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Discussion Starter #1
So, i've been kickin around the idea of running U4.4 in my bike when at the drag strip. My bike has OE header cat delete and mid-pipe delete with slip on, PC5, wideband commander and the usual bolt on suspension stuff for drag racing.
I have a few questions though. A buddy I race with has a gsxr1000, with similar setup as my bike, he runs U4.4 in his and loves it. It seems most people these days are running MR12. I've found they're both oxygenated, MR12 is a 93 octane and U4.4 is 103. Aside from the octane difference and about $10/gal price difference, what are the pros and cons to running U4.4?

Thanks~
 

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I'm sure someone with more experience will chime in, but higher octane is to prevent premature detonation in higher compression systems (like if you have a turbo or supercharger). Not sure that fuel would help you at all, may even be detrimental. Regardless, would definitely require tuning/ecu flash.
 

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Bored so researched the fuel some. General consensus on the net seems to be what I thought, that with a stock motor you won't see any gains over 93 octane since you need a higher compression ratio to take advantage of it.
 

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On NA motors I see a -lot- of guys going fast on MR12, but it is a really maintenance heavy fuel. If you can live with the cost/draining/shelf life it is the way to go on an NA motor, but you need to tune for it as well. I'm sure Gaz can chime in on that. :)
 

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if not tuning for either of these specific fuels, try the u4.4, much closer to a pour in fuel than mr12. seen some et/mph improvements with u4.4 untuned, just depends. if u want to get serious, mr12 with a custom tune for it. mr12 is 87 octane.
 

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what spaz said. everything about mr12 is different from other fuels. date of manufacture on can must be within 6 mos, earlier if possible. once opened 2 mos max life to be effective. seen 3 hp loss in 4 weeks once opened dyno verified.must be tuned, tuned in low/mid range big plus. must be drained/flushed after use which has become simple to do for me. basically nasty stuff requiring some maintaince as stated. 10+hp in midrange, 8 up top, couple ft lbs torque, is gonna cost a little, require a little work. this is what we average on the dyno everytime. relatively fresh, very consistient fuel. zx10's love this fuel, they just rip thru the gears when well tuned on it. u4.4 requires almost same guidlines, little better shelflife all around. both good fuels, as ur friend u will run good on u4.4, u will haul ass on mr12. i go thru 3-4 cans a season. racing is expensive, the look on the face of those busa/14 riders after u walked away from them down the track on a ten is priceless.
 

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Discussion Starter #7
thanks for the advice and info. I have a MR12 tune another member sent me, so, if I decide to use oxygenated race fuel, I'll change the map and get some data from the runs and go from there.
 

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I run MR12 for the strip it makes the most power by far. Not too much of a pain really. Just takes about 20 minutes before and after the trip to the strip to drain and replace the fuel. It is pricy like stated. But like gaz said, racing is expensive. The way I saw it if I was going through paying for a tune and race gas and what not I was going to get the most out of it even if it's a little more each trip to the strip
 

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Discussion Starter #9
I admittedly am very ignorant to oxygenated race fuels. I had my first go at running some over the summer. I've been looking into U4.4 but i'm wondering how much power i'm losing by running U4.4, since it is a 103 octane oxygenated fuel. Comparing to MR12, which I believe has more oxygenates in it compared to u4.4 but also has a lowered octane rating at 87.

Is there a middle ground? Like an oxygenated 89 or 91, maybe even 95??
 

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Since gazx10 is great at explaining stuff I won't even try explaining more than he did, but figure'd I'd add my experience.

I put MR12 in my bike 2 years ago and picked up what seemed about 2mph and .2. Not sure how much I'd pick up now with a little more seat time but that was definitley worth the hassle to drain the gas and retune. If going for every little bit I'd say get some mr12 if you're all motor.

I love the smell of mr12 from the exhaust, hate the smell from the can in the garage lol
 

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ur comparing mr12's 87 labeled octane rating to what ur used to which is pump gas ratings.pump gas is rated on average of 2 octane measurement systems, mon and ron. vp rates are mon which is lower. mr12 is 87 mon and 100 ron or about 93 octane in terms we are used to. it is even better than that due to high evaporation rate which cools the int. charge and being blended very consistient unlike pump gas. this is the fuel for up to 14 to1 compression ratios. lose power with 90+ octane on a near stk. motor. cant put too much compression in a stk piston zx10 for mr12, works even better with thin hg and heads milled max up to .030+. practically all the hp/torque a engine makes is generated in first 20 degrees of rotation after ignition. mr12 is very fast/complete burn fuel that takes advantage of this. u4.4 makes about 4-5 hp tuned right, mr12 will make much more midrange, 10+hp, and 8 up top avg. torque is increased so bike pulls harder everywhere. it is the real deal done right and a major power producer. do'nt recommend someone elses map or self tuning mr12. throttle position dyno tune best for total powerband increases. all out race fuel, has to be treated/tuned as intended. done right produces a holy s--- response over pump gas and other fuels. sadley, most users cut the process short and limit the power this fuel can make.
 

