06 MSRT8 Data Viewer Run

[claude9039u]

Hey guys I really have no idea what I am doing so if someone would be so kind and to look at my data viewer file and let me know if I should to some changes I would be greatful. Thanks inadvance.

[Xavier]

Hey Claude, it's Brandon from the DVMMC meet, the one with the dead radiator fans.

The easiest thing to monitor and adjust for without a full custom CMR dyno tune would be to check your ST/LT Knock Retard and adjust if it's more than 3. If that is the case I'd add 3% fuel to every RPM range.

What is happening, if that is the scenario, is at WOT it is getting lean, causing knock which the computer senses and then retards the timing, decreasing power.

From my limited knowledge and use thus far it's about all I'd really delve into without a proper dyno.

[claude9039u]

Ok I kind of understand so looking at my data file what would be the best thing for me to do?

[claude9039u]

I see 5 guys downloaded the file some help please .

[angrygnat]

I see 5 guys downloaded the file some help please .

I downloaded it but couldn't get it to disply in the viewer... I have a very similar Maggie and wanted to see how my logs compared.

[Quick]

Ok. This is my uninformed opinion.

You have too much knock retard. You are getting consistent knock retard to where you're seeing LT knock retard. What you would like to see is an occassional bump of a couple of degrees of knock retard at most. Preferably only at the shift points and when you floor it or lift.

I'd start by adding fuel. Maybe 5%. Probably across the board. See where you're at.

Then just adjust in the top 2 rpm ranges

Still have consistent knock? Then pull 1* of timing in the top 2 rpm bands where you're seeing knr. See where you're at.
Still have fairly consistent knock? Add another 3% fuel. See where you're at.
Maybe one more round of adding fuel.
Then pull another 1* of timing.
And maybe another 1* of timing.

Then maybe check the lower rpm range by locking it in 5th on the freeway and flooring it. Like at 2500 rpm.

Then get a wideband gauge installed. I kind of like adding fuel until the knr goes away or until it gets down to around 12.0:1
After that I pull timing until the knr goes away.

Get rid of most of those pids you're logging. Something like
rpm
mph
base spark
actual spark cyl 1
ST Knock
LT Knock
ECT
Charge temp (maybe?)

[Xavier]

Ok I kind of understand so looking at my data file what would be the best thing for me to do?

Honestly, you're seeing a little bit of knock so it wouldn't hurt to add ~3% of fuel in all RPM ranges. Other than that, without a wideband O2 and/or a dyno there isn't much else to really customize from my usage so far. Also, I'd suggest you don't follow Quicks advice, because although it is good, that is getting into territory where you can cause damage if you're not sure of what you're doing and should probably be reserved for a pro doing a CMR tune for you.

I see 5 guys downloaded the file some help please .

I downloaded it but couldn't get it to disply in the viewer... I have a very similar Maggie and wanted to see how my logs compared.

I had the same problem. I had to Drag-n-Drop the log file into the open window in the DataViewer to get it to show up. Try that, let me know if it works.

[claude9039u]

Man you are right I am getting alot of different info. I got one that say's drop 2 degrees of spark in the higher rpm range. Its alot and to be honest I have heard that if you dont know dont mess with it since in the past guys have hurt the motor so. I am really lost as to what I should to?

[claude9039u]

ok could someone tell me what cons are there in.
adding 5% of fuel or
droping like 2 degree of spark
And or doing both at the same time

[Xavier]

If you add fuel the only bad effect (if it was unneeded) would be running rich which would just waste a little fuel.

[claude9039u]

ok and reducing spark?

[Quick]

Adding too much fuel (running a good bit too rich) will shorten the life of plugs, possibly causing fouling, and shorten the life of your cats which will run too hot and be burning off the extra fuel. Kind of the same thing with pulling too much spark. As you pull spark you will lose power. The later the timing (past optimal) you won't get a complete burn of the fuel in the charge. In the first case there is more fuel than O2 to burn it with. In the second case there isn't time to burn it all? (maybe not).

That's my understanding. So there are downsides to running too rich although they are not as severe and they're more long term. The bad effects on the other side (detonation) can be very severe and can happen in well less than a second.

[Quick]

Man you are right I am getting alot of different info. I got one that say's drop 2 degrees of spark in the higher rpm range. Its alot and to be honest I have heard that if you dont know dont mess with it since in the past guys have hurt the motor so. I am really lost as to what I should to?

I wouldn't worry about hurting your motor if you add fuel and pull timing. Unless you get really extreme all at once... and then your motor would run like crap and you wouldn't hurt anything anyway.

You're getting the same information from everybody.
I'm suggesting you make a moderate adjustment at a time. Make an adjustment and log it to see what the effect was. This way when you get to what you want (described above) you're not going to overshoot the mark by much, if at all.

Adding 10% to 15% total to any of the Diablo tunes MIGHT get you pig rich (probably only moderately rich) but you're not going to do any immediate damage. If you do the car won't run so good and you're going to end up with black sooty tail pipe tips. I'd say pulling (retarding) up to 5* of timing isn't going to hurt you either. Same thing if it's way too much. Car will just run like it's sort of flat. It'll feel like a V6. Again no immediate damage or even long term.

The Diablo tunes are a great basis. You've got knock retard. The pcm is going to protect you from short term damage. You've got not so good fuel or whatever. I started with the CAI 91 Oct tune (we don't have more than 91 Oct pump gas). I had knock retard that looked similar to yours (although I never saw long term knock). I added fuel until I got all the way down to 12.0:1 and then started pulling timing. I think I must have added somewhere around 10% or more fuel and pulled 3* or more timing in the end. I could probably add 1* timing back and see a couple of bumps of 1* to 2* of knock retard.

Apparently you don't have a wideband to see where you are on a/f. It's likely the Diablo tune has you in the mid to upper 12's. Around 12.7 to 12.8 would be my wild guess. If you ended up adding 10% it might get you down to 12.0 and maybe even 11.7 or so... You'll never know without a wideband or putting it on a dyno to check a/f but it's not going to be a catastrophe. You'll notice that base spark minus knock retard (LT + ST) kind of approximates actual spark? It's approximate because there are a few other factors in that calculation. Basically you would expect to see 1* of knock retard less for each 1* you retard the timing. The best timing advance I could manage without any knock retard at about 12.0:1 a/f was 17* to 18*. Maybe it's a bit conservative but not too bad.

So add 3% fuel across the board and see what effect it has. go from there.
If you don't understand any of the above and don't want to experiment, go to a cmr tuner and let them do it on a dyno.

For a very rough reference, adding about 5% fuel is way way less of a change than pulling a 1* of timing. They're two different things but loosely correlated in the range you're dealing with.

Let me add this: I'm not a tuner. I have some very basic knowledge I believe to be correct and am willing to risk my motor on. You should feel free to ask for more input or learn until you're comfortable or, if it's worth it to you, have it done by a tuner.

[sohfast94]

Quick is correct about what to monitor and adjust. I would agree that 12.0 and 17 deg is rather conservative. But, hey all engines run differently and it also depends at what area of the country you are in etc... etc... I will take a look at your tune and see what I can do for ya. But for now if you caught all of what Quick said that you're on the right path. If you need further help in the meantime you can email me.

[johnc]

I had to Drag-n-Drop the log file into the open window in the DataViewer to get it to show up. Try that, let me know if it works.

The proper way to open the files is to start up the DataViewer and then use Open Log from the File menu OR click on the first icon on the toolbar.