I have heard of people running as rich as 9.0:1 AFR with untuned 3.5 swaps (and I cant say it surprises me).

As of now im running a stock FPR with the 3.5s 270cc injectors and a High Pressure Walbro 255 fuel pump. The car is running SO rich, I firmly think the ECU is in limp mode as is. On top of running incredibly rich, when you floor it it does like when your Knock Sensor is dead: You feel the timing is pretty good at part throttle, but once you reach past half of the gas pedal, it feels dead. Simply put, the car has no power, at least not anywhere as much as it should.

I wont have the money to buy a wideband (A GOOD one, no fawking around) until a few weeks from now, plus you usually wait 1 week+ for it. BUT I have the E-manage Ultimate already installed and running, but bare bones. Just the 3 main harnesses, an USB cable and a laptop.

After speaking with DandyMax I see the only way to tune it right now is to throw an educated guess. Scaling back the airflow by say, 15-20%.

I dont want to scale the airflow back TOO much and run lean. But I am pretty sure right now Im a good deal under 10.0:1 AFR. I mean a regular 3.5 swap already runs rich, an untuned 3.5 swap with a Walbro and no FPR is bound is set an all time record low AFR.

I know what im doing is somewhat dangerous (not knowing what my AFR really is), but can we all agree that I am certainly in the 9:1, 8:1 or below range? Washing down the cylinder walls with fuel and fawking up the rings is my concern, and if the ECU really is in limp mode because of this, we are talking SERIOUSLY rich.

My question is: Is this linear? I mean, if I want to go from say, a 8.0:1 AFR to around 12.5:1, does this mean I will have to scale back the airflow by a whopping 30-35% or so?

 

well it is very hard to say since you really dont know what your afr is at right now.
what if you do cut that much airflow and end up damaging the motor?
i would just take it easy right now, and not beat the car. Get the wideband the tune it up. That's what i would do.
Good luck.
Man, i need an Emanage....

 

Rich mode, as you put it, only initiates @ 2300 RPM and >20% load., other than that, AFR's are are just Dandy. Under that (specified RPM/load), it is rich,(richer than 12.5).

Tune it.(i.e condition the AFR curve) Put the stock airbox on, then, take away mucho timing, negative on the AFC, , and be badder than me, the reign of 4AT Intraweb Humblemkers.

 

Maybe the KS is really acting up as usual.

Im gonna pull out 20% airflow and see what happens. The way the car runs and from dynos I have seen, I am sure its in the single digit AFRs.

All I was asking is whether or not it is linear, which I think it is. Meaning, if I scale back 20% airflow, the AF ratio will go up by the same percentage.

 

Why not just pull out the Walbro and put the OEM fuel pump back in? At least until you can get a wideband. And a AFPR might help to get the fuel pressure back down to where it ought to be. Just my uneducated 2¢.

 

I'm thinking scale it and then keep your ears open. Nothing too detrimental is going to happen NA without hearing the warnings.

 

JClaw its no a linear scale. Currently for example, my highest correction (with an SAFC-1) is at 4500rpm with -20%. That RPM is actually at 13.8 (a sniffer wideband, so its probably 13.3-13.5 in actuallity). But for example, to attain this same a/f at I THINK 3500rpm, I have IIRC -14%. An extra -6% cor to get to -20% might put that same rpm in the low 14s.... not a good idea at all.

So no if you take out 20% fuel across the board it might not be a good idea at all.

Just for reference, my tuning/ fuel setup is...
- SAFC1
- Walbro 190
- Stock FWD 3.5 injectors
- 4th Gen MAF
- FP set to 55psi

 

Definitely not linear. If your concerned about not having enough money to purchase a WB why not go to the dyno and try to adjust your AFR there.

 

The OEM pump had one wire come off of it (stopped the car dead in its tracks) and with alot of the wiring on direct circuit I am simply NOT going to risk it.

I am trying to track down a WB locally. A shop around Mtl wanted 425+tax (CND) for an AEM wideband. Thats 500 bones. They must be taking a healthy profit on it.

I wanted to have BOTH a returnless fuel setup with an aftermarket FPR, which I had for 1-2 weeks, but it crapped out. So now I am out of a regulator and no wideband. The car is barely driveable as is and feels like a 4 cylinder or something. Im sure its running on 6 but running BADLY.

First gear is insanely short even with the 26.8" diameter tires, but once you are out of 1st it is obvious the car is not pulling anywhere near as hard as it should. It does o.k at slight throttle, but mash and it just feels dead, and smells fuel like theres no tomorrow. I am def not driving it the slightest bit as it is.

