regular or premium fuel

[lragan]

Since folks are offering opinions, I will chime in with mine, albeit uninformed.

The whole exercise is to burn the fuel at the right time, and at the right rate, to maximize the power -- traded against the need for complete combustion to avoid leftover combustion products lying around on valves, plugs, etc.  If the engine achieves these two goals, the tradeoff between power and efficiency will be well balanced, too.

I suspect, Guy, that the way the engine "breathes" has a lot to do with it.  The flow of gases through the cylinders may have as much to do with it as the actual compression ratio.

With four carbs and four exhausts, Maggie breathes really well.  Addition of aftermarket pipes and a K&N filter clearly improves the respiration, otherwise one wouldn't need new jets and shims to get the mixture right.

I see no need to go to higher octane, slowing the flame front, unless one experiences pre-ignition (pinging). 

Just my speculation...

[Chad in Michigan]

I run premimum and i really think it makes a difference, at least with my setup. here's a vid taken of my current throttle response with my setup as of today, with premium in the tank, bigger jets, timing curve changed with the dyna 3000.


http://www.fileden.com/getfile.php?file_path=http://www.fileden.com/files/2009/4/8/2396413/QuickThrottle.3g2

click the link and then right click save as - it plays smoother. i play it on quicktime.

if i ran the low octane the throttle response would be slower and i would definately feel it while driving.

[Greg Cothern]

Remember folks higher octane is for higher cylinder temps in higher compression engines.  So as previously stated if you are not having pre-detonation (or PING) then there is no need to slow the burn process down with higher octane..

[Sledge Hammer]

It could very well help in a Ranger, which has a much lower rpm range, and therefore has time to burn the slower-burning high octane fuel. However, that has no correlation to a high-rpm engine like the Magna. If you actually feel that high octane fuel makes a difference, and are willing to pay for it, go ahead. If you choose to believe anecdotal reports from others without scientific backup, go ahead. My own experience has been that it does NOT increase either power or fuel economy, and I have indeed tried to make accurate measurements of both.

You're probably right, Dobie. Running 93 in my 3.0 L Ranger has a much more noticeable effect than in my Magna. I argued with the dealership until I was blue in the face that there is no reason for that engine to require 93 octane to operate properly, but since it wasn't audibly pinging at the time, they wrote it up as No Problem Found, took my money, patted me on the head, and sent me out the door.

With my Jack-and-Jill level of understanding of engine design and operation, what I wonder now is if it possible for pinging to be bad enough to rob the engine of output power without being audible in normal driving.

[Magniac]

With today's computerized fuel delivery and ignition controls, yes, it is possible for pre-ignition and/or detonation to occur and be damped out by the computers to the point of not becoming audible, but still rob the engine of power by retarded timing, etc.

I would like to see a side-by-side comparison of Chad's throttle response clip with both 87 and 93 octane. He says response "would be" slower with 87. Maybe so, but I'd like to see it in a direct comparison. My response (with 87 octane in my '94 with almost 90,000 on the odometer) looks just like his clip.

[Moja]

I run 87... and then I use SeaFoam around winter time each year.  None of the other grades give any kind of discernible improvement on my virtually bone stock (shim mod, thats it) '00 model.

And to all of you who get 50+ mpg, I hate you!  My commute is probably 70-30 highway-city, no traffic, few lights. I get 36-39'ish... The only way I get triple digits before reserve on a single tank is with a sustained, slowish (65-75) highway trip.  Got 107 last weekend before I hit the petcock on the way home of a nearly all highway 60'ish mile trip.  I think the last time I saw 100 was at MOOTMAG at Koyote Ranch (riding 2-up!)

But back to the topic...  the simple mantra I live by on octane (cars, bikes, or any internal combustion method of propulsion):
"Run the lowest you can get away with".  If you get a tangible benefit (placebo or otherwise) and can afford to run the higher octane, then more power to you (*)  I run 93 in my R1 by mandate of Yamaha, and the same in my car.. Volvo's orders.  I feel uneasy running anything less, although I've done it in both in a pinch, and didn't have any adverse effects for a single tank - I suspect it may be different over the long haul though.

CAB

(*) Strictly a figure of speech.. not based on any scientific or verifiable data

[L J VFR]

My pickup's owner manual states 89 or higher octane.  When I put 93 octane in it, I can tell that it runs alot better versus the 87 octane.  My brother-in-law who works for a Ford/Dodge dealership in Fayetteville told me that it wasn't just the seat of my pants feel.  He said my truck computer will automatically retard the timing to keep from spark knocking.  Therefore reducing horsepower.   I don't always buy the premium, but it does run better with it in.

[jgalaw]

My 2 cents.

If you are getting 40 mpg plus on a 3rd generation (regardless of octane) you aren't really riding.  You may be sitting on it, steering, shifting, braking and moving, but you aren't riding the Magna the way it was designed to run.

Jeff Atkins

[lragan]

My 2 cents.

