110 Octane makes a difference on near stock boost?

[rob350]

The last time I went to the strip, I fill up with 110 octane and drove the 30+ miles with 16 psi of boost with my turbo tweak street chip. After awhile, It seemed as if my car was pulling alot harder even though I did not increase the boost yet. Am I crazy or does the fuel help at that PSI? Kind of a weird question, but I was thinking about this the other day.

Thanks,

Rob

 

[chadly]

It could make a difference I suppose. Let’s say your car was knocking and you did not know it. The car would be pulling timing and this would cause the car to run slower times. Now with the 110 octane the car no longer knocked so no timing was pulled and the car indeed would run stronger.

 

[ghall]

It could make a difference I suppose. Let’s say your car was knocking and you did not know it. The car would be pulling timing and this would cause the car to run slower times. Now with the 110 octane the car no longer knocked so no timing was pulled and the car indeed would run stronger.

Unless it's a KB chip:biggrin:, it should not be knocking at 16 psi. If it is not knocking, the 110 will actually slow you down.
Was it knocking before the 110?
What kinda scan tool?

 

[darkred87T]

It could make a difference I suppose. Let’s say your car was knocking and you did not know it. The car would be pulling timing and this would cause the car to run slower times. Now with the 110 octane the car no longer knocked so no timing was pulled and the car indeed would run stronger.

X2. It slows you way down when the car starts pulling timing. I found the best combination for where I'm at now is 93+alky.

 

[GNVenom]

110 octane will slow you down using stock parameters. High octane fuel burns slower. Even with two or three degrees of knock retard, you won't really notice an ET difference using 93 octane fuel. The fuel needs to burn rapidly to produce proper combustion, and slowing it down will slow the vehicle.

Ideally, you should run enough timing advance at WOT to run on the "ragged edge" of combustion. A bit of KR is acceptable, but NO KR is not giving you the ragged edge performance. You need to monitor the KR to know where your combustion stands.

 

[Race Jace]

110 octane will slow you down using stock parameters. High octane fuel burns slower. Even with two or three degrees of knock retard, you won't really notice an ET difference using 93 octane fuel. The fuel needs to burn rapidly to produce proper combustion, and slowing it down will slow the vehicle.

Ideally, you should run enough timing advance at WOT to run on the "ragged edge" of combustion. A bit of KR is acceptable, but NO KR is not giving you the ragged edge performance. You need to monitor the KR to know where your combustion stands.

x2 exactly

 

[Pronto]

16lbs on what boost gauge?
What scan tool?

Cam seems like overkill for a 32lb injectors and stock turbo.

 

[CaptainInsane-O]

It takes more energy to ignite 110 (higher knock resistance) but differences in the actual burn rate of race gas vs pump are negligible...

 

[rob350]

16lbs on what boost gauge?
What scan tool?

Cam seems like overkill for a 32lb injectors and stock turbo.

VDO boost gauge

Scanmaster

Yeah I know, I'v been told several times that my cam is way to big.

Also, I was never seeing any knock at 16 psi with 93 octane.

 

[Pronto]

Was it cooler the time you used the 110 in comparison to the 93? Cool dry air will give you more power.

 

[turbo nasty]

Octane # is the fuels tolerance to cylinder psi

Incease cyl psi by more boost and or timing.

GNVenom has it right it should slow down a little and be richer.

If iy picked up then that would typically lend to teh chips parameters being too much for pump gas. Like teh KB chip that was mentioned

 

[bison]

If it is not knocking, the 110 will actually slow you down.

No. The engine could tolerate 32-33* advance (maybe a little more) at 16psi with straight 110. I can assure you and prove it on any car you choose this spring that it will make considerably more power in a back to back comparison vs. running 93 octane with 18* advance. There is no replacement for octane. I ve seen plenty of cars detonate at 16psi too. With 8:1comp ratio on a nearly stock engine, a fat tune, and 18* advance it likely wont detonate and that is what you commonly see in a chip burned for pump 93 octane. At 12.0:1 a/f with 32* advance and 110 octane you would likely be seeing 40hp more on a nearly stock combo. Something heavily modded with really good heads and a capable valvetrain that can turn some rpm you would see a lot more.

 

[bison]

A bit of KR is acceptable, but NO KR is not giving you the ragged edge performance.

Dont try this making 100+hp per hole or you will see that knock truly is not acceptable. Id be very very careful with that statement since a little to one could mean a lot to another. We all know of nearly stock engines that ran on the grenade mode for years and never broke but you simply dont hear of guys running low 11's or faster with a little detonation getting away it. Tuning for no detonation ever is the most reliable and will likely prevail over one who tolerates a a little but has to at minimum replace head gaskets once in a while.