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Discussion Starter · #1 ·
After having experience a few different race fuel and how they perform differently I have to now ask of additives to pump gas and corrosiveness of race fuels to tanks and fuel pumps, and why is it that lead is OK in Motorcycles besides the fact of no Catalytic converter.

I have tried Sunoco 104GT Plus Unleaded which is a really hot fuel. I tried Sunoco 116 Leaded which was even hotter. I tried VP MR1 and VP MR9. Both of these fuels are very HOT and the MR9 is off the scale. But Sunoco is readily available at the track here in Texas, and besides that, it eats metal parts for breakfast.

I have tried NOS Additive with Nitro Methane with little change from Gas, and I have tried 104 Booster with little change from gas.

Has anybody else experienced problems with VP fuels being super corrosive to their fuel tank?

I am leaning for going directly to VP but after the experience I had with The recent purchase of a GSXR750 that had a FUBAR fuels system, I am shunning away from it.

I know that Sunoco has 4X the oxygen content of VP and this helps explain why it is so corrosive.

Pump gas with additives is more than adequate in my GSXR1000, but the GSXR750 was running fuel before I purchased it and it runs like crap on pump gas. Since I am never going to take it to the street I plan on keeping it fuel only.

I am a NEWBIE to race Fuel. I have only run gas until the 2004. Any Information anybody has or experience would help.

So far the only thing I can realy tell you about race fuel is that it really adds lots of power, and that the sweet smell really turns me on.
 

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you would benefit far more from getting your bike custom mapped for pump gas, rather than wasting your money on race fuel. .unless your a front running expert and need that extra edge there really is no good reason to run race fuel unless you spend less than pump gas on it which is highly doubtful.

and just about everyone drains their tank each weekend when running race fuel. its bad to leave in there as far as i know.
 

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I use VP, no issues with tank corrosion. I do know that you should pull the stuff after you're done with it (reminds me, I need to do that still) but I've seen Nutec do worse things to fuel systems.

I'm not quite sure what your question is though.
 

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To use race gas effectively you will have to remap. Just get a map for pump gas as stated above. To the best of my knowlage you will have to take compression levelsand octane into consideration.

Adam can tell you way more

VP fuel

U4
Used in stock and modified 4-stroke applications, as well as stock 2-strokes. Makes up to 6% more power than pump gas and any basic nonoxygenated racing fuel. Passes fuel rules for AMA amateur racing and is also perfect for club level racing, CCS, WERA and AFM.

• Color: Clear
• Motor Octane: 92
• Specific Gravity: .718 at 60° F

MR1
Recommended for 4-stroke applications where octane requirements are fairly low, e.g. Supersport, Superbike, Formula Extreme and MX. Delivers up to 6% more power than pump gas and any basic nonoxygenated racing fuel. Clean burning - leaves intake and exhaust valves virtually free of deposits for maximum airflow and performance from start to finish. Can be mixed with MR8 to raise octane level for specific applications. AMA legal except Supercross and Outdoor Nationals.

• Color: Clear
• Oxygenated: Yes
• Motor Octane: 90
• Specific Gravity: .749 at 60° F


MR9
VP's newest fuel for 4-stroke applications that can tolerate lower octane values. Makes up to 2-3% more power than VP's MR1, meaning nothing on the market makes more power than MR9! AMA legal except Supercross and Outdoor Nationals.

• Color: Clear
• Oxygenated: Yes
• Motor Octane: 87
• Specific Gravity: .718 at 60° F
 

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As far as lead goes... it's simply a really cheap way of raising octane. In older vehicles, it also served to protect the valve seats. With hardened seats & stainless or ti valves in our bikes - there's no reason to run leaded gas EXCEPT to raise octane in a cost efficient manner. There are, however, plenty of other additives that also raise octane (those used in unleaded high-octane racing fuels), though they're basically more expensive.

The main (if not pretty much the only) reason race fuel is corrosive is just what you described... it's oxygenated. Not all race fuels are oxygenated, but not all race fuels are corrosive either.

Just like Cestode said - you may realize gains with race gas - but if you want the most out of it, you gotta tune for it. And personally, unless it was an oxygenated fuel... I wouldn't bother with it.

And it's usually to your benefit to run the lowest octane you can get away with and still avoid knocking/pre-detonation (as long as you tune for that).
 

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I second what BMFgsxr says. From all my research and arguring with my friends about race fuels it's not really necessary and off course you have to get a custom map with it or you bike will not run properly.
 

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Erhm... Perhaps it's an altitude thing, I dunno - but we do NOT have to custom map bikes to get them to run properly on race fuel here. While you won't see 100% of the gains as you would with a remap, simply pouring the stuff in will help your power and throttle response.
 

