I'm buying the NOS 5124 Kit from a friend this week.

I also am getting Blueprinted 300zx TT Injectors very soon.

I already have a Cartech Adjustable FMU and an APEXi AFC I.
Running a 3.12" Pulley at 9PSI on the V1 SC right now. No detonation, no issues with fuel at the moment - tuned to 12.1:1 A/F Ratio across the board.

What else do I need to run this safely?

Do I NEED a JWT ECU?
Do I NEED the J&S Safeguard with this large of a pulley?
(I know Mardisgras swears by it, but he's like running off a .25"
pulley right now)

Basically I want to know what the minimum cost would be to get this to run safely. Later I will add larger components. If I have to wait until I can afford another $1200 in A/F stuff, then I accept that - but I want to hear opinions.

Also, what will I need to simply run the 300zx injectors without being super rich?

PS: I don't plan on ever running over a 30-shot.



IanS

You should be fine with that, but how many shot is this kit? If its 35 you should still be fine.

Mardis at the time was running around a 2.67 pulley. Way smaller than your current 3.125" It was near 14-15psi.

Dixit

Fine with what, exactly?

Do I need the SARD? Fields?

Fine without the J&S. If you are staying with the 9psi and shooting 35shot, as long as you tune it with either a Fields AFC or Apexi SAFC, you should be fine in not detonating. I think once you start running above 12-13psi, thats where the J&S comes into definete need/use.

Dixit

So do I still need a JWT ECU or some other way to control the Fuel Pressure?

Or will a SARD FPR do everything I need?

All you need is your fmu, a fuel pressure gauge, and some tuning time on a dyno. DONT use the FPR that comes with the nitrous, only use your fmu. If you use the 2 together, your fp will shoot way over 100psi. You need enough "starting" fp to be able to account for the nitrous, but your ending fp cant be too high. Kind of a pain in the butt but its nice when tuned.

You can speak to Jim wolf to control the fuel with the TT injectors and also inform him what shot of Nitrous your using, I believe he can accomodate both of those. I would not use the SAFC I for this combo because I will be doing it. IF you use your current SAFC I with the Nitrous your going to need to plug the numbers in when you run. With the fields or SAFC II it has 3 settings, so you can just press a button and be ready to run.

WOuldn't that be assuming that I'm running the Nitrous straight off the line?

Maybe I'm misunderstanding you - but I was planning on having hte SC at boost and the Nitrous at the same time, after about 2800RPM. Not Nitrous then SC Boost.

Am I htinking about it wrong?

Jay - Yeah - you're right - I'll go with the Fields AFC.

I can't afford a JWT until after my wedding next spring, so that will have to wait awhile - but it will happen eventually. This going to cause any problems besides making it difficult ot tune?

IanS

No I meant you will need enough fp around 3000 rpm, but tuned not to peak more than needeed.

If you wanna run the JWT SC ECU with their nitrous daughter board I suggest 550cc injectors.

Yeah - I may run that eventually - don't have the funds this year or the 1st half of next year (getting married).

So I'm tkaing it I can use a Fields AFC, Keep the Caartech FMU, get the 300z Injectors, and that's all I need?

(I'm a sucker for clarification - sorry guys)

IanS

If I was you Id get the SAFC II you can tune at every 200RPMs vice 700RPMs with the fields, also the SAFC II has all the same features like the fields with three settings.

Good idea!

I'll do that! (Especially since I already have a spot to mount it!)

that is what I am going to do, I have the NOS kit in the garage, window switch but no SAFC II, I have the SAFC I, but may forget to change the Nitrous setting. Three settings is good, one for normal driving, one for boost one for boost and some chilly air.

OK so here is exactly what I'm going to do:

Install the 300zx Injectors
Install the AFC II
Install a Walbro Fuel Pump
Adjust the Cartech to ramp the FP under boost.

And that's ALL I need?!?

Also, can one use Water Injection with Nitrous??

IanS

Read post before this one.....<bump>

Mardi used an adjustable fpr to lower his base fuel pressure to about 26 psi in order to get the 370s to within the ecu's range of adjustability. If you run stock base fuel pressure the ecu can't back off on injector pulse width enough for it to idle properly (it'll be too rich). He also used a 3:1 disk in his fmu, and that was with a 2.62" pulley. Does the Cartech provide a 1:1 ramp capability? You might need to go that low if you stick with your 3.125" pulley.

It was issues like these along with Mardi's change of heart concerning the JWT ecu upgrade that led me to go the JWT ecu and Z32 mafs route for the 370 cc/min injectors. I'll be running a 3" pulley until I figure out what I'm going to do about charge air cooling.

Got link? I missed that one!

Sorry, Icey, I can't find the thread where he first talked about it.

Ok...but what happened? Cliff notes?

Well, basically, Matt talked to Jim Wolf and was persuaded that an ecu programmed by JWT for operation with 370 cc/min (or larger) injectors using stock fuel pressure is superior to cobbling together a system of fmu for coarse afr adjustment and safc (or other means) for fine adjustment of the afr, along with a lot of dyno tuning.

I think the jury is still out about whether the JWT upgrade or a do-it-yourself system with adequate dyno tuning produces the most power (there is the opinion that JWT is too conservative when it comes to afr and timing), but from what I have been reading in other forums (nissanforums.com, for instance) I'm becoming convinced that the JWT ecu provides a safer and proven alternative with respect to detonation.

Thank you~! I've always felt JWT ECU's are a superior solution, but they weren't popular because only 95-96 guys have that option(97 can swap?). Anyways, one of my recent T&HTP mags did a SR20DET swap into a 240. After a baseline dyno, they added Blitz 550cc injectors, a 300z MAF, and a JWT ECU. The A/F curve before the JWT was pig rich down to about 10:1, but after the JWT it was 12.5:1 flat as could be from 3500ish to redline. Amazing IMO that they could tune an ECU for a car they haven't even seen or had with the same mods.

I've always been a JWT product fan, however the customer service hasn't been the greatest.

550's

Funny thing was that they said now with the 550's, they have fuel for 350+whp safely.

Shouldn't they be good for 500+whp?

SR20DET has 4 cylinders, no? 350 X 6/4 = 525 hp So 4 550's gives you 350 hp, 6 of 'em gives you 500+ hp.

I see said the blind man to the deaf dog.

Looks like I'm getting the Fields....mtrai760 is giving it to me for $200....pretty good deal.

IanS

Another one with Blitz 550s and Z32 MAF...

'91 240 w/RB25DET + 100-shot NX:

Uses JDM EF-Sports modified ECU, Blitz 550cc injectors, Z32 MAF, and an Apexi S-AFC.

Says it puts down 350whp w/o N20.