Megasquirt viability opinions, please

[aarang]

I am looking for a stand alone fuel computer for my 280ZXT, but am having a hard time justifying a $1500 price tag for most of the systems like SDS, Electromotive, etc. I was wondering if I built and used the Megasquirt computer to control the fuel side of the engine, could I use a recurved N/A dizzy with no vacuum advance that is controlled by an MSD 6BTM to retard the timing under boost? Does this sound like a viable system? The only thing I don't like is that I wouldn't have a knock sensor, but everything else would be there. The whole setup would cost around $500 including a coil and all the required sensors. I could spend the other $1000 on a new turbo. Is my logic sound, or does this sound like a bad idea? Should I just pony up the dough for an SDS? The more opinions I get the better!

[Forrest]

groups.yahoo.com/group/megasquirt

groups.yahoo.com/group/megasquirtnspark

[Mudge]

I also considered using an NA dis, or you can simply keep the stock computer/dis for the ignition.

[jkube]

I am currently building the Megasquirt FI board to ultimately do what you are doing. My zcar is currently N/A (Carbed) but the intent is to inject it first, then turbo it.

I have the Crane XR 3000 for ignition control. All it seems to provide is the optical sensor to replace the points and an ignition control box. The ignition advance still seems to be from the Dizzy.

I've been told that as long as the compression ratio is kept to about 8.5:1 and you use premium fuel (94 octane) (along with about a hundred other things to watch for like boost level and air intake temp) then all should be well.

It might be a good thing to add some form of manual boost control as well.

[z-ya]

Here are some pictures of our club race car project that will be Megasquirted. Got the MS assembled and tested, now come the installation. I put the motor in last night. It's a 10:1 CR L28, stock injectors and FPR.

 

[Bernardd]

but am having a hard time justifying a $1500 price tag for most of the systems like SDS, Electromotive, etc.

 

You could have a z31 ecu reprogrammed or do it yourself like I did. The entire cost of my fuel system along with 370cc injectors was 300 dollars. That include the eprom burner and eraser.

Bernard

[mobythevan]

or you can simply keep the stock computer/dis for the ignition

 

I don't think you can easily keep the stock ECU for ignition if you use megasquirt. One reason, is that I believe the stock ecu depends on seeing the TPS switch for idle/off idle. You use a potentiometer type TPS with Megasquirt, so you would have to hack something in here. I am not sure so don't take any of this as fact. From what I have read it seems like it would be harder to retain the stock ecu. I plan to use a NA dizzy to get the fuel part of MS working then switch to the squirt'nspark code to control fuel and ignition with the same MS.

 

It seems to me that the knock sensor is over-rated for turbo applications. Typical knock sensing only takes place in cruising range and not during boost. You have to by expensive equipment so the computer can learn the sound signature of your engine to be able to detect knock at higher rpms. I suppose it is better to have some detection than just your ear. What about people that use a microphone and amplifier to listen to the block while they dyno and test the engine. Just need to cram a little guy in the engine compartment to listen while you drive.