Anyone running the stock ECU and 4 720 injecotrs with a SAFC? If so how hard was it to dial in? Any other advice or input appreciated.

 

bump

 

dale clark did (is?)

he said it started up and idled fine before he even made any changes to the S-afc.

just tune the idle down till it's best.

and you really want to use a wide band o2 for other tuning.

 

I run 4x720's on a Field SFC Hyper-R on a G-Force ECU.
Close enough.
They are easily to dial in, but I gotta warn you you're going to have starting problems.  You see, I had this flooding problem that was driving me crazy no matter what I did - pro injector cleaning, pull cranking lead to ECU, etc.  After thinking about it, there is no way to tell the ECU what size fuel injectors on initial cranking of the engine.  The ECU shoots out an initial large pulse of fuel for priming the engine, and it is impossible to modify this short of reprogramming the ECU specifically for this change.  My car starts okay when cold, but there's a 50/50 change it'll flood when hot.  I do have a fuel pump cut-out switch install, so this is a minor inconvenience - I highly recommend you so this if you choose this path.



-Ted

 

Just out of curiousity how much power do you guys make that needs 4x720cc? I know a lot of people run 720 secondaries but im wondering how much power needs 720 primaries too. Thanks!

 

I ran 4 680cc's and an SAFC II. Wasnt hard to tune at all.

 

Ok, sounds good, thanks for the input guys.

 

I hit 253.9hp at the wheels on a DynoJet, and the pulsewidths hit 90%+ with the stock 4x550's! I got a deal on the 4x720's, so that's why I swapped them out all at one time.  I wanted to jack the pulsewidths down to safe ranges, as 90%+ is too high.


-Ted

 

Or does everyone think that maybe 550s for the primaries and 850s for the secondaries would be easier? Would it be as safe? I am running a BNR stage 3 at about 15-17 psi, and I have FMIC. Yes I do have the upgraded rotary performance fuel pump.
Thanks
Jeremy

 

@ what psi?

 

Did you have a upgraded Fuel pump?
What where you running on boost?
All when you did the dyno to get 253hp

 

I am running 2x680s and 2x720s on an SAFC with stock ECU. Why?

 

i am going the get 850cc since i want room to add if i want to add some more upgrades.
But if you have a stock ported engine then i think 850cc would be the max.

 

So J RAT was your set up easy to dial in with the SAFC? Also what other mods do you have?

 

the reason why people use bigger primarys is to prevent running lean before 3800rpm which is when the secondarys start working.


as above it more to do with when the power comes.

but anything over 300RWHP or somewhere you'd probably need bigger then 2 720's.

 

Ya I dont know where I will be for RWHP I sent my turbo to BNR for a stage 3 upgrade with the match ported manifold and turbo it is suppose to be capable of 340-350RWHP. Keyword being capable. So I don't know. I plan on running Sunco power110 most of the time for gas so I do not know how important the timing will be as that is 110 octane. So I know what you are saying that turbo is suppose to hit full boost by 4000rpm so thats what worries me with what CorkSport said about the 550s. So have you or anyone else ran 4-720s on the stock ECU and a SAFC...? Or do you guys have any suggestions? Other than the obvious full stand alone. I will not BS anyone I am not the greatest tuner and I live in ND which is very limited on Dynos and such places to help dail things in. I figured I would just buy a wide band O2 sensor and EGT to help dial it in pretty close. Any other suggestions I am open to ideas or what has worked for others.
Hey Scott I am gonna follow your idea on the FMIC, I just bought a FMIC off ebay, I plan on doing a set up like yours.

 

when it comes time to tune .. take it to Joey @ excessive autosports in Sioux Falls.

 

I run 4x720's, S-AFC RP fuel pump, FCD, stage 4 BNR hybrid

 

How much power are you putting down? I was running 2x680's and 2x720's and I couldn't add anymore fuel. I maxed them out I suppose, twice. (I didnt have 720's the 1st time then added them) MY a/f curve moved but not to much when I added the 720's. I hit between 290-295rwhp.I could not add anymore fuel. The S-afc would not respond.

 

AVC'R was set at 1.0bar, which is about 15psi.



-Ted

 

Walbro 255lph.


About 15psi.


Yes.  The car was running a tiny T5/T6 compressor upgrade.


-Ted

 

Oh I see! How much torque you puttin down at the wheels (HP sells cars; torque wins races )? Thats a nice amount of HP there! Now I see why you would need that much fuel, thanks for clearing it up!

 

My set up isnt tuned yet, as I am waiting for the turbo upgrade before I go to the dyno. So, I just guessed on the settings. Pretty much standard. High/low set at 98/99 percent, with low settings at -24 virtually across the board. With high settings ranging in the -10 to up to 0 at 7k. Not the best, but I am not going to dyno tune when I am just going to put another turbo in.

Mod list:


Bonez downpipe, Bonez midpipe, Dawes Devices MBC, Racing Beat FCD, TurboXS Type S BOV, ACV and Airpump are OUTTA THERE, CAI, TID mod, K2RD Aluminum radiator, Perma-cool finger chopper, Racing Beat catback, 680 primaries, 720 secondaries, GReddy Turbo Timer, APEXi SAFC, TB mod, Walbro 255l in-tank Fuel Pump, Series 5 Turbocharger,

 

My torque was way down, as I run a very aggressive street port (on the exhaust).  Due to the early exhaust port opening, I lose a lot of torque (down low) to the exhaust gases exiting earlier (than stock).

Max torque was 213.4 lbs-ft.

Oh, the run was made in 3rd gear - I think it would've made a little more in 4th.  Hell, I didn't know this back then.



-Ted

 

Thanks for all the input.