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I started building the car for e85, but now that the navy has sent me somewhere with no e85 I need to change plans (car still in the build process). Race gas is also just too expensive for a street car. I'm still trying to finish the project but currently already have all the fuel system components I bought which I intended to use with e85. Should I plan to just run pump gas and meth now? I already have an alky injection progressive system laying around from my last project. My goal was 900 rwhp but I'm not sure if pump gas and meth will support that
I have the following stuff on the car:
TMS 346
twin BW s360
Inter cooler
Meth
10.6:1 CR
160# injectors
-10 feed -8 return with MF 4303
I'd drop your CR ratio down if possible. I really doubt you'll hit the 900whp mark with 10.6:1 and pump gas/meth. I'd want a serious meth inj kit to make that happen. Multiple pumps, lots of volume, direct injection etc...
Have you considered a simple dual fuel setup? Could run around with 600whp pump gas tune, then switch over to to race gas for 900whp on c16? Would be as simple as turning off one pump and turning on another. You wouldn't go through a ton of race fuel this way either.
Thanks for the sketch. If I had known e85 wasn't going to be an option I probably would have dropped the cr off the bat. But the ported 243 are already milled, engine assembled and in the car. So I would REALLY hate to have to tear into that again with so much other stuff left to do.
I also already have the tank in the car and the 4303 pump, line, fittings etc. if need be I will consider selling things and starting over on the fuel system, but I'd like to try to find a way to make my current parts work if possible.
For meth, the kit I have is an Alky Control progressive system, I can't remember the size of the nozzle but I can get bigger ones, or more than one if need be.
So it sounds like my best option here is pump+meth for 600-700 whp on the street, then some sort of additional method of using race gas at the track and turning up the boost? If I did this method is likely just run one tank, and drain and refill at the track, this way I can keep it simple with one pump still. Thanks for the help!
Doing meth injection right isn’t as simple as it sounds at the power level you are talking about.
Alkycontrol kits are really nice, but a single pump can only put out so much volume at “X” pressure before dropping. A single pump can’t keep up. I’ve yet to see a meth inj pump that can maintain more than 30gph at 200 psi. Julio doesn’t publish his pumps flow at the rated 250psi. But I bet it’s less than 30gph.
For me to feel comfortable with 10.6:1 at 1200CHP I’d want to replace at least 30% of the WOT fuel with meth. If you do some quick and dirty math you’ll see even 2 pumps is barely enough.
To make 900whp you’ll need around 1200 crank. So you’re looking for 360hp worth of fuel from aux injection which is roughly 30gph. Then take into consideration that your using meth which requires twice the fuel. So you need 60 GPH. Basically maxing out 2 pumps at 200 psi. That’s 7.5gph worth of fluid at every runner. You also need to calculate what the nozzle flows at 200 psi since they are rated at 100psi. So basically 8 - 5.5gph nozzles. One on each runner. Then you need to tune around all that new fluid being introduced into the tune. Which can be difficult. If one nozzle gets clogged or a pump starts to go south, cylinders will lean out and things get ugly fast.
Much easier to keep your current fuel cell and buy an inline fuel pump that will support your pump gas HP level. Then setup another small 2-3 gallon race fuel cell with C16 for your 4303 pump like mentioned above. Would be cheaper, easier to tune, and almost hassle free.
Mixing race gas is always a crap shoot. You never have the same octane/mixture and it’s always a guess.
Doing meth injection right isn’t as simple as it sounds at the power level you are talking about.
Alkycontrol kits are really nice, but a single pump can only put out so much volume at “X” pressure before dropping. A single pump can’t keep up. I’ve yet to see a meth inj pump that can maintain more than 30gph at 200 psi. Julio doesn’t publish his pumps flow at the rated 250psi. But I bet it’s less than 30gph.
For me to feel comfortable with 10.6:1 at 1200CHP I’d want to replace at least 30% of the WOT fuel with meth. If you do some quick and dirty math you’ll see even 2 pumps is barely enough.
To make 900whp you’ll need around 1200 crank. So you’re looking for 360hp worth of fuel from aux injection which is roughly 30gph. Then take into consideration that your using meth which requires twice the fuel. So you need 60 GPH. Basically maxing out 2 pumps at 200 psi. That’s 7.5gph worth of fluid at every runner. You also need to calculate what the nozzle flows at 200 psi since they are rated at 100psi. So basically 8 - 5.5gph nozzles. One on each runner. Then you need to tune around all that new fluid being introduced into the tune. Which can be difficult. If one nozzle gets clogged or a pump starts to go south, cylinders will lean out and things get ugly fast.
