race fuel or pump fuel..what will you tolerate for power

[masterblaster]

Our group of riders dont want the expense or inconvenience of running race fuel. dont think most surf riders want to bother with race fuel ? Seems like alot of motors these days have port timing setup for race fuel and tend to fall a little flat without the compression and high octane to support the setup. Interested in hearing what pump gas motors have impressed you with really strong bottom end response and power. Besides competitive flatwater riders how many would even consider using race fuels at all in the trade off of reliability,longevity and fuel $ ? It certainly can make more power,how many weekend warriors dont mind the trade off?

 

[IS0LD0UT]

Ive been impressed with my jetmaniac 735 on pump gas. I also have a 5mm stroker that I used to run on race. I swapped it over to pump last year and was still happy with it. I really didnt like the cost of race. 3 times the price and not even close to 3 times the performane. Imo.

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[102nd7]

I ran 110 octane last year. I'm pretty sure I'm going to switch to regular pump gas this year. I might still run a lead additive for reliability reasons.

 

[rubbertoe]

pump gas for me for convenience and $ ,but here in california premium is 91 octane not 93 like other states .so it is wise to mix a 50/50 blend if you plan on running any timing advance or bump up compression at all

 

[KTM434]

I had a dirtbike that was setup for race gas... I hardly rode it. I loved that bike but due to the cost of fuel I would always ride a different bike instead. I'm not going down that road again. I'd rather run a 701 than something on race gas. I definitely know what you're saying about some of the billet SS big bore/super bore cylinders though. They make power but there's a large lag. You don't feel the extra displacement until you hold the throttle down for 2 seconds and keep holding. Definitely a mid range setup for the most part. I'm anti TL but I'd probably run that before race gas

 

[Harbor]

I learned about my 1st superjet's set up and octane the hard way, sharded a piston and combustion chamber @53 mph on 87 octane. After i repaired it and $750 in parts i new a little more. Because i was still learning and scared now, I went a little over board and ran straight 110, after some time i learned that much was not required and setteled @ 50/50 premium and 110 no more problems. fast forward to my current engine set up where I had to chose my compression set up based on what fuel id be runnin, ignition, timing, ridding type, since i was already buying 50% 110 i went with the race gas set up, it's only $24 a tank more for me at this point. Now my cranking compression has fallen some, was set up @215 and now is around 195 so i could run less octane iam told, almosst went back to 50/50 mix BUT i since got an HX3 so iam learning more about timing and curves, so until thats all settled out il keep the 100% 110 so i dont blow another engine. i like the peice of mind too, while i learn my riding style

 

[CRJ]

when i found out race fuel costs, i was pretty set on sticking with the pump gas. here we can get 94 octane from out pumps, but its about $6.10 a gallon. shooting for a 185psi reading, but have larger domes if it comes up high.

 

[McDog]

Im happy with my avgas blend. Avgas is about $5.50 and I mix it with 93 pump 3/2 ratio with compression around 200. I have a 55 gallon drum in my garage that I fill up about once a year.

 

[stagesrt4]

granted the price of race fuel cost most but thats not my main detuerant(tho i still run 100% race fuel)

n could sit in my garage n smell race gas all day long... guys like to ride behind me just so they can smell that sweet smell..


my main issue is chasing down the race fuel. The clostest locations for me to buy race fuel is nearly 45 minutes away. So to drive that far for just 5-10 gallons tends to add up.

 

[Freakrider]

I once put in smaller domes and ran avgas...could definitely feel the low end pull stronger but the hassle of buying it sux...The lead in it even low level helps with lubrication.

 

[yamanube]

it is more the inconvenience than the cost for me, no way am I taking an hour out of my riding session to go get fuel. The cost of race gas over a season or two can bump you up to a more powerful motor option or total loss.

 

[skinnyman]

I run 50/50 in my surf/boat chaser ski dasa 920 and full Vp c12 in my dasa 1100 when I changed from PFP and TL to B-pipe/enhancer It made a huge difference and I like the power and hit of TL and pfp even in the surf So I changed it back to TL and PFP .In my mind if you are running a big HP motor you already have invested in the power why leave it on table ? I have this discussion many times with guys wanting big motors Its not just the motor but all the parts that go with it.Race gas is part of the package in my mind.

 

[powerhouseperformance]

I run 50/50 in my surf/boat chaser ski dasa 920 and full Vp c12 in my dasa 1100 when I changed from PFP and TL to B-pipe/enhancer It made a huge difference and I like the power and hit of TL and pfp even in the surf So I changed it back to TL and PFP .In my mind if you are running a big HP motor you already have invested in the power why leave it on table ? I have this discussion many times with guys wanting big motors Its not just the motor but all the parts that go with it.Race gas is part of the package in my mind.

