Let's compare trucks GM/Chevy to Dodge!

[evilstevie]

And you're not making any more power with 93 than you are with 87. But as long as you "understand how motors work" that's the important thing I guess. Good luck.

 

 

i run 93 in my 5.3 just because i understand how motors work with compression and i want the power the motor as it was designed.

 

[kstruckcountry]

And you're not making any more power with 93 than you are with 87. But as long as you "understand how motors work" that's the important thing I guess. Good luck.

 

What makes you think that?

 

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[Willyone]

Interesting info jgreen. I didn't realize the 5.3 comp is 11:1. I've been filling up with 87 and once in a while 89. I'll try a couple of tanks of 93 and see what happens.

 

fwiw... My 557ci boat engine (bored/stroked GM crate ZZ502/502) had 9.3:1 comp and I used 93 oct. in it. Ran like a raped ape (o:

[roadkill5.3]

And you're not making any more power with 93 than you are with 87. But as long as you "understand how motors work" that's the important thing I guess. Good luck.

 

So on a motor, when you retard the timing, you don't loose power and throttle response? this is new information here. Keep going with your theory's please, I'd love to see which planet they came from. I'll buckle up and go for a ride in your vortex, hoping I can further understand why and how you think this is true.

[evilstevie]

So on a motor, when you retard the timing, you don't loose power and throttle response? this is new information here. Keep going with your theory's please, I'd love to see which planet they came from. I'll buckle up and go for a ride in your vortex, hoping I can further understand why and how you think this is true.

This isn't the 50's anymore brother. It's a DI motor. Google that. Virtually all DI motors from virtually all manufacturers have high compression ratios and run on 87. Ford has a V6 that's rated at 365 hp, not to mention Ram's 395 hp motor. Do you really think GM is going to have the weakest rated truck motor if they could simply certify it at say 380 hp at 93 octane? No they would not.

The motor does not know what octane gas you put it. It only knows when it knocks. It does not knock at 87, so it does not retard timing at 87. It makes the same power at 87 or 91 or 93. Post dyno results from reputable sources that prove otherwise or go play somewhere. Myths and folklore and internet rumors don't cut it for me.

[KARNUT]

Some tuners on here have documented reduced power due to knock retard on 87 grade gas. Just as you can run E85 high octane fuel and gain 25 HP. Sounds responsible to me.

[Donstar]

Lots of Ram talk on the forum lately. Here's a good place to start.

 

http://www.gm-trucks.com/forums/topic/196346-who-traded-in-for-a-ram-and-what-are-your-honest-thoughts/

There has been a couple of very similar posts. If a person is truly interested in more information about RAMS then it would make more sense to look on a RAM forum, imo.

[Colossus]

The difference on a fill up between regular and premium isn't that bad.

 

Example:

 

25 gallons at $2.89 = $72.25

25 gallons at $3.09 = $77.25

 

HEY! I can buy a big mac for that $$$

[Colossus]

There has been a couple of very similar posts. If a person is truly interested in more information about RAMS then it would make more sense to look on a RAM forum, imo.

The kids hanging out over on the Dodge forums are not as friendly and informative as those here.

[redwngr]

From GM site 6.2 is 11.5:1 and the 5.3 is 11:1

6.2L L86 TECH SPECS

Type: 6.2L Gen V V-8 Small-Block

Displacement: 6162 cc

Engine Orientation: Longitudinal

Compression Ratio: 11.5:1

Valve Configuration: Overhead valves

Valves per Cylinder: 2

Assembly Sites: Tonawanda, NY and St. Catharines, Ontario

Valve Lifters: Hydraulic roller

Firing Order: 1 – 8 – 7 – 2 – 6 – 5 – 4 – 3

Bore x Stroke: 103.25 x 92 mm

Fuel System: DI

Fuel Type: Premium recommended

Maximum Engine Speed: 6000 rpm

Emissions Controls: Catalytic converter, three-way catalyst, positive crankcase ventilation

Horsepower: 420 hp (313 kW) @ 5600 rpm*

Torque: 460 lb-ft (624 Nm) @ 4100 rpm*

Block: Cast aluminum

Cylinder Head: Cast aluminum

Intake Manifold: Composite

Exhaust Manifold: Cast nodular iron

Main Bearing Caps: Cast nodular

Crankshaft: Forged steel

Camshaft: Billet steel

Connecting Rods: Forged powder metal

5.3L L83 TECH SPECS

Type 5.3L Gen V V-8 Small Block

Displacement 5328cc

Engine Orientation Longitudinal

Compression Ratio 11.0:1

Valve Configuration Overhead valves

Valves per Cylinder 2

Assembly Sites Tonawanda, NY, Ramos, Mexico, and St. Catharine’s, Ontario

Valve Lifters Hydraulic roller

Firing Order 1 – 8 – 7 – 2 – 6 – 5 – 4 – 3

Bore x Stroke 96.01 x 92 mm

Fuel System SIDI

Fuel Type Regular unleaded and E85

Maximum Engine Speed 5800 rpm

Emissions Controls Catalytic converter, three-way catalyst, positive crankcase ventilation

