Idle air control actuator

[NemanjaGlisic]

Hello,

Does anyone use idle air control actuator (something like Bosch PWM solenoid or some stepper engine), for fine tune of idle. How much is necessary such a thing? Or can be manually tune by screw?

Thank you!

[Warpspeed]

A better way might be not to monkey around with the main throttle body and throttle linkage, and to fit a completely independent idle air bypass valve.

[Kirk Feldkamp]

If you do that, it can't be electronically controlled. The rules are fairly clear about this one. It could be considered (or made into) drive-by-wire, so it's forbidden.

IIRC, I don't think there's anything illegal about having a manual air bleed as long as it's mechanical and all air still passes through the restrictor. Essentially, that's what you're doing with a low throttle stop adjuster anyway, so it's kind of unnecessary.

-Kirk

[Cardriverx]

They won't allow an idle valve if it is electronic in any way. If they did, I would be using one as a throttle blipper...

[NemanjaGlisic]

Thank you all! I always wondered how I have never seen this part on throttle bodies, is quite cumbersome. ( http://www.spectromatic.net/im...ects/object_2088.jpg (http://www.spectromatic.net/images/objects/object_2088.jpg) ) . Now I know that is prohibited.

[murpia]

Originally posted by Cardriverx:
They won't allow an idle valve if it is electronic in any way. If they did, I would be using one as a throttle blipper...
This is something I was curious about. Does FSAE allow a throttle blipper for downshifts, of any technology?

Regards, Ian

[Kirk Feldkamp]

Yes, they're allowed, as long as the device is not electronically controlled. The simplest, most effective downshift blipper I have ever seen/used was a cable-actuated mechanical blipper that simply routed a light, bicycle pull cable from the shifter lever to the backside of the throttle *pedal*. On downshifts, it pulls the throttle open just slightly to blip, and on upshifts it does nothing (you can't push a string!). It takes a little bit of tuning to get it set up right for the right amount of blip, but it's a dream to drive once you dial it in.

-Kirk

[Warpspeed]

Some of these idle bypass air valves are thermostatically controlled, as well as having an electrical pwm control input.

If you want fast idle during engine warm up, and you have a water cooled engine, it's a very good way to do it, and still be within the rules.

[NemanjaGlisic]

So Warpspeed, you recommend me pwm control and say that it is not prohibited?

[NemanjaGlisic]

Our DTA ECU requires Bosch PWM, so we use same as one on the picture. http://i31.photobucket.com/alb...fan/IdleAirValve.gif (http://i31.photobucket.com/albums/c372/preludefan/IdleAirValve.gif)

[murpia]

Originally posted by murpia:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Cardriverx:
They won't allow an idle valve if it is electronic in any way. If they did, I would be using one as a throttle blipper...
This is something I was curious about. Does FSAE allow a throttle blipper for downshifts, of any technology? </div></BLOCKQUOTE>

Originally posted by Kirk Feldkamp:
Yes, they're allowed, as long as the device is not electronically controlled.
Thanks. It was the controlled kind I was referring to, usually a pneumatic actuator if fitted to an aftermarket shift system for a non-drive-by-wire engine.

I assume this is classified as a form of drive-by-wire even if it's open loop and of limited authority?

Thanks, Ian

[Warpspeed]

Originally posted by NemanjaGlisic:
So Warpspeed, you recommend me pwm control and say that it is not prohibited?

I am not recommending anything, only opening up a few ideas about what may be possible for idle speed control.

Electronic control of ignition timing (mapping) is allowed, and electronic control of injector timing is allowed, and I don't see why closed loop electronic control of engine IDLE SPEED through a VERY SMALL air bleed should not also be allowed.

Unless you plan to drive all the dynamic events with the engine idling, it cannot be called in any sense drive by wire.

What is clearly not allowed is FULL THROTTLE CONTROL by other than a direct mechanical linkage.

The intent of the drive by wire rule is very clear, but you would need to gain some clarity about the exact details of how the rule is to be applied from the rules committee.

[Kirk Feldkamp]

Good luck with that argument! Haha. There are a lot of things that should be allowed in FSAE (especially with regard to the engine restrictor), but the rules committee is very afraid of change in this area. If it involves electronics and the ability to throttle the airflow of the engine at all, then you're most likely going to get an emphatic "NO!". I fully recognize and agree that you can make a completely unsafe, purely mechanical system too, but they're afraid of having electronics in the loop with the throttle due to safety concerns. IIRC, there was a period a few years ago where drive by wire systems were allowed with approval, but they changed that very quickly.

-Kirk

[Warpspeed]

A mechanical throttle linkage is pretty simple to judge as safe or unsafe just by looking.

An electronic mystery box with many possible hidden failure modes should very rightly treated with the greatest suspicion.
Especially when it becomes a safety critical component when used for direct throttle, brake or steering control.
No argument with that philosophy at all!

[Kirk Feldkamp]

I think you may be missing the detail of what I was saying. Yes, automatic idle air control is a very small air bleed, but it's probably more than they're going to be willing to accept. If you want fast idle, it's pretty easy to make your own separate mechanism to pop open the throttle a little bit. Based on previous experience with the rules committee, arguing with them as to the "amount" of electronic control is probably not the best use of your team resources. Sucks, but that's life. http://fsae.com/groupee_common/emoticons/icon_rolleyes.gif

-Kirk

[jrickert]

The rules should really be changed to allow electronic idle control and anti stall systems. I understand the safety concern with allowing full on TBW build by students who have limited time money and experience. As a check, teams could be required to be able to command the device full open and demonstrate the the engine does not exceed XXX rpm or percent of full RPM.

As i understant things
Idle screw - Allowed
Dashpot - Allowed
Mechanical auto idle adjustment - Allowed

Any electrical version of the above - Not allowed.

Time and again I see teams who have idles set at like 3000 rpm to avoid starting idling and stalling problems across the coolant temperature range.

[Cardriverx]

I have already asked, it is not allowed by the rules committee. They are very afraid to allow any electronic throttling, idle valve or not. Just look at the DBW rule that was suggested, it never made it through.

Ask the judges if you don't believe me.




Originally posted by Warpspeed:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by NemanjaGlisic:
So Warpspeed, you recommend me pwm control and say that it is not prohibited?

I am not recommending anything, only opening up a few ideas about what may be possible for idle speed control.

Electronic control of ignition timing (mapping) is allowed, and electronic control of injector timing is allowed, and I don't see why closed loop electronic control of engine IDLE SPEED through a VERY SMALL air bleed should not also be allowed.

Unless you plan to drive all the dynamic events with the engine idling, it cannot be called in any sense drive by wire.

What is clearly not allowed is FULL THROTTLE CONTROL by other than a direct mechanical linkage.

The intent of the drive by wire rule is very clear, but you would need to gain some clarity about the exact details of how the rule is to be applied from the rules committee. </div></BLOCKQUOTE>