HPtuners Question and Answer Thread

[DGatzby]

Been playing with E85 since my 06 300CSRT was tuned for it by a local and a DD Tahoe I had for the last ten years. Just roughly figure 30%. The gas stations know it because at least here in MN the cost difference is usually about at 30% off of premium and about every time I looked at either of those vehicles the gas mileage was about 30% difference.

As you guys are discussing it is tough to put your finger on the MPG difference because such a small hit on the accelerator can make it go off, especially in around the town driving. My Redeye gets about 18 in typical suburbia driving. In town like @Speedy! says I believe the 15 mpg, but one fun smack on that throttle can send that number bye-bye.

Looks like your having fun guys. As you know I am just a set of injectors and another tune from @Jon-MooredPerformanceLLC to be in E85 heaven. It is too much more power for the road course and would get about 1-2 mpg compared with like the 4-6 it gets on gas. Could not do too many laps!! Keep doing us proud, love the slips and videos.

 

[ostmike]

I believe mpg with cost of fuel it is cheaper to run e85. You are running out faster but costing a lot less on fill up. Guy at work uses a calculator to compare 87 to e85 in his 2011 f150 5.0 and said it was cheaper with e85. 93 is another .80 cents more or so

Around here E85 at the pump is only about 80-90 cents cheaper than 93 octane. With the additional fuel consumption running E85 you will definitely be paying more than running 93.

 

[ostmike]

No more questions?

 

[covidcommander]

Any thoughts on the flex sensor in the new demon? Hoping it will be available thru dodge. Not sure if you could add one and make it work with the factory pcm

 

[Speedy!]

Mike, we've chatted about this but might be good for this thread. I'm running the Redeye fuel rails that came on the 2.7L supercharger that fell in my lap. I upgraded to a triple pump system recently as well with three 285 pumps. ID1300x injectors. I figured my fuel pump duty cycle in logs would be in the 60% range at WOT on E85 with this setup considering 3 pumps but I'm seeing 85-89% sometimes. Injector DC never goes over like 60% or 11ms pw so I believe it's getting plenty of fuel, just odd the fuel pump dc was higher than I expected.

I'm wondering if the scale for the fuel pressure sensor in the rail needs a tweak since it's a Redeye sensor that's expecting 105psi fuel pressure commanded? I don't see anywhere in HPT to adjust something like that.

@16GoManGoHC2 was going to do a bench test of the two rails to see if a mechanical difference could be determined but it's been an interesting experiment.

 

[16GoManGoHC2]

Mike, we've chatted about this but might be good for this thread. I'm running the Redeye fuel rails that came on the 2.7L supercharger that fell in my lap. I upgraded to a triple pump system recently as well with three 285 pumps. ID1300x injectors. I figured my fuel pump duty cycle in logs would be in the 60% range at WOT on E85 with this setup considering 3 pumps but I'm seeing 85-89% sometimes. Injector DC never goes over like 60% or 11ms pw so I believe it's getting plenty of fuel, just odd the fuel pump dc was higher than I expected.

I'm wondering if the scale for the fuel pressure sensor in the rail needs a tweak since it's a Redeye sensor that's expecting 105psi fuel pressure commanded? I don't see anywhere in HPT to adjust something like that.

@16GoManGoHC2 was going to do a bench test of the two rails to see if a mechanical difference could be determined but it's been an interesting experiment.

Comparing output voltage from a RE sensor and a regular Hellcat sensor is on my to do list as saw the same issue when using RE fuel rails on my hellcat. Fuel pump DC 89% and injector DC lower then before the change which is telling me the fuel pressure is actually higher then what being displayed. I went back to my original Hellcat ported rails and my injector DC is bit higher now but my pump DC never goes to max 89% any longer, it hovers around 83-85% at WOT with a 75 psi desired pressure setting. And I tried it on an extended run to 170+ and never maxed the pumps out and I’m only running dual 295 pumps and hitting 65% DC with ID 1700 XDS injectors.


Having a weird issue though that is stomping me and trying to fix maybe someone can offer a tuning suggestion? At the top of third and fourth gear. The throttle wants to cut almost like it’s hitting rpm limit, but I am not lifting my foot off the gas and it does not say RPM limit it just acts like the throttle closes. Here is a picture of it. The throttle is the green line. Top of 4th you can see the green line dipping. It does not do it all the time anyone have any suggestions?