Exactly... The thing that I have a problem with is the quality of the pump fuel from station to station. Everyone that wants a pump gas engine wants it right on the max for premium. So basically you are one bad fill up from scattering an engine. If we are talking a high dollar billet engine that is a heck of a gamble. With race gas you know exactly what you are getting. The quality is much more consistent. I liken it to buying insurance. If you have a high performance pump gas engine throw a gallon of 110 into 5 gal of premium so you know its going to at least be the stated 93 octane or better even if the pump you are mixing it with is questionable. This also will greatly lengthen the shelf life of the fuel if it sits for a while between rides. The most important thing is to use your head about the type of riding you are going to do. We build a lot of cross over machines that get surf time and race buoys. If you are going to surf ride keep the blend minimal...if you are going to shred a coarse or ride WOT for a sustained period bump up the octane blend. Guys also get to caught up in the compression number thing. It's only a guide line...not to mention gauges will vary. It's more about how much power the engine is really making. You might have a 701 that lives on premium with 190lbs of compression with a b pipe and small carbs. Now you add a dry pipe and some bigger carbs with the same compression and it blows the first time you have it out pinned. I know the cost of race is a pita, but it costs less than a new engine and if you use your head when you blend it you can stretch it pretty far. As much as all of us wish it there is no such thing as an engine that makes huge power, runs on pump gas, and never has to be rebuilt

 

[yamanube]

Exactly... The thing that I have a problem with is the quality of the pump fuel from station to station. Everyone that wants a pump gas engine wants it right on the max for premium. So basically you are one bad fill up from scattering an engine. If we are talking a high dollar billet engine that is a heck of a gamble. With race gas you know exactly what you are getting. The quality is much more consistent. I liken it to buying insurance. If you have a high performance pump gas engine throw a gallon of 110 into 5 gal of premium so you know its going to at least be the stated 93 octane or better even if the pump you are mixing it with is questionable. This also will greatly lengthen the shelf life of the fuel if it sits for a while between rides. The most important thing is to use your head about the type of riding you are going to do. We build a lot of cross over machines that get surf time and race buoys. If you are going to surf ride keep the blend minimal...if you are going to shred a coarse or ride WOT for a sustained period bump up the octane blend. Guys also get to caught up in the compression number thing. It's only a guide line...not to mention gauges will vary. It's more about how much power the engine is really making. You might have a 701 that lives on premium with 190lbs of compression with a b pipe and small carbs. Now you add a dry pipe and some bigger carbs with the same compression and it blows the first time you have it out pinned. I know the cost of race is a pita, but it costs less than a new engine and if you use your head when you blend it you can stretch it pretty far. As much as all of us wish it there is no such thing as an engine that makes huge power, runs on pump gas, and never has to be rebuilt

Get on that.

 

[NVJAY775]

I hate blending, but I love the reliability of as stated above. Was running PFP, but will be running RRP this season. So I may be able to safely lower my compression a bit, but I need to learn a lot more before I go screwing with that. Buuuuuuuut at the same time I love the power and reliability of running higher comp with the right fuel blend. DAMMITTTTT!!!! I'm addicted to brraapp….

 

[Patrick Star]

I want to know what the tolerance for pure 87 octane is as I can get pure 87. I run 185 PSI is a maniac 718 engine in a B1, but mix 93 E10 and 87 pure to get 91 E5, and the ethanol woes go away. That and I run the OEM style water separator, a WR500 inline bowl, and a big paper filter to keep the E gunk at bay, it works too. If I get all clogged up in the surf I can prime my way home. lol and the filters clean up super easy with brake cleaner, non chlorinated.

I have heard that the ethanol adds a little octane rating.

 

[NVJAY775]

As I remember from a previous thread on ethanol fuels, our two stroke oil does not mix with ethanol like regular pump fuel. And you have to really richen your jetting to get it to work right. Be safe and stick with 91 to 93 octane pump fuel. Someone correct me if I'm wrong please.

 

[Patrick Star]

That's what my 87 and 93 mix give me I think, 91 octane.

I had to rejet the FCR MX carb for E10 in my XR650L, and it popped alot due to the leaning out on the pilot circuit.


On a side note: If you have a Jeep TJ Wrangler that cuts out occasionally and hick ups at various speeds, you have to reset the computer to learn the ethanol fuel characteristics. I ohmed all my sensors and was at my wits end, but the disconnected the battery and let it set 24 hours, now all is great!

 

[OCD Solutions]

Nothing but pump gas for me too. I run Shell Premium mixed 32:1 in my SS865 with no issues or complaints.

 

[Harbor]

I want to know what the tolerance for pure 87 octane is as I can get pure 87"

I can get you pretty close, with a dry pipe, 185 compression, msd enhancer and wide open throttle runs on pump 87 I found it removed the top of my piston and sent the pieces thru the engine