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23 Posts
Discussion Starter · #1 ·
Hi All,

First of all, I want to thank everyone who contributes regularly to this forum. I have owned my 04 A4 GTO since 3/31/05. This forum (and the search function) has been valuable beyond words to me over the last 6 months.

I have driven around with the Predator tuner watching the live data function for several weeks. Using the advice of many of you in this forum, I constantly tweak settings.

I'd like all you Predator gurus in this forum to give me a critique of my settings and tell me if they're good, bad, or ugly, and see if there's any room for improvement.

First off, I have only 3 modifications on the engine thus far that would have a bearing on these readings. I have a 160* thermostat (the engine runs 181 to 185) and a Speed Induction Intake with 9" K&N cone filter. (This is similiar to the New Era intake...it has NO heat shield. I plan to put a Lingenfelter intake on it this Winter with the enclosed shield) I have also re-located the IAT sensor to the lower edge of the inside of L.F. fenderwell where it gets close to the ambient air stream. The exhaust system is stock. I only run Shell V-Power 93 (yea, I'm a sucker for that "top tier" gas thing).

My tune is the standard Predator Performance tune with the following tweaks:

LTFT is +3 to +5 at an idle to 2000 RPM's (indicating I'm lean at low RPM)
LTFT is is -2 to 0 at WOT and anything above 3500RPM's
STFT is all over the place in normal driving, but is also 0 at WOT

My O2 Sensors read 450 to 700 in normal driving and flucuate wildly, but all 4 sensors lock on

920 to 925 at WOT.

On sudden WOT I'll get an instant of KR at 0.3. The most KR I've ever seen is 1.7 and that was just for an instant. 99% of the time it stays at 0.0

My timing varies from 15 to 32 degrees in normal driving. It locks on to 24 or 25 at WOT, but will back down to about 22 in an extended WOT run. (I suspect this is due to my non heat shielded intake sucking hot air.) My IAT temps from the relocated sensor read anywhere from 89 to 110 depending on outside temp)

The following was done to obtain these settings:
2K to 4K Fuel +6
4K to 7K Fuel +6

Fuel Injector slope at -6

2K to 4K timing is +2%
4K to 7K timing is +1%
I've tried going up to +3 or +4 on timing in both ranges, and I get 2 or 3 on KR...(I suspect due to unshielded hot air intake)

I know I must be going in the right direction with all this, as my fuel mileage in town has gone from 14.5 to 17.2 and my highway mileage has gone from 22.4 tp 25.1 with an A4. But I still feel like from my SOTP dyno, there is room for more improvement. (and I think my upcoming CAI will help) But I'd really appreciate any feedback on this from all the Predator guru's on here to see
how this compares with those who have had or done dyno pulls with their Predator tunes.

I do not and probably never will race this GTO. It is my daily driver. I simply want it to run at it's maximum efficiency for power and economy.

TIA for any help


· Registered
410 Posts
AGR81 said:
LTFT ... STFT ... WOT ... KR ... IAT ... SOTP ... CAI ...
For those of us that struggle with acronyms and dream of someday have a Predator, SuperChips, or HPTuner, could you spell out some these so we can follow. I laughed at myself when I first realized SOTP is "seat of the pants". For others like me, WOT, wide open throttle; IAT, inlet air temp; CAI, cold air induction; TIA, thanks in advance. I'm lost with the others.

· Registered
23 Posts
Discussion Starter · #3 ·

Sorry about that, I just assumed it would all be Predator guys looking at it and they'd know. Although I ws an ASE certified Master Tech from 86 to 96, that was back in the OBD1 days. This is all OBD2, and I can't say that I understand all of it... I know what it is in theory, from reading so many posts on ls1gto.com and diablosport.com....but I'd be hard pressed to really explain it. But here goes:

LTFT is Long Term Fuel Trims (they are "supposed" to be 0 to -11 according to James at RWTD (running with the devil tuners....he's a Predator guru)
STFT is Short Term Fuel trims (they should be 0 at WOT also.
KR is Knock Reduction It should be 0 to 1 at WOT.
O2 is Oxygen sensor readout expressed in a voltage that I think is kVu <?> It is the oxygen level transmitted to the car's ECM (engine control module, but I'm sure you knew that) and converted to an electrical signal read on a diagnostic tool.

You adjust your fuel and timing in various RPM ranges and your injector slope on the Predator to adjust LTFT and get them in negative numbers to 0. That is the most important setting (per James at RWTD) Injector slope has "something" (I think) to do with injector spraying and A/F ratio...but I don't know what, exactly.

Everything else you firgured out well. So if you know any Predator gurus on this forum...steer them to my post for a critique. Thanks

· Registered
23 Posts
Discussion Starter · #4 ·
Hi again all,

I know my original post is LONG. But I was hoping for more than one reply wanting an explaination of acronyms.

There's got to be some guys on here that have tweaked with their Predators a lot longer than me, and have this down pat. Or maybe even some guys that could share some Fuel, Spark and Slope settings from a RWTD tune to obtain negative LTFT's.

Although I was a 13 year Busch Grand National engine builder and tuner in the 80's, and was an ASE tech from 86 to 96....this PCM tuning is rather new to me. And most of my settings have been monkey read -- monkey do.

Hope someone will look over this and give me some pointers.

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