 

[16GoManGoHC2]

Here it is top of 4th, clean, no throttle cut that run. Weird it happens and doesn’t happen. Seems lower DA it may happen more often, airflow issue/setting?? Whipple 3.0 with stock Thitek ported heads. No one has any tune adjustment suggestions on this issue?

 

[Speedy!]

In my old stick car, it would anticipate hitting the rev limit sometimes and start closing the throttle. Also, I'd not lift shift at the track but the computer still closed the throttle even though my foot was planted through the floor board.

 

[16GoManGoHC2]

In my old stick car, it would anticipate hitting the rev limit sometimes and start closing the throttle. Also, I'd not lift shift at the track but the computer still closed the throttle even though my foot was planted through the floor board.

Rev limiter set to 7200 rpm, it’s not even getting close lol. I shift at 6600, rev limit not being activated, I monitor it.

 

[Speedy!]

Do you log the pid "throttle torque source", if so what does it say when this occurs?

 

[BoostedGTA]

No more questions?

Here's a question for ya... I've got a 2021 Super Stock, only mods are ID1300 injectors and E85. I'm in the process of doing a remote tune with a well known tuner... the latest tune revision I was sent had a TCM tune and increased timing (the only changes since previous version). I made 3 passes on the tune and it looks to me like my car is lean. Commanded EQ ratio goes to 1.0 (lambda) pretty quickly during my 1/8 mile pass. Prior to this latest tune, the commanded EQ was always ~.80 for the entire run and very consistent. A friend mentioned to me that the "throttle torque source" was going to "transmission" instead of "pedal" and maybe that's the culprit... I'm attaching a log of this scenario... Hoping I didn't hurt anything!? (I didn't see any knock retard) I feel like I'm being hung out to dry by the tuner because I haven't heard from him in 3 weeks. Guessing I'll go back to the previous version before this started happening until I hear back.

 

[16GoManGoHC2]

Do you log the pid "throttle torque source", if so what does it say when this occurs?

Yes, I log that, it just says pedal unless I get to 7200 rpm then it will say rpm limit. I think it had something to do with driver torque demand versus actual as actual is exceeding demanded when this happens

 

[ostmike]

Any thoughts on the flex sensor in the new demon? Hoping it will be available thru dodge. Not sure if you could add one and make it work with the factory pcm

No idea but will post up if I find anything out.

Mike, we've chatted about this but might be good for this thread. I'm running the Redeye fuel rails that came on the 2.7L supercharger that fell in my lap. I upgraded to a triple pump system recently as well with three 285 pumps. ID1300x injectors. I figured my fuel pump duty cycle in logs would be in the 60% range at WOT on E85 with this setup considering 3 pumps but I'm seeing 85-89% sometimes. Injector DC never goes over like 60% or 11ms pw so I believe it's getting plenty of fuel, just odd the fuel pump dc was higher than I expected.

I'm wondering if the scale for the fuel pressure sensor in the rail needs a tweak since it's a Redeye sensor that's expecting 105psi fuel pressure commanded? I don't see anywhere in HPT to adjust something like that.

Speedy, I would not get to worried about FP DC and I definitely would not rely on the Fuel Rail Pressure reading logged in HPtuners. InjPW is all I watch and if you are good there (11ms is low) and your lambda is in line then you have enough fuel. We have had the conversation in the past concerning the fact that the Fuel Pressure reading is not an actual reading and is calculated. The FP DC may actually fall into the "calculated" category as well but I am not certain.

@16GoManGoHC2 was going to do a bench test of the two rails to see if a mechanical difference could be determined but it's been an interesting experiment.[/QUOTE]

Here it is top of 4th, clean, no throttle cut that run. Weird it happens and doesn’t happen. Seems lower DA it may happen more often, airflow issue/setting?? Whipple 3.0 with stock Thitek ported heads. No one has any tune adjustment suggestions on this issue?

Assuming that you can actually feel this and it is not a sampling rate error this is a tuning issue. It is a very common problem that we see with cars tuned elsewhere.

