Maintaining the AF ratio for the street turbocharged engine is my topic. I don't know how many are playing with this stuff. There are turbo forums out there, but I think they are dominated by a younger crowd. Very snobbish, and hard to get straight answers at times. Almost more there to show off then help it seems. This is the forum to which I belong , so Ill give it a go. When turbocharging, the bolting together is the easy part. The method of tuning varies.
This is what I have been doing to get my forced induction feet wet. Running 4-6 psi on a stock factory performance engine. You don't want to blow your wad, so like $1200 max budget. That gets you get turbo kit, big fuel pump, big injectors, msd btm, intercooler, lines, filter, pipes, fittings, wastegate, controller, bov, RRFPR, etc.
You take a weekend and bolt it together. A simple method, is a rising rate fpr at 2:1 will enrich for boost, and the msd btm will retard the timing for the boost pressure. At 4 psi that works well. At 6, the part throttle boost it can be pushing safe limits. OBD2 also sometimes has a problem with closed loop at boosted part throttle enrichment. OBD1 seems better. Its possible there are more flaws, I have not encountered. A rising rate FPR and the msd btm worked extremely well at low boost levels in a obd1 system. Do you agree/have you tried it? You can tune with an a/f gauge , no dyno necessary.
Now going further, my project is working with a OBD2 system and higher boost. Looking for 8-10 psi. To satisfy the fuel requirement it seems I need a different strategy . What do you think of the piggy back style extra fuel injector enrichment systems? I like /want something that keeps the original injection systems' functionality . That way, off boost it remains stock, MPG unchanged for the most part. The Simple Digital System EM-5
extra injector system is independent and is plug and play with turn of knob simplicity. Add some injectors to the intake plenum and when in boost they spray. It is boost and rpm dependent / tunable. Stuffing fuel injectors all over sounds like fun right?
Has anyone here used this type of supplemental enrichment system? The fact that the fuel system remains stock is worth the $1000 addition budgetary requirement. It will also allow experimentation into 11+ psi levels of play.
A pic from there site, hope they do not mind.
I m not ready for the megasquirt deal, or other stand alone system. I want things close to factory, or retaining the original equipment as much as possible.