16198259 corvette

[delcowizzid]

if you arnt going over 12psi just get a 2bar or you end up with half the cells to tune in for no reason. we have been running 16psi on a 2bar during the gearchange.resistor packs and low impedance injectors can be a dog you change the opening time of the injector too much.if its staying TBI injection youll want 4 injectors that are way bigger if you change to individual cylinder injectors in the manifold then 60Lb seimens will probably be enough

[keto]

we are running the TPI (tuned point injection) inlet manifold, so eight injectors, so with the resistor pack you would except some extra fuel dump in the lower ranges? or would the whole lot be all over the show?

what could i get some siemens 60lb injectors out of? or are they only aftermarket?

also how do you know your not spiking to 20psi when changing gear? are you logging boost off another sensor?

[delcowizzid]

seimens deka 60's are on ebay they are aftermarket and very controllable down low for how big they are and give huge flow up top at longer opening times .its what most people use with boost or the 80lb version if you need more.with the resistor packs the injectors take longer to open which can make them dribble on the first crack as well as taking too long to open so you need to open them longer to get the right fuel amount then you run out of time to open and close them before they need to open again making them lower flowing than what they really are

we log everything in realtime on the ecu with the laptop 10 samples a second for every sensor the ecu has so we have upto date map readings all the time you can setup 12P to log even faster

[keto]

thanks for the explanation! but i think there not really in the budget at the moment, might have to be a future upgrade when i get sick of failing to tune

what i ment about the logging is that a 2bar sensor would be putting out 5V at 15psi so unless you had another pressure sensor logging into the computer how would you know you didn't have 20psi there insted of 16psi?

[delcowizzid]

they show higher than the 14psi limit and it hasnt hit the boost cut so we know we are under full max limit turn the cut off can run 20psi as long as you tune the last colomn to suit

[keto]

thats good to hear, think i'll hunt out a 2bar then.... i guess the sensor prob won't like getting over-pressured on a regular basis but it'll only be occasionally if ever, have you guys used map sensors off other cars than GM? like off a jap car?


i think i've hunted out some injectors in my size range and high resistance... they are 13.7ohms(so about 3.43ohms total when paralleled) the standard's are 15.7ohm (about 4.04ohm when paralleled)

would the computer be able to deal with the load changes? seeing as its all getting remapped, i just wanted to make sure it wouldn't fry one of the transistors or something before i go spending more money on these injectors



almost got the suspension and brakes finished then should finish building the motor end of this week, then probably wire it up next week so we can run it in(n/a) before refitting turbos and doing some tuning

also think i scored a vn v8 loom and computer - i'll probably hack this loom up and use rather than the corvette with its stupid VATS system (and extra crap added into the engine loom like wipers and washers)

[delcowizzid]

injectors will be fine.the vn loom shouldnt need much hacking

[keto]

engines built and in the car, fuel tank 80% finished, went to pull the vn v8 loom out of the wreak and it got taken away the day before

brought a 3082 computer just in case, and got a v6 loom to hack up and remake, nvram and usb converter on its way from aussie(thanks VL400)

one thing thats got me confused is the knock sensor and how it talks to the computer, on my corvette v8 loom it uses a dissy with a external knock control so (guessing here) it sends a clean signal to the computer, and has no filter on the memcal, but on the 12P software it uses a raw signal straight from the sensor and uses a filter on the memcal

so heres a diagram to show what i mean,



havent heard back from the guy with the eprom burner, which sucks cause i wanted to read my memcal and turn the VATS off to run the engine in, so now im looking at making a circuit, aparently its only a 30hz square wave...
and guy with the wideband doesn't want to sell anymore argggg have to keep hunting

[VL400]

Pin B7 of the 808/3082 should work with the external module. The only thing is you wont get any fault detection when running 12P and would need to turn of code 43 MALF processing. In US vehicles the knock sensor fault detection is done by advancing timing under certain conditions until knock occurs, in aussie vehicles we just measure the resistance of the sensor to make sure its there but dont test the operation - cant measure the resistance with the module.

[keto]

thats a relief i wassn't too keen on tuning without a knock sensor... thanks heaps!