Octane Booster

[flying V]

Does anyone know if the v rod will benefit from octane booster in near stock form ; or is it "max" tuned for 93 octane.
Thanx...KEO

[ChopperSteve]

I have not seen a need for anything above 93octane.
Best:Steve

[SuperKaz]

Not inless you do major mods of tweak the timing.It will actually make more power or 91/92 than 100 in stock form.Now if you have the cash$8.00-$21.00 gallon gets some OXCEGENATED RACE FUEL like NuTec or VP Utimate 4.Thats worth about 3-4 rwhp!
Kaz........

[Ketsugo]

Absolutely NO reason to up octane above 91 or 92. You bike will be slower with 100 octane than with 92. The higher the octane, the slower the burn. The V-Rod's compression ratio isn't high enough to burn all the fuel at 100 octane. And besides, those octane boosting products are worthless.

John

[RussD1500]

There is an "old" Timer Sunoco station about 15 miles from me, They still have the 110 and 115 octane racing fuels in stand alone pumps. When I'm near by, I make it a point to stop and get a 50/50 mix of the 93 and 110, SHE loves this combo, just seems to run better, smoother, and a little quicker, But the 110 is 5.50 per gal, never even looked at the 115 pump, the added benefits are not worth a constant diet of this, BTW my V is 100% stock

[VRodDrew]

The best octane rating for any motor vehicle is the LOWEST that does not cause engine knock. The only way to gain any benefit whatsover from higher octane rated fuels would be to increase the compression ratio of the engine (i.e. modified pistons, etc.)

Stick with the factory recommendations - don't waste your money on octane boosters, aviation gas, etc.

[Ketsugo]

No offense Russ, but the perceived increase in performance is in your mind. Higher octane than the minimum needed, lowers performance. This is NOT an opinion, it's fact.

John

[mjw930]

Drew,

You're spot on regarding running the lowest octane designated for your motor (91 for the V-Rod) but not entirely true on the rest. Increasing timing and leaning out the mixture are two benefits from higher octane fuel that WILL add power to the rear wheel. To take advantage you would need separate maps for each fuel grade. The separate maps are easy, it's the downloading that's the problem. Maybe HD will come up with a PDA version of the RT.

However, if you don't have your tune set for the higher octane then you're just throwing away money. It won't make any more power though it may run a bit smoother due to slightly smoother flame front.

[Polizzio]

I'm with John on this topic. A couple years ago, Hot Rod Magazine did an in depth article and dyno test on this topic, obviously with high performance automotive V-8 engines. Bottom line was high octane race gas did nothing for an engine, actually made slightly less power than 93 pump gas, unless the engine had a very high compression ratio, dictating the need for high octane race fuel. Run only as much octane to eliminate detonation or preignition.

[mjw930]

This reminds me of the amusement we had at the expense of some competitors durring the 1999 - 2000 APBA Offshore race season. Mercury Marine had just come out with their fuel injected 415 HP magnum 502 and it was certified for "E" class (basically 100% stock boats 22' - 28'. single engine). Anyway, we found out early in the season that the EFI was calibrated for 87 octane fuel after we noticed a 4 mph top end loss of speed with 93 octane. Many of the other teams never spent to time to test and started using 93 from day one thinking "more is better". We even went so far as to label our fuel jugs "93" just to perpetuate the myth. Needless to say we cleaned up in the first few races and were challenged every time but nothing could be found.

Here's what was happening (from the Merc EFI specialist): The system was designed to use knock sensing to determine the optimum advance curve. In their design they would advance the timing until they sensed the onset of knock then back off, always keeping the motor at the edge of pre-ignition to get the maximum performance. There was a safeguard built in just in case the knock sensor was defective. If the system advanced the timing past a certain point relative to the base curve without sensing knock it would assume a broken knock sensor and subtract 20 degrees of timing! It would then slowly work it's way back up and when it hit the magic number drop off again. Well, with 93 octane fuel and such a relatively low compression motor there never was pre-ignition so the system was always running in a failure mode

Bottom line, run the fuel that manufacturer programmed the motor for and nothing more, you may end up costing ourself some performance and you are definately wasting money.

[SuperKaz]

Mark is RIGHT!If your Bike/Car is Lean or you put a ton of timing in them they will make more power with the higher octain fuel which well prevent detonation.Believe me I know First Hand!!!!!!!!!! On a stock machine the Lowest as you said that does not Ping will make the most power.
Kaz.......

[bill_pro199]

I have been running Union 76 Premium my 03 for the last 5000 miles. When I was on the way back on a ride I stopped off to fill up at a Chevron. After about 20 miles of ridding I noticed a gain in power and throttle response after filling up there. Its like it cleaned out the motor. Maybe it’s the Techron additive? They say it cleans out the deposits on the intake and valves.

[Karl Scott]

OK, I have REALLY learned something here!

I have ALWAYS thought that you increased the Octane to go faster. We have pretty high octane fuels In Australia it seems. Fuels like BP Optimax is 98 and I have been using it when I can get it, or a 98 octane equivelent, but smaller gas stations don't always have it. Premium is 95 and available everywhere. Standard is 93. The dealership is recommending 95 octane unleaded as a minimum.

I just spoke to one of the guys in service over here and he didn't know diddly, and I think he would have learned as much as me reading these posts re fuel and performance to be honest.

I think the bikes that come out here have a different injection map for this? Anyway to find out?

[ChopperSteve]

Well Karl, I will try to sum it up. The "Octane Rating" tells you how much resistance to detonation it has. Unfortunatley most octane boosters slow flame speed[ keep it stable ] This can make an engine miss its "peek cylinder-Crank Angle mark" resulting in the engine making less power. You can fix this by bumping the timing up or raising the effective compression ratio, but then you would have to run the high octane all the time. To some up: Run the proper octane for the engine design Octane is not "energy potential" but a resistance top "Knock". Most Octane boosters are some form of Alcohol, with its "latent Heat" can increase intake charge volume, if you make the air/fuel richer. Thats why [IMHO] some people feel octane boosters add power.
Best: Steve

[chris_1001]

Hey RussD1500, I'm over her in Norton MA... Where is this Sunocco? I'm curious?

I just run 91-93 (depending on what the gas station has), I dont worry unless I hear knock...