Demon Injectors in Hellcat

[jonx96]

A few weeks ago on the Facebook group there was a lot of discussion on if Demon injectors are enough. There were a few pretty well known tuners strongly saying not to do it and a lot of people saying to do it. I choose to go with Demon Injectors for the price point and knowing sooner or later I'll want to go e85. I have found very little actual real world experience. I'm going to share a few screenshots and if anyone wants more information let me know. I'm not saying to do them or not. I'm just sharing what I have witnessed. The 89.5 is the highest I've witnessed and logged many pulls around 80%. I have logged two pulls over 85% and they are both listed below. I wish I could compare to FIC 775s. I am going to continue to closely monitor all year.

My Mods are 2.85 grip tech pulley with Demon Injectors on a 2018 Challenger with 26k miles on it. I will say most these pulls I did it 16 to 17 psi of boost even though I have a 2.85 but that's a different discussion.

Last weekend at the track DA was around positive 400 to 500 for this pull. I ran 10.5 at 133.4mph with a 1.65 60ft.
As you can see there was a quick spike which hit 89.5%


-400 DA. Just a pull while I was datalogging. Pull was to the top of 4th. Injector Duty Cycle hit 84.45%/

Da was less that a 1000 is all I have logged for this one. Pull was to the top of 4th. Injector Duty cycle was 77%

 

[Speedy!]

That's too high on inj pw. Playing with fire IMO.

 

[jonx96]

That's too high on inj pw. Playing with fire IMO.

It's definitely high enough where I feel every time I do anything I have to log it. That's why I stated this thread is for informational purposes and it's for people to make their own educated decisions. When I looked I found numerous people stating they were very happy with demon injectors. They provided no logs or details. I have a feeling I'm going to be changing injectors.
These logs are all in really good air quality and hopefully won't spike higher.

 

[moparjim]

It's definitely high enough where I feel every time I do anything I have to log it. That's why I stated this thread is for informational purposes and it's for people to make their own educated decisions. When I looked I found numerous people stating they were very happy with demon injectors. They provided no logs or details. I have a feeling I'm going to be changing injectors.
These logs are all in really good air quality and hopefully won't spike higher.

What is the fuel pump duty cycle?
I am going to go eventualy with a 10% lower and flex fuel tune this year. My tuner suggested 1200fic or I'd 1300. I asked about ID 1050's and was told not a great idea.

 

[Speedy!]

I bet the car is going in to torque reduction as a result of that inj pw. Factory limit at 6200 rpm is 13.7ms and that's way higher.

 

[jonx96]

What is the fuel pump duty cycle?
I am going to go eventualy with a 10% lower and flex fuel tune this year. My tuner suggested 1200fic or I'd 1300. I asked about ID 1050's and was told not a great idea.

Do you know what I have to log for the fuel pump duty cycle? I’m not sure I’m currently logging that.

 

[jonx96]

I bet the car is going in to torque reduction as a result of that inj pw. Factory limit at 6200 rpm is 13.7ms and that's way higher.

Is there something I can log to check this?

 

[Speedy!]

I don't use Diablo anymore so I'm not sure how it would show it, but in HPT you can compare supercharger bypass position 1 to position 2.

 

[jonx96]

I don't use Diablo anymore so I'm not sure how it would show it, but in HPT you can compare supercharger bypass position 1 to position 2.

I also have an hp tuners. I’ll see if I can use that to log if I don’t see it with Diablo.

 

[ACMAVRO]

Your tuner should be able to give you some wiggle room on the injectors assuming your fuel pump can keep up

 

[moparjim]

Do you know what I have to log for the fuel pump duty cycle? I’m not sure I’m currently logging that.

It's in HPTuners. I switched and found out what my issue was. I couldn't find the fp duty cycle on diablo.
My car was going into cat overtemp early due to the recall. I found out my pump and injectors were maxed. Luckily the car was pig rich doing this and not lean.
Injector DC is easier to read also as there is a pid for that on hptuners.

 

[jonx96]

I bet the car is going in to torque reduction as a result of that inj pw. Factory limit at 6200 rpm is 13.7ms and that's way higher.

I think you are right. I uploaded this unlisted video you can hear right at 20 seconds when it shifts gears that it lost power.

Your tuner should be able to give you some wiggle room on the injectors assuming your fuel pump can keep up

I asked him he told me to just replace Injectors or fuel pump or just do both.....
Do you work for Dusterhoff by chance? I see you post in his vendor tab sometimes.

 

[fumanchu182]

I would go with bigger injectors for sure.

 

[ACMAVRO]

I think you are right. I uploaded this unlisted video you can hear right at 20 seconds when it shifts gears that it lost power.

I asked him he told me to just replace Injectors or fuel pump or just do both.....
Do you work for Dusterhoff by chance? I see you post in his vendor tab sometimes.

Yeah he gave me some breathing room as I was close on inj too. I needed some help with my fuel pump first though.

 

[jonx96]

Just an update for anyone who finds this thread down the road. After hearing the above video and the car cutting out like it did I ordered bigger injectors and a dual pump. With that being said I also reached out to Dusterhoff and am going flex fuel. I had another thread a month ago where I kept fighting knock issues. Just not worth the risk of me getting bad fuel in spring and fall. When I went to the track I had to dump a ton of octane boost in. I don't care for running octane booster.

 

[Speedy!]

Wise move.

 

[Slows2k]

80% duty cycle or less at WOT has been the rule of thumb.