(Turbo planning) Need imput on best AFC? KA-T fuel Options

[Red]

Doing searches and reading.. It looks as if JWT is good, BUT they like to program rich Air/Fuel mix.... So I'm looking towards the AFC direction.. may require dyno tune.. But I have more versatility in the way I can use an AFC if I get a good one.

So who makes the best AFC do you guys/gals think?


Also does any side feed injector for our KA's? Is it worth the extra cash to get ones that fit stock location?

And where do I find a damn Walbro 255 fuel pump for a 95 240sx that drops in with no moddin?

[kapower]

I just picked up a KA24DE and I plan on building it through out the year (turbo build) I plan on building my turbo setup in two stages. 1st stage; around 12psi(hopefully anyways) piggy backs, z32 maf, and 370cc injectors (or if at all possible 50lb injectors) for the second stage I plan on running a standalone, and 15-18 psi daily driven, and 20+ on the dyno, at the 1/4 mile strip with race fuel. How many psi can I run with a z32 maf, 370cc injectors and a piggy back (lets say a apexi S-AFC II with a capabilaty of adjusting injectors +50% to -50% every 50 rpm's) I DO NOT WANT TO RUN A RETUNED ECU!!! with 370cc injectors @ +50% should give me 555cc's +45% will give me 536.5cc's right?how much boost could i run with 536.5cc's? and how big of an injector can I run with only piggy backs and a z32 maf? I would like to buy a fuel rail and large injectors right off the bat, and just run them for my stage one plans and stage two. thanks in advance to everyone, I have been reading threads on this forum for atleast 4 months now and I finally have some Questions. I'am also very aquainted with the search button. :)

[Jeff240sx]

Originally posted by Red
Doing searches and reading.. It looks as if JWT is good, BUT they like to program rich Air/Fuel mix.... So I'm looking towards the AFC direction.. may require dyno tune.. But I have more versatility in the way I can use an AFC if I get a good one.

So who makes the best AFC do you guys/gals think?


Also does any side feed injector for our KA's? Is it worth the extra cash to get ones that fit stock location?

And where do I find a damn Walbro 255 fuel pump for a 95 240sx that drops in with no moddin?

JWT is awesome because they give you a safe boost threshold that you can run w/o tuning. Example, my Cobra maf/50# injector combo can run 15psi just plug-and-go.
And AFC is an Apexi unit, Super-Air Fuel Controler(Convertor). The other options are a Greddy Emanage and a Standalone. My thoughts.. Rich is good. Get a JWT and go. For $600, that's about the price of an AFC and 2 hours of dyno tuning.

Side feed injectors.. 370cc injectors from a '95-'96 300zx TT or any SR motor's injectors fit in the stock rail. After that, it's cheaper to get a new rail and MSD injectors.

Finally, www.FTFmotorsports.com is the only place that carries a
Walbro pump kit for the S14. It's not on their site, you'll have to email the guy to get a kit. He pieces it together from 2 kits, and the only difference between stock and the kit is that the s14 stock pickup sock is about 1.5" longer. Other than that, I love the FTF kit. It's $122.
-Jeff

[Jeff240sx]

Not a single high power KA that I know of has run a standalone system. Duy, Chris May, BoostedS14, Dennis and TY all run/ran JWT ecu. Get over the richness and use the AFC to run the fuel map leaner to get more power.
What you are missing is that with virtual (AFC-driven) 555cc injectors, you can run about 18psi, but there are 2 problems.
1) You wont have a timing retard that the JWT ecu has.
and
2) The AFC won't open injectors further than they can. The +/- adjustment will make them open faster than the ECU map will.. so you can add fuel where you need it, but you can't open the injector up anymore. More than 370cc from a 370cc injector requires a fuel pressure raise. You can, however, fool the ECU to make it think 555cc injectors are 370cc, by running a -27%(or about.. do the math), and the AFC will withhold 27% of the air signal from the ecu.
-Jeff

[kapower]

ok, how big of an injector can I run with a z32 maf and piggyback setup? I would like to run the same injectors through both stages. I just figure that after piggy backs, boost controller, and retuned ECU, that I would be in the same price range as a standalone. And one more question how many psi could I get out of 370cc injectors?

[Red]

Hmm few questions.. What HP are the 370cc and 550cc's rated for?
And the $600 for the JWT does that come with a Cobra MAF? or is that extra?
And do you think I should just go with 550cc injectors off the bat and get the fuel rail for few hundred?, Asad on Freshalloy said he ran fine with that setup with no turbo. That should give me the option to turn up the boots quite a bit later if I get a rebuild.