Here's a question for ya... I've got a 2021 Super Stock, only mods are ID1300 injectors and E85. I'm in the process of doing a remote tune with a well known tuner... the latest tune revision I was sent had a TCM tune and increased timing (the only changes since previous version). I made 3 passes on the tune and it looks to me like my car is lean. Commanded EQ ratio goes to 1.0 (lambda) pretty quickly during my 1/8 mile pass. Prior to this latest tune, the commanded EQ was always ~.80 for the entire run and very consistent. A friend mentioned to me that the "throttle torque source" was going to "transmission" instead of "pedal" and maybe that's the culprit... I'm attaching a log of this scenario... Hoping I didn't hurt anything!? (I didn't see any knock retard) I feel like I'm being hung out to dry by the tuner because I haven't heard from him in 3 weeks. Guessing I'll go back to the previous version before this started happening until I hear back.

1. Do not look at "Commanded EQ". You should be watching the lambda readings from your widebands.
2. If your Throttle Torque Source is showing "transmission" anywhere other than the shift it is tuning related.
3. If your tuner is reputable with this platform he will be busy. It is not unusual for me to be 2-3 weeks behind in responding with revisions. I start email tuning revisions first thing in the morning and limit my time to 3 hours. I then go to the shop and tune cars on the dyno the remainder of the day. I leave the evenings and weekends for work around the house and family. I always list my expected response times in my email signature for my customers but that is all I can offer.

 

[BoostedGTA]

1. Do not look at "Commanded EQ". You should be watching the lambda readings from your widebands.
2. If your Throttle Torque Source is showing "transmission" anywhere other than the shift it is tuning related.
3. If your tuner is reputable with this platform he will be busy. It is not unusual for me to be 2-3 weeks behind in responding with revisions. I start email tuning revisions first thing in the morning and limit my time to 3 hours. I then go to the shop and tune cars on the dyno the remainder of the day. I leave the evenings and weekends for work around the house and family. I always list my expected response times in my email signature for my customers but that is all I can offer.

Thank you for taking the time to respond Mike. I should have clarified I was looking at both commanded EQ as well as WB EQ Ratio readings, and they were following the commanded very closely. I guess I had 2 questions, why was it commanding 1.0 (stoich) if I should be in PE mode at WOT during a pass; and secondly, if I'm looking at the correct PIDS (see below) that it is way too lean if it's following the commanded up to 1.0.


Also, that is very admirable that you list expected response times... that would be super helpful!

 

[Speedy!]

Not trying to speak for Mike but it appears to me something is up with the commanded fueling. That looks lean based on how my car is setup. What exactly is different between your tune that had .80 on the wide bands? The log would indicate commanding .90 - 1.0 lambda which isn't right.

 

[Jon-MooredPerformanceLLC]

Thank you for taking the time to respond Mike. I should have clarified I was looking at both commanded EQ as well as WB EQ Ratio readings, and they were following the commanded very closely. I guess I had 2 questions, why was it commanding 1.0 (stoich) if I should be in PE mode at WOT during a pass; and secondly, if I'm looking at the correct PIDS (see below) that it is way too lean if it's following the commanded up to 1.0.
View attachment 103397

Also, that is very admirable that you list expected response times... that would be super helpful!

Yours transmission is going into torque management and your tuner is using fuel as one of the methods of torque management.

 

[Speedy!]

I bet that's it, good catch. I don't like using fuel for tq mgmt. Mine would get a deg or two of STKR at shifts with that enabled so I turned the fuel part of it off and rely on spark.

 

[BoostedGTA]

Not trying to speak for Mike but it appears to me something is up with the commanded fueling. That looks lean based on how my car is setup. What exactly is different between your tune that had .80 on the wide bands? The log would indicate commanding .90 - 1.0 lambda which isn't right.

Thanks Speedy. The only change since the previous version was increased timing of 4 degrees and a TCM tune. All previous logs would show approx .80 lambda for my entire pass, and throttle torque source would always be pedal except during a shift.

 

[BoostedGTA]

Yours transmission is going into torque management and your tuner is using fuel as one of the methods of torque management.

Thanks Jon. So why would anyone want to cut fuel or command leaner for torque management? I would think timing retard would be the safer method? It's probably over my head... all I know is, it looks bad to me that it's doing this at WOT and under full boost.

 

[Speedy!]

Factory uses timing and fueling for torque management. It's pretty easy to disable the fueling part and timing is plenty to control it.

Once that's addressed the next big question is why it's entering tq mgmt. Sounds like the tuner may have not raised a limit to avoid that at your updated power level.