mattmarrx3

jsut go 2 2200 and be done with it and run your base pressure at 35 psi mine is and ive got then in primry ( not a pp ) and idles fine

nvmarx

iTrader: (1)

injector dynamics do a 1600cc injector but they are discontinued now, but new ones pop up for sale every now and then. i think aerosev has a point to we have discussed this befor however i cant see this engine making 350hp at fly wheel evin with 2200cc injectors. my problem being id 2200cc are 340nzd new for one thats mad lol if i could find id 1600cc injectors new that could be the go do you think....

John Huijben

iTrader: (1)

A good fuel injected PP should get better bsfc than 0.65
ID2000's will probably work, but I highly doubt you can get a 13B PP to make soo much power that you will actually need them.

Jobro

iTrader: (2)

What would the peak pressure be at an injector installed into the factory oil metering jet hole?

The rotor will have just begun compression at that time.

Will spraying fuel directly onto the hottest part of the engine promote pre ignition or detonation?

Liborek

Well, I´m not sure if conventional injector designed for port injection would be able to deliver requested fuel mass in very limited time before comression, for operation with fixed deltaP. Something like this would be neededhttp://www.bosch-motorsport.com/cont.../html/3444.htm

Spraying fuel to hottest air is most efficient in regards to charge cooling, plus there are other benefits like no fuel loss in runner wetting.

I have paper which concerns direct injection of E85 into piston engine and they compared three techniques - port injection, direct injection during intake stroke and direct just after intake closing. Last approach allowed highest manifold pressure and at the same time, pressure and temperature after compression was lowest. My conclusion is, that measuring what happens in intake is pretty much meaningless as it doesn´t necessarily reflect what will happen in combustion chamber. And I think this is very applicable to rotary

j9fd3s

iTrader: (3)

the PP does much much better than .65 BSFC, its more like .5.....

i have 3 examples. one the 787B sae paper, they reach .49 two if you look for diyman25's engine dyno they were in the low .5's.

and then the third. i did a track day with a friend of mine who has a 6 port FC. he went thru a tank and a half of gas, i have done 1.5 track days on the same tank.

with more fuel pressure you could run 2x720's... but the ID1000's seem like the best choice

aerosev

Yeah your probably right, using the 787b as an example is probably not that useful, they would have spent millions developing it to be efficiant, and remember it features suchs as tripple plugs per rotor and variable intake tracts, we are working on a hundreds not thousands budjet let alone milions, the car will be used on the street so will have to have an alaborate exhaust which Im sure will mess up the efficiantsy, the flip side to that of course as that you will loose power out of this so in theory you wouldn't need as bigger fuel injectors, I am intersted in diyman25's engine that would be worth looking at,
I myself have a 12app with a nikki carburator, Im the first to admit that this is not the most efficent setup however it is a real world example, I had trouble on the dyno where I couldn't get it to stop leaning out up top, I was making around 183rwhp and I had about 1450cc minute of fuel flow per minute into the float bowls, It was running lean with afr's into the 14's and when I took the jets up a size it would just get worse, I did some mods and managed to increase my fuel flow to 2000cc a minute and then made 194rwhp and got the mixture back into the 13's, with this real world example in mind 183rwhp needed 1450cc/minute of fuel, if you work that out I think that comes to around .65, Like I say I am aware that a niiki carb on a pp is not going to be very efficient and a 12a less efficent than a 13b, but you are better to have more than not enough in my opinion.

Liborek

787B actually run as low as 0.464 around peak torque, peak power appears to be about 0.5. In case of diyman25's engine, its very interesting how BSFC is low when the engine is in tuned range and substantially worse outside.

I also did some calculations: 350hp with 0.55 BSFC and 85% duty cycle, which, according to ID is manageable even at 10k rpms, would require 1225cc static flow, which according to spreadsheet bellow is doable at 65 psi base pressure. We also have fuel pump data and OP's pump can supply required flow up to 90-110 psi, depending on voltage.

j9fd3s

iTrader: (3)

https://www.rx7club.com/showthread.p...highlight=dyno

.55...

my 12A pp is running a weber carb, and afr is in the 11's with a 175 jet.... hp is in the 170Rwhp area on the butt dyno. hp will come up when i can redo the exhaust, and ditch the stock 12A air cleaner!

just out of curiosity how did you measure the fuel flow? i was thinking about doing something like that, but i don't see how!