[Jeff240sx]

Originally posted by kapower
ok, how big of an injector can I run with a z32 maf and piggyback setup? I would like to run the same injectors through both stages. I just figure that after piggy backs, boost controller, and retuned ECU, that I would be in the same price range as a standalone. And one more question how many psi could I get out of 370cc injectors?

I merged both of these threads, because they are VERY similar...

What standalone would you use? Read above.. all high powered KA-Ts use JWT's ecu.
370cc injectors and Z32 maf on a JWT ecu are good to 12psi, I believe. Roughly 270-280rwhp.
-Jeff

[Jeff240sx]

Originally posted by Red
Hmm few questions.. What HP are the 370cc and 550cc's rated for?
And the $600 for the JWT does that come with a Cobra MAF? or is that extra?
And do you think I should just go with 550cc injectors off the bat and get the fuel rail for few hundred?, Asad on Freshalloy said he ran fine with that setup with no turbo. That should give me the option to turn up the boots quite a bit later if I get a rebuild.

370cc are good to 270rwhp or so. 550 (50# injectors are 525cc) are good to 360rwhp from T.Y.
Cobra MAF is extra, and you can get them for $130 if you look hard enough, or they're $150 from Autozone without a core.
Go to Unstable Hybrids for their $130 fuel rail. Asad ran a Cobra maf and 50# injectors, and said "It runs, but. Idle issues..." Not fine, and he didn't recommend anyone running that. I think the quote was "Pig-ass rich" or something to that effect.
Get the JWT setup and run low boost, that's ok. Even lean it out with a piggyback (AFC, emanage) unit.
-Jeff

[d240t2]

Duy's car ran a haltech...but it wasn't a street car. The only times that car ran on the street was when it was going to the track, or going to street races. My car, Chris's car, etc. are all daily driven.

I have yet to see a high-hp street KA running anything other than JWT ECU. Many people have made ~240-250rwhp with other setups, but not more.

Dennis

[Jeff240sx]

Originally posted by d240t2
Duy's car ran a haltech...but it wasn't a street car.

Doh! I knew that.
-Jeff

[Red]

http://www.nissantrader.com/adcycle/adclick.cgi?gid=5&id=1029

This is the only place I have seen special set ups for a JWT ecu. Can I order from JWT direct with a special order?

And what is a 3bar system?

[Jeff240sx]

Originally posted by Red
http://www.nissantrader.com/adcycle/adclick.cgi?gid=5&id=1029

This is the only place I have seen special set ups for a JWT ecu. Can I order from JWT direct with a special order?

And what is a 3bar system?

That link just makes Zivlia pop up.. I don't know.
You can order from JWT, but they give discounts to companies, so that the companies go through the paperwork, and JWT just gets the ecu.
www.CIPmotorsports.com has good prices on the JWT ecu.
A 3 bar system is a term for the standard fuel pressure we run, 3 bar. When you get a 50# setup, you have the choice of 3 bar or 4 bar. 4 bar requires a new fuel pressure regulator.
-Jeff

[AceInHole]

Originally posted by Jeff240sx
Asad ran a Cobra maf and 50# injectors, and said "It runs, but. Idle issues..." Not fine, and he didn't recommend anyone running that. I think the quote was "Pig-ass rich" or something to that effect.

That statement is kind of distorted.... the Cobra MAF on a stock ECU has idle issues. The Cobra MAF on a JWT is perfectly fine, supposedly.

Best thing about the JWT is that it's been proven, although lately, all I've heard about from people with JWT ECU's are problems (idle and pinging problems). Those may be isolated cases though. Also, people forget that the JWT ECU also remaps the timing, which is a DEFINITE plus. Higher rev limit and cut speed limiter are also plusses (although I get the feeling JWT's wire cut is similar to the speed sensor wire cut... since I've heard of "issues" with stalling coming out of gear on JWT's. It's just a theory though, should ask JWT directly).


If you really want to save some $$ and still run pretty well, do the hacked MAF for a baseline, and use the AFC to tune it out later as you go along, although the hacked MAF is still "tuneable" without an AFC. The more I use my car, the more confidence I have in the hacked MAF. Between Orion (on FA) and me, the hacked MAF has MORE than proven itself as a viable option for 240sx's.