yeah, that surge is annoying, that's why I just run the No DOD tune... running on all 8 all the time and I still get 20mpg.

Interesting, I never got a tranny code... or any codes for that matter... Hmmm....

How do your ltft numbers look?? maybe it's too rich??? If you go too rich, it will affect the tranny performance/response/shifting - ran into that myself a little...

 

set the code about 10 seconds after the car was rolling, right after the install. Less than 25% (at a guess) throttle, just leaving the cul-de-sac.

Numbers hovered between 9.7 and 10.8 almost all the time, occasionally would drop to the mid 7's during throttle transitions. O2 would jump to 0.93 on tip-in, then drop to 0.84-0.86 during sustained WOT. WOT O2 after program went to 0.89, have not checked the LTFT since modifying it yet.

edit below:
also had a tranny shudder, felt like the converter was locking/unlocking rapidly a few times at low speeds (< 5 MPH). Reset the code and it has not repeated, car drove fine.

as an aside, I did my logging on the highway at 55 MPH, just to insure I was not getting into the C.O.T. fueling.

 

for my car, mine likes to be a little positive rather than zero or negative - otherwise I get the wierd tranny issues - bogging, sluggish, doesn't really downshift when it should, etc. Especially when I made it so my ltft's were ALL negative - made it too rich and got the tranny issues as well.

so for my adjustments with my average ltft being +6, I set my slope to -5%. Now my average ltft is at 1.5 - perfect (for me)! ...and it runs like a beast...

Maybe try setting yours to -8% instead of the -10... just a thought...

 

why not? Don't cost nothin'

 

Well, took my readings from the Diablo Non-DOD tune to determine changes to LTFT slope and PE then adjusted the parameters on the Diablo Tune (with DOD), figuring the tunes were the same except for the TM. Apparently not.

In a word: Rich.
extremely rich. Took my final readings with the car in 3rd gear to eliminate it from switching to 4 mode.

Trim readings are all over the place. Only good thing is my O2 reading at WOT are solid at .89x

 

Try disconnecting the battery first. I did logs before adjusted trims w/o adding PE and it went richer on o2 voltage. I've read conflicting docs one saying if you minus trims you should lean the PE and the other to add PE. When I did -5 my o2 went from .85 to .87. Logs are showing I could use -1 more for a total of -6. These were with out PE adjustments. I will disconnect the battery and try just -6. I don’t trust using the stock o2 voltage to go any richer. I don't want to loose power on top or get knock retard.

Good luck.

 

knock retard was practically non-existant (as I would expect with it being so rich), couple degrees on tip-in, that is it. I went ahead and moved the slope up 3 and the PE back 3 to get it closer. After that, breathing on the long pedal from a stop will spin the tires. Will run it for a time and then log again. I will win, eventually.

 

just ran 350 miles of highway today, car seems just fine with the exception of the DIC being wildly optimistic now. 50 miles of in town, followed (essentially) by 300 highway. Where my DIC used to be pessimistic by about 4%, it is now optimistic by ~19%. While it was fun watching the average soar up to 26.1 from 18.2 (with the instants hardly getting below 30 on the highway part), filling the tank showed an actual 22 MPG, or less than 10% better than what I would have expected with the completely stock program. Will log again tommorow most likely and see where it sits.

 

At what speed was the majority of the trip? From those numbers i'd guess you spent some time at or above 75mph?


Is anyone having trouble with excessive soot on your tailpipes/tips? I've got the magnaflow bubbles (tips) on there now, and the left side in particular gets REAL sooty...the right isn't nearly as bad (which is wierd to say the least). In one day it went from clean to black with the Diablo93noDoD tune with the slope and PE tables adjusted to achieve .89v & 0 FT at WOT and 1.xx FT at cruising. I believe the slope was -8 or so and +6 or so on the PE tables to get these numbers.

 

~70 almost the entire way, couple of passes up to 80, but pretty much steady. Diablo DOD tune, better than stock under the same conditions. Obviously I could not tell what the true mileage was in the first 50 miles (DIC must have still been in error and it only showed 18.2, around 15.x if the error is the same across the board), so I am not unhappy at all with the highway mileage.

 

If you get a chance leave your trim to -8 and reset the PE to 0. Run it for a day with clean tips and log it. I'd love to see the o2 voltage and see how clean the tips are. Also see how it feels now that everything is warming up.