If you are getting 40 mpg plus on a 3rd generation (regardless of octane) you aren't really riding.  You may be sitting on it, steering, shifting, braking and moving, but you aren't riding the Magna the way it was designed to run.

Jeff Atkins

C'mon Jeff,

I enjoy the fresh air, the feeling of freedom, the maneuverability, and the camaraderie with other riders.  It really isn't necessary to scrape the pegs and ride like a bat out of h*** to have a good time on the Magna.

As for how it was "designed to run" -- I have worked with a number of Japanese engineers in my career, but have never had the privilege of meeting any of the Honda guys.  The only data I have is the operator's manual which calls for upshifting, if memory serves, at 3000 to 3500 rpm!  Perhaps the designers didn't have a chance to talk to the guys that wrote the manual...

What data do you wish to present about how it was "designed to run"??  

[roboto65]

To chime in here and agree with  Jeff the Magnas engine was born of the VFR engine which was a race bike the Magna does not even start making any power till about 6000 rpm and drops off at around 8500 or 9000ish so to shift at 3000 to 3500 well thats fine but not putting the bike into optimal power!!! Now that being said it does a good job of cruising around at 3500 or 4000 but it is lugging at those RPMs and would not get out of it's own way..  Unless you downshift and twist the throttle and let it go  of course you would be around the 6000 or above mark!!!!

[lragan]

You are right, Allen.  If you want to accelerate quickly, you have to wind it up.  I have seen the torque and power curves.

So here is an interesting question.  When you are cruising at steady speed, at say 55 mph (assuming you ever actually steady out that slow) what gear do you use on your 3rd gen?

Put another way, do you keep the engine revved into the optimum power range above 6000 rpm when cruising at steady speed? 

When I find myself in traffic, I will keep it above 5000 in case I need to make a quick move, but on the back country roads, I don't rev it that high -- typically keep above 3500, and like it about 4000 to 4500.  Curious what others do.

[Sledge Hammer]

On back roads, Lawrence, mine gets a litttle buzzy around 3500, so I keep it either around 3000 rpm or 4000 rpm. I haven't noticed that the higher revs hurt the gas mileage all that much and that may be an indicator that the engine is actually less efficient at lower RPM. In any case, I keep my speed down on surface streets. Whatever the bike is designed to handle, the streets themselves are most definitely NOT designed for aggressive riding, no matter what the rider's level of skill is, real or imagined.

On my short stretches of highway driving, I usually have to run 70-75 mph to avoid having people running all over me, and even then I'd say at least 10% of the drivers out there thinking I'm holding them up in what is supposed to be a 55 mpoh speed zone. At 70-75 mph, I think the bike is running 5000-5300 rpm indicated on the tachometer in 5th gear.

[dgc67]

As for how it was "designed to run" -- I have worked with a number of Japanese engineers in my career, but have never had the privilege of meeting any of the Honda guys.  The only data I have is the operator's manual which calls for upshifting, if memory serves, at 3000 to 3500 rpm!  Perhaps the designers didn't have a chance to talk to the guys that wrote the manual...

IMO the manual is written by lawyers and warranty minded people.  Nothing wrong with casual riding, not that I do.   
I agreee these bikes were built to be opened up now and again and gladly do that.  Talking to my friend the other day I commented on making cosmetic changes with my "budget" and he pointed out I should do performance upgrades as that is why I really ride, not to be seen or look cool, but to go fast and enjoy the power when I feel like it.

Unless I have a need to take off fast I shift pretty quickly throught the gears.  I get it up into 6th even on 30mph streets.  On the highway I ride 70-80 and don't care about the rpm.  If I need to something urgent, in either case, I downshift.  I have been riding so many years I find that I count as I downshift and upshift sub-conscioulsy keeping track of what gear I am in.

[roboto65]

Well back and forth to work I stay at 70 or more  constant and the revs are around 5500 or so now when I am riding with a group yes I do keep the revs down but when I get in the twistys and from one turn to the next I stay at 6000 or above in the hp...

[MarylandMagnav45]

You are right, Allen.  If you want to accelerate quickly, you have to wind it up.  I have seen the torque and power curves.

So here is an interesting question.  When you are cruising at steady speed, at say 55 mph (assuming you ever actually steady out that slow) what gear do you use on your 3rd gen?

Put another way, do you keep the engine revved into the optimum power range above 6000 rpm when cruising at steady speed? 

When I find myself in traffic, I will keep it above 5000 in case I need to make a quick move, but on the back country roads, I don't rev it that high -- typically keep above 3500, and like it about 4000 to 4500.  Curious what others do.

Cruising?  I'm always in 6th gear, getting probably 60 mpg at 55 mph. 

I do not keep my Magna in the optimum power range most of the time.  I actually like cruising around town in the highest gear putting around at 30 mph.  When I get below 3000 RPM, my bike makes beautiful music...and I don't mean I'm lugging the engine or anything... My bike sounds loudest at around 2500-3000 RPM in highest gear for someone reason haha.