Hello,

I have a T04S running around 15 PSI and I'm using a do it yourself wideband setup from www.techedge.com.au to do some tuning.

The car was already tuned once over the summer by Dave/KDRotary so it's running pretty well but I want to fine tune...

Here are some questions for the experienced tuners out there

1) At idle speed, I want the car to smell the least bad that I can get it... so should I attempt to tune it to close to 14.7:1 at idle? Right now it's at something like 12:1 at idle.

2) At steady-state cruising around 50-80 mph speeds, is it a good idea to try to tune near 14:1 or is it better (safer) to keep it a little rich just to be safe?

3) When Dave tuned my car he was using a Bailey AFR setup... it was around 11.5:1 or so. That was done over the summer... now that it's winter time, I'm using this DIY kit and I'm seeing around 10.5-11. I am wondering if this is due to differences in the accuracy of the two AFR setups or if it is more related to temp differences. Does anyone know how much variation is normal from one wideband setup to the next?

Thanks so much!

Brian

 

1) tune it so it runs the best

2) i would say same as #1, but you could also do somthing like what the factory map does, have it run 14.7:1 (closed loop) up until the point where the turbos can spool faster than the computer (3200rpms stock)

3) could be a bit of both, the outside temps will affect things though

mike

 

I'm no experienced tuner but I can share some ...

At idle, be sure you tune post warm-up as the correction factors dump alot of addl fuel until the coolant temps come up to normal. My car idles nicely in the mid-13 AFR range.

At cruise, you can lean out in the 14's and 15's or leaner. Go excessive lean and it may surge or buck a bit and closed loop may not be as smooth as before. May have to adjust your accel fuel corrections if you take out alot of fuel and suffer from lean conditions at throttle tip-in.

Never heard of the Bailey Wideband, interested to see if folks have experienced that great of a diff in widebands. May just be in your intake temp corrections but 0.5 to 1.0 AFR diff is alot of fuel (4 to 10+%).

 

Shoot me a PM, I'll reply with email and you can send me some logs for analysis. I know of a couple holes you might have in your map, based on what you have told us.

Tony