswitch? We're talking multiple solenoids and lots of mbc's right?
i'm just using my n249 i deleted as my dual stage solenoid, works awesome... waste gate pressure (10psi) and an mbc (18psi)...
another frankenturbo guy (spartiati) is running his own microswitch setup, low boost 1st gear then full 2nd through 6th... he likes it, i'm debating doing the same only incorporating 2nd in there as well... but yea i feel like it will get a little messy running a few mbc's and solenoids, just gotta find a good place to store it all
how are you switching between your n249 and the mbc?
I would like to employ the microswitch as well, but id like to have the boost change after 2nd gear rather than 1st if that's possible-i dont know how i would keep the microswitch on during 1st and 2nd gear.
work... the selenoid is powered and grounded, and you just run a toggle switch into the cabin somewhere... from what I know with the micro switches I would just loop 2 of them on the same
circuit to the low boost side of the selenoid, then once you hit 3rd and higher it'll be off the micro switch and run high boost... I'm actually trying to do that pretty soon too... I'm gonna email this thread to my buddy running it, hopefully he'll haves couple pictures or a little better explanation
Yrah.. mk4boost has it right. You'd need a microswitch per gear for each gear that you wanted a specific amount of boost in. If you wanted X psi for both 1st and 2nd.. you could use one solenoid/one MBC for the low boost stage... but if you wanted different boost for 2nd gear.. you'd then need two solenoids and two MBCs to configure your 1st and 2nd gear boost stages.
science: it's for real.
Are you guys running micro switches in the shift area of the car and having the stick whack the microswitch when you shift?
I'm looking forward to some pictures.
yeah x2, where do the microswitches actually go-by the shifter makes the most sense to me, I can't imagine how you could get them to work on/around the shift tower on the tranny. So let's say I want 1st, 2nd, and 3-5 all at different boost levels. I would need 2 switches, 2 solenoids and 3 mbc's right?
Hall effect might be more reliable... but I think most people are going to have sub-optimal/hard-to-configure setups since they will have to bend and screw brackets in and adjust them perfectly. A DIY gear-based boost control that relies on the physical position of the shifter seems like a foolhardy endeavour to me.
science: it's for real.
Maybe a combination of the Vehicle Speed Sensor (speed of the axles) + crank position sensor (speed of the engine). Take those two variables and determine what gear you're in.
Do those two sensors output the same waveforms for all forms of the 1.8t?
If so, I would be happy to start an open source 1.8t gear based boost controller based on the Parallax Propeller.
Last edited by groggory; 04-18-2012 at 04:27 PM.