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Discussion Starter · #8 ·
The engine has a higher than normal compression. It has Milled Heads and a modified Piston. To make a long story short I am not sure that it will ever run good on Pump Gas Again, mapped or not. I contacted VP and they told me just to run pump gas through it when I am done to prevent it's corrosive and gunking properties.

Now brings up another problem is that I can get Sunoco for 5 dollars a gallon, or MR9 for 29 dollars a gallon. If you have never run Sunoco 116 Leaded fuel before you might want to give it a shot before you spend another $30.00 on a gallon of VP.

And to answer your question PB. I can tell you that my GSXR 1000 has a significantly higher HP just buy switching to fuel.... No mapping required...And It's has nothing to do with the altitude... But this bike has been mapped for Fuel, has been modified for higher compression, and runs smooth on fuel.. Not GAS.

Please Dont get me wrong, I would love to get the Dyno'd 144hp out of this 2002 GSXR750 with pump gas and save my money for more tires. It just wont do it without fuel though.
 

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Erhm... Perhaps it's an altitude thing, I dunno - but we do NOT have to custom map bikes to get them to run properly on race fuel here. While you won't see 100% of the gains as you would with a remap, simply pouring the stuff in will help your power and throttle response.
that's exactly what I said, in different words.
 

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daing the fuel and runnig the bike with pump gas is fine.

vp does funny stuff in wet environments thats the reason for the corrosion

u4 will give you 4 to 6 hp. to get the full gain you will need to map for it, but you will get a gain without a map.

ive said time and time again, you cant buy 4-6 hoursepower any cheaper than u4 ask anyone who has built a motor.

i would not even remap for pump gas unless you have soft spots in your powerband..its a waiste of money
 

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Discussion Starter · #11 ·
Wizard I think you hit it on the head. This Bike was raced in the south and south east last year in very humid conditions. The extent of rust and corrosion that was built up in the tank was unlike anything I have ever seen before.
 

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If you have hi-comp, you DON'T want MR-9 as that a low octane fuel. MR-1 is their hi-comp oxygenated fuel.

MR-9 is kinda corrosive, but MR-1 isn't. U4 get gummy but not corrosive.

The only time I had issues with any corrisive properties was with repaired fuel tanks.
 

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that must have bee nutec run in that bike. or a shit load of water

vp tends to be white powdery and gums up filters an screens
 

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That just like tons of water.

Nutec turns to brown syrup.
 

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damn... that's nasty




getting back to the tuning thing....

oxygenated race fuel is alot like nitrous... it's composed of oxygen bearing compounds that allow for the combustion of the the volatile agents in fuel, if present. So in general, if you don't richen up the mixture when running race fuel - you're giving up HP.

the second thing is timing. These oxygen bearing compounds don't release any significant amounts of oxygen until the combustion process begins. so if you want to get max HP... you've got to prolong the combustion process as long as possible... in other words, advance ignition timing.

you may get some gains out of race gas out of the box, but if you want the real deal... you gotta tune for it.
 

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That also means the mixture needs to be tuned by A/F ratio as well and not just expected airflow from the intake. Need to compensate for that, since that added oxygen won't show up anywhere but the exhaust.
 

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U4 rocks. I've done the drop in and go a few times. It's awfull on the fuel seals left in there any length of time. Just drain your tank and run some gas through it after every weekend. Remap for best results but not neccessary.
 

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If you have a so called "built" motor, you really shouldn't even be asking about fuels and maps. If it is massaged, you NEED to remap and you really need to use a higher octane fuel due to the higher compression numbers you'd have. Also, the deal with your pump, etc. looks way too much like a water issue which means condensation. It looks like that thing has been sitting for a long time with water in the tank and then you just kept adding fuel. VP MR9 is common to be greatly effected by condensation and so is Nutec. You need to drain any of the MR VP fuels and all the Nutec crap. U4 can stay in IF you are racing on a regular basis, but it makes sense to drain the U4 sue to the oxygen content.

Most racers run exactly the amount of fuel needed for each race. It is a weight deal, but it also helps in that if there is 1/4 of a gallon left and you don't drain it until the next day, it won't cause an issue with the new stuff you pour on top of it. U4 is not corrosive like the others and isn't as bad on your o-rings.

Get a better fuel and don't think about running pump gas with a built motor. You shouldn't even need to ask that. However, if you've spent all that time and money building a high end 1000 motor, why on God's green earth would you even consider not mapping for the better fuel? You want optimum performance - get it...
 

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yeah, didnt realize you had a built motor with higher compression. you will most likely "need" to run race fuel in this bike in that case. and where you would certainly make the most of your gains with a custom map, you dont "have" to. you will get some gains running a stock map with race fuel, but certainly not optimum.
 
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