Yeah you guys are right, I need a WB to get anything good out of this. I want to have the gauge in my face all the time to be sure I wont blow anything. I already have an aftermarket tach + water temp gauge (operating temps stay around 185-190 with the fans on, which seems normal). I need a WB but I am NOT shelling out 500 bucks for it. Thats just ridiculous. Even if I had 10,000$ of disposable income I would NOT pay 500 for a wideband, unless it tunes itself alone while I am sleeping. I have seen too many go for 200 bucks.

If anyone has WB for sale, especially in Canada, let me know.

 

Now that I think about it... it was the sender unit that was the problem not the actual pump itself. I changed the sender unit a while back (250+ at the stealer).

Does anyone know how much power the OEM S13 fuel pump can flow? It could very well be the same as a maxima pump, most nissans from that era probably have the same pump.

If that is the case, I would basically be running the same way I was back when I had my max (same ECU, same flow pump). But ONLY if the S13 fuel pump flows as much as a 4th gen fuel pump.

 

Just spend the money to get a wb. It would eliminate a lot of questions and is also a very nice tool to have especially with the frankenstein/using parts from all these cars type of endeavor.

 

I owe a bunch of money right now. I am shoving the stock KA24E fuel pump in the car tomorrow, changing back to my spare VQ35 knock sensor, and changing that damn master cylinder since the car has no braking power right now (I already bought all new handbrake cables for safety). Then I will report back on how it feels.

The plan is to run the car like this till I have the expandable income for a GOOD FPR, a fuel pressure gauge, a GOOD wideband and the EU wideband harness. THEN the walbro will go back in the car. This will definately take a few weeks.

I read that the stock KA24 fuel pump is good for a SR20DET swap up to around 9-10 psi. Which is in the low 200 whp area.

If the stock S13 fuel pump flows the same as a stock maxima fuel pump, this car should run like my 4.5 gen did 2 years ago. Theorically. Same FPR, same injectors.

 

Buy my AFPR.
http://www.courtesyparts.com/Merchan...=22670-RR710US

 

ok Jclaw, went outside to check my settings on the SAFC. There are the corrections I have as of right now (I havent changed them since I did this dyno http://forums.maxima.org/showthread.php?t=517640) Keep in mind that was a sniffer wideband, from the many times that I've gone to this place, the difference bet'n an actual wideband and a sniffer type is their sniffer reads about .4:1 leaner than actual a/f.

anyways,

3500= -14%
4000= -17%
4500= -18%
5000= -14%
5500= -13%
6000= -11%
6500= -9%

So assuming that your engine is in the same condition as mine is, I wouldnt go more than -8% through the powerband, also going richer towards redline to be safe.

However, you mentioned you were currently running the stock FPR, thus 43psi? If so, thats less fuel that what I flow at 55psi, so I wouldnt do more than -6% correction throughout the powerband for now until you get the WB.

Disclaimer= This is what I would do in your shoes. You may do as you please, at your own risk. I am no encoraging you to do it, but if you are going to, you might as well have some comparison data to base your changes on, hense this post

 

Not sure about you guys, but a flat AF curve seems to be better to make more powah. This is re:A33B's, not sure if it applies to you fellas, but just food for thought.

 

Hey you could do some wot runs and then pull the plugs and read them to see how its running!

 

I could do that after the OEM S13 fuel pump goes in too. I have been doing some research and have found some guys running mid to high 200 whp on OEM S13 fuel pumps. One claims 251whp and another 287whp.

Realistically with the stock 240sx exhaust system I have on (plus 350z headers) and stock 3.0L cams, I am probably barely passing 200whp if at all (with a working KS and an acceptable AFR of course).

So OEM fuel pump it is. Im sure it will run MUCH better already. I wouldnt even go about logging WOT runs with the car running in its current state. Its that bad. I will reset the ECU after changing to the stock VQ35 KS and Stock 4th gen FPR.

 

NMexMax- I say to have it a tad richer towards redline since as you know timing advance goes higher towards there, and since at this point he doesnt know where the a/f really is, its just to have a margin of safety there (ex. timing advanced+not enough fuel= knock=no good, lol). Temporary safety until he has the proper tuning equipment before he goes crazy with it

JClaw- I must have missed this so sorry if you covered it on another thread. Why is it that you're running the 3.0 cams vs the 3.5 cams? To avoid having to use spacers/ drill holes into the cams?

I wonder, since the 3.0 cams are milder than the 3.5s, could they be causing the engine to not breathe enough air into the chambers? since at this point being untuned, the amount of fuel going in is a constant (at WOT only, closed loop o2s will take care of fuel), just a thought in the air

 

The stock 3.0 cams are temporary just like the stock 240 exhaust is temporary. I have nismo 262 cams sitting here, but they will need to be custom drilled to retard them and peak higher.

