Boost control options/opinions/discussion

[TouringBubble]

Continued from clutch thread ... lol.

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ECU controlled boost is great when a really wide powerband is needed. Auto-x and road course cars are a good example of this. You can bump the TQ down low w/ more boost while tuning in a purposeful taper up top for thermal management. This gives more options for up/down shift points. However, depending on the solenoid and setup, transient boost response may be affected.

It's also useful for drag cars as an active boost control method usually allows for less taper up top. Most manual boost controllers will only allow 90% to 95% of the available boost pressure at redline ... they will leak a little pressure to the WG. An electronic solenoid can easily shut the WG flow completely off, the it's the WG's job to hold closed.

[BlewByYouEvoVIII]

Nice to have a technical Guru with us ;) Thanks for the explenation. This is just my DD so I believe the MBC should do just fine. I dont plan to autox or track the car at all. I have my blue one for that.

So say in my case. Stock car + exhaust and maybe a MBC, will I actually lose power from loss of boost pressure up top or should it hold alright considering the fairly stock manner of the car? Also is it possible to emphasize on the EBC. Why would it shut the WG completely?

[TouringBubble]

Not sure what you mean by lose power ... personally, I dial down the boost at high RPM for thermal management as stated above. I run about 25 psi from 3500 to about 5000 and then slowly taper to about 21 at 7300 or so. This was the best curve I found for my car on pump fuel.

Now, a MBC will taper on it's own simply due to how they function. They generally rely on a ball seat with spring pressure. Think of how a spring works ... it will give no matter how little pressure is applied because there is only pressure on one side of the spring ... the mani side of the controller. So, even 2 psi of boost will ever so slightly open the MBC.

Any pressure that passes the MBC will aid the WG in opening to regulate boost. So, in most cases the WG actuator will always see boost pressure from a MBC. Given, some MBC's are better than others.

In the case of an electronic solenoid, it can actively be completely shut and send no pressure to the WG actuator. This allows the actuator to use its full spring tension to hold the flapper shut and therefore hold more boost.

Solenoids also (essentially) activate instantly to a given duty cycle in comparison the a MBC's constant and gradual change to regulate pressure. This allows the solenoid to allow for faster spool and response while eliminating spikes. Again, not all boost solenoids are created equal, but these principles hold true for most.

MBC's are also linear in their operation. If you want to reduce taper up top, you have to crank up the spring tension which means more boost down low. Using ECU controlled boost via a solenoid, you can custom tailor your boost curve and response.

So, as for losing power, it's relative to your driving style, vehicle and setup. If you have the ability to make the most of maximum boost, then you might give up some power if you use a MBC. For the normal daily driver there is little difference between the 2 setups.

[BlewByYouEvoVIII]

Explained exactly how I needed. When I said losing power I was merely comparing MBC to EBC. Even with a EBC it would be tuned to taper at redline, but I have heard that its better to run a EBC if done correctly. I will likely go with a Hallman Pro for the time being and may upgrade to a EVC VI down the road, not sure yet. I dont know if I want to spend the extra cash on my DD or not.

[TouringBubble]

If Sharif has done his research, he could probably set up your stock boost control system for ECU based control. You simply need to modify a restrictor pill just before the LICP in the stock boost control line, and then tune the ECU.

[blkonblk2red]

^ think i need to go ahead and get rid of the hallman rx pro? and go with the ecu controller boost? how much would it cost?

[bomjoon]

If Sharif has done his research, he could probably set up your stock boost control system for ECU based control. You simply need to modify a restrictor pill just before the LICP in the stock boost control line, and then tune the ECU.

if? you testing him? lol

j/k

im sure he knows about it.

[TouringBubble]

Nah, not calling out Sharif. I just know that the Evos are still kind of new to him and ECU boost requires some extra tables that aren't in the basic definitions for it to work well. Only someone who's actively followed the progress would know about these tables. I'm just not sure he knows about it yet.

I'm lucky to have been there when everyone first started tuning boost with the stock solenoid. I've been through 3 different ECU based boost control setups on my own car and have helped in testing several of the recent stock ECU tuning advancements.

