ALS discussion

[RickRST]

This is not directly related to MS2, but shows some of the things which are happeneing at this very moment on this old system.

Proper Antilag and launch control, which i would love to see in Ms2 extra. Launch control is not just a simple rev limiter, but retards the ignition and adds fuel to get some proper boost. 10psi on a huge t4 at 4000rpm!

thread ans videos here:
http://www.passionford.com/forum/viewtopic.php?t=270396

[muythaibxr]

It would probably be pretty easy to do... how much retard are you talking about? I think it already retards ignition, but I don't know about adding fuel.

As for ALS, I don't think it'd be that hard to do that either, but I need to see how others do it.

Ken

[Maglin]

For proper ALS you need to open the IAC to full and inject fuel and retard timing to a ridiculous amount. And this happens with the throttle closed. I'm not sure if an IAC can move enough air to do the job correctly but it could be a smaller system. I'm not to sure how you would want to control this. I/O's are getting used up. You would want a switched input to turn on ALS at will and not have it run all the time. The excessive heat caused by this will eventually kill the turbo's turbine wheel. You will want to play with retard amounts but it's best to just let the user put a static amount in for it. With a user defined range. Then have to code try to do 2 things with timing. One have it's neutral be the defined timing (which is probably going to be ATDC) and the second being to move the timing with-in the user defined window to try and maintain a user defined RPM setting for ALS. These can't be a set value that can be written in code as turbo size will greatly effect what needs to be run. It's usually not a very good idea to try and run ALS with the PCM. This is usually best left to a stand alone ALS system. This is something I can see people blowing their cars up with, or catching their garages/houses on fire with as they tend to shoot flames out the exhaust from the very rich mixture being ignited towards the end of the power cycle to use the energy generated by the combustion to power the turbo instead of powering the engine.

I don't think it is as easy to implement as you might think. So in a nutshell it has to do the following:
1. Control Timing very retarted to try and best maintain user defined RPM
2. Open an air valve to let more air pass around the T/B
3. Add a defined amount of fuel to richen up the mixture (I would think just a +ms amount to be the best solution for this)
4. User defined Timing amount
5. User defined RPM
6. User defined Timing threshold
7. And of course has to disable EGO control

Another side effect of this is fire hitting O2 Sensors. Not a good idea. They can't take that much heat for very long and live.

[RickRST]

Timing is fixed at around 20degrees ATDC. Extra fuel is injected, and the ISCV is opened as much as possible. This is "mild" ALS - to get more, you need an extra air bypass valve, but the one in the video uses the std item.

This level seems to be reliable on a std T series turbo, although my turbo is designed for full on ALS use. As for launch control, i dont think the timing needs altering at all, hold it at 20ATDC - the launch rpm can be controlled by a normal spark cut.

So for LC - press button, which hsets rev limit, retards ignition, injects more fuel...

ALS - press button, retard ignition, open idle valve, inject fuel.

A 10 second time limit should be put in so that it doesn't stay on for too long.

[muythaibxr]

Yeah, neither of these sounds very hard... although I'm surprised you can even keep an engine at a certain rpm at 20 ATDC.

I do think these are very dangerous to implement for the average tuner...

I'll have to discuss with James whether we really want to do these features or not.

Ken

[RickRST]

Well, yes they can be dangerous, but so are a lot of things if not done properly. It would be massively useful for a rally car i'm mapping as otherwise i'd need IAW.

I think when enabling it in Megatune it should come with a stark warning, but genuine users should not be robbed of a useful tool.

Rick.

[muythaibxr]

Well, yes they can be dangerous, but so are a lot of things if not done properly. It would be massively useful for a rally car i'm mapping as otherwise i'd need IAW.

I think when enabling it in Megatune it should come with a stark warning, but genuine users should not be robbed of a useful tool.

Rick.

I agree, but will still want to talk things over with James first rather than just committing to do it without discussion.

I'm not saying we won't do it, just that I want to talk it over first.

Ken

[Maglin]

Rick what works for your might not work for others. It's why I would suggest allowing it to be totally adjustable by the user.

