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timing parameter

Predator support for GM gas vehicles

Moderators: mikel, 06MonteSS, Vas@Diablosport, JonDiablosport

Post Thu Jun 20, 2013 6:36 pm

Posts: 116
Location: Louisiana
Well it'll be close from what you can see but from my experience the injector slopes help to an extent. If you add or pull to much fuel it will make you lean or rich everywhere else except the rpm your setting your cruise datalog for. If its saying -3% your adding 3% fuel across the board which will get you we're u want to be at that engine speed to make your ltft 0 but at the same time your adding 3% fuel for idle as well which will richer up your mix because you aren't pulling the same air volume. At the same time you may be going rich on the big end as well. Or lean in both cases.

That's why custom tuning the maf table is rescaled. Gives you fuel or pulls it were it needs be for more accurate tune across the board and better on engine your mpg and performance all the way around. Once that's dialed in then the wot timing adjustment can be done...

And you said something about rear o2s being gone? I hope you have a wideband or other means of fuel readout?

Now I only used the Intune never had a predator so my thought process may be a little off :p

Post Thu Jun 20, 2013 7:56 pm

Posts: 267
I have option for lean/rich 2k-3k and 3k-6k , injector slope , and idle. Nope no rear o2s. Got option for that 2. No egr. Got option. The old. Pred gives u all the sheeeeet the epa didnt want u to have. I no I'm supposed to b round 12:9 13:0 on a/f with wideband. But since no wb I watch ltft stft and knock like a hawk. Wat you said makes a lot of sense. Genius.

Post Thu Jun 20, 2013 10:59 pm

Posts: 116
Location: Louisiana
Yeap maybe your engine is different but optimum afr for most things is 14.75:1 at idle part throttle steady cruising etc. while at wot it should be 12.4-12.7 if I remember correctly.

Now try tuning a turbocharged car... It's even more fun get to play wit variable valve timing and boost spikes :p gets really tricky plus it's almost like dealing with 2 completely different sets of tunes that you have to peice into one before you could even think about hammering down and build boost.

My old motor I sold to a budy of mine roughly 650 hp at 22.5psi maxed fuel system on e85
I had it at 700hp but my fuel system was done for 1200hp rated for my new motor 700hp was max on the rods on this block so that's were I set boost for.

http://youtu.be/r_x0uwq8stE

No vids of my current build still working the kinks out before I send it down the track.

Post Fri Jun 21, 2013 5:37 pm

Posts: 267
Sik ride. Nice build. I got the 12:9 13:0 from wot on dyno. o5 Silverado 5.3 cai, headers, 3" true duels, diablo toon. 306Whp 312ftlbs. Ill post dyno sheet if I can find it.

Post Fri Jun 21, 2013 10:41 pm

Posts: 116
Location: Louisiana
Haha I have a 2001 4.8l cai flow master duals diablew tuned 335hp 343ft-lb torque.

May be higher since I put 4.11:1 rear gears that was my output with 3.42:1 factory gears with 33s
Although I was really impressed with those numbers :)

Post Sat Jun 22, 2013 9:01 am

Posts: 267
Wow. I guess im not as good as I thought at toonin. Do you think a real custom toon is gunna net 30hp over mine?

Post Sat Jun 22, 2013 11:00 am

Posts: 116
Location: Louisiana
Hard to say. It's possible. But that all depends on weather conditions fuel condition of everything on the engine(spark plugs fuel pump/filter) every minor thing you have on that vehicle plays a part. Even down to your transmission rear axle ratio and tire size. Just the way a dyno works.

Now if it were an flywheel(engine) dyno our outputs would be way higher and more acurate to tune with as you loose alot of power through the drivetrain. Especially with automatic transmissions. A rough average of drivetrain powerless (tranny/rear gear/tiresize)is about 33% while most manual trannys are a smaller amount roughly 10-20% .

Weather condition plays big role as well. Density and temperature and humidity. A cold non humid day is when you'll make the most power as the air is denser. If its hot and humidity of 90% like here in south Louisiana you'll get less power. Thinner air with alot of moisture(water particles)

And let's just say there is a trick for spark plugs...of course gap to specs with correct plugs plus If you have the fire of each plug shooting a certain direction inside the combustion chamber you could gain up to 3% more power but I can't tell everyone all my tricks :p although its extremely time consuming its worth it on the racecars I work on.

Every detail counts


Post Sat Jun 22, 2013 2:04 pm

Posts: 15670
Location: CT

Egoresb wrote:
And let's just say there is a trick for spark plugs...of course gap to specs with correct plugs plus If you have the fire of each plug shooting a certain direction inside the combustion chamber you could gain up to 3% more power but I can't tell everyone all my tricks :p although its extremely time consuming its worth it on the racecars I work on.

Every detail counts


aaaah.. ye ol' clocking of the plugs... ;)

same goes for the MAF sensor... how you have that clocked makes a difference as well, as far as how well it reads the airflow across the sensors... ;)
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2014 Camaro SS - 2SS, RS pkg., short-throw shifter, NPP perf. exhaust, BMR strut-tower brace, Cold Air Inductions cold air intake

Post Sat Jun 22, 2013 3:27 pm

Posts: 267
Im guessing u have to tap/die sparkies so they all seat at the same such and such angle??? Or maybe add a thin washer. Is it safe to use the crc maf cleaner??? Please tell me more. If I change springs and rockers but same cam will that effect anything??? I want sum rollers and I guess beehives. Cam and tbss intake later.

Post Sun Jun 23, 2013 2:06 pm

Posts: 116
Location: Louisiana
Theirs a few methods to clock spark plugs correctly... Like I said very time consuming. And yes crc maf cleaner works good.

As far as changing rockers... May affect it a little but normally not because you still have to set the lifters for the cam specs.

That's just me... If your going to trouble to changing that might as well cam it up and do it all at once.

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