96 riviera dhp scan to 110mph

Devin and I took his DHP scanner out for a run in my car a few hours ago. as soon as he sends me the XML file i will post it up for review, but here are the basics from what i remember.

ambient temp: 75*, moderate humidity (90%), a/c off, trac off.
ran from a ~10mph roll (pulled a U-turn) and didnt get on the brakes till ~110mph (little over 1/4 mile)

saw 0 KR (not even blips at shift points)all the way to around 90 where it slowly stated to increase from .1* to 2.5* to a max of 3.2* at 110mph. (~4400rpm IIRC)

the reason i believe i had some small knock was due to my car running slightly lean.
my O2's were locking in at 890's, but LTFT was a consistent 0 for most of the WOT run.

anyways, i really dont have any performance tuning on my car yet. Tony and I altered shift points some, removed speed limit and tq management, but no A/F tuning.

here are the questions i have:

1.can i add some timing? and if so, where/how?
2.how can i improve my MPG with cruse timing?
3. why does LTFT jump to -100 for a split second randomly? (devins car does it too)
4. what should i do to run KR free past 110?(i'm sure some 1.84 RR's would help)
5. can the powrtuner do a CASE learn?

thanks,
Matt

1) You can advance timing, but it will probably make your KR worse. There are spark tables that allow you to do this with DHP.
2) Advancing timing in the portions of the spark tables used during cruise could give you better MPG. I have not tried this, but some at the DHP board have had good results.
3) LTFT jumping to -100 is a fluke. I've never liked the DHP scan tool.
4) Where you're seeing KR is exactly where it's expected. There is so much load shifting into 3rd at WOT, you would probably see as much KR in a stock engine. For your set-up, 2-3º isn't bad at all.
5) Yes, DHP can do CASE learn. I've never actually done it.

I would want a little more fuel than 890s, that's probably why you are seeing some KR up top. You may want to add a little more fuel to the upper end of the MAF table, I can tell you where after I see your scan, but it's usually over 7000 Hz.

I wouldn't change any timing yet, until your fueling is where you want it. Certainly not on the high load areas yet.

The PT can do a CASE learn. I think it's under the tools menu.

Adjust the MAFF in that area so you see around 930 O2; your KR may completely go away. You're right to think the engine is running slightly lean with a 3.4" SC pulley and stock tune.

here is matts scan. i hate him! with his no knock car!

http://www.scandepot.net/viewscan.php?pk=4686

Something is up wiith that scan - I notice right away, comparing TP% and RPM, several of the RPMs are the same, when they should be climbing, and I'm sure they were... Your injector PW follows the same pattern - there is a pattern where there should not be.

It seems like the O2 and MAF were updating properly, though, so we can still make a few asjustments - I'd like to see a little more fuel on the top end, where your O2s start to fall off. In your case I'd add 5% fuel to the MAF table above 8000 Hz for starters, and look at the table for fuel enrichment over time - it's usually crazy in it's stock form, I'd rather see it reworked a bit to add more fuel over time, and that will help out the KR at the end of a long pull like that.

Don't change any timing yet. You may be able to add a little but after you straighten out your O2s and have 0 KR.

did another scan today. it was 90* out and my car was slightly heat soaked from sitting in traffic before the big run.
first scan was to 120mph. saw no KR till about 110 and only little blips of 2.8max. nothing ever at partial throttle or under 100mph.
my O2's were still only 870's.
so we adjusted my MAF table +5% above 7000 and a little before that to make it smooth.
let the fuel trims reset and scanned again to 90mph. this is what we got:

http://www.scandepot.net/viewscan.php?pk=4698

what else can i change to get more power? and better econ?

also, we tried the CASE learn, but it kept failing for some reason. (session timed out) will it tell me to rev or do i have to do it at a certain time?
TIA,
Matthew

LTFT at idle and cruise should be taken care of before tuning any more up top. MAFF from 2800-7000 needs to be richened. Try 1% for every % it is above zero. It's worse down around 2-3kHz, and not so bad at 4k-above.

Once you do that, may want to add about 2% more to MAFF at 8000 up, if it's still a problem. Then advance timing for some more power. Or, you could try dropping to a 3.3" pulley. I've got one here you can try if you want.

You should be very happy your tuning is going so smoothly. Most will drool at your results.

i know. i was thinking about posting on clubgp about how i'm at almost 0 KR with a 3.4 pulley supported by plog and DP in 90* heat on a 150k mile motor. but i dont want to heas 100 people call BS on my scan and tell me that's not possible.

i am going to scan again this week sometime to see if my LTFT's have settled down some.(they were locking in at 0 before the reset and tune)

i also want to clean my injectors soon since they are probably a little dirty at 150k miles.

cant wait to see some new track times this winter

Mr.Riviera wrote:

i was thinking about posting on clubgp about how i'm at almost 0 KR with a 3.4 pulley supported by plog and DP in 90* heat on a 150k mile motor.

now there's a wasted effort!

Don't forget the Riv has better air intake and better cat-back exhaust, so it's easier to run this stuff.

I wish I knew how to tune before I got as far along as I did. Without tuning, I had to use 1.9 rockers to be KR free on the 3.4.

i need to take a ride up 2 orlando and have devin scan my car lol. haven't scanned it since i dropped 2 a 3.4 pulley but i was fine runing a 3.5. and i added a 3inch DP, cat delete, and p&p tb before i dropped to the 3.4.

but ya never know i still have the 3.5 if i have to much kr.