Electronic Boost Controller for 2.0T

[RockJGC]

Is it possible to install an electronic boost controller on the 2.0T? I see some of the B7 guys do it, but I haven't seen any B8 guys doing anything other than piggyback tunes or full software tunes like APR.

I've had older turbo cars that I just wanted to be able to dial in a few more pounds of boost every now and then...and an electronic boost controller worked great. Can it be done on these cars?

[BMWManiac]

Is it possible to install an electronic boost controller on the 2.0T? I see some of the B7 guys do it, but I haven't seen any B8 guys doing anything other than piggyback tunes or full software tunes like APR.

I've had older turbo cars that I just wanted to be able to dial in a few more pounds of boost every now and then...and an electronic boost controller worked great. Can it be done on these cars?

I don't think it is worth it. Is it possible, yes. Here are going to be your issues:

1) The 2.0T has an internal wastegate and while the rod I believe to be adjustable, you are going to have to play with it. The 2.0T tuning is designed to work within the limits of this wastegate and maximize boost throughout the rev range. Your aftermarket tunes account for this too. The problem with "dial in a few more pounds of boost every now and then" is that you aren't accounting for the additional forced air with the additional fuel....this is not how this works. Overboosting for more power is not just about turning up the wick....

2) Typically you run a boost controller with an aftermarket wastegate. My eboost2 on my 97 M3 has 4 x different boost levels, which is why I have a boost controller.

So, can you, yes....should you, there is absolutely zero reason to in a stock 2.0T configuration.

[RockJGC]

....The problem with "dial in a few more pounds of boost every now and then" is that you aren't accounting for the additional forced air with the additional fuel....this is not how this works. Overboosting for more power is not just about turning up the wick....

My older turbo cars would automatically compensate to keep the air/fuel ratio where it needed to be when the boost level was increased. In other words, if more air is forced into the engine because the boost level is increased, the fuel would also increase automatically. Are you saying that these engines don't do that too?

[BMWManiac]

My older turbo cars would automatically compensate to keep the air/fuel ratio where it needed to be when the boost level was increased. In other words, if more air is forced into the engine because the boost level is increased, the fuel would also increase automatically. Are you saying that these engines don't do that too?

We have a MAF based system and I don't know the limits of the stock ECU to compensate enough. Your engine will see X amount of air. It will compensate with Y amount of fuel. When you up the boost, you are forcing X+n amount of air. There will be a point, I don't know if it is 1 psi or 20 psi, before your engine is sending X+n amount of air and ONLY Y+n amount of fuel. If it isn't enough, you will run dangerously lean and, hopefully, just blow your headgasket. At worst, cause detonation and destroy your pistons, rods, block...

Bottom line, if you aren't a tuner, monitoring knock, monitoring air/fuel ratio, then your assumptions could lead to catastrophic failures.

[RockJGC]

We have a MAF based system and I don't know the limits of the stock ECU to compensate enough. Your engine will see X amount of air. It will compensate with Y amount of fuel. When you up the boost, you are forcing X+n amount of air. There will be a point, I don't know if it is 1 psi or 20 psi, before your engine is sending X+n amount of air and ONLY Y+n amount of fuel. If it isn't enough, you will run dangerously lean and, hopefully, just blow your headgasket. At worst, cause detonation and destroy your pistons, rods, block...

Bottom line, if you aren't a tuner, monitoring knock, monitoring air/fuel ratio, then your assumptions could lead to catastrophic failures.

Right, but that's exactly my point. Piggyback tunes basically up the boost level and allow the car's ECU to compensate for additional boost by adding more fuel. Some of the piggyback units allow for an additional 8 psi over stock boost levels, so we know these cars are capable of compensating at least up to that additional 8 psi. So why would it be a problem to just use an electronic boost controller to dial in that extra boost and allow the car to figure out the A/F ratios? That's how my older turbo cars worked, but I'm not entirely sure these cars would do the same. In theory, I think so, but I'm not really sure.

[BMWManiac]

Right, but that's exactly my point. Piggyback tunes basically up the boost level and allow the car's ECU to compensate for additional boost by adding more fuel. Some of the piggyback units allow for an additional 8 psi over stock boost levels, so we know these cars are capable of compensating at least up to that additional 8 psi. So why would it be a problem to just use an electronic boost controller to dial in that extra boost and allow the car to figure out the A/F ratios? That's how my older turbo cars worked, but I'm not entirely sure these cars would do the same. In theory, I think so, but I'm not really sure.

Here is the thing....the piggybacks are doing 5-8% additional boost, correct? The MAf signal is being manipulated to account for more air and for the ECU to add more fuel. You are asking the boost controller to now manipulate the wastegate pressure, without manipulating the MAF. What I think would happen, is that the MAF/ECU will now throw a code because the amount of air being anticipated will go beyond the thresholds, therefore MIL.