Chintan, it's up to you. ECU controlled boost isn't for everyone since it's difficult for the end user to modify the boost curve on their own. I like to give my customers the freedom to tweak their tune if they want and most aren't comfortable with modifying the boost tables. I don't blame them ... it's complicated.

If you do want the absolute most out of the car then ECU controlled boost is for you. But, honestly, in your application I'd suggest cam gears before hopping to ECU controlled boost. If you want ECU controlled boost, the setup fee is $35 and it takes a while, much like injector scaling.

[blkonblk2red]

^ cool i'll look into the cam gears... :-P i can get the gears just don't want to pay 400 again to install them and get it "retimed" i'll see if niel can do them... but lets see if the tb seals fix the fake knock... you think by dialing the gears back a few... i might be able to get more power out of them.. (cams)

[TouringBubble]

Yes. If you roll back the gears it will shift the power to the right and increase peak power. You're graph was quite square so I think you could benefit from this.

[BlewByYouEvoVIII]

^ cool i'll look into the cam gears... :-P i can get the gears just don't want to pay 400 again to install them and get it "retimed" i'll see if niel can do them... but lets see if the tb seals fix the fake knock... you think by dialing the gears back a few... i might be able to get more power out of them.. (cams)

are you insinuating that it did not need to be put in time?

[TouringBubble]

Let's not start that guys ... please try to keep personal discussion to PMs. We can all agree that all cars need to be timed correctly.

[BlewByYouEvoVIII]

Agreed, back on topic. Matt what do you believe are some of the better EBC options out there? I dont care about messing with it myself. I just want to have it set and leave it.

[TouringBubble]

There are some great EBC options, but even the basic EBC is superior to most MBC setups in theory. This id due to how the solenoid works as explained above. Any EBC that allows for RPM based control and/or has a closed loop boost target (as opposed to a simply duty cycle/gain setup) will be superior to most other options.

A quick list would be something like this ... listed from least function to most.

MBC
MBC w/ cockpit control
ProfecB (or equivalent) EBC
ECU Boost Control
AVCR EBC

I list the AVCR as better than an ECU based setup not because it's technically a better solution, but because they are similar solutions and the AVCR is easier to use.

[BlewByYouEvoVIII]

where does the EVC VI fit into that?

[TouringBubble]

The EVC IV would be just below the AVCR, and the EVC EZ would be just below the Profec B. This is based on a quick look at the function of the unit though ... I've never used one.

[TouringBubble]

Actually, let me revise that classification ...

Tier 1: basic control.
MBC

Tier 2: remote control
MBC w/ cockpit control
HKs EVC EX
Other basic single setting EBCs

Tier 3: Fuzzy Logic
Greddy Profec B Spec-II
HKS EVC IV/VI
Other duty cycle/gain based EBCs

Tier 4: Full Closed Loop
ECU Boost Control
Apexi AVC-R
Blitz SBC i-D

[em1toevo]

What level of boost control is impractical for the street? Tier 4?

[TouringBubble]

Any of the listed boost control options could be used on a street car. The tier 4 options are a little more difficult to tune and are generally more expensive (ECU based being the exception), so the time and money sink in this category would be the main deterrent for most owners.

Most Evo owners don't need more than Tier 2. anything above that would just be fluff IMO. If you're looking for every single ounce of power out of your setup, tier 4 would be the way to go. Plus, the higher end solutions look pretty sweet blinking and such all over your dash.

[BlewByYouEvoVIII]

Is the EVC VI in the same category as the EVC IV? This is the one I am considering for my MR. Im assuming this is more than sufficient for a DD/ sporty driving if not overkill.

[TouringBubble]

Again, I haven't used it but it seems like it's a slightly improved version of the IV. More than what you need but a cool gadget either way. You're apparently a baller and can afford a $600 boost controller. More power to you!

