Tuning with autotap and maft+

[m.malloy]

i just ordered these 2 items and i want to know what i'm looking for. i'm trying to get all the power out of my car i can.

now what are idea settings i'm looking for; ie , o2 sensors, LT trims, timing , etc.

i want to car to run like a dream, i need your help!

[John_D.]

This is a big question, and yet a simple one too...

You can monitor all kinds of things. Injector pulse widths (to calculate duty cycle). Exact engine coolant temp. Air flow, before and after intake and exhaust mods. Knock retard with different grades of gas.

The main thing, is to tweak your o2's at wot. The pcm will counteract anything you do at less than wot, to maintain a 14.7:1 ratio. At wot, it quits monitoring o2's, and falls back on preset parameters. There is where you can play with the maft to hit .87-.89 o2's na, or .90-.91 o2's with power adders.

Magnus posted some on this not too long ago. Basically, move the wot dial on the maft to get your numbers where you want them.

[m.malloy]

SO BASICALLY just get my o2's in that ballpark and what area does my timing need to be. i know this is a broad question, but i need to learn this stuff .. thank you

[John_D.]

I don't have the maft plus, so I can only change maf readings, not timing.

If I had the maft plus, I would experiment and try to find the max timing advance I could run without causing detonation or knock retard. It is not as accurate as remapping timing advance at various points like a programmer could do if one was available, but it will let you bring the overall curve up.

Basically more timing advance equals more power, up to a point. A tech tip article on www.superchargersonline.com by Jim Bell says that a 4 degree timing change is 20hp. So you could probably figure 5hp per 1 degree of advance.

And you can use the timing feature to retard the timing slightly if you get into detonation with power adders.

[camaro97]

does the timing advance mod for the LT-1 work for our cars???? I put one on my friends car yesterday and all it is is a resistor that plugs into the sensor in the side of the air tube near the TB(forgot the name) and it basically tricks the engine into thinking its getting colder air than it really is and it advances your timing about 4-5deg for a dyno tested 20-30HP at the wheels(tested on a LS1 so im sure wed get less if it even works for us). It seems to improve the already modded LT1's throttle response some and quite a bit more pull through the top end(above 4000-4300 RPM). Maybe someone knows? if we could use it, if so i dbe willing to try it....> [img]graemlins/dunce.gif[/img]

[ July 02, 2002: Message edited by: camaro97 ]</p>

[Magnus]

I only use my MAF T+ at the track. My settings are a little agressive and I don't like the extra risk for the street..

Leaning out the motor could cause damage.. but its very unlikely in ours when only naturally aspirated. We have rock solid motors.

Too much timing advance can cause detonation which can destroy a piston. The PCM will hear the detonation and just pull more timing than your trying to add.. so while you will be safe from KR, you will have less timing advance than if you didn't make any changes at all..

Leave the base settings alone.

At the track I incrase timing advance until I start to see KR. One time I was pushing 31 degrees. For NA USE ONLY... lean out the car a little. try .860 or even .850 02's.. Once you start to LOSE mph you know your losing HP.

Make a change, and MPH goes up, it was a good change.