You could always try this and then everyone would stop buying piggybacks and tunes and just get the eboost2 :-)

[RockJGC]

Here is the thing....the piggybacks are doing 5-8% additional boost, correct? The MAf signal is being manipulated to account for more air and for the ECU to add more fuel. You are asking the boost controller to now manipulate the wastegate pressure, without manipulating the MAF. What I think would happen, is that the MAF/ECU will now throw a code because the amount of air being anticipated will go beyond the thresholds, therefore MIL.

You could always try this and then everyone would stop buying piggybacks and tunes and just get the eboost2 :-)

No, not 5-8% additional.....I'm talking 8 psi additional. I think that's what Neuspeed has and I know there are a bunch of guys using them on the forum. MAF just measures air. So if more boost produces more air, the MAF will see it and the fuel will be adjusted to keep the ratios where they should be (actually, isn't that the function of the O2 sensor for the most part?) But of course everything has limitations, so if the threshold is truly exceeded, something would definitely happen. In my older turbo cars, it would basically shut the boost down momentarily (due to an overboost conditions, not a really a good thing obviously), so it was important to make sure the boost controller stayed within the limitations of the fuel system.

On my old HKS EVC boost controller, I had push-button control of the boost level. I left one button set for stock boost level and had the other two buttons set up as "mid" and "high" boost. And then there was a circular dial that was flush with the face of the unit. If you push on the button, it popped out and allowed you to dial in whatever boost level you wanted. That's where you needed to be careful. I could always get a little more maximum boost in the cold winter air (good density) without hitting an overboost conditions compared to hot summer days. Having this control was awesome in a unit no bigger than a radar detector.

A true software tune is definitely a better option, but I can see a boost controller working at least as well as a piggyback tune because it should do just about the same exact thing.

[old guy]

A true software tune is definitely a better option, but I can see a boost controller working at least as well as a piggyback tune because it should do just about the same exact thing.

RaceChip is a piggyback that lets you select up to 7 different settings. Basically it just varies the resistance on the boost sensor and lets you pick the amount you want.

[RockJGC]

RaceChip is a piggyback that lets you select up to 7 different settings. Basically it just varies the resistance on the boost sensor and lets you pick the amount you want.

Yeah, that's pretty cool for a piggyback....but it still doesn't allow for on-the-fly boost level changes the way an electronic boost controller does. I read that they do have an app that works via Bluetooth, but it's so much easier if you have a button inside your car that can instantly alter your boost levels the way a boost controller can. Here's a picture of the HKS EVC I had in one of my older turbo cars. Total push button control of boost levels without any need to use Bluetooth phone apps.

hks-evc-1.jpg

[RockJGC]

I've been doing a bit more research to understand how boost in controlled on our 2.0T engine. I found a pretty good link about the N75 solenoid. The article is written for the 1.8T, but everything applies to our 2.0T as well. Good info here:

https://18t-tuning.co.uk/engine-advi...ing-n75-valve/

[old guy]

Basically an electronic boost controller;-)

[RockJGC]

Basically an electronic boost controller;-)

Well, yes and no. It definitely controls boost electronically, but not in the conventional sense or at least the way you'd think an aftermarket boost controller does. My old EVC was just an electronic version of a manual boost controller, meaning that it would all different amounts of bleed via a control switch mounted inside the car. The N75 solenoid seems to be doing a whole lot more in combination with the software.

I could see someone making a performance version of the N75 that basically does everything that the OEM one does, but at higher boost pressures across the board. I bet that wouldn't be too difficult to do.

[old guy]

Well, yes and no. It definitely controls boost electronically, but not in the conventional sense or at least the way you'd think an aftermarket boost controller does. My old EVC was just an electronic version of a manual boost controller, meaning that it would all different amounts of bleed via a control switch mounted inside the car. The N75 solenoid seems to be doing a whole lot more in combination with the software.

I could see someone making a performance version of the N75 that basically does everything that the OEM one does, but at higher boost pressures across the board. I bet that wouldn't be too difficult to do.

Which is essentially what a piggyback does. It raises the boost but keeps all the other ECU controls in play.

[RockJGC]

Which is essentially what a piggyback does. It raises the boost but keeps all the other ECU controls in play.

Right. So it seems that it wouldn't be too difficult to just modify an N75 valve to act similarly to a piggyback. Then again, I still love the idea of an electronic boost controller simply because of the push button capabilities to vary maximum boost pressure instantly. Having "low", "mid", and "high" boost buttons is awesome. I can't believe nobody offers that already on these cars, but I can see how it's a bit more complicated now because we're actually dealing with varying levels of boost depending upon several factors such as load, rpm, etc... Whereas my old HKS boost controller would allow the turbo to hit and hold whatever maximum boost pressure it was set to make, given the capabilities of the turbo itself. I used to run like 22 psi on my old first generation Eagle Talon (Mitsubishi Eclipse twin) with the stock turbo. When I hit that high button, the turbo would spool up to 22 psi and hold rock steady the entire time. It was awesome. Then I could hit the low button and it would dial back down to I think like 12 psi. Mid button I think was about 18 psi.