cardriverx

iTrader: (12)

Ok, with the GM boost control solenoid, voltage=closed, no voltage=open, correct? So what if we simply set the duty cycle to full boost in cold conditions, then when it gets warm out, we use a variable resistor to de-amplify the MS output, thus allowing for more boost. This means we could have an infinite amount of boost controller maps for any temp.

I know its a pulse width output, and a resistor wont actually change the duty cycle (right?), but I figured maybe changing the amplitude of the pulse will make the solenoid react slower/weaker, allowing for more boost?

Then again will this effect when you have the solenoid closed (100% duty)?

Or will it not work at all?

I would love to have some way to make the MS boost control better lol.

EDIT-----

Is there such thing as a variable low pass filter (make the circut maybe, a filter like this is made up of a resistor and capaciator in series right? What if the resistor was adjustable?)? I know amplifiers can vary the freq. it filters out... that would directly be able to change the pulse the boost solenoid sees... but I don't know how to implement something like that...

Im just throwing out ideas...

patsmx5

iTrader: (16)

It's more complicated than that. The best/simplest thing you could do, IMO, would be to have an extra solenoid that swtiches between to different MBC's (or EBC's) so that you can switch to a cold and hot setting. IE-set one MBC for 12 PSI when it's 80*F out and set the other MBC for 12 PSI at 40*F and use a solenoid to switch between them. Not ideal though.

cardriverx

iTrader: (12)

For that you could just use brains idea of a MBC and EBC... if my idea really more complicated than so be it, it would just be interesting to have a quickly, eaisly adjustable boost control with infinite adjustment.

richyvrlimited

iTrader: (1)

Just wait..... Keith is working on a PID control for Idle, once done he's going to copy it over to boost control problem solved.

OR you could get a superior way of applying Forced Induction, i.e. a Supercharger

spike

A real simple solution would be to just get rid of the GM solenoid and get a much better solenoid.

The GM solenoid does a shitty job at holding solid boost.

richyvrlimited

iTrader: (1)

A solenoid is only as good as what's controlling it. MegaSquirt's issue is the code is rubbish, not the solenoid...

patsmx5

iTrader: (16)

The DENSITY of the air going in the engine increases as ambient temps drop. More in, more out. More out without opening the wastegate more means a % of the "more" goes across the turbine, performing more work, hence more boost.

spike

I don't know about that,but I could be wrong.

Last summer,I went with a friend to have his Megasquirt tuned,I removed his GM solenoid,installed the Mac Valve,the tuner set the frequency for the new valve,made a dyno run and the new valve gave a smoother,more rock solid boost ramp,boost also came on earlier.His tuning map was not changed at all except for setting the frequency for the new solenoid.

Having quality parts do make a difference.

cardriverx

iTrader: (12)

thats not the problem im trying to fix... read my post and pats post please.