Ben

iTrader: (33)

On paper, 1000cc injectors are maxed out at 400hp when running E85 at 60psi differential pressure.

Savington

iTrader: (31)

tl;dr: Your car is broken, larger injectors probably won't fix it, you are throwing money at a problem that can be solved with a small amount of diagnostic work (which you claim to do for a living), please answer my questions so I can help you run the tests that will determine where the actual fault in your system lies (hint: it's not the injectors).

soviet

iTrader: (10)

There is no such thing as "safe margin" for a fuel injector.

Its a simple, mechanical solenoid that is either on, or off. How is it that being on 80% of the time vs bein on 97% of the time is a safety margin?

92mazdaspeed

im not. its been out of the garage for 1 track sension. did some datalogging and put it back in the garage untill i get this all figured out.

Savington

iTrader: (31)

erm

soviet

iTrader: (10)

If only there was someone running e85 with 1000cc injectors at 60psi differential pressure - then we wouldn't need "on paper" estimates.

Savington

iTrader: (31)

You do realize that posters on this forum/in this thread have made 15% more power than that on those exact injectors on that fuel at that differential pressure, right?

On paper, reality is impossible

e:f,b

Ben

iTrader: (33)

Cool, how many is people, 1?

Math doesn't lie. 85% DC is good for ~400 whp @ 60psi differential. 95% DC should get you to ~450. Not everyone is comfortable running that high DC or that high FP. If you are, your call.

soviet

iTrader: (10)

Ben

iTrader: (33)

status: BALLEOUR

92mazdaspeed

This would go along with my datalog info. as it was a shake down and have not had it to a dyno yet to fully tune i would have to guess that its running around 400-430 hp at the wheels based on on paper. This is also why I have not been chassing maybe problems witht the fuel system. pressure regulator is reading right at idle at 62psi exactly. have not checked at fuel rail as i would need to buy an fitting adapters for fuel pressure gauge.

I very well could have a problem. However, my line of thinking was in the same direction as ben. 1000cc injectors will not net 500rwhp. they are to small for my goals datalog aside. I just included that as a main reason for switching to larger injectors becuase it was obvious I was sold undersized injectors.

Im asking what injectors would people suggest for track use that still idle for 500rwhp.
if the answer is 1300 so be it. if its 2000 great.

Yes. I know how to diagnose and fix cars on a day to day basis. however, building big power reliable miata track car is not my thing as of yet. just looking for some guidence. my build started off as a day driver that i wanted more power8 yrs ago. fm offered a 2500 option for more power. i took it. since then I have just been changing it up. now its what it is and again. im just looking for some guidance.

soviet

iTrader: (10)

your pressure regulator at idle should be reading 50psi because idle vaccuum is about 10psi below ambient.

but I guess you know better since you troubleshoot cars for a living :|

FAB

iTrader: (4)

Just to add to the conversation - My NB hit 445whp on E85 before taking out the trans on the dyno, I'm using the latest DW1300's with a base fuel pressure of 47psi and if I recall I have plenty of DC to go. Usually I won't go past 85% DC without telling someone to buy bigger injectors so I wouldn't do it on my own car..

At 500 crank on a turbo e85 car, 1000cc injectors should be around 85% DC with a base fuel pressure of 44psi.. So 1300's should give you PLENTY of room to be comfortable. I'm not sure why this is even a discussion. There are formulas to figure this out, I just use an old spreadsheet and punch the values in. Granted there are other variables but it's certainly enough to help you confidently purchase a set of injectors.

Also - the car idles like it's stock.

92mazdaspeed

My FPB has a PSI Gauge. Set screw is turned in so at idle PSI its set at 62.
referance port has its own referance from the intake.

concealer404

iTrader: (3)

Ok so you're running more like ~72psi base fuel pressure.

Yeah. There's no way in hell you should be maxing out those injectors. Definitely suggest you figure that out before you max out 2000cc injectors trying to make 500hp.

soviet

iTrader: (10)

Which is wrong, it should be 50 psi at idle (if you want to run 60 differential pressure) and sharing the reference line with the MAP sensor

This is the last piece of advice that I'll give you - you are too stubborn and its like talking to wall.

You're still on DW300 pump? Or something else?

Savington

iTrader: (31)

Respectfully, there's no way you're making 400whp at 19psi through a '95 head. I can explain why I know that if you're interested, or you can take my word for it. On a '95 head, E85, and a soft timing map, I'd estimate your current power to be somewhere around 350-370whp.

If you're seeing 62psi at idle, the FPR is seeing vacuum from the intake and reducing fuel pressure. You're probably somewhere around 70psi with the key off, which is what we refer to as "base" pressure.

As Concealer said, there's no way you're maxing your ID1000s at your current power/boost levels and your current fuel pressure. Absolutely no way.

92mazdaspeed

Im sorry you feel this way. im not trying to. 60 psi at idle is the recommended pressure for the FPR for the FM flex fuel system. its in the directions. THat is why it is set there.

its on the dw300 pump which is included in the kit.

when i get home after work im going to double check some things. however, im pretty sure I dont have a problem with the fuel system.

concealer404

iTrader: (3)

You're going to want to read FM's instructions again. They do not specify 60psi at idle at any point in the instructions, especially if you're referencing vacuum/boost to use the regulator as a 1:1 unit.

sixshooter

iTrader: (12)

I think you are running out of fuel pump. And it may just be an amperage issue, which is an easy fix.

One of the local dyno operators said his most common problems on customers' cars was inadequate fueling. The most common problem was not a big enough pump.

The second most common fuel problem was a big enough pump but stock wiring and relay that isn't able to keep up with the electrical demand when the pump gets worked to the max. Many aftermarket fuel pumps are serious amperage hogs. The wiring, grounding, and the relay often needs to be upgraded to a higher amperage capable unit.