Race Gas Questions

A few race gas questions for you guys and gals. All based on VP U4.2 fuel BTW. Also, note that I live in Alberta Canada where we have VP race fuel and 91 octane pump gas to choose from, nothing else available.

- is it worth it to run race gas at all? At $120 for a 20l can, it's pretty pricey, roughly 5 times more expensive than pump gas.

- Will the FI system on my 2008 SMR450 with power-up kit installed automatically compensate for the different (better) fuel compared to pump gas?

- Would you mix the race gas with pump gas or just run it straight? It's so expensive, I'm not sure I want to run it straight for day to day use in the SMR but have no problem using it in the TC250 since it doesn't get ridden as much

- What performance gain can you expect running race gas compared to 91 octane pump gas?

- Would you run race gas in TC250 for break-in?

- What jetting would you recommend for a TC250 at roughly 4,000ft elevation?

- What is the shelf life of race gas, how long can an open can be stored before it goes bad?

- Do you need to drain the tank and carb after using race gas if the bike will sit for a couple of weeks before it's next use?

True, the U4.2 is higher octane but the real benefit is that it is an oxygenated fuel and that is where the real performance gain is coming from.

most cut it 4 to 1 with pump gas and there by getting a hybrid that doesn't hurt the wallet and still gives some boost through the oxygenation . Most is wasted when runnning stright though unless super high compression ratios (which none of us are)

Joe

Hey Wardy when did you get the SMR ????? COOL !!!


My 08 TC 250 works good up here(think you rode it??).....stock pilot....needle 1st clip slot from top...and go up one size from stock on the main....I''ll give you a call...tommorow

I have had no trouble with pump premium....91 mon comes pretty close to 98 ron(husky calls for 98 RON)....but mix in a bit of race fuel..sure wont hurt.....It will burn my eyes as I eat your dust though...LOL

Motor Octane Number (MON)
There is another type of octane rating, called Motor Octane Number (MON), or the aviation lean octane rating, which is a better measure of how the fuel behaves when under load as it is done at 900rpm instead of the 600 rpm of the RON[2][3]. MON testing uses a similar test engine to that used in RON testing, but with a preheated fuel mixture, a higher engine speed, and variable ignition timing to further stress the fuel's knock resistance. Depending on the composition of the fuel, the MON of a modern gasoline will be about 8 to 10 points lower than the RON. Normally, fuel specifications require both a minimum RON and a minimum MON.

Difference between RON and AKI

Because of the 8 to 10 point difference noted above, the octane rating shown in the United States is 4 to 5 points lower than the rating shown elsewhere in the world for the same fuel. For example, 87 AKI octane fuel, the "regular" gasoline in the US and Canada, is 91–92 RON in Europe. 93 AKI octane fuel, the "premium" gasoline, is 97-98 RON in Europe.

However most European pumps deliver 95 RON as "EuroSuper" or "EuroPremium" (equivalent to 90–91 AKI). In Germany, Great Britain and some other countries, 98 RON as "SuperPlus" (93-94 AKI) is available almost everywhere. Even 100 RON (95-96 AKI), is widely sold, and BP sell 102 RON, marketed as "BP Ultimate 102", at some very select few filling stations.[4]

Troy, I figured I would be proactive and changed the jets as per your note here before I even gassed it up. Headed out to MacLean for the big break-in ride and the poor girl wouldn't even run. Thankfully Dave helped me out and we ended up going up 1 on the pilot to a 45, left the 180 main in, changed the needle to 2nd groove from top and set fuel screw at about 2 turns out. Ran like a champ for the rest of the day, started hot or cold in 5 kicks or less even in gear with clutch pulled and never had the pop-stall issue so I think the jetting is pretty close. Now that Dave has 6 weeks of free time, I'll try to get him out to fine tune the jetting once I have 10-12 hrs on it and she is nicely loosened up.

Can't wait to hit the MX track with it, let me know the next time your out.

I did manage to bust up the left side upper rad shroud already. Darn things stick out way too far for bush riding, should have cut it down before hitting the trail. Beside that, I love it! Forks are stiff and harsh but have potential and the bike feels so light and flickable compared to the old TE.

Jaro: Good to hear the bike worked well for you. I find out monday if I need a plate and hardware for my wrist.

Dave

OH NO !!


I had to get the kid up to speed as he was a little tentative after his big get off so we had a late start and it was a logistical nightmare with dog baby sitter and had to drive nephew around to find where his gear was(dont ask)....we ended up trying to pursue you guys a little later in the day...sorry to say we never found you guys

And Dave.....what on earth happened to you.... :jawdrop:

sorry this thread got off topic...it will come back around I'm sure

I just bought some VP C12 this weekend and cut it 60/40 (60% 93 Octane pump/40% C12). We ran it in our 2 strokes ('09 CR 125 and '09 WR 300). First time I've used race fuel in a bike and the difference was huge, especially in the 300. Both bikes seemed to have much better hit in the mid. With pump gas, the 300 tended to have slight detonation while lugging at idle... gone with the C-12. And I know this is probably my imagination, but both bikes seemed to have better cold start characteristics. I'll be using this stuff from now on. Especially at races. C12 is a leaded, non-oxygenated fuel with 108 motor octane.