2011 PPV L77
A thought occurred to me...there is nothing on the dash saying "premium fuel only" etc etc and these cars have 10.4:1 compression.....
I always put super in it thinking I need to because of the compression.....but if it isn't required then is the timing really weak from the factory meaning if we bump the timing up a bunch even on a stock motor we can make a bunch more power and just have to always put super in it?
What is the stock timing like?
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Re: What is the stock timing like?
The dynamic compression is probably pretty low allowing for low octane fuel also the stock cam timing in typical GM fashion is pretty lazy. Most LS engines really wake up with a cam swap and a tune.
Re: What is the stock timing like?
stock timing is all over the tables , i run nothing but 87 in mine
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Re: What is the stock timing like?
I had a feel it's all over the place Since it's a dog off the line then pulls real hard. I figure it's a mix of the drive by wire and the timing. But though I have HP tuners and can pull the tune to look at it, I wouldn't honestly know by looking at it if it was a lazy tune or not.
I could try to compare it to the 550hp tune in my chevelle (I didn't do the tune) but that could be like apples and oranges.
Why would the dynamic compression be low? Would it be something like cam overlap causing cyl pressure to bleed off etc?
I could try to compare it to the 550hp tune in my chevelle (I didn't do the tune) but that could be like apples and oranges.
Why would the dynamic compression be low? Would it be something like cam overlap causing cyl pressure to bleed off etc?
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Re: What is the stock timing like?
The cars were fleet vehicles, so a requirement for the OEM was that they run on 87 octane. If you want to run premium only, then you can bump up the timing 5-15 degrees across the board.
As a side note, I have ran my HPtuners scanner in several cars that were advertised as "premium fuel only" but with 87 in the gas tank and looked for engine knock with HP tuners, and I have yet to find a stock vehicle that was "premium only" and then had knock detected with 87. So basically if you have a stock, untuned car (of any kind) you are probably wasting your money on 91-93 gas because your car isnt running timing for it even tho the manual may say so.
As a side note, I have ran my HPtuners scanner in several cars that were advertised as "premium fuel only" but with 87 in the gas tank and looked for engine knock with HP tuners, and I have yet to find a stock vehicle that was "premium only" and then had knock detected with 87. So basically if you have a stock, untuned car (of any kind) you are probably wasting your money on 91-93 gas because your car isnt running timing for it even tho the manual may say so.
2013 PPV Phantom black 1,077 RWHP 1,015 RWTQ 9.9@148
LS3 stroker 417ci, Callies crank w/ Malhe pistons & Darton sleeves. 11.5:1
Procharger F1a94. 22 psi boost E85
Water/Meth + 180hp N20
BTR custom cam 235/257 .638/.629 116, BTR shaft rockers Johnson 2126 lifters
BTR Trinity intake Kooks headers w/ Solo exhaust 3"
CDT Level 4 trans build w triple disc TC
Holley 120lb injectors
MT ET Street R 305/45/R18 on 10" widened OEM wheels.
LS3 stroker 417ci, Callies crank w/ Malhe pistons & Darton sleeves. 11.5:1
Procharger F1a94. 22 psi boost E85
Water/Meth + 180hp N20
BTR custom cam 235/257 .638/.629 116, BTR shaft rockers Johnson 2126 lifters
BTR Trinity intake Kooks headers w/ Solo exhaust 3"
CDT Level 4 trans build w triple disc TC
Holley 120lb injectors
MT ET Street R 305/45/R18 on 10" widened OEM wheels.
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- Joined: Sun Jun 27, 2021 5:27 pm
- Location: North of Philadelphia
Re: What is the stock timing like?
with gas being so expensive right now I will just run 87 until someday I do a cam and a tune.
Re: What is the stock timing like?
Keep in mind that these cars are Flex Fuel also. The fuel management can tell what inlet air temp, coolant temp, throttle position, load, octane and alcohol content is available. The fuel management controls injector pulse width and the spark. The spark tables to choose from are HUGE.
Maurice
Maurice
Maurice Sheil
mhsheil@gmail.com
2011 Caprice Phantom Black 9C3
2012 Impala 9C1
1995 9C1 Caprice
1996 GMC Sierra C1500
1996 Chevrolet K2500 Extended Cab, long box, 454, 91,000 rust free miles
1974 SJ Grand Prix 455 well optioned with factory moon roof
mhsheil@gmail.com
2011 Caprice Phantom Black 9C3
2012 Impala 9C1
1995 9C1 Caprice
1996 GMC Sierra C1500
1996 Chevrolet K2500 Extended Cab, long box, 454, 91,000 rust free miles
1974 SJ Grand Prix 455 well optioned with factory moon roof
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- Joined: Sun Jun 27, 2021 5:27 pm
- Location: North of Philadelphia
Re: What is the stock timing like?
had no idea the ECU could see the octane.
That would make sense why it doesn't "require" super unleaded. if it can sense cheap gas it would pull timing I guess. I have run it with both and getting on it I can feel no difference though.
That would make sense why it doesn't "require" super unleaded. if it can sense cheap gas it would pull timing I guess. I have run it with both and getting on it I can feel no difference though.
Re: What is the stock timing like?
For anyone curious here are the stock timing advance maps for high and low octane. Substantial power potential difference.
2014 Caprice PPV 6.0L - TSP Stage 1 Cam, Solo 3in Mach Cat Back, VCM OTR, Pedders Coilovers, HP Tuned
2002 Avalanche 5.3L - MBRP Exhaust, RC 6in Lift
2002 Avalanche 5.3L - MBRP Exhaust, RC 6in Lift