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Discussion Starter · #1 · (Edited)
Update on this issue!!! Been working with my Tuner today and he figured out my issue was in the HP Tuners Flex map. Something in there wasn’t working for us. We did a straight tune and the car runs great and shifts great. So for now I’m going to have an E85 map and a 93 map. Not ideal but im happy the car is doing great and we figured out the issue. I really thought it was something in the torque management but I guess it was something in the flex map tables. More to follow. 5-14-2021.


I'm moving to E85 on my redeye and the car feels real strong but it's cutting out at 6000RPM and from the data logs it looks as if the bypass valve is opening. I've been reading a bit on maybe the TCM hitting a sensed upper torque limit. If I put the car in track it goes to the normal shift point but the shift is delayed and not a hard normal shift like maybe the trans limit is reached or close to the track torque limit as well. And I'm working with a tuner. We are trying to sort it out tomorrow. But I wanted to ask the community as I have an asset here I want to protect. E85, 17.5 psi, 1200cc injectors.

Stephen
 

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Discussion Starter · #2 ·
Ran another data log today per tuner request looking at more parameters and the car ran perfect. Shifted perfect and everything. It was 87F out. Where the issues were happening it was about 40-45F out. So I could have been right on a threshold. Or it could have been just the ECU not acclimated to all the flashing and short runs. I don’t like when something isn’t known or repeatable! Ha


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I think sometimes you can juuussttt get right on the edge before MECO
 

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Discussion Starter · #4 ·
I think sometimes you can juuussttt get right on the edge before MECO
you maybe hot gotgap. but we also did a lot of flashing and short runs getting the flex dialed in. Since I put some miles on it today it has ran and shifted great. So I'm hoping the PCM was just like enough flashing! ha
 

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If it’s only doing this on cold weather on e85 you may be hitting 90% duty cycle on the injectors snd it will start to open the bypass valve and bleed boost. I know this from first hand experience. You may be running out of fuel pump or injector, or your tuner did not turn up the injector pulse width time allowance at higher rpm.
 

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Discussion Starter · #6 ·
If it’s only doing this on cold weather on e85 you may be hitting 90% duty cycle on the injectors snd it will start to open the bypass valve and bleed boost. I know this from first hand experience. You may be running out of fuel pump or injector, or your tuner did not turn up the injector pulse width time allowance at higher rpm.
Thanks for the reply. I'm running 1200cc FIC's and only showing 56% IDC max. I think it was either just flashing the ECU so much getting the tune straight or a peak Torque limit sensed in the trans. I'll be logging all the bypass valve parameters for some time to come to see if it reproduces itself.

Stephen
 

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Discussion Starter · #7 ·
So it came back this morning. Cool morning full pull triggered it. Once this cutout is implemented by whatever is implementing it, the only way you can restore everything such that the car will go above 6000 to the shift point is to disconnect the battery for 15 minutes. And there are no codes thrown when this happens. 1000-1050HP Redeye on E85 with 1200cc FIC’s. 17.5psi. Thanks in advance for your input. And it does not do this in the afternoon at 80F ambient. It’s only done this on cold-ish morning runs around 50F ambient.

Stephen


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Discussion Starter · #8 ·
Update on this issue, talked to some other redeye's with this issue. Seems to be an anticipatory cutoff if you are coming up to Rev Limit or Fuel cut too quickly as you would see during wheel spin. So modified redeye's are pulling so quickly through the RPM range the PCM is killing it early to protect everything. So i'm thinking a combination of lowering the shift points and raising the rev-limit/fuel-cut so the PCM would see a bit more margin and not cut the car off early. So I don't believe its a torque limit as I was previously thinking.
 

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An Experienced Hellcat Tuner will know how to work out the Bypass blow off valve.
Torque management. It is known now what to do.
This was very frustrating to my husband @Top Cat back in 2015. My husband and [email protected]
and me were at the track 3Xs a week together for R&D + T&T.
Eventually when Josh figured it out there were not any other Hellcats that could get past 9.8
My husband and I both had 9.7s
That's the number for a Hellcat to get past the T management.
Once past many of the HHP Hellcats were changing in and out of the Top spot.
It was fun for those guys.

BTW if this is not done correctly Engines had been blown gaining experience.

Linda :)
 

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Discussion Starter · #10 ·
An Experienced Hellcat Tuner will know how to work out the Bypass blow off valve.
Torque management. It is known now what to do.
This was very frustrating to my husband @Top Cat back in 2015. My husband and [email protected]
and me were at the track 3Xs a week together for R&D + T&T.
Eventually when Josh figured it out there were not any other Hellcats that could get past 9.8
My husband and I both had 9.7s
That's the number for a Hellcat to get past the T management.
Once past many of the HHP Hellcats were changing in and out of the Top spot.
It was fun for those guys.

BTW if this is not done correctly Engines had been blown gaining experience.

Linda :)
Thank you Linda !


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Discussion Starter · #12 ·
kind of unrelated, but what kind of tires are you using to hook with 1000+ HP?
Red Aye good question. And actually very related to this issue in lower gears. Part of this 6000 RPM limit is to protect the engine from over rev during wheel spin when the acceleration rate is so fast that the fuel cut/ rev limit would be greatly exceeded and possibly damage the SC or engine. As I'm new to Hellcat world I'm learning a lot from members. On stock power level cars they were seeing this during wheel spin and correcting it with drag radials. I was seeing it in 5th gear at 130+ mph. In my case it was a torque management issue. As for my daily driving tire it's an Atturo 315/35/20 AZ850. This tire is cheap and oddly, fairly sticky. But traction is limited under 70 mph. The Atturo is sticker than most street tires I have tried. I have a set of Demon Wheels and 305/45/18 MT Street R's for the strip and serious business. ha.
 

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Discussion Starter · #14 ·
It was something in the HP Tuners Flex Map! Thank goodness it wasn’t an issue with the car!


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