The OEM fuel pump is back in the car but its still not pulling like it should. Pulls as much at half throttle than it does at full throttle. The timing is being pulled on the WOT map. The car runs alot better already though, much smoother. But the wheelspin isnt there yet, just some slight wheel hop/spin in first. First pulls like a **** though.

Traction is excellent so far on 215/70/15 Toyo summer tires, despite the very short gearing. The positive thing is that I KNOW now that this car will HOOK like its the end of the world when its on slicks. Its gonna be seriously ridiculous. The AWD guys are going to cry.

 

Oh, and if you guys think changing a Knock Sensor on a maxima is a pain in the @ss, you try doing it on a VQ 240. I just got done pulling the KS, and my hand is a bloody mess.

The KS that came with this engine has some corrosion on it, the base is pretty dirty, and some calcium on the bolt.

EDIT: I tried putting the new KS (well not new, its from my first VQ35) in the stock location but I just cant. Its too far and I have NO visual referrence, just touching. My hand is even more of a mess now. I Need to relocate it. Ive buffed the base real good (chrome) on the replacement KS.

Where can I relocate the KS without it being dangerous? There is a square shape with 4 bolt ones right next to the stock KS location but if I put it there, the base of the KS will not FULLY be touching the block and those holes are 10mm instead of 12mm. The KS base is about 1-inch wide.

 

C'mon JClaw.. stop being Cheap.. you gonna drop nice parts into the motor, but then go cheap cheap on the tuning?? There is NO Guessing with A/F Tuning..

There is WBO2 Tune Or Tuned by @SS.

 

Did you miss the extremely obvious section where I dropped the OEM fuel pump in and called it a day? Lets stop beating a dead horse, Ive taken the advice already.

As Ive already said, the car runs much better already and has the same manners, and same idle I had on my maxima 2 years ago, because these are the same injectors, same FPR, same fuel filter and probably same flow fuel pump (OEM Nissan) I had. The problem right now is that timing is being pulled on the WOT map.

I am going to wait until I get an adjustable FPR to set it to 50 psi returnless, and a good WB to tune it. I have not touched anything as of yet, its running the 100% stock ECU settings right now, which is about as dangerous as a regular untuned 3.5 swap.

 

Double post

 

sorry if that came off wrong..
my main idea was don't try to tune it blindly.. my V-afc2 settings range from (+3 to -12) at various rpms to get the A/F curve flat at 13.5ish..

PLX is a Great wideband.. If costs More but the features/datalogging are great (R-300/500)
http://www.plxdevices.com/products/r500/

If you have an EU.. an M250/300 is a cheaper alternative without datalogging, as the EU does it's own datalogging.. it needs a Linear WB signal and PLX is compatible
http://www.plxdevices.com/products/m300

 

hey jclaw, wat MAF are u using? the Maxima maf or the 240maf? I ask because the correction factor will be different bet'n the two, thus afecting your ECU's tune.

 

The setup is a VQ35DE using VQ30 timing chain, ECU, wiring harness, MAF, TPS all from a 4th gen maxima. The sensors are all maxima, its just the fuel pump thats from the 240sx.

If the SR20DET guys can squeeze 250whp out of the OEM fuel pump (one made 287whp with the stock pump) and dont blow their turboed engines by running too lean (and we all know the optimal AFR ceiling with a turbo is lower), then I can get by with my lowly NA VQ35 thats choked by a 140 HP 240 exhaust system (cheap again I know ), even if I install the aftermarket cams (custom drilled to mimic VTCs at full retard), Im not making more than 240whp (with full timing at WOT back though!).

 

Your setup sounds very similar to the setup I am going to try this summer with my S13 swap.

Try to reset the ECU. Maybe now that it is running dog rich, the ECU can give some good ignition timing. It is worth a try if you haven't already.

I don't think the stock S13 fuel pump will be a huge problem now. Run it with the stock one until you get your other problems settled and get some money to be able to properly tune it.

 

Yeah but if someone knows anyone who is making 220+whp on a stock S13 fuel pump let me know.

 

I'm surpised you're happy with the acceleration grip. Is this a hint at how low power levels are right now?

I didn't realize you put in the 30 cams. I'm doing the same right now.

FYI, I ran the swap on the stock pump for a month or so.

 

With the 30 cams power seems to be concentrated in the 4000-6000 range. There is a noticeable drop off after 6 grand. Its probably peaking around 5500 tops. Its all mid range.