aerosev

All I did was whipped the bung's out of the float bowl and ran it for 1 minute on the stop watch to see what I had, I think under full throttle there is actually a bit of vacume in the float bowl and the actual ammount of fuel being consumed will be even higher again, This theory is backed up by the fact that my fuel pump which sat in the original fuel pump position just foward of left rear wheel, does not have enough vacume to suck fuel up and over the diff if it gets an air lock, Not ideal so if I have only 10 litres of fuel in the tank and go round a sharp corner it will suck air then die, No amount of sitting there with the fuel pump running will get it to flow fuel again when this happens.
I discovered however if I have this happen and the car dies (usually a few 100m from the sharp corner) if I put my foot flat to the floor and change down a gear or two to get the rpm up it will suck the fuel back up and away it goes again!
So there must be a vacume of 1-2psi in the float chamber under full throttle so I would imagine it would have a similar effect to raising fuel pressure as there would be a larger differential pressure.
On the dyno when I ran the 183hp the fuel pressure had dropped to 1psi, I measured the total flow being delivered to the carb also this worked out to around 1950cc / minute, I changed fuel pumps and got that figure to 2500cc / minute so it was able to hold the fuel pressure better but that didn't change the fuel flow to the float bowl that much, from memory it might have got it to 1650cc ish? I then modified the float needle seats and got the fuel flow out to about 2000cc/minute, so now it has way more than it needs! Then I took it back to the dyno and made 194rwhp,
Its not a very efficent setup and not huge numbers but respectable for what it is, If I have got my calculations right its running in the .65 bsfc range, I am going to fuel inject it soon and I am expecting that figure to drop a bit, and the power etc to be up quite a bit, I think its pretty strangled at current.

j9fd3s

iTrader: (3)

that's an interesting way to do it, and i guess it gives you a gross number, like you get BSFC for a minute, instead of by rpm, unless you're really nuts!

if your car is the yellow S1, its F-ing cool....

i should try that test too, my car is also pretty strangled, i need a muffler that muffles

nvmarx

iTrader: (1)

its pretty clear aerosev is the brains behind this efi set up i am still learning, original plan was to get the rb 51mm ida carb. that went out the window after catching up with aerosev. i never really wanted to go with a carb it was just cheaper at the time so far the money i have put into the efi set up is well below the price of a rb 51mm ida sent to new zealand. but in saying that the injectors and microtech will out weigh that price, i think any way.
is there a conclusion? pity there is no middle ground between the id1000's and id2000's i read that the id1600's got recalled due to high fuel temp problems or some thing along those lines. is there a injector that is similar to injector dynamics range that is in the 1400cc to 1600cc range? or should i buy the id1000's and see how they work out come tuning time as they are cheap here and can always sell them.

aerosev

Just get the 1000's and lets see how it goes? If they max out we could always pull the rev limit down etc to stop it getting into a maxed out situation, And in reality your probably not going to make 350hp so its probably never going to be an issue.

mattmarrx3

dont be tight with money jsut spend it on the wise parts first time

nvmarx

iTrader: (1)

if you have any spere time could you mesure the injectors that are in there to see if the id1000's will go strait in

nvmarx

iTrader: (1)

dude i have owned this car over 3 years. it has been taken off me twice. once by police and once by the courts. i have had to sell my tv at one stage (brand new at the time) to get 1g to bribe the bailiff to get my car back. its getting to the point where i am taking major short cuts just to fast track the build. plus the engine has sat for all most 2 years that thing needs to be fired up haha. BUT in saying that i would never skip out on getting parts just because they are cheaper especially parts as important as injectors. from my understanding injector dynamics are up with the best if not are the best. based on the feedback i have plus stu's experience i'm sure the id1000's will deliver for my application. and its not 160nzd per injector is that much to pay if later on down the track when and if i decide to get competitive with this car allot more than the injectors will need to be changed probably even the car will get ditched for some thing lighter.

mattmarrx3

email paul at nzperformance and ask him they should be get them adn go hard , dont worry my block sat around for 4 years till i got it running lol

nvmarx

iTrader: (1)

**** 4 years! hell the way my work is at the mo i think mine might be the same haha.

Liborek

Food for thought concerning very same topic.
http://www.efi101.com/forum/viewtopi...1be47bc21e04c1

j9fd3s

iTrader: (3)

this is the most important part "... the engine will surprise you. Give it what it wants, not what you think it wants."

diyman25

Here is my experience on ID2200

i have 13B PP with 56MM ITB with 2 ID2200, this is the recommand i get from Racing beat

their theory is by keeping just 2 injectors , they are no lagging time between low speed injectors

and hight speed injectors

first we set psi at 70PSI. with 300WHP i made from dyno. i am not 60% duty cycle of injectors

but the trade off is , hard to make a smooth mid end response and idile


so i put back psi down 60PSI which is stilll pretty high for normal injectors

but the car response and idile is much better with it

J

23Racer

This is soooo true. On mine, we have spent too much time using predictive software and targeting specific A/F's. The last session out, we just started playing with the settings and ignoring everything else other than giving the motor what it needed to work right and we ended up far leaner than we were before and the car running heaps better.

Now I just have to figure out what we have done and what its telling me.

Eric