one of my winter projects, is to try to integrate a drive by wire throttle body before my standard throttle body.

the megasquirt has boost control targets related to engine rpm and throttle position. it outputs a pwm output based on initial settings, but will modify the pwm output if the boost is higher or lower than the target.

the throttle body, has a motor with a spring on it, and 2 pots (like a tps) which provide position information.

I am working on a small uP to convert the pwm to position.

I originally considered the blow off valve, or the possibility of controlling the sc bypass valve. Either way is fairly complicated, and I figured I would have a better chance of success with the controlability of a throttle body.

In my case, I have room for an additional throttle body, and have purchased a rather large one, since I don't want to restrict the intake in any way.

 

Do you have an M45 with an external bypass block?

If so, you could simply turn the screw which presents the stopping point for the flapper plate a few times.

This ways, you can prevent the bypass from closing completly and you'll get al lower boost.

No additional parts needed except a screwdriver

 

I don't think this will reduce the boost in a linear fashion. I think you will reduce your low rpm boost greatly, and your upper rpm boost by a smaller amount.

my car has a quite small diameter bypass, and when I wire it open, at high rpms, I still get about 5psi boost, while at low rpms where I normally get good numbers, practically nothing.

still will work though...

 

I'm planing to put EBC on my dual SC setup. I have bypass valves that will open (recirculating the compressor and killing boost) with either vacuum or boost. I plan to use a line from the charge pipes(they will always be under boost) and run that to the boost solenoid, then T off to each bypass valve. My question is would I need dual solenoids more than likely or would be just the same as if I only had one bypass to operate?

 

Shawn, I don't know if you know Joe C. or not but he is trying something on his SC vette that might intrest you.

http://www.tidewaterracing.com/forum...threadid=32465

He's a great guy and alway up for car conversations.