How much more fuel can the stock system flow?

[cOoTeR]

Once my vandemon exhaust arrives I'm going to have my bike tuned again. Not just for the new exhaust, I'm going to add a race fuel mode. Since the woolich software allows each power mode to be tuned independently I should be able to do it without an aftermarket switch. Since I don't think I will ever use the medium power mode I'm going to use it for the race fuel mode. I think there is a chance I might use the low power mode if I get caught in inclement weather. Once I get it tuned instead of having a "medium power" mode I'll have a "Monster" mode for when I go to the track or half mile races.

Right now I'm trying to decide which fuel to go with and VP fuels C16 and Q16 are currently at the top of my list. The Q16 requires 4%-6% more fuel flow to get the most out of it according to the VP website. I don't want to drop $100 on a tank full of race fuel only to find out that the pump and or injectors can't supply enough fuel.

Does anyone know how much fuel the H2 SX SE flows and how much more it can flow? Does anyone know how to find out?

[Champ87]

Does anyone know how much fuel the H2 SX SE flows and how much more it can flow? Does anyone know how to find out?

My immediate thought (without any backup evidence) is that the injectors would be your limiting factor. If you can identify the type of injector it may be possible to find flow data. Alternatively, you could pull an injector and have a injector shop measure the flow. They will give you a static flow rate in c.c./min. The issue is you have upper and lower injectors so delivery is shared. However, if upper and lower are both capable of flowing the necessary amount on their own then that becomes a non-issue.

[Champ87]

The Q16 requires 4%-6% more fuel flow to get the most out of it according to the VP website. I don't want to drop $100 on a tank full of race fuel only to find out that the pump and or injectors can't supply enough fuel.

Think back to when your bike was on the dyno at ESP. When they changed the ETV settings to give 100% throttle at the top end the thing was running so rich that the O2 readings went nuts. To be that rich would need a substantial amount of excess fuel - much more than 6%. So there you have a practical demonstration that at 100% throttle/13,000 rpm the FI system is capable of delivering enough fuel.

Q16 is an oxygenated fuel. From my limited knowledge of such substances I believe you'll need to pull quite a bit of ignition timing. Obviously, that's something your tuner would do when they're remapping the fuel tables but if you know in advance you can sound all clever about it.

And another thing; those fuels don't keep long. My buddy was using VP race fuel in his highly tuned R1 (I think it was VP MR9). Any fuel he took home from the track was pretty much wasted. Also, Q16 is a leaded fuel so don't use until you get the new exhaust or your cat will be wrecked (which you may not care about anyway).

DISCLAIMER: My lawyer says that the above information is an example only. Your results may vary. If you blow it up it ain't my fault but please send us the pics

[cOoTeR]

Does anyone know how much fuel the H2 SX SE flows and how much more it can flow? Does anyone know how to find out?

My immediate thought (without any backup evidence) is that the injectors would be your limiting factor. If you can identify the type of injector it may be possible to find flow data. Alternatively, you could pull an injector and have a injector shop measure the flow. They will give you a static flow rate in c.c./min. The issue is you have upper and lower injectors so delivery is shared. However, if upper and lower are both capable of flowing the necessary amount on their own then that becomes a non-issue.

I think I have the part #: 49033-0027. It appears to be the same injector for the ZX10R. But it may be the upper injector.

[Champ87]

H2 SX Primary (Lower) Injector is Part # 49033-0027. As you said it's the same part # as ZX10 Injector (Upper & Lower)

H2 SX Secondary (Upper) Injector is Part # 49033-0036. Also used on KX450F

From quick look at the maps using Woolich software it appears the fueling is roughly 50% Upper/50% Lower injectors.

[vcyclenut]

I am going to use E85 its easily available , cheap and boosted motors love it. Plus it adds the added safety of cooling and It is great at preventing predetonation


I am going to data log while tuning and check my fuel pressure to make sure the pump is good,

the injectors you will know when they are maxed out when you are basically at a duty cycle of 1

it would be nice to know in advance if you will run into a wall but basically it will be a guess until you test it. blazing new paths can be tough


I agree with champ with the amount of fuel im pulling away at this point it will likely be ok but cant wait to find out!!

[Champ87]

it would be nice to know in advance if you will run into a wall but basically it will be a guess until you test it.

Pretty much sums it up.

Service manual gives performance limits for fuel pump but that doesn't help because it's a minimum below which the fuel pump should be replaced. The manual doesn't tell you what the pump is capable of. Even if it did you still don't know what fuel flow will be required with the new exhaust and race fuel.

The pump or injectors are the obvious limit points but don't forget the tank vent. Fuel pump is gonna have a hard time delivering if you can't get enough air in to replace fuel out. The only reason I mention it is because those vent pipes tend to be quite small. If that it turned out to be a restriction then you could waste a lot of time figuring it out (easy test - open the gas cap when checking fuel flow).

[cOoTeR]

it would be nice to know in advance if you will run into a wall but basically it will be a guess until you test it.

Pretty much sums it up.

Service manual gives performance limits for fuel pump but that doesn't help because it's a minimum below which the fuel pump should be replaced. The manual doesn't tell you what the pump is capable of. Even if it did you still don't know what fuel flow will be required with the new exhaust and race fuel.

The pump or injectors are the obvious limit points but don't forget the tank vent. Fuel pump is gonna have a hard time delivering if you can't get enough air in to replace fuel out. The only reason I mention it is because those vent pipes tend to be quite small. If that it turned out to be a restriction then you could waste a lot of time figuring it out (easy test - open the gas cap when checking fuel flow).

I think I already have an issue with tank venting. The cap hisses and whistles for hours after riding (could do it while riding and I can't hear it) and the vent tube dumps fuel out on to the inside of the left fairing. I've been careful to not over fill it with fuel yet it still leaks.

I took it in for a warranty claim and now I'm fighting with that because Kawasaki says it's normal so I'm being charged the labor to look at it. The tech just extended the vent hose beyond the fairing so it wouldn't get on there. I'm pretty annoyed with them right now.

[Champ87]

.....the vent tube dumps fuel out on to the inside of the left fairing. I've been careful to not over fill it with fuel yet it still leaks. ...............Kawasaki says it's normal.......

Doesn't sound normal to me. They would have a big problem with that in California. I think all US models are built to be CA compliant so it's a defect.

[cOoTeR]

.....the vent tube dumps fuel out on to the inside of the left fairing. I've been careful to not over fill it with fuel yet it still leaks. ...............Kawasaki says it's normal.......

Doesn't sound normal to me. They would have a big problem with that in California. I think all US models are built to be CA compliant so it's a defect.

That's the funny part, they originally claimed it was leaking fuel because I removed the charcoal canister. I specifically ordered a non-California which never had a charcoal canister. So I asked if Kawasaki is claiming that all non- California bikes are leaking fuel randomly. They didn't have an answer for that.