Just got off the phone with JWT for ordering my ECU with s/c program, 370 injectors, and MAF and raised Rev limiter...

Well the tech said I wont need to change out the FPR ....He told me to stay with the Stock OEM FPR and I will be fine ??

I will be running with the 3.125 pulley...


-matt

 

Yeah, that's what they say. But they also told me they tune to 11.5:1 afr and I got more like 13:1. I didn't like that, so I used an adjustable fpr to raise base fuel pressure to about 40 psi at idle. It still idles at stoich and closed loop afr is also still stoichiometric, but the afr at WOT dropped to a safer 11.5:1.

I'm not using an AFC to do this because JWT maintains that the timing maps are in part determined by maf voltage, so messing with the maf voltage with an AFC may screw up ignition timing.

 

So definetly order JWT-ECU and dont use an S-AFC....as far as the FPR, hook that up as well
im new to all of this and it really confusing...im about to sell all this cause its soo confusing

-matt

 

Shouldn't we get an adjustable FPR and AFC so we can finely tune our set up? I mean it is not exactly what the numbers tells us as far as what JWT tells us.

 

im just mad confused about all of this
Can I just install:
V1 S/C
AEM FPR
Walbro in-tank
JWT ECU
370's
Z32-MAF

and be fine ??

you cant run the AFC with the JWT-ECU ???

-matt

 

JWT claims they tune their maps on a 1:1 FP so "technically" no FPR other than stock(since its a 1:1) should be needed unless you have to lower you FP back down because of a Walbro 255 or something, but as Stephen pointed out, thats far from the case!

and yeah I'm pretty sure JWT is right about the MAF voltage and AFC...the same thing happens on some the HOndas I've done the "AFC hack" on...as you manipulate the voltage the timing advances...at least thats a proven fact on Hondas and MAPs, not sure if its the truth for MAF vehicles, btu I don't see why it would be different! but thats where an Emamnage would do the trick and allow you to retard timing

 

You should be fine with that setup.

If you have been following other threads, you may have seen that placement of the maf can be an issue. JWT recommends placing it before the blower (i.e. the non-charged side) at a distance of at least 18" from the blower inlet. To accomplish that you will probably have to use something like the maf crossover pipe that is part of the 5th gen Stillen kit, and you need to recirculate the air from the blow off valve back to the blower inlet so that you don't lose metered air to atmosphere.

Using the A32 maf on the charged side is much simpler, but you will be maf limited to around 290-300 hp. See Iansw' recent thread about that.

I have been running the Z32 maf on the charged side for half a year with no problems. But that doesn't mean I won't blow the maf in the future. Be warned if you follow my example.

As far as the AFC is concerned, you can use it with the JWT ecu (I have although I am not right now), but it is best used sparingly if you don't want it to mess with timing. Keep the adjustments down around 5% or less. Some people in other forums claim to have experienced inexplicable driveability problems with the AFC that were only solved by removing it completely. Could be due to faulty installation, but they seemed to be smart people.

 

I doubt that's a problem...at least not on 5th gens..

Ignition timing is based off injector pulse width and RPM, so yes if you condition MAF voltage it can indirectly affect timing, but doubt that's an issue.

 

so its not really smart to use an AFC with the JWT ?? what about knock in the engine at midrange throttle ??

I always thaught that if you buy a JWT your set for tuning things for ever...just buy an AFC to tune down the afr to 11.5:1 and your set ?? cause it comes at 12:1

I am really confused now

-matt

 

yeah now that I think about it, it just sounds like JWT trying to imply they don't need any "over-tuning"...you know how they are sometimes

 

JWT just doesn't want you to tinker with their OVERconservative, plug-n-play, one program fits all *YEARS* and hundreds, maybe thousands, of dyno pull experience and end up blowing your car up giving them bad publicity...yada...yada.

 

it gets complicated when we deal with tuning and retarding timing and stuff. just take it little bit at a time.damn air, fuel and ignition...i was way confused b4 u.

 

So ECU, 370's, Walbro, MAF, FPR and no AFC...thats what Im gonna go with

-matt

 

Matt, dyno after you install everything.

 

ECU was on order today...4-7 weeks for that...so looks like 2 months before this bad boy is on

-matt

 

i doubt JWT even dyno tests their ECU programs....have you seen their shop before? unless they have somoene else do dynoing for them...i dunno

 

I have seen at least one person over in nissanforums.com talk about dynoing at JWT and fine tuning their ecu during the dyno session. Maybe they use somebody else's dyno, like you say. I know in your case Clark and Jim tuned while driving your car.

 

I believe they recently purchased a DynaPack AWD dyno or something. Cattman just got back from there and they are working on a IHI TT 350z for Nissan IIRC. I'll ask.

They used to have some old dinosaur water-brake dyno or something they used for load tuning, but that's not useful for publishing dyno sheets to the public.

 

How accurate can we expect from JWT? If you give them the info on your cars moddifications, they will pinpoint the settings for you, but not every car runs the same even with what mods you tell them.

 

If you have the SC with x-pulley, 370s, Z32 MAF, it's pretty damn close, but still conservative.

However, once you start varying from the norm, ie Pathfinder TB, matched IM, 3" piping, etc. you're moving more air then JWT expects like StephenMax as an example and you'll get 'hicups' like some detonation at part throttle. That is one of the HARDEST areas to program EVEN ON THE CAR. Honestly, I can't phathom HOW in the hell JWT does it through the mail.

IMO, JWT is good for SAFE ballpark tuning to accomodate 370cc or bigger injectors, a Z32 MAF, and the raised limiter. Then use an AFC to fine tune.