Hello, I am preparing to load our bikes for this weekends two dayevent at Barber Motorsports Park in Birmingham, Alabama. After taking to a friend who is coming as well to race we were having a conversation about having every thing ready to go. I told him that I had 2- 16 Gal drums of 110 octane leaded race fuel and he told that this fuel is wrong &will take away power compared to VP's MR9 which he always uses. In the manual for VP MR9 they state that it is 91 octane.

In the past I have heardother racers say the same thing, but I am lost now because I could not ask my friend the reason why because he is from greece and hisenglish is a problem. I was always taught that the higher octane helps cool better so would this be the factor. I have to dyno alot on my two bikes because we need to trick the map system but never was told this side of the story. The tuner who helps us with the bikes always weighs the fuel and enters the specifec gravity in his map program and never told usanything different. I have been trying to get hold of him but he closes his shop at 5.We are running the stock injection systems but emc filters.

Thanks

 

VP is an oxygenated Unleaded fuel. DO NOT USE LEADED FUELS IN THIS ENGINE, YOU WILL RUIN IT IN A BIG, BIG WAY!!!!!!!

In this instance, the MR9 will outperform the 110 Leaded every single time. Use the MR9.

I think your understanding of Octane rating is a little misguided. before i start in on you, tell me what you think the difference between 91 Octane and 110 Octane.

 

Hello Knightslugger, Thank You for trying to help. The MR9 is also a leaded fuel. I have the catolog from the trackside dealer in my hand at this moment so I am really confused. I just came back in the door from asking a different tuner who strictly dyno tunes dragsters and he is very unaware of what goes on in the motorcycle world. He felt that using the 110 octance would only benefit with the 14 to1 compression ratio I have but he again went to the specific gravity thing. The only thing he said he could touch on is timing and that is all the would matter.
I am not certain where this is leading to because my cbr 600 with cam mods makes 134.39 at the rear wheel on this fuel. With other fuel I lose about 1.63 hp. That is the main reason I was taking the fuel and going to use it in my 600 & 1000.

Thanks

 

When I went to VP's website, i clicked the Unleaded button there and it shot me down to a list of fuels and the page kept bumping (loading) and all of a sudden i saw unleaded. i looked twice more after it loaded just a little while ago and it came back as leaded. sorry.

I didn't realize you had such a heavily modified motorcycle. 134 is formula extreme numbers last i heard... wow. well, i'm no full time racer, but i think if i were i'd run the fuel that gives me higher HP gains. if your map is set to your 110, and you don't have a lot of time, run that. otherwise i'd see what the VP gives you in comparison or at least plan to give it a try after the race.

g'luck.

 

Hello again Knightslugger, I must say there is never a better person than one who admits to a mistake. With thatsaid, my hats is off to You. I am not the guy who builds the engines I just the guy who pays for them and hangs on. I have been told by other racers that they have more and have seen their sheets and they are not wrong. I am under them by 1.5 to 2 hp and they tell me it is my oil. I use 5-20 petro base they use 5-20 syn. I change my oil after 4 races if the are only 6-8 laps each. I change the filter after every weekend. They do they say routine as well. Their temps are the same as mine so I don't know if I should go that route but racing is expensive to the point of unbelieveable.
The tires are what really hurts and you have to have them to ride fast. Last week my tire bill was $840. for the 600 and $670. for the 1000. I ran less races on the 1000 because there are less classes but I run the 600 against the 1 litre classes and have better lap times. I know that sounds weird but it is all about cornerspeed. I hate paying the $105 a can for MR9 so I have been runing Track fuel and that has been working. I not saying that I have the best fuel but the price is only $5.91 a gal. so I am cutting cost where I think it helps. If you or anybody can give me better advice I am always very open minded.
Just the other day I had a neighbor stop over and was in the garage checking out my bikes and he thought it looked "really cool" andasked if he wanted to start how much and, I told him the cheapest thing is buying the bikes. Wait until you buy suspension,exhaust,rearsets, real clipons,racebody,engine mods etc it take another 15-20k per bike plus gettin to the tracks and entry fees. He was then pale, I keep very close accounting on my expences and the average weekend which isalways two days of racing and fri for practice for both bikes total combinedis 2500-3000 so it takes more than just wanting to have fun. I have been doing this since the late seventys and I am 50 and I often wonder how I did it this long.

Thanks

 

is this weekend a CCS race? I'm heading down to Jennings for a WERA race so I guess I'll miss it but I LOVE Barber.

anyway, the MR9 is what I believe most of the AMA teams were running last year(actually I think it was the year before)and I'm pretty sure it would give you better performance but as you said, its pretty expensive. Not sure if a higher octane VP fuel would be better for this purpose, you should probably check with the VP rep at the track if one is there and see what they suggest.
To save money, I use pump gas for practice and trackdays and run U4 for my actual races, you might could try something like that depending on how picky your bike is about mapping (my SV isn't at all but its a simple stock 80hp twin).

I'm pretty sure most of the guys with "built" motors are using MR9 but you might want to do a search on the WERA or CCS forums, that would probably get you morefirst hand info

wow I can't imagine that kind of tire bill, my SV tires last a full race weekend and some practice sessions (for most tracks) lol.

 

Hi Woodyracing, Thanks for the help, I am leaving here now and just cleaning up the last things on my desk. Yes I know the tire bill is big, but that is what it takes to keep up with the big guys. I am glad that CCS holds their events 2 weeks apart. I save the take offs and keep them for track day but I chew 2 of them sometimes 3 in one day. I usally get 1 front to two rears on race day. Again thanx for the info we have a 12 1/2 hour drive to Barber.