Jordan123

one on my friends says 4.6l respond good to timing adjusters. What is that? how does it work? can i run it with nitrous?

cliffyk

"One of your friends" doesn't know what they are talking about.

There is a significant benefit to be hab from bumping the timing of the stock 87 octane tune, however using a "timing adjuster" to do it is the wrong way to go about it--buy a decent tuner like Sniper's Special Forces and do it right...

Jbauer

Hey cliffy, i know your the big Tuner guy around here. I just bought a diablo tuner, you think i'll feel a diffrence on the stock 93 octane? i've got intake/exhaust. I got it for cheap on ebay..should be here soon. I only really bought it for the Gears but i figured heck if the 93 octane tune is useless and wont give me any power like everyone is saying i figured i'll just go get a 87 octane tune so i can still use my updated gear ratios (you cant program gear ratios on the diablo tuner unless your on a performance tune)

Didn't want to make a thread calling you out so i thought i'd corner you and hi jack a thread

cliffyk

The Diablo Predator is very much like the Granatelli Fuego, which was the first tuner I bought (the Fuego is a good tuner, however it does nothing else Granatelli claims it does).

I have no direct knowledge of what the Predator does, however I suspect that like most handhelds, with a 93 octane tune, it will bump global timing by 2-3° and maybe lean the WOT mix out a bit. The OEM AFR at WOT is overly rich at 11.0:1 to 11.5:1, probably to make sure there's no detonation with 87 octane swill.

The main problem with handhelds (and mail-order tunes) is that the people that make them do not want to be responsible for blowing up your engine, so everything they do is very conservative.

As stated above my first tuner was a Granatelli Fuego and it's 93 octane tune (tweaked for more spark advance) made a noticeable performance difference, Sniper's Special Forces package let me get more, and the Sniper Commando package and a permanently wired Innovate LC-1 wideband O2 sensor let me really dial things in...

So, if you want to know my real opinion:

Get a wideband O2 sensor, then;

1. A handheld and a tweaked 93 octane tune is better than nothing;

2. Get Sniper Special Forces;

3. Get Sniper Commando and really be in control;

If I had it to do over again I would have bought Sniper Commando right up front and saved $250 versus buying the Fuego first and realizing that handheld tuners suck...

Jbauer

Ok, so i'll just install the 93 octane tune since its better then nothing.. will i atleast get the 15-20 HP and TQ they are claiming? I mean, that seems like an awful lot of Horse power.

cliffyk

The stock 87 octane tune sucks, and not just because it's an 87 octane tune--it's a crappy tune that has the AFR at WOT in the 11.0:1 to 11.5:1 range (s/b around 12.5:1 for an n/a engine), and in which the overall timing is 2° to 3° less advanced than it could. I am certain these are both deliberate to make damned sure there's no way anyone or any pump gas can blow up the engine.

No one wants to listen, however after replacing the stock exhaust a tuning system (handheld, PC-based or whatever) should be the next mod for anyone serious about upgrading. Soon to be followed by or In conjunction with a TB/plenum package. While on the topic, other than the JLT products aftermarket CAIs are a stone cold waste of money. The OEM intake is a CAI, and not a bad one.

So, what are your other mods?

I went from 220/243 peak rwHP/TQ when I first bought the car--the only mods were and o/r H-pipe and welded in Flowmasters (absurdly loud)--to 246/276 with a 70 mm TB, plenum, catted-X, Magnaflow catback, and a tweaked 93 octane Granatelli Fuego tune.

That's 26 HP peak, with non-peak gains of 10 to 25 HP (peak HP is NOT everything by a long shot.

Here's a link to my accumulated dyno runs...

The Sniper Special Forces tuner let me get to 252/295 peak, with 5 to 20 HP gains in the midrange. I upgraded to Sniper Commando in August and hit 260/298 peak by dialing in the AFR between 5k and 6k rpm, I got lazy and haven't updated the chart yet.

So if you are currently running the stock tune, an additional 15 to 20 peak rwHP is entirely possible from even a generic 93 octane tune.

Jbauer

wow, 15 HP out of a POS Diablo stock 93 generic tune?

I haven't replaced my catback with 2.5 yet but my engine mods are as follows:

O/R H, MAC mufflers, Accufab plenum, PP 75mm TB, K&N FIPK II Intake

cliffyk

I have no idea exactly what Diablo's canned tune does, however I have analyzed the Fuego and a SCT mail-order tune, and Sniper's SF 93 octane tune. They do more or less the following:

• Change AF and Lambda Blending to make the switch to open loop, and changes in AFR happen faster;
• Set the Global Spark Adder values to 2.0° to 3.0°;
• Raise the MAF Maximum Allowed Voltage to 4.99 V (from 4.79 V stock)--this buys a bit more overhead in the MAF readings;
• Raise the WOT air charge correction factor, to not let the PCM artificially limit the air flow;
• Change the Spark Borderline table to more spark advance at load above 70% and at higher rpms adding 2.0° across the board--this boosts power at high loads.
• Modify the Stabilised Open Loop Fuel table to lean the mix out a bit (not enough generally) at higher TPS voltages--this is to compensate for the too rich mixture the stock tune provides near and at WOT.

Beyond these settings, with 93 octane, you can usually add another 2° spark advance at the rpm ranges the tuner provides, and another 2.0° to 2.5° global spark. If, and only if, you have a wideband O2 sensor you can lean things out a bit more at WOT to get the AFR to 12.5:1 (I actually head a bit richer, 12.2:1 or so, as it let's you get a bit more aggressive with the timing and/or provides a bit of added detonation safety margin).

There it is...

Jbauer

Thanks cliffy.
I'll play it safe and not touch anything. they claim 15-20 HP..if i get 11 to the rear wheels i'm more than happy
I'll let you know what i think of the tuner after i install it mid next week.