What is the stock timing like?

Caprice and GM-related general tech topics. Questions & topics on vehicle tuning, HP Tuners use, etc.....
Post Reply
leonpiper69
Posts: 42
Joined: Sun Jun 27, 2021 10:27 pm
Location: North of Philadelphia

What is the stock timing like?

Post by leonpiper69 » Tue Jul 06, 2021 4:10 pm

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?

ProjectGoFast
Posts: 2
Joined: Sat Jun 19, 2021 10:02 pm

Re: What is the stock timing like?

Post by ProjectGoFast » Tue Jul 20, 2021 11:35 am

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.

s/c'd cav
Posts: 1098
Joined: Mon May 30, 2016 8:12 am
Location: PHOENIX AZ

Re: What is the stock timing like?

Post by s/c'd cav » Tue Jul 20, 2021 3:55 pm

stock timing is all over the tables , i run nothing but 87 in mine

leonpiper69
Posts: 42
Joined: Sun Jun 27, 2021 10:27 pm
Location: North of Philadelphia

Re: What is the stock timing like?

Post by leonpiper69 » Tue Jul 27, 2021 2:54 pm

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?

andrewquant
Posts: 18
Joined: Fri May 28, 2021 7:47 pm

Re: What is the stock timing like?

Post by andrewquant » Mon Aug 16, 2021 3:48 pm

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.
2013 PPV Phantom black (father son project car)
LS3 stroker 416ci, Lunati crank w/ Malhe pistons. 11.5:1
TSP Stage 3 cam w/ springs. BTR shaft rocker system
Kooks headers w/ Solo exhaust
Wideband O2 and HPtuners Pro (self tuned, WIP)
CDT Level 4 transmission rebuild and 3200 stall.
All done by my son and I, summer 2021

leonpiper69
Posts: 42
Joined: Sun Jun 27, 2021 10:27 pm
Location: North of Philadelphia

Re: What is the stock timing like?

Post by leonpiper69 » Tue Aug 24, 2021 2:56 pm

with gas being so expensive right now I will just run 87 until someday I do a cam and a tune.

Pursuit
Administration Staff
Posts: 824
Joined: Tue Apr 23, 2013 8:39 pm
Location: Omaha, NE area

Re: What is the stock timing like?

Post by Pursuit » Wed Aug 25, 2021 2:49 pm

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 Sheil

mhsheil@gmail.com

2011 Caprice Phantom Black 9C3
2012 Impala 9C1
1995 9C1 Caprice
1996 GMC Sierra C1500
1974 SJ Grand Prix 455 well optioned with factory moon roof

leonpiper69
Posts: 42
Joined: Sun Jun 27, 2021 10:27 pm
Location: North of Philadelphia

Re: What is the stock timing like?

Post by leonpiper69 » Fri Aug 27, 2021 2:39 am

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.

BluesBro
Posts: 41
Joined: Tue Aug 03, 2021 6:26 am

Re: What is the stock timing like?

Post by BluesBro » Fri Aug 27, 2021 2:27 pm

For anyone curious here are the stock timing advance maps for high and low octane. Substantial power potential difference.
Low Octane Timing Adv.jpg
Stock 2014 Timing Advance - Low Octane
Low Octane Timing Adv.jpg (367.83 KiB) Viewed 2770 times
High Octane Timing Adv.jpg
Stock 2014 Timing Advance - High Octane
High Octane Timing Adv.jpg (409.41 KiB) Viewed 2770 times
2014 Caprice PPV 6.0L - TSP Stage 1 Cam, Solo 3in Mach Cat Back, HP Tuned
2002 Avalanche 5.3L - MBRP Exhaust, RC 6in Lift

Post Reply