Much easier to keep your current fuel cell and buy an inline fuel pump that will support your pump gas HP level. Then setup another small 2-3 gallon race fuel cell with C16 for your 4303 pump like mentioned above. Would be cheaper, easier to tune, and almost hassle free.
Mixing race gas is always a crap shoot. You never have the same octane/mixture and it’s always a guess.
IIRC mark's mustang (matt. h) used meth injection with a single pump and got to low 8s, i think 8.1 that had to be more than 1000Whp thru a th400
IIRC mark's mustang (matt. h) used meth injection with a single pump and got to low 8s, i think 8.1 that had to be more than 1000Whp thru a th400
Fastest Mark went on pump gas was 8.32 @ 164 putting it right around 900whp at his claimed 3050 race weight. (this was also an old weight figure. I suspect the car may have been lighter.)
Marks car isn't relevant to the OP's. Plenty of people have gone faster on pump gas with no meth injection. Mark also ran a larger motor with much less compression in a very light weight chassis.
Great info forcefed, thanks for all the details. It definitely sound like your idea would be best, easier to tune, simple operation, not dependent on meth etc.
A smallish fuel cell for race gas only with a separate pump and FPR does make sense now that you've pointed all this out. Any idea how to set up the switch for changing between fuel cells? Something manual in the cabin would probably be nice.
Also, I imagine my 4303 would be more than enough for the race gas, if you have any recommendations for an in line pump for the pump gas let me know, something in line.
Dead head style set ups work for so many, I was reluctant to use one but for this case it would be required like you pointed out.. I just worry a bit about the fuel getting too hot.
Guy use two cells each with ball valves that he manually cuts on and off under the car. This would be pretty simple. Wonder if you could just run feed lines from both tanks into a Y fitting, ball valves before the Y. Then after the y you only need one in line pump.
If you wanted a return system, you could just have another ball valve that directs whatever fuel your running back into the appropriate tank I suppose.
What about the tune? I'm on the factory ECM so I don't know if I would have the ability to switch between two tunes, one for pump and one for race gas. Maybe one tune is only needed? I'll have to pick my tuners brain about that.
Coolest part about the setup is you don't need ball valves or complicated mechanical switching mechanisms. Which ever pump has power is the pump supplying the fuel. Simple check valves in place of your ball valves right at the "Y" will automatically stop the fuels from mixing. I'd have 2 switches on the dash/console. One for pump gas, one for race gas. Would be as simple as turning off one switch and turning on the other. All done easily from the drivers seat. Burnout or a few minutes idling would clear out the fuel in the fuel rail.
The tune wouldn't change much with race gas/pump gas.
Since you'd have separate fuel pressure regulator for each system you can also adjust the tune manually with the base fuel pressure. You can adjust these as needed and it will affect the entire fuel curve. Stock LS dead head fuel rail would work just fine. Guys making over 850whp on e85 with them.
The pump gas pump you choose will depend how much power you want to make. If you want to go cheap and simple 2 walbro 255's in parallel will flow more than you'd ever need. I made a rig like this with china AN fittings and push lock hose for about $225. The pumps are about 90$ shipped with the AN6 fittings.
Last edited by Forcefed86; 08-06-2015 at 07:43 PM.
I like that simple set up for the pump gas side... And I've always heard those pumps are very reliable. So you can literally drive to the track, hit the switch, burnout, and go on full boost.... Pretty awesome!
But what about when you switch back to the pump gas? Do you also have to adjust the boost? If you don't, wouldn't you quickly blow past the limit of the pump gas supply if you went WOT on the street for example?
Or just drop the compression a bit and **** all this dual fuel/race gas ****.
pump+meth will make a load of power if done sensibly, certainly the 900hp goal wont pose any problems.
The simple approach is usually always the best.
10+ years ago on here people were daft and running silly low CR's with boost for fear of **** knows what.
Now everyone seems obsessed with running CR's higher than their fuel/goals will allow, then looking for all sorts of band aids to make it work.
Just build the damn thing right in the first place to meet your goals with the fuel etc you have available !
I like that simple set up for the pump gas side... And I've always heard those pumps are very reliable. So you can literally drive to the track, hit the switch, burnout, and go on full boost.... Pretty awesome!
But what about when you switch back to the pump gas? Do you also have to adjust the boost? If you don't, wouldn't you quickly blow past the limit of the pump gas supply if you went WOT on the street for example?
Depends how fancy you want to get. You could setup boost control through the fuel pump switches. Low boost with the pump gas pump active and high boost with the race fuel pump active. Would need a solenoid setup to bypass the boost controller when the pump gas switch is on. When the race gas switch was activated it would force the signal through the MBC to your desired “race boost” level.
