Do i have to get up on a dyno to tune my AFC

[xXEclipse]

I have 550cc Injectors in my 98 GSX, I was running really rich, my mechanic tuned but not with the AFC, he says he just adjusted some screws, the AFC Airmap is turned off right now.. Do i have to get on a dyno to tune it so the car runs normal.. Or can someone tune it without a dyno..

Forgot to mention, i have a 14B with a 16G O2 housing

 

[williillii]

Do you have an adjustable fuel pressure regulator? If not, the only screw I can think of to adjust is the MAF calibration screw. Which you dont want to mess with. It doesnt really do anything useful. So you want to get that back to where it was if you can. Its on the bottom of the MAF. Big phillips head plastic screw.

As far as tuning, no you dont need a dyno, but you do need to at least have a wideband o2 sensor. Without one, you really have no idea what you're doing.

Just to get it driving I would take out 10-12% fuel all the way across and DO NOT beat on the car. It will probably still run rich at that setting but it is better to be safe until you get it tuned.

 

[xXEclipse]

SO it can be done with a wideband... And i have a A/F Gauge on my turbo timer.. idk if that can work.. Basically this guy is bullshitting and doesnt know what hes doing in my opinion? If i take it to someone with a wideband they can do it properly?

 

[crash89]

If your serious about tuning your car and keeping it running correctly Id suggest buying a wideband. The A/F "gauge" on you turbo time is pretty inaccurate. Dont forget a data logger!!

 

[knochgoon24]

The A/F gauge on your turbo timer is meant to tie into your narrowband o2 sensor. It won't tell you much.

You should get a wideband o2 sensor.

With 550cc injectors, you need to pull about some of the fuel out (just like I said in your other thread about this problem). It's going to be about 18% unless he tried to fix your problem with your fuel pressure regulator by dropping the base fuel pressure.

If I were you, I'd either swap your 450cc injectors back in and keep your boost turned down or:
-Set your base fuel pressure to 43.5psi.
-Turn your boost down.
-Pull out about 12% across the whole RPM and hi/low throttle setting on the SAFC. Your ECU should be able to adjust from there. It will still be rich though.
-Buy a wideband o2 sensor.
-Tune your AFR after getting the new SAFC.

Do you have a logger of some sort? You could rough in a tune using your fuel trims. It wouldn't be perfect, but it would work better that what you're doing now.

 

[xXEclipse]

I wanted to switch to stock 450's but my boost wont go down. It wont go down past 15-17 I have no idea why and neither does the mechanic.. -_-

 

[williillii]

Does it go straight to 17 or does it creep up? If it creeps you need to port out the wastegate passage so it can bypass enough exhaust to keep the boost down.

 

[JayRolla]

You and your mechanic sound like you guys dont know too much about your car. Best bet is to find out what local dyno shop works on dsm's and have them look at or tune your car. They will know what is up with the car instead of some random mechanic that doesnt actually know dsm's. Or buy a wbo2 and do lots of studying. I learned to fully tune my car by reading forums, was never showed or anything so it can be done.

 

[talontsiboy24]

Do you have an adjustable fuel pressure regulator? If not, the only screw I can think of to adjust is the MAF calibration screw. Which you dont want to mess with. It doesnt really do anything useful. So you want to get that back to where it was if you can. Its on the bottom of the MAF. Big phillips head plastic screw.

As far as tuning, no you dont need a dyno, but you do need to at least have a wideband o2 sensor. Without one, you really have no idea what you're doing.

Just to get it driving I would take out 10-12% fuel all the way across and DO NOT beat on the car. It will probably still run rich at that setting but it is better to be safe until you get it tuned.

I noticed my calibration screw underneath the maf has the silicone removed so how do i know if its in the stock position? do i have to turn it to the right or left to put it back to the factory settings?