So whats the best bet for a 4th gen vq 3.0 N/A? SMT6 Or SMT7.

One guy said that the 6 was not as good as the 7, but why..... Looks like the 7 has extra features that the 3.0 couldn't put to use anyway.

 

hey sr20, so if the Lspec only raises the rev limiter, and the afc adjusts a/f, what do you do about timing?

also, i have a jwt ecu right now and was thinking of gettin an afc to fine tune. do you guys recommend this option or maybe selling the jwt and getting one of these piggyback systems? my best guess right now is tuning just the a/f would be much easier than setting up a piggyback and gains from either setup shouldn't vary by too much, but just looking for opinions.

 

In that case you do nothing about the timing unless you get a SMT6, SMT7 or Greddy Emanage Ultimate.

Piggybacks don't work well at all with JWT software because JWT doesn't use a static map above 40% throttle. You would have to specify your own software paramaters to them before doing so.
And if you start doing that they'll attempt to belittle you for modding a Maxima.

 

Ya I can't wait to ask JWT for my own software specs and get b!tched at... Whatever happened to the customer always being right?

I just want rev limiter increase, 900 rpm idle, and no speed limiter. Also none of the funky crap that they do to an ECU, but I have a feeling the changes I want will cause them to load their non-static crap map on my ECU.

 

Why so high an idle and I didnt know we have speed limiter?

 

so you're saying an AFC would not work well in conjunction with a JWT or technosquare ecu that had their own timing and a/f maps?

1. sorry to be a noob, what's the static map or non-static map at different % throttle?

2. also, i'm just curious because i think i've read different things, but what % throttle range does an JWT ecu actually differ from a stock ecu? i've heard just @ WOT, but i feel like it's at partial throttle too?

3. and a SAFC or VAFC only tunes A/F at WOT? or can you adjust those ratios for partial throttle and cruising as well?

thanks guys.

 

1. Don't know that myself

2. It is completely different, including start-up and timing. Some even hear pinging at partial throttl, ie Stephen Max.

3. You can set the percentages. They have a Hi and Lo throttle setting that you can set yourself, but if you get too for the TPS input, the ecu starts learning it, thus defeating its purpose. I have my HI set to 40% throttle and do not have anything else set.
Steve

 

well since im doin a 4th vq35 swap and i have a stock ecu i want to tune it what should i get any info would be greatly appreciated

 

any word on the SMT-7?

 

just from my case. I tune my car with the safc2 and hours or days later loses the tunning like the ecu relearns by itself?my car doesn't feel consistent and sometimes is powerfull other times just changes and loses power. I guess i need a wideband all the time displaying to see if it changes by itself?
by the way i have a 2003 altima.

 

At least with the 4th gen ECU, the open loop maps begin at 3000 RPM and at 40% throttle. You should set your hi-throttle to 40% and make a/f corrections from 3000 RPM and up. Someone correct me if the 5.5 gen ECU doesn't operate in the same way.

 

The Altima ECU should be similar to the A33B ECU however the Altima does run on the CAN BUS and the A33B does not (except for the TCM). So long as the Altima isn't using wideband O2 sensors (ULEV) you should be able to tune in the static map area above 40% throttle. Beloew that is pointless unless you're trying to reset the fuel trims to zero for some reason.

 

it uses a can network if that is what you are refering to. do you think is normal to substract 14% at 5000 rpms? i think that is wicked and the ecu it's readjusting cause that is way too lean but on the dyno shows perfect a/f. if someone has an exhaust leak, will it show as lean or rich?

 

An exhaust leak will usually cause a rich condition.

 

On hot days only, but not any more since I moved the intake piping.

 

I wasn't talking at all about CAN. That has nothing to do with using a wideband O2 sensor.

Those settings are accurate for the way these cars operate. Most VQ35s run too rich up top and it takes quite a bit of MAF adjustment to corrct it back to the 13.0-13.5 A/F area.

An exhaust leak would likely cause the wideband to show a leaner condition but I would not worry about it unless it is a huge leak.

 

I'll elaborate a little here. An exhaust leak will introduce air into the exhaust pipe. This may seem counterintuitive since the exhaust stream is generally at higher pressure than atmospheric, but the pressure actually fluctuates due to valves opening and closing. The pressure in the pipe can actually go negative momentarily because of the inertia of the exhaust gases travelling down the pipe. If there is an exhaust leak, fresh air will enter the exhaust pipe at that time.

If the leak is before an oxygen sensor used by the ecu in closed loop, then the O2 sensor will read a false lean condition and the ecu will compensate by adding fuel, resulting in excess richness in the combustion chambers, and excessive fuel consumption.

If the ecu is in open loop and ignoring O2 sensor information, then the afr will remain unchanged, but a wideband O2 sensor will give a false lean condition because of the excess air.

 

Well that's what i meant guys. The o2's will read lean and then cause the ECU to dump excess fuel to compensate.

 

Yeah, I knew you meant that, but I thought other people might be confused because SR seemed to be saying the opposite.

 

useful information. a lot of experienced people here and very helpfull. hopefully i can contribute some info later on. let me ask you another question. i read about setting up the lo-throttle on the safc2 at 40%. how about the hi throttle on the vq35?

 

He and I were saying essentually the same thing. But the question was reguarding the readings for external wideband on the dyno. SO that is how I tried to answer it. I still don't think a small leak will have any adverse effects on the wideband or the onboard O2 sensors.

 

i'm on ebay trying to buy the lm1. should i get it with the rpm converter? what can be done with the rpm converter ?

 

where did u get ur SMT from....i have been looking into piggybacks....e-manage was ll i knew of until now

 

Oh well I thought this would be a quick and easy mod for someone that wasnt that advanced with cars but I thought wrong. I have alot to learn before I can do something like this. Does advancing the timing hurt anything and can it be advanced to much?

 

Yes, especially without the correct grade of fuel.

You can get detonation, ping etc .. and that causes power loss due to KS retard, as well as potential engine damage.

 

sooo, about this emanage thing...

1) does it work on a 2002?
2) can you use it to adjust the a/f?
3) can it be used to change timing?
4) it cant and doesnt change the rev limiter?
5) is it easy to use?

 

http://forums.maxima.org/showthread.php?t=424181

You're welcome.....

 

My SMT6 gains:
http://forums.maxima.org/showthread.php?t=444631

 

Funny I was thinking about it earlier today.

The SMT-6 is the third known product (known to the org at least) that the user can directly advance the timing on the 4th gens and keep it there permanently. JWT and TS were the first and second respectively. Also SRs SAFC tweaks are of great merit as well.

And now we have two independent dynos to prove it and Perfect Power engineers told me it couldn't be done.

Also I hope to get another great SMT related project working before Maxus, if I can get motivated and find the cash I will persue it.

 

Could you give some more info about static maps? I would like to get a tuning device such as a VAFC or SMT-6/7, but with my JWT ECU, I'm not sure which is best suited to work with it. My JWT ECU also has a seperate nitrous program, so it sounds like the dual programs on the SMT-6 would work well with that, but if these devices don't work well with an aftermarket ECU.....then I don't really know what to do. I would like to do some compensation for the larger 290cc injectors in the DE-K motor since the JWT ECU is set for the stock 240cc injectors.

Edit- Aside from price, isn't the SMT-6/7 superior to the SAFC II or VAFC in pretty much every aspect?

 

You probably won't be doing much piggyback tuning in front of JWT software. From what I've seen their entire maps are dynamic. You would need to get them to change the maps back to static in order to effectively do your own tuning via a piggyback.

 

Can you explain one more time what dynamic and static maps are please?