Responding to this and your PM in one post.
Originally Posted by Project84 via PM
Care to shed some more light on the use of EMB, 305cc injectors, 190HP FP, and RRFPR for me? I just bought a tuning cable and software from GiffTech for the EMB. I also have the boost sensor.
I'm a total newb to modifications this extensive. I bought the car for what I thought was a good deal and I'm just trying to figure out what it needs at this point to run safely and make decent power with what I already have lying around.
My turbo is a T04E w/ .63 A/R, I'm looking to "upgrade" to a smaller turbo (OEM Saab unit) so I won't have so much lag.... but I still have never driven the car w/ its current setup.
I guess my goal is 200+whp.
After a RRFPR will I still need more supporting mods?
The EMB cannot directly reduce injector pulse lengths. It compensates for increased injector size by modifying the AFM/MAF signal. This is in contrast to the EMU, where the injector signals actually pass through the unit, and it can divide down the length of the injector signals without altering the airflow signal. This latter method is far more precise.
As a result, there is a practical limitation to the size of injector you can install on the EMB and still maintain a decent idle. It's not a hard-and-fast rule, simply a matter of degrees. As injector size goes up, the capability for precise and minute adjustment is degraded. Common wisdom holds that injectors in the low to mid 300s are "acceptable".
Now, if you do limit yourself to ~300cc injectors, you won't have enough fuel at stock rail pressure to make your 200+ WHP. At 0.6 BSFC and allowing 90% duty cycle, 305s will max out at around 170 crank HP, which will be maybe 150-155 at the wheels. So those wishing to make big HP with reasonably sized injectors on the EMB have historically needed to use a rising-rate fuel pressure regulator as well, with the EMB acting as a fine-tuning instrument.
Now that's not to say that you can't throw 430cc injectors on the car. People have done it, and it does work. You just have to live with idling at about 11:1 and probably a bit of a rich tip-in accompanied by hesitation on light throttle. It's entirely a matter of what you can live with in the car.
As to the fuel pump. The stock pump works just fine at the 200-250 HP range, assuming that rail pressure is kept stock. The shortfall of the stock pump is that it has trouble maintaining flow at higher than stock pressures, which is the case when running an RRFPR. Years ago, that was pretty much the only way to deal with boost- aftermarket ECUs were profoundly expensive, rather complicated, and a bit scary, so most folks stuck with the tried-and-true RRFPR. It is from this era that the stock pump earned it's bad rep.
When you say that the EMB "came with the car", is it installed in the car already, or just in a box?