Barwick

I'm getting conflicting reports on this.. one guy says the stock 550's are still plenty for almost 300 hp with upgraded pump, and another guy says that the 4 720cc injectors on the car now aren't enough to run this turbo that I'm running and this setup... I only want to run it at 10 lbs, and maybe 15 at the track, it's got an NPR front mount (crappy I know...) it's got the Walbro pump, and an SX fuel pressure regulator, and aftermarket external wastegate (turbonetics racegate I *think*).

I'm 99% sure I'm picking up a used Wolf3D from a guy in town who installs and tunes them. He says if I want to keep the 720's in the primaries, I should have at least 1100's in the secondaries. What's your thoughts?

$150FC

according to rx7.com's fuel calculator, 4x550 at 100% duty cycle will net you 317bhp.

edit: NPR? I thought you were going with the perfect sized intercooler for a 13B?

Barwick

The NPR is why the topic even came up, I'm ditching that thing as soon as I possibly can.

So then why is everyone telling me that I'll need these HUGE injectors? I dunno.. see my other post coming up...

frode

Thats because everyone isnt running at 100% dutycycle. Most are keeping it around 80% to have a bit of fuel in backup.

Barwick

the 4 720's shouldn't need a 100% duty cycle either though..

$150FC

for my money, 1600s are so cheap and leave room for more power later on.

i mean, ****, you can get them for $50 each on ebay, new. why spend $120 each on 720s?

Barwick

I've already got the 720's... I suppose I could get 1600's, but what brand and type do you recommend (new) to pick up that'll fit into the rail without modification?

Barwick

oh yeah, I'm 99% sure I'm picking up a used (old style) Wolf3D and having a local guy who's set them up on many rotaries, tune it.

Now, how hard would it be to run 2 more injectors (for a total of 6)? Wouldn't that give better fuel atomization and better control too?

eViLRotor

iTrader: (2)

720/1600 will be just fine. Why mess with extra injectors.

Plus, the staging method of the Wolf EMS allows you to run a larger injector size spread, since it stages the secondaries as a percentage of the primaries (I'm running 84%), so you always get that smooth transition.

Barwick

yeah but wouldn't it atomize better? I dunno..

$150FC

Yeah, it'd atomize "better" in theory, but in practice there's not much of a point, as far as I know.

Also, to my knowledge, all 1600cc injectors will require modification of either the rail or the injector (or a new fuel rail). But it is not difficult to mod them.

machinis

Crappy, huh? I'll take that crappy NPR off your hands.

widebody2

Max cooper's calculator: with a fuel pump 4 720s is good for 307 WHP at 85% injector duty

ZenkiBrokie

you could run secondary injectors before the intake manifold.

RacerXtreme7

iTrader: (2)

Just curious, your running a 60-1 wheel inside a T04E housing, or a 60 trim T04E?

~Mike..............

RacerXtreme7

iTrader: (2)

Band-Aid of an idea. This is for people too lazy or not knowledgable enough to do things propperly. injectos before your intake manifold is good for poor fuel distribution between runners ( these manifolds are designed as DRY manifolds and designed only to carry AIR), is good for fuel puddling, and is good for developing varnish on your throttle plates, and the entire inner surfaces in your manifold.

Run injectors in the stock locations (sizes between the primary and secondaries are more or less a prefference, as there is good and bad for different combos just as long as you run enough TOTAL fuel for your intended power level), or if you want to add more injectors, put them in the intake runners.

~Mike...............

RacerXtreme7

iTrader: (2)

The reason for an 80% injector duty cycle isn't for reserve fuel capability. You shouldn't run over 80% because your injector will get hot and FAIL. Injectors are not meant to be used as full duty. You shouldn't run excessive fuel pressure either, as this puts more of a load on your injectors also. The higher the pressure, the more work it takes to open the injector to fight against the fuel pressure keeping it closed. Again, duty cycles are kept lower then 100% simply to save the life of the injector, NOT for a margin to add more fuel if you need it.

~Mike.....................