I remember reading a while back where people were joking about getting an afc to tune their JWT ecu! I think I am quite ready to do this myself. I smell gas all the time at the tail pipe after a wot run--and I know my car is running super rich with this ecu. In a way I think that is good because I am not going to touch my timing when I run my 55 dry shot of nitrous---I think the car is running so rich it won't hurt at all if the ecu adds timing. Does anyone know how far the JWT ecu advances timing at wot? I have the base at 15--and could probably even advance it a bit more.....I run only 93 or 94 octane. Is there a lot of power to be gained on these cars like most others by running leaner at wot?

thanks for any tips.

To find the answer you'd have to get a fuel tuning device and do some dyno runs while having the A/F ratio logged. There might be some power by leaning it out, but only dyno tuning could prove or disprove your theory.

Originally posted by santraser
I remember reading a while back where people were joking about getting an afc to tune their JWT ecu! I think I am quite ready to do this myself. I smell gas all the time at the tail pipe after a wot run--and I know my car is running super rich with this ecu. In a way I think that is good because I am not going to touch my timing when I run my 55 dry shot of nitrous---I think the car is running so rich it won't hurt at all if the ecu adds timing. Does anyone know how far the JWT ecu advances timing at wot? I have the base at 15--and could probably even advance it a bit more.....I run only 93 or 94 octane. Is there a lot of power to be gained on these cars like most others by running leaner at wot?

thanks for any tips.

I'd stick it on a dyno with a wideband. That way, you'll know for sure what your a/f is. I had a prob with my car running rich after switching out setups and whatnot. I tried resetting the ecu, disconnecting the battery, nothing worked. And I couldn't find a mechanical prob anywhere. Someone posted some info about the TPS and I did the procedure listed to recalibrate the TPS. Car runs absolutely perfect now. A/Fs are all correct, and it makes lots of power :)

Khiem

I have heard that JWT purposely programs their ECUs to run a bit rich. My car for one runs a bit rich. I lean it out with a NISMO FPR!

when I dyno'd my car with the wideband, my a/fs were between 11.2-11.7 with JWT. I'd rather be a little bit rich than have the motor blow up! Plus, on a roadcourse, running a little rich helps keep things cool which further reduces the chance of blowing things up.

Serban--can you or someone else explain to me how a fuel pressure regulator can make a car run lean when adjusted>? That makes no sense to me at all. All you can do with that is raise fuel pressure if it the diaphram type I am thinking of. Is the return orifice larger dia than stock? That is the only way that could possible lower stock rail pressure--

please explain

Also---since you have Andreas name in your signature--I assume the Nismo FPR really does have a biger return orifice---or you/he drilled out the stock return. Where did you score the FPR? I see them for the rwd SR20 only--can they be modified to fit our cars? I assume you have a 1:1 rising rate since you are running turbo?

Mark

You can adjust the Nismo FPR to whatever pressure you want, including below stock (I think). I have mine set at 4 bar pressure. I could lean out the a/f mixture by going a little below that(my ecu is programmed 4bar). I got my FPR from Andreas. No modifications needed to make it fit the rail.

Khiem

4 bar? You are running 56 psi rail pressure? Is that your base fuel pressure? Sounds way too high to be your base pressure. As far as adjusting the Nismo FPR below stock---I will wait for Serban or Andreas to confirm that before I order one. I doubt it can go below stock. I may just open up my outlet orifice anyways to lower my base pressure. Anyone know what our stock base pressure is?

thanks guys

Mark

I sent my ECUs back to JWT for a program update, and since then both my SE-Rs are idling high, with the AAC reading way up at 95%.

Anybody has a clue??

My car idles at 1200. When I swapped the G20 ECU for the JWt, it jumped up. This is with my base idle at 750 and 950.

I have never had any issues with my idle.My JWT ECU seems to make my idle fine. Keep in mind I have S4 cams with no cam program. My idle is very radical. My car idles at 850 RPM's.

And yes you can lower your fuel pressure below stock pressure with a NISMO FPR.

The lowest I have taken a Nismo FPR is 25 PSI at idle with the Vacum line on. I am sure it can go lower I just never had to go lower than 25 PSI. 25 PSI is 11 PSI lower than stock. In my opinion the Nismo FPR is the best one you can get for your nissan.

Andreas Miko