Damn. How many VQ35 swaps has Tilley performed?

 

Like I have said one too many times, you can tune for WOT with SAFC, SMT

 

My guess would be 3-4....with plenty more to come

I've looked around for an Apexi SAFC II and it looks like the best price on Ebay is about $250......can I get on even cheaper somewhere else?

 

where do you guys mount the SAFC-II? on the dash or on your steering column?

 

I would advise against mounting it at these locations. My friend got his V-AFC stolen, and he mounted in clear view on his dash.

 

jay25 might have one



he custom mounted his above his CD player flush with the rest of the dash. it looks HOT

 

That would look awesome

 

 

damn, that looks good. i was looking at places id mount it, and i figured down there would be best. Is it only possible to tune with these at a dyno? Anyone know what the a/f ratio should be at certain rpms, or is it car specific. I plan on dynoing this weekend, but i should have the a/f controller before then.

 

You need a Wideband O2 with gauge to tune on the street. I would prefer a dyno tune.

 

so while at the dyno, do they do the dynoing and tuning, or am i doing it?

 

Depends, some dyno shop will tune for you. I am pretty sure you will have to tune by looking at the AF wideband graphs after each run.

 

can the SAFC only adjust a/f ratio at WOT? and cannot advance timing correct?

 

It cannot advance timing, but it indirectly does. Messing with AF also makes the ECU mess with timing.

 

It can adjust at lower RPM's too, but we won't need that.

 

I found a used safc-II but it doesnt come with the original instructions. Would I be able to get them off the internet? It has everything else to mount it and make it work, just no instructions. I set up an appointment for saturday to dyno tune. they charge 100/hr, about how many runs should i be able to get in in one hour?

 

wow people, if you really want to learn about the SAFC go to apexi's web site and read. Im sure kevlo just loves to answer all these questions, but jeeze lousie.

To get a 3.5 to run great on a 3.0 ecu alls ya need to do is get a 3.5 flash on the ecu. Maybe the same can be done for a dek on a 4th gen ecu. All an ecu is a computer and all it does is read information. I dont see why the maps cant be down loaded.

Oh and i have been testing a way to lean out the car a bit. It involves modifing the MAF. I have monitered the voltage readings on the maf and I have gotten lower numbers. Makes the car think less air, so less fuel goes in. When in reality more air is goin in . I dont have any hard evidence yet (ie A/F or dyno comparisons, or track time slips) but the car does feel better. All closed loop driving should be normal anyhow since the O2 sensors are busy sniffing away. I shall call it the secret sausage MAF. I have pix on one of my web pages but gool luck finding it.

 

ehh, i decided to spend the extra 30 bucks and get it brand new. ill have it in 2 days. Im just asking about the dyno part of the safc, i read up on it and what it does already.

 

Just installed my VAFC 2 last week and I will be going to the dyno tomorrow and I will let you all know how it goes...

 

That's assuming the ECU can fully adjust to any infiinite change in fuel and not just to some limited percentage - which I'm not sure is the case. As I said elsewhere, from firsthand experience I can tell you that on some other cars like GM's LT1's for example, the closed loop can only compensate for a 25% difference... after that it can't adjust any more. And based on my gas mileage after switching to the DE-K injectors (yes even in closed loop driving) I suspect I'm still running rich.. or at least maybe close to the limit (if there is one).

 

DEK injectors are same as 350Z injectors-290cc, 5.5gen Maxima uses 270cc injectors with higher fuel pressure than the DE-K.

S-AFC will help you tune the A/F but the real power on a 3.5L comes from advancing the timing, 3.0Ls benefit from this also. I constantly run 13.3-13.5:1 AFs on 93 octane here under WOT. After Adding headers it changed the A/F dramatically, form rich to lean, why I am able to get up to 34MPG on the highway at 65MPH with no AC.

 

I am pretty sure the 4th gen ECU adjusts fine to the larger injectors in Closed Loop. I still get 500+ HWY tanks


I love to answers question that are answered somewhere else

 

Do you have any data on this? Maybe I've just missed it somewhere but I haven't seen any hard numbers that show that a/f remains close to stoich under closed loop after upsizing to DEK injectors (not to mention my other mods). I originally thought that it would compensate just fine, like you're assuming... but my mileage has gotten so bad after the swap it's making me question it (nothing else has changed). I'm not saying you're wrong I'm just questioning it now whereas I didn't before...

I'll be doing some datalogging and will get it tuned one way or another soon but unless something significantly changed all of a sudden that I'm not aware of... for now I'm assuming the dive in my gas mileage is likely injector related. I maintain the car well - filters, oil, tire pressures, alignment etc - maintenance habits have not changed and even disciplining myself not to put the pedal on the floor (it's hard.. ) the mileage has still tanked after the VI swap.

Is this directed at me? Based on some comments farther up I'm thinking maybe not...

 

my mileage is horrible after the VI swap. i got like 230 miles to my last fill up. im like WTF? is it because im running and the ecu is telling the injectors to supply more fuel? Im used to like 360-400 miles on a highway full tank. I got 300 on my last all highway trip with the VI. And I'm asking a lot of questions because im new to this stuff. BTW, about how many runs should i expect to get in one hour on the dyno?

 

Yes. An intake leak will do that. An exhaust leak that allows free air to the O2 sensors will have the same effect.

 

LOL, Naa man I am just messing with you guys, someone said earlier that I prob love to answer all the questions.



My mpg was bad for a few weeks, I don't know if it was the gas or what. But know it is pretty close to normal, I know it is not exact because city MPG is not too hot. There is a feature on the SMT that takes away fuel for the entire RPM band so I might use that once I get the SMT fully functional and a wideband

 

Hehe... yeah I thought that's what you were referring to...

I'll have a wideband soon and then we'll see what's up. I don't think I have any vacuum problems, I checked for that.

 

is that why im now getting the 0115 code now, and no longer the 0210?