jack vo Posted March 28, 2019 Report Share Posted March 28, 2019 I dont know much about switching to race fuel but some where i heard race fuel is not worth it because of higher compression but why? What is the benefit of 110 vs 120 race gas Quote Link to comment Share on other sites More sharing options...
SKEETER Posted March 28, 2019 Report Share Posted March 28, 2019 More importantly, what do you have done to your bike, and what is your compression, elevation? Quote Link to comment Share on other sites More sharing options...
jack vo Posted March 29, 2019 Author Report Share Posted March 29, 2019 915 feet Stock bore Milled head Vf4 Shearer pipe Stock carb Dune port Airbox lid delete Quote Link to comment Share on other sites More sharing options...
Keno Posted April 1, 2019 Report Share Posted April 1, 2019 What is your compression? Although not a definite indicator of needed octane, it is usually a reliable indicator. Increased octane is used to prevent donation due to increased compression and/or timing. Quote Link to comment Share on other sites More sharing options...
n2otoofast4u Posted April 1, 2019 Report Share Posted April 1, 2019 What do you use the bike for? Trails, dunes, mx, drag? Quote Link to comment Share on other sites More sharing options...
SKEETER Posted April 1, 2019 Report Share Posted April 1, 2019 16 minutes ago, n2otoofast4u said: What do you use the bike for? Trails, dunes, mx, drag? Recreation. Duh Quote Link to comment Share on other sites More sharing options...
Keno Posted April 1, 2019 Report Share Posted April 1, 2019 If this is for an RD400. Leave it pump gas friendly. 0 sense in wasting race fuel putting around town. Quote Link to comment Share on other sites More sharing options...
trickedcarbine Posted April 5, 2019 Report Share Posted April 5, 2019 120 is up there. Are we talking RON or MON octane numbers? It is gonna take a lot of compression to light that kind of fuel. So, the next question is what type of riding and how wide open do the rpms stay? If you’re running long stretches, a two stroke with that much compression won’t stay happy for long. Quote Link to comment Share on other sites More sharing options...
fixitrod Posted September 26, 2019 Report Share Posted September 26, 2019 I know this topic is old but at one time I went from 130 on 97 pump gas to 190psi 113 octane klotz on a 4mm long rod with 35mm PWKs and slightly wild port. I could ride a balanced wheelie to a crawl but my top end really suffered. Trails were slightly better, mx track was slightly better, up the dunes at glamis in 4th or 5th it actually suffered more than I liked. My times were faster with the right head and pump gas than an over compressed expensive fuel requiring head because I liked riding "in the power" at those high rpms. It was disappointing for me but some people really like gaining that lower end. It also blows me away how different every banshee seems to ride so differently. A mod on one person's quad may not feel the same on yours. Bottom line, it depends what your main riding is, can you afford to go back or try something different if you don't like it and can you afford the now insane race fuel prices? Quote Link to comment Share on other sites More sharing options...
ClaudeMachining Posted September 26, 2019 Report Share Posted September 26, 2019 Here in Canada,VP fuel is off the chart for someone who actually ride his Shee.Too much comp and the engine will fight itself...I run 100LL fuel, i find it a good compremise vs expensive race fuel.I run it at 160-165psi.Race fuel will always be the best fuel for racers.Envoyé de mon SM-G965W en utilisant Tapatalk Quote Link to comment Share on other sites More sharing options...
Ayesully810 Posted September 27, 2019 Report Share Posted September 27, 2019 (edited) 22 hours ago, fixitrod said: I know this topic is old but at one time I went from 130 on 97 pump gas to 190psi 113 octane klotz on a 4mm long rod with 35mm PWKs and slightly wild port. I could ride a balanced wheelie to a crawl but my top end really suffered. Trails were slightly better, mx track was slightly better, up the dunes at glamis in 4th or 5th it actually suffered more than I liked. My times were faster with the right head and pump gas than an over compressed expensive fuel requiring head because I liked riding "in the power" at those high rpms. It was disappointing for me but some people really like gaining that lower end. It also blows me away how different every banshee seems to ride so differently. A mod on one person's quad may not feel the same on yours. Bottom line, it depends what your main riding is, can you afford to go back or try something different if you don't like it and can you afford the now insane race fuel prices? i will never run race fuel again, unless I ever built a drag bike. The gains are minimal, especially on a play bike. running 93 in mine and ill never change it. I ran 110 in my old 4 mil with 35s and clearly spent an arm and a leg on a motor that drank gas like ddq drinks whiskey. On my 7 mil i have it setup for pump gas (155 psi) and have a stronger torque curve (a few more peak hp) on this motor than my race fuel 4 mil did, i say bigger stroke on pump gas and save money overtime. Edited September 27, 2019 by Ayesully810 2 Quote Link to comment Share on other sites More sharing options...
locogato11283 Posted September 29, 2019 Report Share Posted September 29, 2019 Pump gas to race gas gains are not minimal. What you gain overall from increasing compression and timing and running race gas is a huge increase in power from top to bottom. What does a pump gas 4mm Serval make, 85HP?My race gas 4mm Serval is at 100. 15HP is a very noticeable difference. You will especially feel it when you’re in the trails, where you need that grunt down low. The compression will shine there. There’s a fine line in compression for a drag motor. Yes, you want that RPM, but you also want the torque to get you out of the hole. Quote Link to comment Share on other sites More sharing options...
ride.race.live Posted October 1, 2019 Report Share Posted October 1, 2019 huh.... last i checked pump gas serval where in the mid 90's...... https://www.bansheehq.com/forums/index.php?/topic/189428-90hp-redline-pump-gas-421-serval-duner/&page=1 Quote Link to comment Share on other sites More sharing options...
ClaudeMachining Posted October 1, 2019 Report Share Posted October 1, 2019 huh.... last i checked pump gas serval where in the mid 90's...... https://www.bansheehq.com/forums/index.php?/topic/189428-90hp-redline-pump-gas-421-serval-duner/&page=1I dont think stock port timing serval does mid 90 on pump, but i can be wrongEnvoyé de mon SM-G965W en utilisant Tapatalk Quote Link to comment Share on other sites More sharing options...
ride.race.live Posted October 1, 2019 Report Share Posted October 1, 2019 nah not stock port timing... but dune porting it will... cant really compare a stock 4m serval on pump... to a ported 4mil serval on race 1 Quote Link to comment Share on other sites More sharing options...
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