Mine were very sooty. I've cleaned them since resetting the slope to -6 and PE to 0 but have not driven much. The SS is not my daily driver. How long did it take yours to get black? I'll make the effort (excuse) to run it later this week and will let you know. Also, how often is your right foot glued to the floor

 

If you're looking for good gas mileage, I used the Factory Hp tune with 87 octane gas. No knock, runs better than the Diablo DoD tune, gets banging gas mileage and stills pulls pretty good. Since gas is $3.00 a for regular this is about the best option. One thing I did notice is the AFR ratio at WOT jumps to almost 17 but the 02 is good at about .88 .89 is there any way to adjust that because I know it should be near 12.

 

The WOT A/F on the tool is not correct. Download the log and review. Mine stock was 12.19, DIablo 93 was 12.39.

The Factory HP tune is supossed to be the stock tune that you can adjust. I tried that tune and still had the 4-8 DOD surge which Diablo could not understand. But if it works for you, go for it.

 

Thanks Jabronie,

A few MPG is not that big a deal to me, it would be nice (I will run about 30K a year on the little car), however, I grew up in a time where torque was king. Matter of fact, the first time anyone in my family had anything smaller than a 400 motor was in 1980.

anyway, torque-junkie here, have been since I was a lad (and while more modern iron will flat-out run away from the old barges, you have not lived until you have wacked open the throttle on a high compression big-block through an M21 tranny and deep gears... ) The LS4 pulls well enough to get me by, but I find myself gazing lovingly at the LT1 Caprice resting quietly in the driveway everytime I walk by (330 lb*ft @ 3300-ish stock and she ain't stock anymore.)

While I am sure there is something less than a few percentage points of torque lost with the 87 Octane tune, I just can't do it....

I am weak like that.

 

No I don't have any surge with the factory hp tune. Yeah I know it's nice to have every bit of hp and torque out of your car but mainly driving my car to work it's nice to get better gas mileage once in awhile. I don't know if you guys have messed with the RPM limits in drive or not but I tried to raise them a little and it still shifts before redline. Plus there is no option to raise the speed limit or to adjust for tire size changes. Hopefully Diablo will offer some updates soon.

 

while everyone seems to be reading, I was wondering about the commanded throttle opening vs the actual. The tool will read that I am asking for 100% throttle, but the actual opening says something like 88%.

Does anyone know if this is correct? Seems a lot like the old 400 'birds where the factory put on a throttle limiter to prevent real WOT. (a screw driver and 30 seconds would take care of that little problem!)

edit below:

might be a quick way to get some power if we can use the electronic equivalent

 

The rev limiter will only be in effect when you are shifting it manually. If you just leave it in D and go, the computer will still shift before redline for you, but if you drive/shift it manually, you will be able to hit the raised rev limit.

The speed limiter is removed/raised automatically in the tune itself, so there is no manual parameter to change/adjust.

 

Has anyone needed the speed limiter removed yet? I hit 141'ish about a year ago, pre-tune, and haven't tried more than 125mph with the tune now. When i hit 141, it didn't kick back or cut off...i had to slow for vehicles up ahead...it's possible i had the 154mph limiter that the C&D test drive vehicle had...???

Can anyone confirm that the limiter is, indeed, removed or raised with these tunes?

 

Mike from Diablo had told me a while back that the speed limiter is removed in our tunes.

 

OK... as i told you in the eMail, I reinstalled the Diablo tune after reverting to stock a couple days ago. I ran a log today and found that with the Diablo tune, no adjustments, my FT's at cruising were around +10 and my o2 was averaging .82 or so at WOT, with the FT's locking in at 0 during this time...ambient temp was showing about 68* with intake temps just a bit higher. From this info, it's showing a lean condition, correct? So it is adding more fuel to the mix to compensate, right? Ultimately this would be adversely affecting my mileage...because it is adding fuel to the mix?

After the log, I wiped the tips clean of the accumulated soot from running the Diablo tune with no adjustments for 2 days (only about 20mi...which i took pics of, before and after wiping them...see below). I then brought the slope to -8 and only sent the PE tables +3 on each....I'll do a log in a couple of days and report back then. BUT!...this is further enrichening the mixture, right? Going - on the slope tells the computer that the injectors are smaller and to shoot more fuel, correct? This ain't gonna help the soot issue at all....which brings me to my next point...

Here's the deal: I drove LESS THAN 1 MILE and parked. I came back out to the car and the left tip is full of soot again (worse than the pic above)...the right is as well, just not as bad as the left. I'll post more pics later to show you how bad it is with these settings, and it will only have been driven a total of 6 miles by that time this evening. I don't know what's happening here. If others aren't this bad, what could be causing this to happen in the first place. It can't be good for the cat, all this crap shooting through it.

Here are the tips before i wiped them this afternoon. This is from the Diablo tune before any adjustments...2 days since last cleaning:




Here are the tips after wiping them out (notice how bad they are after wiping them out from the contant barrage of enrichened exhaust):