I have a 5$ boost **** on my dash. I turn it all the way down for street driving and turn it up at the track. You’d have to remember to turn it down but it doesn’t get any cheaper/easier IMO for cockpit boost control.
Originally Posted by stevieturbo
Or just drop the compression a bit and **** all this dual fuel/race gas ****.
pump+meth will make a load of power if done sensibly, certainly the 900hp goal wont pose any problems.
The simple approach is usually always the best.
10+ years ago on here people were daft and running silly low CR's with boost for fear of **** knows what.
Now everyone seems obsessed with running CR's higher than their fuel/goals will allow, then looking for all sorts of band aids to make it work.
Just build the damn thing right in the first place to meet your goals with the fuel etc you have available !
I’m all for low compression, but if you have an assembled long block ready to go, I’d have a hard time tearing it all down. Race gas is the simplest approach in his case. This system would be very cheap/easy to implement.
Spoke with skinnies and a few others running the dual fuel setups and they all love it. I know my setups not “on the fly” dual fuel. But it’s pretty close for 1/10 the cost.
I’m tired of dealing with the pitfalls of E85 myself and was thinking of switching over to race/pump. You can literally get by with half the fuel system running a setup like I suggested. Factory fuel lines, baby injectors, reasonable fuel pumps etc… And you can run factory compression 10:1 engines without "blowing your wad" on expensive aftermarket parts to drop compression.
I dont even have an option of E85 unless buying it as race E85...so isnt even worth considering. And race fuel is even more expensive, circa 5x the normal expensive pump gas price !
And I dont mean low, just lower lol
I was running mine at 28psi boost for the 1km the other weekend. No fancy fuel, pump+meth and no problems....and 4 bolt too. I'm around 9:1 CR
But yes if it's been built and you're stuck with parts....it's a hard decision. But ultimately what works best long term makes most sense.
As for those who dont like separate meth systems, simply adding around 20% meth/fuel is a foolproof approach if that works for you.
Obviously the main fuel system needs to cope with the extra fuel flow this will require though but it offers good performance benefits too, and there is no meth system to fail or worry about.
I was thinking you really wouldn’t use much race fuel with a dual fuel system. Most of the time you can cruise around on lowish boost and pump gas. I had to do the rough math to justify the cost.
C12 is roughly $9 a gallon (at my track anyway)
Premium is roughly $3.
So we are looking at an additional $6 a gallon to run race fuel. Doubt the OP will use more than .75 gallons per run. So we are talking about $4.50 per pass of additional cost. Which is pretty low IMO for a 1000 HP car.
So even if he made 100 passes in a year (which most don't), that’s an additional $450. $450 isn’t going to get you an E85 capable fuel system or a pay for new pistons/machine work/etc…
Buying a drum of fuel would most likely be cheaper. Could also switch back to pump gas right after the run to cruise the pits. Then switch back to race fuel just before the burn out. Not to mention the additional performance bump he'll get running the higher compression.
I was thinking you really wouldn’t use much race fuel with a dual fuel system. Most of the time you can cruise around on lowish boost and pump gas. I had to do the rough math to justify the cost.
C12 is roughly $9 a gallon (at my track anyway)
Premium is roughly $3.
So we are looking at an additional $6 a gallon to run race fuel. Doubt the OP will use more than .75 gallons per run. So we are talking about $4.50 per pass of additional cost. Which is pretty low IMO for a 1000 HP car.
So even if he made 100 passes in a year (which most don't), that’s an additional $450. $450 isn’t going to get you an E85 capable fuel system or a pay for new pistons/machine work/etc…
Buying a drum of fuel would most likely be cheaper. Could also switch back to pump gas right after the run to cruise the pits. Then switch back to race fuel just before the burn out. Not to mention the additional performance bump he'll get running the higher compression.
Yeah honestly were looking at track visits twice a month so not a lot of race gas if I were to go that route. so I've pretty much decided on the two tank idea, makes the most sense given that E85 isn't available here at our new duty station.
Having a boost referenced ability to switch between tanks/supply would be really cool. Much better than ball valves or adjusting boost mechanically. Although I'm not sure how much that would cost vs doing it Che simpler way.
I have yet to talk to my tuner about it, going to see him tomorrow, some friends seem to like the idea as well, but they seem very sure that a second tune will be needed when switching between fuel.
I'm planning to set it up like Forcefed's drawing on post #3, using the two Walbro 255's for the 91 octane tank and my MF4303 pump for the small fuel cell with race gas. I already have pre and post filters for the 4303, should the Walbros also have pre and post filters?
I suppose it would also be possible to just run a pre filter on each, and one post filter after the Y
08-06-2015, 09:06 AM
Could use some help with fuel system 
