hellcat wot afr

[CactusG8]

I had a wideband in tail which usually reads .3 leaner than when I install one at collector
factory sensor reads .85 lambda, or 1bout 12.1 on e10 and read 12.4 at tail, so everything seems in line. It just loved it there

My bad. So it was 12.1 at the collector. Can you check the heads up display on this? I hear it may read 11.8 like mine. And it seems according to the hellcat forum members that 11.8 is about 12.1 with a device that you used. Basically Dodge got it right by having it run lean at 12.1. Did it take more timing at all rpms with the leaner afr of 12.1? If so how many degrees over stock? What type of gasoline were you using?

[mbray01]

Next one I get in I'll check against heads up, I usually don't pay much mind to dash displays, as in my experience they are usually inaccurate. As far as timing on stock setups, I am sure there is much more to be had. Every one I have done, we pullied it, then tuned, so I haven't tried one stock. On the 15-16lb pulleys they like the factory tables, and knock sensors stock.
On cars that see heavy track use, we will loosen up knock sensors and see where they like timing, and I will say this, each one has been different as to where they land timing wise, but they all liked timing

[RonSSnova]

The internal O2 sensors are widebands and read in Lambda. You can get that data in the scan with hpt.
We have added a WB bung ahead of the cats and verified that what's reported internally is spot on.
We don't pay attention to what the dash board reading is.

Put some 104 unleaded race fuel and add timing. They like it...a lot.

[10_SS]

On the hellcat forum I am on the tuners state it was only lean to pass emissions. But adding around 5% fuel to it picked up 30 plus horsepower.

Not sure when Emissions started checking at WOT or even any PE... I don't think they do, so PE/WOT lean requirement would have nothing to do with Emissions if that is the case.

[Jay@HAP]

I am using a diablo handheld tuner for the Hellcat. I still have hp tuners. I used that for my stroker G8. However I have no clue on tuning a Hellcat. But Diablo agrees with you. On their test cars without pulley additions they state from the factory it comes in the low 12s. 12.1-12.3. They stated adding fuel just slows it down. That this car likes to run lean to make the most power which is a little unusual. A few are saying that it is done for EPA reasons. But as far as I know EPA does not test at WOT. But I may be wrong on that. I think they loosened up the knock sensors a bit and maybe added a slight amount of timing on their 93 tunes. Not much. But you said that did not even do anything for the hellcat. So basically if you are near stock just stay with the stock tune. You can utilize the Diablo though to up the rev limiter 600, turn on the fans sooner, and play with the throttle booster. I hear if you up the rev limiter and put her in manual with the automatic she will shift at 6300 automatically without having to hit the paddle shifters. That is good since it is still building a little power up to 6300 rpm.

All of this is true.

[Jay@HAP]

Also don't forget that stoich for the Hellcats are 13.65 and reading a wideband in AFR(14.7) there will always be about a 6% difference.

[CactusG8]

Ron, what do you consider alot? I added 3 in the lower rpms. 1 from 4000-5000 and 3 over 5000. No knock and it seems like it liked that.

[2therock]

I keep hearing about adding more fuel and losing power. Thats a given is it not?
Don't we walk a tight rope between how much timing we can get away with, and how little fuel we can get away with and not blow an engine or get knock?

Maybe I am missing why you are adding fuel to begin with? You gotta love how Dodge engineers leave so little on the table.

[mbray01]

I keep hearing about adding more fuel and losing power. Thats a given is it not?

When on a dyno, and dialing everything in, its always good practice to swing fuel rich/lean, same thing with timing, add/subtract. You have to go both ways to see what the engine likes. The reference to adding fuel was in an attemp to find more power, which there was non to be found

If we only tune by "what is assumed" more often than not, we would be leaving a lot on the table. Every engine is different.

[Hemituna]

Ditto...

When on a dyno, and dialing everything in, its always good practice to swing fuel rich/lean, same thing with timing, add/subtract. You have to go both ways to see what the engine likes. The reference to adding fuel was in an attemp to find more power, which there was non to be found

If we only tune by "what is assumed" more often than not, we would be leaving a lot on the table. Every engine is different.

[06300CSRT8]

x2

my car made the most power around 0.72 lambda...went to .75 and lost 7-8whp and same in torque. Most guys "assume" 0.78-0.80 is best for FI

Also my timing is outside the norm, makes peak power at 27-28* of timing. That's higher than most would "assume" for a 19psi supercharged application. Go figure.

[tbrtuning]

Race gas 300?

[2therock]

I hear you guys on the trial and error, also a given, but you seemed to be put off by the loss of power by enriching. Anyways, it just goes to show you MOPAR did a good job in not leaving too much on the table. We rung my stock 2013 R/T out on the Dyno as much as we could and only got a little over 10hp & tq. But the other calibrations made it drive and feel like 25 hp & tq. Wish I could afford a Hellcat.

[06300CSRT8]

Race gas 300?

93 pump gas and meth injection (A LOT). Even with MS109 and meth injection, still liked around 0.70

[CactusG8]

I converted mine to E85 with a tune, 1050ix injectors, and a 21 volt kenne bell boost a pump. I put her on a dyno. It seemed the E85 liked to run leaner. On a gasoline scale of 14.7 she showed the most power at a lambda of .82. 12.1 to 12.2. Making it richer on E85 made it less powerful. Making it leaner at a lambda of .83 to .84 did not show a power drop. But why do it if .82 showed the same results. We left it at 18 degrees of timing since I have a 10 percent lower and a 2.65 upper. She now runs high nines at full weight at a DA of 5000 feet.

[curt@injected]

When we first started tuning hellcats I spent a bunch of time on the dyno with them. Sweeping fueling, timing, the cam etc. They definitely like to be leaner than almost all other hemis but IDK about as lean as some here are saying. Of course we are speaking in afr and not lambda which can kind of confuse things. Low .8s seems to be about where they like to be.

[CactusG8]

Weird. Even on E85 with a boost a pump and 1050ix injectors the most timing I can get is 14 with little or no knock. That is with a 10 percent lower and 2.65 upper. Everyone talks about 18 to 21 on E85. Maybe that is on stock boost?

[Jay@HAP]

Weird. Even on E85 with a boost a pump and 1050ix injectors the most timing I can get is 14 with little or no knock. That is with a 10 percent lower and 2.65 upper. Everyone talks about 18 to 21 on E85. Maybe that is on stock boost?

The blowers are noisy which makes the knock sensors pick up false knock. TM also uses the knock sensors to pull timing.

[JoshCP527]

The blowers are noisy which makes the knock sensors pick up false knock. TM also uses the knock sensors to pull timing.

Spot on with the noise. Its the hardest thing to accept.

I have yet to see TM on a hellcat come up as knock.... I see IAT corrections and Knock then TM pulling boost and or timing with no Knock registering....... I have yet to see TM come up as knock anyone have a log of this that clearly states TM as knock. The whole old timing limit in the mid rpms was TM kicking in and it never showed up as Knock. I also have yet to see the tip in maps be used in a hellcat. I think this TM to knock is like the tip in map and its none boosted or old dodge algorithm. I could be way off but the demon and hellcats I have done do not show this.

[Speedy!]

So I'm having to convert my thinking from AFR to Lamda and I'm curious if anyone knows why the Hellcat seems to reference a stoich point that's different from gasoline's 14.7:1? We all know it's 13.65 as mentioned, and there's a table that seems to take in to account alcohol content, is that the deal or ?

Also, is there a way in HPT to add an option in VCM Scanner for WB EQ Ratio channel for 13.65:1? The defaults are like diesel, gasoline, ethanol, etc. If not I guess I just need to get used to looking at Lamda values.