Mark30

Does anyone know if megasquirt can be used to control the computer controlled quadrajet? The 7 wire distributor shouldn't be a problem.

joe_padavano

The CCC Qjet would require only a single "injector" driver to operate the mixture control solenoid. I don't know if the current draw or impedance of the coil is close to what the MS unit can accept.

The bigger question is, why bother? All you can control on the CCC system is primary mixture and spark timing (along with the on/off functions like converter lockup, evap canister purge, EGR valve solenoid, etc). It would be much easier to just burn a different PROM for the stock ECU, or use an emulator for real-time control, but frankly, the amount of change you can affect in the primary mixture control is minuscule considering the trouble to swap to an MS computer.

Mark30

Thanks for the reply Joe. All I am wanting to do is to control primary mixture and timing but the lockup control would be nice as well. I would like to put this on an older non computer Olds 350. For the 02 I was planning on using a wideband for tuning anyway. I just figured that having an ecm to tune with would be nicer than tearing into the carb to adjust the apt and the electronic control of ignition sounds good too. Perhaps what I am looking to do isn't possible. I agree that the megasquirt, even the ms1 computer is overkill for what I want to do but the factory ecm seems like it would not be as user friendly to me as I don't have an egr or evap system.

joe_padavano

That's a whole lot of work for virtually no effect. The range of tuning is very limited. Frankly, you'd be better off with an earlier Qjet and an assortment of rods and jets. The amount of difference you can make simply by varying the mixture control solenoid frequency is very small. Keep in mind that the rods are sized for an emissions 307 and you really can't get different primary rods. This is a project that sounds a lot better in your head than in practice. You'd be light years ahead to swap the carb for an early TBI unit and use the MS to drive that.

Mark30

Thanks Joe. I was thinking I could get something similar to the old Holley dial a mile set up. But if I am not going to be able to get much adjustability from the carb, then all I will have is an expensive convoluted timing control device. I have looked at the tbi set up and it looks like the way to go. Looks like I will have to do some more research.

I really appreciate the input and help on the subject.

The Stickman

You could do what we are doing. We are using a MegaSquirt to control a 454 TBI which is a 2 inch bore and 670 cfm TBI. The injectors are 80 pounders. You can get adapter plates on ebay easy, just make sure you get the right one. The standard TBI's are smaller diameter than the 454's. You can get a TBI in tank fuel pump and pretty much be set.

olds 307 and 403

The factory early 454 TBI to Qjet manifold adapter is nice. About 1" tall and has optional heater hose connections to run coolant through, more for cold weather driving. An inline pump doesn't work as well as a good in tank pump.