For instance. I'm using a HX52 on my 2.0L 4G63. It flows roughly 120 lbs/min. If I wanted to use ALS on it I would need a lot of fuel and very dangerous retard to get it to even spool 10 PSI. Allowing it user definable will let others tune it for their needs. But again it's very dangerous. It needs warnings and even document changes for people to check it and ensure it's not enabled do to a bad flash or something similar.

If you needed more air and are using a PWM idle valve you could maybe install another one and readjust your idle valve settings. That would allow you to pretty much very closely mimic a fully stand alone ALS.

I'm all for it being implemented. It isn't something I would use. My setup is a drag car, but I have others that autoX and a few friends that are getting into RallyX and this would be something they would really want to have.

Would it be possible to run two PWM idle valves off the single Fidle output?

[muythaibxr]

2 idle valves off one output shouldn't be that difficult as long as the transistor being used can handle the amount of current needed to drive to valves.

[RickRST]

Maglin, that really is a big turbo, and ALS on such a thing would indeed require something very lairy.

The std idle valve will do about 1 bar absolute on idle and still be ok on non ALS turbo's. It doesn't sound a lot, but it massively increases the response in twisty sections of rally stages. Basically, the setup would be mimicking that used in WRC cars. Being able to adjust the values defo should be implemented. Lots of ECU's by Pectel, OMEX, etc support this.

It's not for everyone, but for those few it is very valuable.

[RickRST]

Have done a little more reseach into this.

Indeed the retard needs to vary depending on how much air/fuel is being injected. The range is around 90 degrees ATDC to 1 degree ATDC. Essentially, as more air/fuel is injected through a fully open (or additional) idle valve, more retard is needed to stop the rpm from rising, and the energy instead spools up the turbo.

It will require a lot of tuning, but myself and others would be very grateful if this could be implemented

Rick.

[UnaClocker]

If you want to make it safe, in a way that a bad flash can't accidentally enable it, how about making it a seperate option in the compile.. Put the code in a seperate .c file that's only included in the build when a specific flag is checked. It's kind of like a fork in the code, but not quite. The person that wants this feature would simply have to install the compiler, download the latest code, compile it himself with the -als or whatever option, then it would be possible to enable it in MT..
Is that do-able? Or am I dreaming?

[Maglin]

I like your idea for it Unaclocker. That way for the 95% of MS community that don't want it wouldn't have to worry about it getting enabled. I would also say to have it h/w enabled. So I'm thinking 2 inputs would be used. One for a on/off switch and then one for a clutch switch. Or you could just have a on/off switch and use a TPS switch point. Maybe the latter is more of a friendly idea. The MSII is lacking in i/o ports as is.

[jassem99]

Just thought I'd add my voice to this thread and say that it would be nice to include some form of mild antilag (using ISV for example) in the final version of the MS1 code before all development shifts over to the MS2 code.

Basil

[jsmcortina]

Isn't the existing launch control able to help spool a turbo? You can floor the throttle and set 9ATDC timing.

James

[Jon k]

Isn't the existing launch control able to help spool a turbo? You can floor the throttle and set 9ATDC timing.

James

Sure as hell helps me - I open my WG, 14 psi, in neutral with a holset truck turbo on a BMW 2.5L! I'd say it's working!

When i added methanol injection I saw the 14 psi, before methanol I only say like 7 or 8

[Jon k]

jsmcortina that is not the problem the Launch control is grate for hen u are going off the line, how ever when u are driving in a rally or on a track u cant use it like that.

With the turbos we use you loose all boost when you come into a corner as you have to life throttle, this is where you need the antilag so we can keep our turbos spooled up.

I believe the best way to do it is with a table on the bottom you have rpm and on the side you have TPS % you cant do it with boost, this is how GeMs, pectel and a few others do it.

I believe this is a featuer MS supports, called flat shift?

[rb26dett]

nah, he wants to be able to lift in gear and then floor it again and not have lag. he wants als. i've been having a serious think about als for the ute, and decided that i want to try full blown air injection als as this is not hard on the exhaust valves and cooling system and head. it also leaves the throttle closed so your brake booster works.

fred.