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[DasPoop]

Ok I built a setup similar to this a while back on my civic and i was wondering if you guys could see a way to simplify it a tad but. Basically it was a run down like this

4-5 hobbs switches that are tuned to different boost pressures

2 z6 fuel rails plumbed into the system in the upper IC pipe that run the injectors at 100% duty cycle when the hobbs switches are tripped off thus supplying fuel for both cooling the intake charge and providing enrichment

My question is I had this idea to use a 555 or similar timer IC and a dedicated map sensor to pulse the injectors in reference to boost pressure now I also had the thought to run this setup with cheap rpm dependent switches to effectively give me both pressure and rpm dependent enrichment without effecting timing like an afc would.

I have a question is there a way to make a circuit to pulse injectors once it crosses a certain threshold using a maf that would do away with both rpm and boost pressure and rely solely on what kind of airflow the engine is taking in.

Ok now that I have sounded like a dumb ass the reason I ask these questions is for the ability to boost cars that were never designed to be boosted somewhat safer and more reliable than an fmu or an afc. I have a couple ideas of what i want to boost in wacky projects that will require tuning even if it is kinda crude but then again some control over enrichment is better than none. One thing I have in mind is something like this

The Junkyard runs 11.99@117 on a 140hp $90 Dodge Caravan motor from the junkyard. First pass.

http://www.youtube.com/user/GreatDepressionRace#p/u/10/W6klErTRqHA

Apparently 12v 6g72s are crazy strong is you dont detonate them

[Joseph Davis]

Overcomplicated control mechanism.

Use VTEC to switch the smaller of the two sets of injectors on wide open, and use the VTEC fuel map to tune the larger injectors. 

[DasPoop]

Ok so this is a SUPER ghetto run down of the system. Works like this

You have boost switches(I found that low side 80's gm A/C cut out switches are adjustable from 30psi down to 1psi and there basically free from the JY so I am going to grab a bunch.

Set them to predetermined psi so as the turbo spools it will start turning on injectors how many injectors will depend on your fueling needs as the turbo spools. Reason I am not Rpm dependent at this stage is if your cruising at 3000rpm out of boost the system is not on and flooding your motor. Once you stuff the throttle as boost rolls on it is load dependent.

Once you reach your max psi. the system will continue to work and now it switches on the rpm side of thing where your now tuning off of rpm due to the fact your turbo is no longer making more than X psi but your motor needs additional fueling.

Starting at the rpm where your turbo spools to max psi it automatically kicks on the rpm side of things and here again you tune your fueling needs off rpm rather than boost.

This system allows it to be both load and rpm dependent for cars that were never designed to be boosted.

I am just going to be using JY parts and so far I am thinking you can have a 100% tunable aux fuel system for around say 120$ I also found a diy rpm activated switch diagram that can be made for about 5$ a piece and was planning on running 4 honda fuel rails all shooting at the center of the upper charge pipe with bungs and either brackets or just big hose clamps to hold them in.

Going to be running a whole lot of boost and a whole lot of e85 so yes i presume i will need 16 240cc injectors as the idea i am basing this off of used 2100ccs of meth and still ran out of fuel enrichment up top. this at full capacity will be around 3500ccs of fuel.

Oh and the motor will be a 3.0L 12v 6g72 much the same in the video but i would like to keep it somewhat reliable and not blow a headgasket everytime you go to the track.

Yes I have thought of MS but I see this as easier to tune and get running as its more of a mechanical/electronic fuel enrichment. 

What do ya think JD will it work(?) and yes i know its super complicated and might be a bit of a bitch to tune but hey I like being different in a mad scientist way.

[SDRAWKCAB]

FRONT PAGE!

[Ntrain2k]

I know that Duster and it's owner.

It is bad ass and sleeper as hell.

[Foowee]

this reminds me of an erl mf2...



http://www.aquamist.co.uk/cp/mf2/mf2.html

I think the old Turbonetics kits included one of these w/a msd btm to use as supplementary form of em...  I found one for dirt a few years back.  I'm sure you could do the same, if you are able to tolerate people that would spend 5grand on a "kit".

[DasPoop]

hmm read up that therr mf2 found out it can only control 4 injectors MAX and 2 are recommended. Far shy of my needs. Good idea though.   

[Foowee]

Who says you can't run more than one?...

[DasPoop]

Rpm dependent switch diagram can anyone explain this a little better to me so i can start turning these out gonna need a bunch

[Joseph Davis]

Who says you can't run more than one?...

With 1600cc being $50 a pop, who says you need to run more than one?

[DasPoop]

hmm perhaps  but however tuning 240ccs at a time should give me plenty to room to tune to damn near perfection. I am trying to do this as cheap as possible and allow for a lot of boost. and a lot of air. From my calc 22 240cc inj, will have enough fuel for 550 hp at 43psi with a bsfc of .70 so it should be good for what i am looking for plus i get the ability to tune one injector at a time 

[dvst8r]

Where would you put 22 injectors?

[DasPoop]

6 in the motor and 16 in the upper charge pipe 

[dvst8r]

This to me sounds like a sure way to have some really rich cylinders and some really lean ones. EGT or 02 on each cylinder sounds like a needed thing.

[DasPoop]

ah you see but the joy of equal length runners of a transverse v6 

[dvst8r]

I still think you will have some serious differences.

[Joseph Davis]

ah you see but the joy of equal length runners of a transverse v6 

Irrelevant.

[Ntrain2k]

The SOHC 6G72 upper plenum isn't exactly a model for even distribution.

Might want to look at installing spacers between the upper and lower intakes and putting the injectors there. Otherwise you are going to flood the back 2 cylinders and lean the front two.

Even when ported well it's still way off.

I've been messing with them since 1998.

