Cascade Crew

blue89 · Posted: Thu Dec 06, 2007 8:18 am Post subject: LT1 datalog peek

What do you guys think? I had traction trouble through 1st and second. You can see the first blip when i went 60% tps (lost traction in first) and then again when it shifted and I lost traction again in 2nd. I hit 6150 on the tach on the top of 2nd at 90mph (wasnt really going that fast, but the tires were) and then 4975 at 120 in 3rd. I really have no business driving that fast, but man did it get there in a hurry!

Decent log other than that? I'm trying to figure out why my gas mileage is bad (15-17mpg).

91RSVert · Posted: Thu Dec 06, 2007 9:44 am Post subject: Re: LT1 datalog peek

91RSVert · Posted: Thu Dec 06, 2007 9:49 am Post subject:

Can you do a log of just the o2 sensors?

Also, what exact setup do you have?

94 LT1
t56?
what gears
what tires

blue89 · Posted: Thu Dec 06, 2007 10:00 am Post subject:

Your wish is my command.....

O2 would mean nothing without TPS and RPM, so I left them in there.

stock 94LT1, shorty headers, "cold" air intake, A4, 3.07 posi rear 245/45r18 tires. 36/24 bars, deCarbon rear shocks, full urethane front, urethane rear panhard.

RPM, O2 read on the left, TPS on the right axis.

O2 is in mV. so 1000 = 1 volt.

91RSVert · Posted: Thu Dec 06, 2007 11:55 am Post subject:

Dewey316 · Posted: Thu Dec 06, 2007 12:01 pm Post subject:

blue89 · Posted: Thu Dec 06, 2007 12:29 pm Post subject:

yes, thats what happened. It follows the tps nicely. Take a look when you get home Dew. I'm going to replace the plugs and see if it helps the gas mileage any. I had to clean them up a bit when I dropped the motor in.

I might put the 4.11 disk rear in the LT1 for a little bit. Just to see how it does. I need a beefier axle when i do my motor swap....

91RSVert · Posted: Thu Dec 06, 2007 12:59 pm Post subject:

blue89 · Posted: Thu Dec 06, 2007 1:34 pm Post subject:

Really? Thats how it works. Decel Fuel Cut Owoejkfasdnfk. It was actually reading 4.44mV at that point. So not quite 0, but close.

There is a table that sets when it cuts fuel. If you set it low you can save gas. Its like the fuel enrich on 2.8's is set to 2 seconds or something goofy. I also heard that automatics are set to wait longer before DFCO than manuals. Maybe Dew can confirm.

Dewey316 · Posted: Thu Dec 06, 2007 1:38 pm Post subject:

I can't say that I have ever looked at the DFCO values in an the auto's codes. It also may have varied by computer and application. I have my DFCO set really low right now. 1650rpm threshold. I think that and the hiway mode are the reason I got such good milage on the trip to k-falls.

--John

blue89 · Posted: Thu Dec 06, 2007 1:41 pm Post subject:

What did you pull? Maybe I'll set the LT1 low as well. Bet that would help my 15mpg.

Dewey316 · Posted: Thu Dec 06, 2007 1:42 pm Post subject:

It was 300 miles of freeway, I did it all on 1 tank, I got 32mpg.

--John

83Z28BlackBetty · Posted: Thu Dec 06, 2007 1:44 pm Post subject:

91RSVert · Posted: Thu Dec 06, 2007 1:47 pm Post subject:

I never knew what dfco stood for. I just got edumacated, can I go home now? Laughing

Will have to see where/if thats in mine, and see what its set for. My o2 readings are all in the .7-.9 zone right now Shocked

and never leave. Its so rich, it cant even ping down.

blue89 · Posted: Thu Dec 06, 2007 1:55 pm Post subject:

ya dude, you need to fix that. Just start by scaling all of your fuel tables down. Multiply everything by .1 repeatedly until you get the o2 readings down'ish! Once you get it down a bit, the BLM's will get more towards 128. Thats the goal at least.

Dewey316 · Posted: Thu Dec 06, 2007 2:01 pm Post subject:

91RSVert · Posted: Thu Dec 06, 2007 5:13 pm Post subject:

I dunno what mode I am in. But the setup is from a vortec L31 motor, and now its on a TPI with TBI heads. Low end TQ like a mother, but no top end. Still working on scaling fuel charts down as well getting it to idle on its own.

Yesterday I was pulling full front suspension travel Very Happy

NHRA427 · Posted: Fri Dec 07, 2007 7:25 am Post subject:

What kind of equipment do you have to have to get those logs? I need to do something with my LT1 because it just doesnt seem to right the way I think it should. doing 60 and mashing it down and the car feels like it doesnt have much power and when letting off it will have a small backfire out the exhaust, might be a small exhaust leak. but i would like to check it out with some kind of computer. I have had it scanned and it doesnt throw codes.

blue89 · Posted: Fri Dec 07, 2007 7:30 am Post subject:

Is your's a 12 pin ALDL port? If it is then you're in luck. I used an aldl adapter from moates.net and then tunerproRT. Took me about an hour to set it up. If we have the same setups I can walk you through it. If you have a 16 pin ALDL you probably are OBDII. Then you should talk to 91vert. Its more expensive to get going.

91RSVert · Posted: Fri Dec 07, 2007 9:02 am Post subject:

my program doesnt support LT1's. Its 98 and newer IIRC.

Heres mine n what it supports.
http://www.efilive.com/supvehicle.aspx