[blkonblk2red]

are you insinuating that it did not need to be put in time?

no i was just stating i'm not sure how to do cam gears... thats why i would never mess with them... not sure if it counts as a timing job thats all... not sure if there is a way to do the gears without doing timing... and i'm glad that dylan (not sure if i missed spelled it sorry) did what he had to... because that was the best place to start.... thats what i thought it was from the beginning ... and i would have paid extra to put it back in time... because we took the belt off 3 times... so it was prob. off anyway :-D... this forum has so much hatred...but anyways matt back to what you where saying :-D


only reason i was thinking ecu boost ... is because when i switch over... its going to be hard to up the boost to 28 pounds or what not... and then back to 21 or what not.... but i can get a good ebc... and if it has a memory where i can just switch back and forth that would be cool...

i just upgraded a few parts now... and i think i need to upgrade a little bit more.. to get the car where i want it to be... its just its going to take some time for me to get the money thats all... i can't afford 600 dollar boost controllers :-P i do the home depot style 5 dollars and i'm set :-P just making a list on what else i need... cam gears and prob a ebc... and bigger turbo... then on to the suspension :-D but that'll prob be a year or two down the road..

[TouringBubble]

Your right. For switching between E85 and 93 ECU boost is great. I can set up the ROm to automatically switch boost levels at the same time as fuel and timing. I do that on a few cars, including mine. I only bump it about .5 psi though on Toluene.

[hope666]

Any of the listed boost control options could be used on a street car. The tier 4 options are a little more difficult to tune and are generally more expensive (ECU based being the exception), so the time and money sink in this category would be the main deterrent for most owners.

Most Evo owners don't need more than Tier 2. anything above that would just be fluff IMO. If you're looking for every single ounce of power out of your setup, tier 4 would be the way to go. Plus, the higher end solutions look pretty sweet blinking and such all over your dash.

Well I have AVC-R on my car (tier 4) and I don't think it is in any way too much. All two different boost setting, boost duty by gears with "gear judge" and also by RPM duty settings are in use on my car. Also very good device to monitor the boost etc. with ability to see peak boost values and graphs.
My personal opinion is that it is probably one of the best boost controllers out ther.
I think that tier 4 devices are great even for street use in right hands.
However they are kinda hard to setup.

[bomjoon]

i haz tier 1.5 :P

manual remote control from inside.

who needs boost controll?

hell who needs turbo?

i would hook up a giant straw straight to my engine and blow on it when i need boost.
instant 600000lbs of boost. YAY!

no spool time or nothing. i hit full boost at idle.

[hope666]

i haz tier 1.5 :P

manual remote control from inside.

who needs boost controll?

hell who needs turbo?

i would hook up a giant straw straight to my engine and blow on it when i need boost.
instant 600000lbs of boost. YAY!

no spool time or nothing. i hit full boost at idle.

I don't really need boost controller, I need vacuum controller.
That can operate safely at 45psi of vacuum. :)
And I need big turbo... like 100R so when it fully spool at 15000 RPM it will generate so much suction that it will just destroy things surrounding inlet area... EXTREME!!!
Imagine that: "...Our turbos are so big, that on full boost if you get too close to inlet it can just rip your hands off brother...!!"

:D:D:D

[TouringBubble]

Joey, I grouped the MBC w/ remote control in tier 2 since it is basically the same as the most basic EBC w/o fuzzy logic.

[bomjoon]

dude its raining here today and for some reason the car feels a lil slower...

after i put the IC ive been feeling the power but today it felt weak.
i know the colder weather helped the car in more HP but usually when it rains it feels pretty good. but not today.

oh and i hit 12.0 on the wideband at nights at WOT when its cold. but it dont knock.

[TouringBubble]

I'm starting to think that WBO2 gauges are more of a curse than a blessing for the average driver. Now, yours may be around 12:1, but I think it's probably only there for a brief moment and you're not always running at 12:1. We'll take a look when you're back in town. If you're worried about it, bump the boost down 1psi or so. Cold weather can cause higher boost levels.

Q told me he was in the low 10's all the time ... I rode with him and it was at 11.2 to 11.4 the majority of the time. There was a small area at peak torque in 5th and 6th that hit 10.7 or 10.8. This is much different than his reports.

[bomjoon]

im not always in 12's it was just when at nights when its cold outside.
on 5th i gunned it and it stayed 12.0 till i let off.

im not worried about it. as long as its somewhat safe.
if my engine blows ... well built engine yo~! lol

j/k :P