Newbie Questions - Changing Tunes, Gas And Clearing Computer

[jmulvihill]

I just got my Predator U7193 for my stock 2004 SSR with the 5.3L. Sorry, these are probably basic, silly questions for you all. I just want to make sure I do not mess anything up as I learn more about this tuning system. I have never used one before, so am in new territory.

I plan to run the 91 or 93 octane tune (my stations are Shell and Texaco, so please advise if these will work OK... Mobil is 35 miles away one way in the opposite direction that I usually drive...), but currently have Shell 87 in the tank. Should I just wait until I use up the current tank, or can/should I install the 87 tune, then swap back to stock when I make the switch over, then reinstall the 91 or 93 tune? If I install the 87 tune, then fill up with and run the higher octane on the 87 tune till I get home to reprogram, will it cause problems? Is the Stock-87-91/3 tune process OK, or should I go stock-87-stock-91/3?

After the install of the tune, should I pull the fuse for the engine computer to reset for the new tune/fuel? I think I saw somewhere it is fuse #27 on my SSR. If I have to go through the tuning swap above, should I do this computer reset process each time between tune changes?

I also have a new Amsoil nanofiber filter on order. When I get this, will I need to tweak anything on the Predator tunes to get the best performance for the hopefully improved airflow? I was also thinking about going from the 75mm TB to the GM 80mm performance TB, so same question there on the tune as with the filter change. Anyone installed this TB, and if so, did it make any noticeable difference by itself without porting the intakes?

Thanks, and again, sorry for the basic, newbie questions. I am really hoping that I will see some increased performance on the SSR. I love the car, even the way it is, but have been told this will put a nice litttle extra kick in her step! Won't make it a race car, but that is not why I got it. Just trying to make some low-intrusion changes to stock for improved performance and maybe extra MPG given the way I usually drive it (not hard at all).

Thanks all!

Joe ...
Blue Ridge, TX

[jmulvihill]

I am looking at my manual for the locations of the fuses, and it seems that fuse #27 is not the one I need to remove for 10 minutes to clear the computer. #27 is the windshield washer....

I see 2 fuses for the Powertrain Control Module ( PCM fuses #13 and #29) and one for the Throttle Actuator Control (TAC fuse #20). I guess I just need to know which one(s) I should pull to reset the computer to null and ready to relearn with the new tune/fuel combination.

Thanks all!

Joe ...

[mikel]

No need to pull the fuse after flashing.
Go ahead and install the 93 octane tune if you have access to 93 octane fuel, if not, use the 91 tune.
Wait until you get rid of the 87 that is in there now, then tune the truck.
The air filter will have no impact on the tune.

Thanks

[jmulvihill]

Mike -

Thanks for the quick response. I will burn this tank out and then switch to the Shell 93 octane. If I put in the 93 tune, and then am traveling and can only find 91, will that cause a big problem, other than performance will not be optimum until I get back to the 93? Is there a general rule of thumb when it comes to burning lower octane on a higher tune, or higher octane on a lower tune? Again, I know performance will not be as good with the mismatched tune/fuel, but will either of these situations harm the engine if the situation of available fuel warranted it?

Again, sorry for the silly questions. I am not an engine expert by any stretch of the imagination.

Thanks so much!

Joe ...

[06MonteSS]

don't use Shell if you don't have to... use Mobil (first choice), exxon, sunoco, amoco, bp.

I used to use Shell 93 all the time, until I started doing logs when I got my Predator and noticed all the KR I was getting. After speaking with the guys here at Diablosport and found out that they recommend the brands I just listed, I switched to Mobil 93... and low-n-behold, most of my KR went away.

Also, if you run a 93 tune and only put in 91, you'll get knock/ping - due to the 93 tune having more aggressive spark advance/timing settings that the lower octane gas can't handle. General rule is, don't do it. Use the tune matched for the fuel octane you're using.

keep the predator in the truck... if you have to fill up with 91, install the 91 tune. then switch it back when you put in 93 octane.

[joeyz71]

[quote=I used to use Shell 93 all the time, until I started doing logs when I got my Predator and noticed all the KR I was getting.quote]

When you were getting KR from other brands of gas, did you hear it too, or was it just viewable with the Preditor? Also, did it show up in LTFT's and O2 voltages?

[jmulvihill]

06MonteSS -
Thanks for the info. I would go for the Mobil, but the closest station is 35 miles away. I would have to burn 3~.5 gallons just to fill up each time. I will see if I can locate an Exxon close. I think there is one down in town. As for keeping the Predator in the truck, it is hot here in north Texas and I would be fearful that the heat could kill the unit if left in a hot car all the time. Maybe I could only put it in if I were traveling, since I know I can readily get 93 octane here in this area.

Thanks again!

Joe ...

[06MonteSS]

When you were getting KR from other brands of gas, did you hear it too, or was it just viewable with the Preditor? Also, did it show up in LTFT's and O2 voltages?

no, it wasn't audible knock.. but showed up in the Predator logs - sometimes as high as 8 or 10....

need to log the Total Knock Spark Retard... ltft's and O2 data won't show ya, not that I've seen or noticed anyway...

[FastBlueSS]

How much longer till TCM support?