MalcolmV8

A few months ago I was playing with the boost controller option on the S300 but was unable to get consistent results so eventually disabled it and gave up on it. I'm getting ready to look at it again or possibly just get another 3rd party stand alone boost controller if it works right.

The issue is you don't set a boost level you adjust the duty cycle of the boost controller solenoid. So if you have a 10 lb spring in there and you want to run 12 lbs of boost you play around with the duty cycle in there and make some pulls and until you have it hitting 12 lbs. All good. However as the weather changes or even air temp/engine temp etc. you would need a different duty cycle but that's not how it works so suddenly the next day you're making 14 or so lbs in the morning on the cooler air and then by mid day heat could be down to 11 maybe 12 again.

Do all boost controllers work this way or are there some where you can set a target of say 12 or 14lbs and it'll adjust the duty cycle of the solenoid accordingly to achieve that boost level?

Or is there a way to make the S300 behave more consistently? I would have liked to use the boost by gear future down the road too.

sp00led

S300 has the ability to correct the duty cycle based on air temp.

0mtber

iTrader: (2)

Most boost controllers work off a fixed duty cycle percentage (AEM tru-boost, greddy etc).

Use the s300 & simply use gear based duty cycle and setup the air temperature compensation table.

justYncredible

iTrader: (1)

And that outside temp?

MalcolmV8

Humm ok looks like I will need to fine tune the air temp Vs duty cycle settings. I wonder why the S300 doesn't just look at actual boost and adjust the duty cycle accordingly. Would be so much easier and more consistent.

justYncredible

iTrader: (1)

That would make to much sense

Muckman

iTrader: (2)

The issue is the boost control is static. There is no feedback like O2 closed loop where the ECU can manipulate duty cycle to achieve the target boost. Some of the better standalone boost controllers like AEM, TurboSmart, Greddy have intelligence to control the duty cycle for you. I dont know why the ECU based EBC cant figure that out...

MalcolmV8

That's just it though, the S300 is in a feedback setup and knows exactly what my boost is. It even has a boost cut off feature so that if boost goes to high it just shuts off fuel and the car falls flat on it's face. I don't know why they didn't just make it regulate the duty cycle of the boost solenoid instead.

Glad to hear some of the other brands can do that.

TheShodan

iTrader: (14)

I've noticed this as well. Even the AEM "truboost", like the Hondata is strictly duty cycle based (even though the Hondata uses that duty cycle and can tabulate it based upon rpm and / or VSS(?) signal to check what gear the car is in). Its like the AEM acts as a manual boost controller but can be controlled from inside the cabin of the car.

The AVC-R, GReddy and turbosmarts have a solenoid that utilizes a "fuzzy logic" intelligence system to utilize a "gain" feature to get target boost. To help prevent spikes from cooler ambient temps, but even that isn't fool proof, and depending upon the day, may have to be slightly adjusted occassionally.

Muckman

iTrader: (2)

I thought the AEM TruBoost did that too. But I could be wrong. I dont understand why the ECU software isnt there yet to worked in a closed loop function like we are talking about. I dont care if it takes 75% or 80% duty cycle to make my target boost. Just make it happen!

This would also help combat boost taper as duty cycle could rise inversly to boost taper.

TheShodan

iTrader: (14)

Exactly. We used the TruBoost on a few higher HP Subaru STis, and it was strictly duty cycle. When we switched to an independent GReddy, it used its own solenoid, and signal to it.. Much easier to control from the cabin, too.

However, that still goes to say that any boost controller will need to have slight adjustments between warm and cooler ambient temperatures due to the cooler, denser air that the turbo is converting to pressurized airflow. So I wouldn't call it inconsistent.. more that cooler air must allow small changes.

Muckman

iTrader: (2)

Despite the short comings of ECU based boost control I still prefer it for the gear based boost function. I ramp up duty with rpm anyways. It’s just not as pretty.

TheShodan

iTrader: (14)

I can definitely respect that. In circuit racing, gear based boost control doesn't really help us, as there's no "launching" and throttle control is a must while being in a variety of gears

shanebadoo

Errrr.... Muckman, please correct me if I'm wrong, but Hondata and Neptune both have target based boost control. Both systems allow you to run:-

1.fixed duty cycle boost control
2. boost by gear by rpm
3. Gear target pwm boost control

Number 3 tries to target the boost by restricting duty cycle to your user input data you previously input. Maybe that is not enough but have you tried it?

TheShodan

iTrader: (14)

Again, these just look at duty cycle percentage only in its calculation for all 3 features. No physical stepper motors to fine tune responsiveness

Root of all Evil

Not sure why you say that? I have the s300 setup to ramp up boost and it works great! Previously i was using a multi stage manual setup with two switches in the cabin. I don't want to worry about manually flipping switches so bbg is a great way around it. My home track has a nice mix of high and low speed corners and 2 long straights so I use 12psi for 1-2, 16 for 3rd and 18psi for 4th and 5th. I always here people say that your right foot should be your boost controller but when going hard through a bumpy corner on 1000lbs springs with a quick spooling turbo can be difficult for me at least. This setup has me 1.4 seconds off the fwd track record which i will break if it kills me lol.

TheShodan

iTrader: (14)

Perhaps its experience and differing tracks. I use a remote switch at the steering wheel from my GReddy Boost controller. I've had much better success with two stages as well, but I suppose I'm just old. I've tried the BBG and it was just too much changing on differing tracks. Maybe I'll try my AVC-R with its rpm and gear based settings to try it again. But I will not change my management for such a feature.

MalcolmV8

Shodan what engine management do you run? You seem to have the best of everything so I'm surprised its not the S300 which appears to be top notch. Now I'm curious what's better.

TheShodan

iTrader: (14)

Its more better for me, as few people on this forum run it as you can't just go anywhere to tune it or understand it when it really is a great system. I'm running Apex'i Power FC standalone management on the Hondas, and Cobb Accessport on the Evolution. I work for what's best for my use, and not based on any consensus.

MalcolmV8

Update to this thread...

I was playing around with this last night and found that air temp compensation is only available in the S300 if you are doing boost by gear using duty cycle (one of three options it has).

I've been using fixed duty cycle and after reading the help it does not reference the temp compensation table in this mode. Last night for example it was 39F out and while I'd been running around 10 ~ 11 lbs in the high 50s to low 60s out last night I kept hitting the 14 lb boost cut every time I punched it.

So I played around with the settings some more and found the S300 actually does have a way to set a boost level by PSI and then let it figure out the duty cycle of the solenoid. This would keep consistent boost levels as temps outside change. Very cool. You have to use boost by gear & RPM and then you can set PSI. Once the weather changes some more I'll see if it stays at the same PSI as I anticipate it now will.

Steeve_Civic

Is it working fine?

Which solenoid are you using?

MalcolmV8

Hell no it isn't. Man WTF. Weather changes and my boost does again. Did some more digging and the dang thing was very misleading. What they do is have an option to do boost by gear where you can put in the PSI you want. I thought I had this licked only to realize it in turn references another second table which has PSI Vs Duty Cycle. So it's just a long winded way of still having to adjust a specific duty cycle per boost which of course is still affected by weather. Oh well.

I use this boost solenoid

http://www.phearable.net/shoppingcar...noid-p-95.html

Steeve_Civic

Bad news!

Thank you for the solenoid link :-)

hon2984

I had no idea about this, but definatly gonna check it out. Had problems with mine hitting boost cut, and turned the duty cycle down 5% and had no problems since. its amazing how much 30 degree change in temp makes!

boostedteg4dr

With your set up, when you increase the duty cycle does the boost increase or decrease?