I have been doing some research on this subject, but can't find a definitive answer. When only putting 5-7lbs of boost through a 1fz, is there a need for an engine control unit, or will the mass airflow sensor take care of you?
Less than 5 psi it will cope ok, but wont be optimum for the $ spent.
Intercooled and with premium ULP you can run 10 psi of boost, if you run an aftermarket piggy back to adjust fuel and ing timing, but you will have to run extra injectors on a pre 95 unit, and perhaps fuel pump as well, and a rising rate fuel reg.
How much you spend, and how much pwer you want for your money, vs cost makes the difference in how far you go with this.
5 psi and no tune, shouldnt be an issue with detonation, as long as the head hasnt been machined previously, and yyou should see around 200 hp at the wheels, and about 15-30% increase in fual usage for the same driving, but 10 psi, piggy back, fuel pump and rising rate fuel reg and you should see 300 hp at the wheels, and an improvement in economy for the same driving.
Of course driving it harder, and using all the extra power will see an increase in fuel usage also.
I only want a slight increase in power. I am not worried about money spent, I am wanting a reliable system with a slight increase in power. I do NOT want a standalone unit, as engine calibration is rarely OEM quality (starting in sub zero temperatures, running on poor quality fuel, etc). I considered purchasing the TRD supercharger, but I am much more of a turbo buff, and I love to fabricate. 5psi is ok for me.
TRD says that the mass airflow meter should handle 5psi boost level. What differs the 93-94 from the 95-97 units? Would I be better off buying a 95-97 ecu/wire harness/injectors/fuel pump and swapping oil pans to accommodate the crank angle sensor?
having a 93 does have it's limitations. The problem is with the type of AFM that is used on that year. To meet your demands you should sell that truck and get a 95+ one and then add a SC. That will give you exactly what you want.
Converting to OBDII is a little more complex than just switching the harness and ECU.
This thread goes into some of the issues.
The AFM runs lean with forced induction whereas the MAF on an OBDII will run rich. I think you can run an AFM with low boost, but it won't run as well as it does on an OBDII with a MAF. If you have Landtank's MAF I understand that the fuel metering/AFR responds much better to forced induction and higher boost than the stock MAF on the OBDII trucks. There is a ton of info out there if you can search.