Yeah im kinda surprised about the grip too. The tires are Toyo Tourevo ls 215-70-15 (26.85" tall) they are a luxury touring tire ( ) which means the sidewall lends itself well for drag racing, but unfortunately the threadwear is 700. Im running them at 22.5 psi on the drivers side and 22 psi on passenger side because of the weight of the car.

Oh yeah and the car doesnt wobble or "dive" with NO swaybar up front. I havent pushed it yet. The front tires are V-rated (149 mph) no-name summer tires (Matador Aquilla, aggressive thread but I think the rubber is rock). The sidewalls are super stiff for a 205-65-15 tire though. Running them at 25 psi on stock wheels with no center caps and thus the car general looks like @ss. You should see the primered, ondulated, hammer-formed stock hood on there. Got lots of looks as we went around the neighboorhood lol!

The car handles better than stock so far, despite the ridiculous setup. From what little I have seen the frame feels ultra-stiff. Im on stock suspension, stock open diff and 180k mile bushings everywhere. We had to cut a coil and drop the car 2 inches up front.

I think that when the car starts making power Im gonna have to launch it at 2500 in 2nd gear. Doing 0-55 mph without shifting is gonna help my times I guess.

Oh believe me the way the 3.79 first gear almost hooks right now... even with a bunch more power the 2.32 (launch) second gear is going to hook pretty good on the track.

With the maxima even with a non-working KS first gear was all wheelspin. All it needs is power and brakes right now. Its gonna hook. Trust me. Its a general feel. It doesnt seem to want to spin even with my current ultra-getho setup. This thing is gonna have a lot of personality when it hauls @ss looking like an absolute beater.

 

YES!!! I love it. Thats exactly where I wanted it.

The gearing explains the grip a bit. I'm running a 3.92 with the 25.5" OD tire.

Keep up the good work man.

 

That and my car is probably about 200 lbs heavier than yours. I have the dash, door panels, two seats, carpet, all ceiling trim with a manual sunroof. It certainly weighs in the 2250-2300 range. My front end is probably as light as yours but the rest of the car is a bunch heavier.

 

I have been thinking about just using the VQ30 cams for a while now too, and I was wondering about going with the VQ35 exhaust cam with the VQ30 intake. I am not sure if the staggered cams would be any better or worse. I haven't completely decided.

I am really glad to hear the VQ30 cams don't kill the power too bad though. My friend has a "Rev up" IM he is not using since he has the MREV2, so I was toying with the idea of using it and seeing how the power band would be then compared to the 287hp IM and VQ35 cams. I might just want the torque anyway.

I will also find it very interesting to see how the stock 4 lug wheels and whatever tires are on there hold to the new power.

 

i always get confused by you three guys!!! Jclaw I thought you still had a 4.5 gen?

 

Ready when you are, guys.....

 

lol, I sold my maxima to my brother about a year ago. I put a stock VQ30 in it with a y-pipe and the rest of the exhaust I had . I kept that engine and eventually sold it now I have another VQ35 in my S13.

He is swapping a 00 VI on it. With the y-pipe and Cattman exhaust system its gonna be fairly fast. Stock rev limit FTL though...

 

http://forums.maxima.org/showthread.php?t=488944
http://forums.maxima.org/showthread.php?t=458593

 

I will tell you this soon. I drilled the nismo cams and threw them in yesterday I also removed the lower IM, buffed the KS and the KS mounting surface on the block. Hopefully the timing is back to normal.

The way I drilled the cams... is somewhat gettho, and I dont even know if its going to work, but anyway (these are 96Sleepers cams, left to right: Stock VQ30; Stock VQ35; JWT VQ35):



You know that small hole 180 degrees from the stock VQ35 dowel pin hole? I enlarged it in three stages. 3 different drill sizes until I got the hole big enough for the dowel pin. I did that for both intake cams and left the exhaust cams alone.

I had to plug weld the holes Stephen Max drilled (those are Chrismaxs old nismo R-tune cams) because they were obviously drilled wrong (one hole was 2-3 mm different from one cam to the other). After I drilled the new holes I welded the dowel pins to all 4 cams because Im paranoid.

So that means that I reduced overlap, and basically I am immitating a 2k2 with VTCs unplugged. The intake cams are set to full retard 100% of the time, and the exhaust cams were left untouched.

So with the gradual powerband from the cams and NO low end I imagine its going to hook pretty good... Or its gonna start spinning like nuts after 4 grand.

To ban me or to lock the thread?

Cmon... its gonna be interesting at least. Either I blow my engine or it pulls like nuts!