Horsepower 355 hp (264 kW) @ 5600 rpm*

Torque 382 lb-ft ( 519 Nm ) @ 4100 rpm*

Block Cast aluminum

Cylinder Head Cast aluminum

Intake Manifold Composite

Exhaust Manifold Cast nodular iron

Main Bearing Caps Powder metal

Crankshaft Cast nodular iron

Camshaft Billet steel

Connecting Rods Forged powder metal

[roadkill5.3]

This isn't the 50's anymore brother. It's a DI motor. Google that. Virtually all DI motors from virtually all manufacturers have high compression ratios and run on 87. Ford has a V6 that's rated at 365 hp, not to mention Ram's 395 hp motor. Do you really think GM is going to have the weakest rated truck motor if they could simply certify it at say 380 hp at 93 octane? No they would not.

The motor does not know what octane gas you put it. It only knows when it knocks. It does not knock at 87, so it does not retard timing at 87. It makes the same power at 87 or 91 or 93. Post dyno results from reputable sources that prove otherwise or go play somewhere. Myths and folklore and internet rumors don't cut it for me.

The trucks do know what type of fuel is in the motors. They sense it by pinging or fuel knock caused by early detonation caused by compression . They automatically retard the timing of injection and spark to make the fuel, air, and spark all work how it was designed to. Which leads to poor throttle response and minimal HP loss. Just because it has DI does not mean it does not retard the timing, every motor does this whether you think it or not. In the 50's you had to manually retard the timing by adjusting the distributor with a timing light.

Your statements are very uneducated just because you fail to understand how motors work with current technology being used. And I also will agree I'd love to see dynos of 87 89 93. That would be awesome! And as someone else posted, throw e85 in it and it will make 25hp more, how? Timing.

[Dock Rocker]

The trucks do know what type of fuel is in the motors. They sense it by pinging or fuel knock caused by early detonation caused by compression . They automatically retard the timing of injection and spark to make the fuel, air, and spark all work how it was designed to. Which leads to poor throttle response and minimal HP loss. Just because it has DI does not mean it does not retard the timing, every motor does this whether you think it or not. In the 50's you had to manually retard the timing by adjusting the distributor with a timing light.

Your statements are very uneducated just because you fail to understand how motors work with current technology being used. And I also will agree I'd love to see dynos of 87 89 93. That would be awesome! And as someone else posted, throw e85 in it and it will make 25hp more, how? Timing.

E85 is close to the equivalent of 100 octane. The turbo guys love it because that are able to add some serious timing using gas from a pump.

 

 

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[evilstevie]

The trucks do know what type of fuel is in the motors. They sense it by pinging or fuel knock caused by early detonation caused by compression . They automatically retard the timing of injection and spark to make the fuel, air, and spark all work how it was designed to. Which leads to poor throttle response and minimal HP loss. Just because it has DI does not mean it does not retard the timing, every motor does this whether you think it or not. In the 50's you had to manually retard the timing by adjusting the distributor with a timing light.

Your statements are very uneducated just because you fail to understand how motors work with current technology being used. And I also will agree I'd love to see dynos of 87 89 93. That would be awesome! And as someone else posted, throw e85 in it and it will make 25hp more, how? Timing.

There is no magical gasoline octane detector these GM trucks, nor is there is a higher octane map for 91 or 93 octane in the 5.3 There is a flex fuel sensor in the flex fuel trucks, which detects the presence of E85, NOT 91 or 93 octane gasoline. Of course there's a knock detector like there is in any modern vehicle, but there is no mechanism in these trucks to modify the timing to give you more than 355 hp if you put in higher octane gasoline. If your butt dyno tells you that you're making +50 hp with 93 octane gas I can't help you.

[kstruckcountry]

There isn't a map for "91" or "93", but you can be very sure the PCM switches maps when knocking is detected. Which is about guaranteed to happen on an 11:1 engine running 87 under any real load.

 

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[roadkill5.3]

There is no magical gasoline octane detector these GM trucks, nor is there is a higher octane map for 91 or 93 octane in the 5.3 There is a flex fuel sensor in the flex fuel trucks, which detects the presence of E85, NOT 91 or 93 octane gasoline. Of course there's a knock detector like there is in any modern vehicle, but there is no mechanism in these trucks to modify the timing to give you more than 355 hp if you put in higher octane gasoline. If your butt dyno tells you that you're making +50 hp with 93 octane gas I can't help you.

The knock sensor retards timing to prevent fuel knock or pinging. It will also advance timing if non is detected which creates more power. Nobody said any thing about +50hp on 93. We said +25 on e85 with stock tune. Here is some free ASE material on knock sensors. http://www.freeasestudyguides.com/knock-sensor-symptoms.html

And to your statement about it having knock sensors but it doesn't modify timing, what would the purpose of knock sensors be then? You seem highly intelligent and are looking more and more incompetent, I really hope you don't work on your own vehicles.