about to turbo the 420a and am confused and concerned about tuning. I read the pinned topic but I'm not understanding how the tuning works. can someone explain this to me?

bump

As far as using a fuel controller or engine management?

I guess both. I just don't want the engine to go boom so I need to know about the tuning to avoid that.

Me personally I am running a 12:1 FMU and an AFC Neo Fuel Controller. You will also need a missing link for your MAP sensor, bigger injectors, and gauges to monitor your engine. I went with Oil pressure, boost, fuel pressure, and EGT. Prosport gauges are pretty good.

I got the 12:1 FMU. no missing link or fuel controller. and actually have the Prosport gauges in boost, oil pressure and A/F ratio. this may be a dumb question but do I need the missing link and fuel controller? or am I ok without them

It is. Yes. you need them :P

well thanks for not holding back. haha

Its what i do best... jk

will an apexi safc work?

Should

alright cool. one last question. I found a missing link on ebay(can't link cuz on an iPod) but it is a synapse missing link for the 420a. junk or does it not matter?

anything about the missing link?

well, the missing link is the cheapest easiest way to go but does work. However, it depends on how much boost you want to go with, and how much money/time you want to spend. Under 14psi it will be ok. Above 15 psi they start to fail.

the best thing, but more expensive, is to get rid of your FMU. get an aeromotive 1:1 rising rate fuel pressure regulator. create a return fuel system using a -4AN(female) to -6AN(male) adapter and attach that to the fitting on the end of your fuel rail after removing the core inside of it (just like a valve stem core in your tires). Run the fitting with hose from the rail to the FPR, then run a return line from the FPR to the return fitting on your fuel pump housing. Then,,,, get a GM 3 BAR MAP sensor and run a vacuum/boost line to it. Unplug your stock MAP sensor but leave it there. Cut the wires from your stock MAP sensor plug and wire up the GM sensor as follows:

with the nipple of the sensor facing you so that you can see where the plug would go in to number the contacts 1, 2, 3. contact 1 is your ground. contact 2 is your sensor output signal. contact 3 is your 5v source. I can't remember the exact colors of the wiring on your car but a chilton's manual will tell you. I can look them up if you need, i'm just at work right now.

You will have to increase fuel pressure and use an AFC to adjust fuel characteristics to make it work. The reason is almost ALL map sensors use a 5V signal. your stock one will send 5v at 0mm/hg and 0psi. the 3 BAR map will send a 5v signal near 30psi. so we are basically "tricking" the ECU into believing there is no boost, compensating with the AFC and fuel pressure regulator instead of using the missing link to "hide" the boost.

this way is much more difficult but you will get a better tune out of it. The missing link isn't bad but don't be scared if it leaks and you fuel cut.

it is a good idea, especially since you want to stay with a stock engine for now, to get some kind of wideband sensor to watch your air fuel ratio. They usually run around $279 for a good one depending on what brand and who you get it from but they are well worth it.

thanks for that write up. I am going to be running no more than 8 psi. haven't decided the amount yet. I'll def have to look into the FMU alternative. and I have an air/ fuel ratio guage. but I know that it isn't nearly as accurate as a wideband

http://www.mobilecomputerhelp.com/chip%20tuning/chip.htm