strange fueling in 2nd gear

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Bigmike7645
Posts: 17
Joined: December 2nd, 2017, 3:23 am

strange fueling in 2nd gear

Post by Bigmike7645 »

I've noticed occasionally while I'm logging that only in 2nd gear after I hit my load target of 1.9 injector dc will start climbing rapidly(into the 90's), itll go pig rich, and it will show a desired afr of 14.7. It's like it's changing fuel strategies. Yet in 3rd on up, im hitting my load target of 2.4 with a steady afr and injector dc in the 78-82 range. I've had too much rain to take any more logs with fuel system status as a parameter, but does anybody have any idea what it's trying to do?
mituc
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Posts: 1324
Joined: December 17th, 2011, 2:47 pm
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Re: strange fueling in 2nd gear

Post by mituc »

Welcome to the world of steering angle hysteria and loss of grip in 2nd gear :)
2008 Cosmic Blue Mazda 3MPS
Built engine + WMI + GTX3071 gen2, ~509BHP @34PSI
2008 Icy Blue Mazda CX7
Stock engine and exhaust (YES!!), JBR3" + GTX2867 gen2 + Autotech HPFP, self-tuned to 330-ish BHP
Bigmike7645
Posts: 17
Joined: December 2nd, 2017, 3:23 am

Re: strange fueling in 2nd gear

Post by Bigmike7645 »

Even with all the swas and traction control disabled?
mituc
VersaTuner guru
Posts: 1324
Joined: December 17th, 2011, 2:47 pm
Location: Iasi/Romania

Re: strange fueling in 2nd gear

Post by mituc »

Bigmike7645 wrote:Even with all the swas and traction control disabled?
What car do you have? If it's a speed3/3MPS then there's no chance you hit load 1.9 in 2nd on street tires and hold it while having full grip. Maybe with semi-slicks and a nice smooth and warm asphalt.
2008 Cosmic Blue Mazda 3MPS
Built engine + WMI + GTX3071 gen2, ~509BHP @34PSI
2008 Icy Blue Mazda CX7
Stock engine and exhaust (YES!!), JBR3" + GTX2867 gen2 + Autotech HPFP, self-tuned to 330-ish BHP
Bigmike7645
Posts: 17
Joined: December 2nd, 2017, 3:23 am

Re: strange fueling in 2nd gear

Post by Bigmike7645 »

its a gen 2 speed 3 running 225 radials. I run a reverse taper boost/load curve in first through 3rd to help with street traction. In 2nd it starts at 1.5 at 3000 with a gradual curve to 1.9 at 6000. And yes I know its hazing the tires, and the load flattens or falls off when that happens. Depending on if i roll on or stomp it, it will hit 1.9 usually around 5000-5500 and taper off to 1.8 by 6500. I have the swas/traction control torque reduction disabled in the tune customizer. I don't feel any loss of power or change in engine sound when it happens. I just get the idc climbing into the 90's, afr going into the 9's, and the commanded afr changes from 11.7 to 14.7 right when this happens.
mituc
VersaTuner guru
Posts: 1324
Joined: December 17th, 2011, 2:47 pm
Location: Iasi/Romania

Re: strange fueling in 2nd gear

Post by mituc »

Do you have any sort of aux fuelling? Maybe that is adding a bit more than you'd expect during WOT. Also, to determine if it's a calibration issue or a tune logic issue try logging both the commanded and actual AFR.

If it's a tune made by you and you didn't pay a tuner for it may worth posting it here along with some logs (both in 2nd and 3rd/4th) to figure it out in case it'a tune issue.
2008 Cosmic Blue Mazda 3MPS
Built engine + WMI + GTX3071 gen2, ~509BHP @34PSI
2008 Icy Blue Mazda CX7
Stock engine and exhaust (YES!!), JBR3" + GTX2867 gen2 + Autotech HPFP, self-tuned to 330-ish BHP
Bigmike7645
Posts: 17
Joined: December 2nd, 2017, 3:23 am

Re: strange fueling in 2nd gear

Post by Bigmike7645 »

I am running a boost based progressive 100% methanol setup. I also log desired vs actual afr while im dialing in my methanol. I'm leaning towards a logic issue because right when everything goes rich and the injector duty cycle takes off, the desired afr changes from 11.7 to 14.7. This only occurs in 2nd gear. It may happen in 1st as well, but i don't log 1st gear since its a smoke show. So at 255g/sec maf in 2nd gear im getting 9.9 afr, 98% idc @ roughly 17psi. But in 3rd i get 355g/sec, 11.3 afr, 78%idc @ 23 psi.

As soon as this rain lets up, I'll change a few of my log parameters and take some fresh logs.
Bigmike7645
Posts: 17
Joined: December 2nd, 2017, 3:23 am

Re: strange fueling in 2nd gear

Post by Bigmike7645 »

So I finally got a break in the rain and went to make some logs. My clutch stopped holding full boost....Awesome! Just got an act 6 puck ordered. More to follow soon, hopefully.
mituc
VersaTuner guru
Posts: 1324
Joined: December 17th, 2011, 2:47 pm
Location: Iasi/Romania

Re: strange fueling in 2nd gear

Post by mituc »

Good luck!
At those airflow values with the MAF scalled down for meth you were pushing quite a bit of power so clutches tend to let go.
2008 Cosmic Blue Mazda 3MPS
Built engine + WMI + GTX3071 gen2, ~509BHP @34PSI
2008 Icy Blue Mazda CX7
Stock engine and exhaust (YES!!), JBR3" + GTX2867 gen2 + Autotech HPFP, self-tuned to 330-ish BHP
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