Race gas Vs Pump gas

[FL-cracker]

I was just wondering how much of a power difference there is between runing 200+lb compression on race fuel vs 180lb on pump gas- on a ported 780cc with dual 46 red tops on a 62t with limited B1 pipe, on a B1. Is it worth it to run the race gas setup just for F-ing off? Is there a big difference in reliability? Will I need to re prop- I think im runnig a 13/17 concord j. Thanks everyone, this forum is the SHIZZEL!:woot:

 

[Freestyleriverrat]

Power is the same. Race gas just burns a little cleaner and allows you to run higher compression on the motor (195+ psi) w/o detonation......which translates into more power.

 

[Waste Land]

Power is the same. Race gas just burns a little cleaner and allows you to run higher compression on the motor (195+ psi) w/o detonation......which translates into more power.

He understands that.

He asked the diffrence between 200psi compression on race gas and 180 psi compression on pump has. Is the diffrence between PSIs make enough power for the cost of race gas

 

[ski4]

i'd be betting not worth it. if just for f'ing around

 

[Freestyleriverrat]

He understands that.

He asked the diffrence between 200psi compression on race gas and 180 psi compression on pump has. Is the diffrence between PSIs make enough power for the cost of race gas

My bad..............IMHO it is not woth the hastle to bump the compression. Put the $$ you would blow on race gas towards something like TL, light flywheel or a lamey. You sacrafice some reliablity/durablity of the motor when you up the compression to 200+ psi. If you get gas cheap why not, but it does not make the ski different enough to justify the cost.

 

[keefer]

I went from 180 to 210 comp this season and started running 110 octane that I get for $5.00 a gal at a local pump. It is not race legal but the boat makes noticeable more power. I had to step up to a concord prop because the extra low end power caused cavitation with my existing X prop. The engine runs very clean and I like it so far. If I buy the race gas by the 50 gal drum I can get it for $4.80. It makes the difference of spending $15 per ride to $25. I think it is worth it, but if I had to pay $7 to $8 I probably would not do it. Decisions, Decisions....

 

[FL-cracker]

Cool thanks peeps! The top end I bought has flat tops, and has like 200lbs compression, I plan to detune the motor by running a raider head gasket with the girdled head with flat top domes "for pump gas". Not sure exactly what the compression will be, Im guessing 180/185lb. I realy wont know till I get the motor together. Yes, I know to be carefull. This is the first mod 2-stroke I have ever done. Should be a realy nice motor. The porting was done buy TLR, freestyle ported.

 

[Mile9c1]

My Able brochure quotes a 6 increase in horsepower for every 10 increase in PSI. So bump your compression from 185 to 215 and you'd gain approximately 15 horsepower. Not too shabby.

Race gas smells sweet, that was my favorite thing abou it. My engine is only running 175psi now so I can't justify it.

 

[keefer]

I am no expert, but it seems to me if you run a thick head gasket you will have one huge squish band to go along with the lowered comp. Why dont you just get some larger cc domes with the squish properly cut for the flat tops and that way you can go back to 93 pump gas and retain the proper squish. This will allow you to get the maximum HP on pump gas. I would ask Paul at Magoos about your setup and he can probably hook you up with the best solution.

http://www.jrmagoos.com

 

[ucsspirit]

just run your 180-185 and go out and buy aviation gas, 100 octane, with a lead additive, and its like $4.00 a gallon, and cheaper in some places. it burns better, and is better for the motor (lead) just my $.02. with a noticaeable all be it slight but noticeable power gain.