[DasPoop]

The SOHC 6G72 upper plenum isn't exactly a model for even distribution.

Might want to look at installing spacers between the upper and lower intakes and putting the injectors there. Otherwise you are going to flood the back 2 cylinders and lean the front two.

Even when ported well it's still way off.

I've been messing with them since 1998.

I was planning on building a custom upper intake. Would it be a better decision to plumb them into the upper intake. firing them off equally? I plan on having wb's in both the front and rear runner.

[snm95ls]

Adding a metric fuckton of fuel to a manifold that was designed for dry flow, air only, sounds like a sure fire way to end up with massive fuel distribution problems.

But hey, you will have 22 injectors!  that in itself is something to brag about.

 

[Joseph Davis]

Those motors are feces.

[DasPoop]

if feces make 500whp then you sir have some serious shits. Better look at getting one of those high flow toilets or was yours make by dynojet 

[Joseph Davis]

Right.  My criticism of a motor/package that was designed with such care that every bellhousing bolt breaks off the first time you go to do a clutch is unwarranted, and if I mention that the 3000GT/Stealth AWD jobbers use the DSM gearset with far less spectacular results due to the extra torque I'm just making shit up.

Motorsports is generally lighting money on fire to have fun, not dissimilar to crack rocks only you usually have something to sell when you're done to recoup a portion of your money, but that particular package is really fucking expensive for what you get.  To the point that when I meet a rabid fan IRL I smile and nod while backing away slowly.

[Robb]

Right.  My criticism of a motor/package that was designed with such care that every bellhousing bolt breaks off the first time you go to do a clutch is unwarranted, and if I mention that the 3000GT/Stealth AWD jobbers use the DSM gearset with far less spectacular results due to the extra torque I'm just making shit up.

Motorsports is generally lighting money on fire to have fun, not dissimilar to crack rocks only you usually have something to sell when you're done to recoup a portion of your money, but that particular package is really fucking expensive for what you get.  To the point that when I meet a rabid fan IRL I smile and nod while backing away slowly.

You forgot to mention an oiling system that makes a y8 look badass.

Das, there are folks making 500whp on the 7bolt sohc 4g64, stock longblocks. How long will it make that power? That depends on the fuel...

[DasPoop]

ok regardless of engine this is about a fuel system. I understand this is pry very complicated and very archaic in nature by not relying on electronics rather relying on a more mechanical side of things. I am going to build this regardless just to see how well it will work. From caclulations it should react plenty quick to boost level changes. It should also be quite accurate as far as metering fuel as well

[dvst8r]

...From caclulations it should react plenty quick to boost level changes. It should also be quite accurate as far as metering fuel as well

I am not doubting this part (maybe others are, but I am not) what I am doubting is being able to get decent distribution of this fuel, as spraying 22 injectors close together the atomized droplets of fuel are going to come together and are going to result in terrible distribution.

Don't that let that stop you from building it, but keep in mind when one bank is reading 9:1 and another one is reading 16:1, we will be here to say "I told you so" 

[DasPoop]

...From caclulations it should react plenty quick to boost level changes. It should also be quite accurate as far as metering fuel as well

I am not doubting this part (maybe others are, but I am not) what I am doubting is being able to get decent distribution of this fuel, as spraying 22 injectors close together the atomized droplets of fuel are going to come together and are going to result in terrible distribution.

Don't that let that stop you from building it, but keep in mind when one bank is reading 9:1 and another one is reading 16:1, we will be here to say "I told you so" 

Well I am going to be making a custom upper intake manifold with the TB on the pass side and i suppose i should consider plumbing them in 8 per side equally distributed among the banks and intake ports. Do you roughly know which cyl typically run leaner on this motor? Reason I ask is this will bias which cyl will get more of the injectors in there region. I am guessing the front 2 with regards to the tb position will run leaner than the others. Any one have an idea how tall a honda fuel rail is with injectors? I am trying to figure out making the manifold taller and plumping them into the bottom of the manifold down the center. it may not distribute 100% evenly but firing them off front to back should be as close as i can get it.

1   2    3
4   5    6

[Ntrain2k]

I'm telling you, throw one or two injectors in each runner. Spraying into the open plenum is going to be a disaster.

1 and 4 typically run the leanest in an N/A configuration getting richer as you get closer to the TB. Porting improves it slightly. If you add fuel into the flow, it's going to do the opposite. Seen it plenty of times on a wet shot.

If you end up spraying into the manifold, I predict the two end cylinders opposite from the throttle body are going to run rich, and get leaner as it gets closer to the TB.

[DasPoop]

I'm telling you, throw one or two injectors in each runner. Spraying into the open plenum is going to be a disaster.

1 and 4 typically run the leanest in an N/A configuration getting richer as you get closer to the TB. Porting improves it slightly. If you add fuel into the flow, it's going to do the opposite. Seen it plenty of times on a wet shot.

If you end up spraying into the manifold, I predict the two end cylinders opposite from the throttle body are going to run rich, and get leaner as it gets closer to the TB.

ok thats what i was thinking I suppose i should plumb the injectors close to the TB and those runners. I know I am not going to get 100% equal distribution but even if I tune it 11.5:1 A/F and if I get close front to back I will consider it a win. I am also going to be putting the wb sensors in the no 1 and no4 exhaust runners to get a better check on how they are running. My dad has a bunch of extra pyrometer setups from our drag sleds that will allow me to have one egt probe in each exhaust runner to keep a tab on how there running. This is going to be a crap shot into this venture and if i can get it to run even half ass and not blow up well then I will consider it a success

[Joseph Davis]

I'm telling you, throw one or two injectors in each runner. Spraying into the open plenum is going to be a disaster.

I think this is a lot of work and fucking around for lackluster results, but at very least follow this man's advice.