How much more fuel can the stock system flow?

[vcyclenut]

hmm

when I was on my trip my tank would build up so much pressure that you could hear it when I would open the tank, a couple times it even blew fuel out.

it stopped doing it and I forgot about it but I agree this is something that may hold me back as power levels get up there

[roadczar]

Perhaps venting issues can be resolved with aftermarket gas cap? I've used Vortex V3 on my ZX14R.

[vcyclenut]

my tank actually seemed like it had positive pressure, I don't see how this could be unless the heat from underneath was pressurizing it.


pressure would help fuel flow, vacuum would hurt it

[cOoTeR]

my tank actually seemed like it had positive pressure, I don't see how this could be unless the heat from underneath was pressurizing it.


pressure would help fuel flow, vacuum would hurt it

It seems like my issue is most likely a positive pressure issue as well. When I open the cap it seems like pressure is being released. Also it seems like fuel is being forced out of the vent tube on mine. My main concern is if fuel is being forced out that could be very hazardous. But there is definetly something happening with the tank.

[vcyclenut]

my tank actually seemed like it had positive pressure, I don't see how this could be unless the heat from underneath was pressurizing it.


pressure would help fuel flow, vacuum would hurt it

It seems like my issue is most likely a positive pressure issue as well. When I open the cap it seems like pressure is being released. Also it seems like fuel is being forced out of the vent tube on mine. My main concern is if fuel is being forced out that could be very hazardous. But there is definetly something happening with the tank.

only thing that I think could do that is the tank getting hot and the fuel expanding. I wonder if some heat shield on the bottom of the tank would help

[cOoTeR]

my tank actually seemed like it had positive pressure, I don't see how this could be unless the heat from underneath was pressurizing it.


pressure would help fuel flow, vacuum would hurt it

It seems like my issue is most likely a positive pressure issue as well. When I open the cap it seems like pressure is being released. Also it seems like fuel is being forced out of the vent tube on mine. My main concern is if fuel is being forced out that could be very hazardous. But there is definetly something happening with the tank.

only thing that I think could do that is the tank getting hot and the fuel expanding. I wonder if some heat shield on the bottom of the tank would help

Heat always seems like a variable that's in play when it started whistling.

On another note I may try the E-85 route as well. From what I've been reading the C16 or Q16 seem to do better than E85 in large displacement engines. But the EVO guys seem to swear by it. A lot of small engine turbod car forums seem to claim the E85 makes more power on their cars as long as the fuel system can keep up.

I've found very little on forced induction motorcycle engines and nothing on supercharged engines that seems relevant. A 2 liter Evo motor pushing 20psi seems closer to the H2 SX motor than a 6 liter v8 pushing 7-12 psi.

It's not readily available in my area but I can get it for races and stuff. I just can't run the bike on it all the time.

I'm going to reach out to the local car club guys that run it and see how consistent the ethanol percentage is in it. A lot of them run flex fuel setups though.

[vcyclenut]

yes I run E85 in my supercharged car but it has a flex sensor

from what ive been told as long as your over 60% content it doesn't make much difference but this is a real concern. Ive been meaning to buy one of those cheap little testing kits

[cOoTeR]

yes I run E85 in my supercharged car but it has a flex sensor

from what ive been told as long as your over 60% content it doesn't make much difference but this is a real concern. Ive been meaning to buy one of those cheap little testing kits

The H2 SX ECU is made by Mitsubishi right? I wonder if there is a flex fuel kit that can tap into that.

On the H2 forum it looks like Ricky Gadson was running E85 and only ran out of injector with the stage 2 supercharger gears. He seemed confident that the stock system would keep up with the fueling demands of an H2 running stock boost pressures. I need to see if the H2 has the same injectors as tree H2 SX SE.

[vcyclenut]

yes it is

on my car the stock ecu was not set up for flex fuel but the software to tune it uses two pins not being used on the ecu to look at the signal from the sensor and adjust the fuel and timing table

a software company would have to develop this for our bike. They already have a hard enough time keeping up with new models as they come out I doubt they would take the time to develop something like this

[Champ87]

on my car the stock ecu was not set up for flex fuel but the software to tune it uses two pins not being used on the ecu to look at the signal from the sensor and adjust the fuel and timing table

Does it adjust timing real time? I read somewhere that for engines set up as "Flex Fuel" the ECU will adjust timing on-the-fly based on info from the knock sensor(s). I don't know enough about flex fuel to know if that's correct. From previous reports on this site it seems our bikes simply go into a "safe mode" when the knock sensor gets busy.

Flex-fuel vehicles can have Gasoline, E85 or a combination of either in the same tank and the ECU will adjust fuel and timing to deal with the resulting blend. Although our bikes don't do that we do have the advantage of selectable power modes. From what you're saying, it sounds as if using one of the modes to map fuel and timing for E85 is not a big deal. How is the transition handled when you've been running on regular gas then switch to E85? The gas tank is not totally empty when you fill up so the blend is changing. Similar thing with winter mixes when the suppliers change the mix of ethanol/gasoline.

I'm curious.