anybody use this for an LT1 (obd-1)? i have been playing with it, but have not yet loaded any programming (other than one my friend made for me). anybody have any tips of things i should be careful of and what would be good things for a bolt on LT1.

 

Start with the simple stuff.. Set your fans to come on earlier and get yourself a 160 deg thermostat. I have my primary fan set to come on at 180, off at 170, and my secondary fan set to come on at 185, off at 175. I rarely get over 190 on a hot day in traffic, and hang right around 170-175 on the freeway.

You will also want to look at your blm values (when scanning) are they right around 128? If so, great, your fuel tables are good. If not, are they above or below?? If below 128, your motor is tending to run rich. If above, you have a tendancy to run lean. When I installed my new cam, under low RPMs I was running EXTREMELY rich, and was lean under high rpms. To get data for this, I typically leave the car in idle, and go from 1000rpm up to 2000rpm in 100 rpm intervals (keeping it at 2100 for example, for 15 seconds). I then go out, and run around on some nice flat roads, going through the gears, to get a wide band of RPMs. When running on flat roads, you will get medium values of MAP for your fuel tables. Next, I find some good hills. Go up and down a bunch of hill at various RPMs. Now look at your data, in something like excel. I take all of say, 2000rpms at 42.5-47.5 kPa, and average the BLM values. Say I get something like 120. Now I take 120/128, and multply this correction value by that entry in my fuel table.

Finally, you can look at your spark advance, but you need to be VERY careful here. I take my stock spark advance table, and advance timing by 1 degree (dont get greedy here.. you can do some serious damage to your engine). I then go out and drive around, and note my performance (on a flat surface, look at TPS vs speed.. do you have to push the pedal more or less to maintain the speed?) Keep advancing spark until 1) performance goes down, 2) you get knock, At this point you retard timing by 1 degree, and should be at your optimal spark.

That is a very brief and generalized description of how to tune at part throttle. To do tuning at WOT you need a wide band O2 sensor, but if you get your fuel curves and spark under part throttle, you are 90% of the way there (WOT is based on your learned fuel and spark values from part throttle, so a good part throttle tune will do wonders for WOT).

Hope this made some sense.. I'll stop my rambling now.

-Mark

 

i already have my REV limiter raised, my fans set to come on at lower temps, and my VATS disabled. i also have a program (very similar to the HPP) installed and my knock lowered. i am doing some changes to the program to make it better, because o know the HPP programs are terrible. i just messed with a program to combine the STOCK vette program with a STOCK f body program, to see what happens. there are some pretty considerable differences in the 2 programs. i don't understand why it should not work, since everything is the same. i will laod it when i get a cable and see what happens. what should i use for scanning? i was going to purchase a scanmaster, but would like to find a cheaper way.

any info you can give me, mark, is helpful. i just started trying this stuff and am trying to learn as much as possible.

 

I use TTS datamaster, and a homemade ALDL cable, and it works great.

-Mark