so i was looking into the 8 injector setup and was wondering....why cant you get the secondary fuel rail setup....lets say ive got stock injectors controled by the ecu, then secondary...say another set of stock or above.... do the same series setup with fuel...then link all four secondary injectors to one 12v sorce (or 5v?)....use the sfmu to adjust the fuel pressure for the combined injectors just like you would with big ones, and then use a boost switch/vacuum switch that kicks the secondary injectors on at 0psi, or .5psi....... the sfmu will adjust the fuel pressure through both rails still..... would this work at all.....or maybe this...get a signal off of each stock injector and wire it through a relay that is contoled off of the boost switch... have four boost switches set equally and 4 relays...each injector pulse (if boost is kicking in) will also send a pulse to the secondary injectors.... i dont see why this wouldnt work....it may take time to dial in the switches to be equal, but it saves you 300$ in eic purchase.... give me some good input, not just spend the money crap

doug

Originally posted by lickscissors
so i was looking into the 8 injector setup and was wondering....why cant you get the secondary fuel rail setup....lets say ive got stock injectors controled by the ecu, then secondary...say another set of stock or above.... do the same series setup with fuel...then link all four secondary injectors to one 12v sorce (or 5v?)....use the sfmu to adjust the fuel pressure for the combined injectors just like you would with big ones, and then use a boost switch/vacuum switch that kicks the secondary injectors on at 0psi, or .5psi....... the sfmu will adjust the fuel pressure through both rails still..... would this work at all.....or maybe this...get a signal off of each stock injector and wire it through a relay that is contoled off of the boost switch... have four boost switches set equally and 4 relays...each injector pulse (if boost is kicking in) will also send a pulse to the secondary injectors.... i dont see why this wouldnt work....it may take time to dial in the switches to be equal, but it saves you 300$ in eic purchase.... give me some good input, not just spend the money crap doug

you have to have a way to control the flow rate (duty cycle) of the secondaries in relation to + pressure (boost). your ECU works to maintain a stoich 14.7:1 ratio, so it would not be able to raise or lower the fuel flow of the secondaies in relation to boost. Not to mention the votage differeance between running 4 vs. 8 injectors from one ECU might cause more issues than its worth...
just spned the money:P ! you can get the 034EIC off ebay from javad for $240.00 (at least i did)

keep in mind that even under boost your stock ECU still thinks/sees a 14/7:1 ratio and works to maintain that. thats why you need another "ECU" to handle the boost side of things...

Spend the damn money you cheap bastard. I bet you could buy a used 034 off a board member for cheap (now that people are switching to the MS). You need a system that will adjust injector pulse width based on intake manifold pressure. It will also have to match the injector frequency to the engine RPM (pulses per minute). It takes more than relays and pressure switches to do that. We are interested in more than just dumping fuel. We need just the right amount to get good driveability.

Corbin

'95 ESI-T
Now with more power and fewer leaks



Gimme fuel...Gimme fire...Gimme that which I desire

Originally posted by Corbin
I bet you could buy a used 034 off a board member for cheap (now that people are switching to the MS).

Exactly what I did. Just bought one for 150. You can afford that:thumbsup

I'm a novice listen to what I say and make your own conclusion. If I'm wrong tell me and I will learn.

I'll sell my 034efi (brand new with all harnesses and software) for $200.

Originally posted by Corbin
Spend the damn money you cheap bastard.

^^^what he said, I have a MS unit for sale if your interested, its one that Lee made me. It needs a case and its good to go. $150 takes it.

ok...lets try this again... put the money issue behind us... i just want to try something different.... if i can run 440's with the sfmu and stock ecu, why cant i run 440 worth of injectors with the stock ecu????
- the stock injectors will be controlled by the ecu
- the stock injectors will not be affected by the sfmu
ok, so everything is running stock...now boost kicks in,it activates the boost switch which activates a 4 prong relay (1 for each injector pulse)...then the sfmu starts rising fuel pressure for 440 injectors... the same amount of fuel is being thrown in, just now with a better idle.... the only thing i was concerned about was if the stock ecu would be able to pulse the secondary injectors also....i dont know if you can put a voltage amplifier inline with each one to help out or if the stock ecu would be fine...it is in parrallel... so why wouldnt this work? its basically tuning with the SFMU.... what is the stock injector voltage 5 or 12v? the one thing that would make this better is if i could signal the ground to the secondaries, that way the stock ecu would be unaffected..... serious input....i know i can get an EIC, and we know it works....i have all winter to mess with this.... thanks
doug

Go for it man. Go for it.

I for one think it will not work for shit. At all. Probably get all kinds of weird things happening. Do it the right way, or don't do it at all.

Originally posted by lickscissors
ok...lets try this again... put the money issue behind us... i just want to try something different.... if i can run 440's with the sfmu and stock ecu, why cant i run 440 worth of injectors with the stock ecu???? - the stock injectors will be controlled by the ecu - the stock injectors will not be affected by the sfmu ok, so everything is running stock...now boost kicks in,it activates the boost switch which activates a 4 prong relay (1 for each injector pulse)...then the sfmu starts rising fuel pressure for 440 injectors... the same amount of fuel is being thrown in, just now with a better idle.... the only thing i was concerned about was if the stock ecu would be able to pulse the secondary injectors also....i dont know if you can put a voltage amplifier inline with each one to help out or if the stock ecu would be fine...it is in parrallel... so why wouldnt this work? its basically tuning with the SFMU.... what is the stock injector voltage 5 or 12v? the one thing that would make this better is if i could signal the ground to the secondaries, that way the stock ecu would be unaffected..... serious input....i know i can get an EIC, and we know it works....i have all winter to mess with this.... thanks doug

How you can possibly imagine this giving your the right amount of fuel at any point on your fuel curve is beyond me. This is flat out the worst idea I've ever heard. Let's just say you can get around frying the injector drivers in your ECU, you'd never be able to get the right amount of fuel to be supplied by just tinkering with your SFMU. It wouldn't even be close. You'd "turn on" your 2nd set of injectors ... if it doesn't fry your ECU at this point ... and you'd just dump a random amount of fuel because you have no idea how much fuel your stock injectors are supplying ... most likely running ridiculously rich (if it runs at all at this point). Stupid stupid stupid. You've obviously didn't think this through at all. What's your beef with your idle anyway. 440s and SFMU at the right fuel pressures almost idles like stock anyway (if it doesn't you f'd up).

thanks guys...i appreciate it!
doug