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Discussion Starter #12
Thanks for the great info gazx. Tuning probably wont happen next season, since i'll be changing the bike setup over the winter. This year was my first real season racing, especially a bike that is capable of running quite quick. I'll spend this next season getting used to the new setup, increasing my launch rpm to find the sweet spot and running u4 to see what happens.
 

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Thanks for the great info gazx. Tuning probably wont happen next season, since i'll be changing the bike setup over the winter. This year was my first real season racing, especially a bike that is capable of running quite quick. I'll spend this next season getting used to the new setup, increasing my launch rpm to find the sweet spot and running u4 to see what happens.
what gazx said was pretty spot on. The other this is mr12 doesn't like heat. Doesn't work as good. The u4.4 is consistant, adds the 4-6whp he talked about across the board and doesn't change the afr much over pump gas. Plus it's half the price of mr12. But I'll say this about mr12, it's not a joke when he says that Mr 12 makes good power because the first time you twist the throttle with it in the tank you're going to shiat a purple Twinkie. Lol its heroin for street bikes lol. Yay yay. That fuel alone with a decent tune would put you at 150-151 traps on your current setup. That being said I run u4.4 in my bike, have in all my race quads/dirt bikes as well and recommend it for sure. Consistant, affordable, easy to get, adds 5hp and smells damn good. Lol
 

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Discussion Starter #14
with U4.4 is there any benefit to fatten the bike up and bring the afr down 13:1 vs. 13.5:1?
 

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yeah bring it to 13.0, need fuel for accleration leaving the line and to mph on top end. pretty sure u will see a difference if ur afr autotune reading is correct. some are finding a difference of several points between autotune reading and dyno comparision with bike being dyno'd.
 

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Discussion Starter #16
I don't have autotune or a dyno tune. I have an old school wideband commander which datalogs. Then I export that info to a file and look at AFR readings, and make manual adjustments from there.
 

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Discussion Starter #17
I have a few questions to throw in here: I was looking around the VP website and getting pricing ideas for fuel. MR12 seems to be the hot ticket these days, but, I'm not willing to pay the $30/gal for it. I've been planning to buy some u4.4, then noticed the new array of oxygenated race fuels.
1st question: has anybody used the VP t4 fuel? It too is oxygenated, but, is unleaded and is 30% more affordable than u4.4. Anybody try the u4e, it's about the same price as u4.4, maybe a few bucks cheaper.
I also noticed the stated octane rating for u4.4 is 108, that seems quite excessive to dump in a stock bike engine.

What fancy fuels are others using?
 

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Great info from Gaz and Spaz knows his stuff also!Australias fuel quality and specs are different to what's offered in the U.S I could have heard in the past!buying from petrol outlets are a lucky dip with fuel quality and age so I have been using the same race fuel since buying my bike in 2012!I buy 20liter containers from his fuel depo knowing I'm getting a fresh consistent batch!I only ride sunny Sundays and use his unleaded 100.4octane~3.59%oxygenated fuel on his advice!Im not specifically focused at overall performance results as I'm not qualified or know enough about fuel and it's benefits but like to be educated
 

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The only fancy fuels I usually use are water and methanol... sometimes even at the same time. :badteeth:

But you are correct about the excessive octane. All things being equal, you want to use the lowest octane you can get away with on your set-up if you are looking for the most power. However, it gets murky when you start messing with oxygenated fuels. A person may see more power with the "High Octane" race fuel, when in reality they are getting that power from additives and added oxygen content, not the "octane" in the fuel. When we're talking about NA motors, it still looks like the king around the paddock is additive/oxygenated fuels, even if they are a little heavy on the octane for a given application. I'd go as far as to say that ANY fuel like that will give you a power increase, so long as you tune for it. But that is the real trick: you have to tune for it if you want to see improvements. If you have the ability to tune it yourself, try one out! If someone else is doing your tuning, ask them what they use and why, or they're willing to experiment..... you may find something new either way that you didn't have before. :)
 

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Discussion Starter #20
I have a data logger on my bike. Figured for the price, I'd buy a pail of the t4, put more fuel into the bike and get some data to see what's happening. My goal is 13:1 AFR. That's going off advice from gazx10 and looking at the MR12 tune I got from another member on here.
 
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