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Red Eye "Torque Reserve"

Rollieman

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#1
From what I understand the "Torque Reserve" feature spools up the SC more efficiently for anti-lag off the line; and, when engaged gives the engine an "unusual sound".

Is the about right; and, how is it engaged?

Thank you !
 


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Confuzed1

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#2
Cut and pasted:
Demon's unique exhaust sound is the product of an advanced torque reserve launch system—the first ever designed for drag racing in a production car. This system allows more air to flow through the engine before launch, building rpms in the supercharger without overwhelming the brakes and spinning the tires. Torque reserve is triggered when Launch Mode is selected and engine speed is greater than 1,000 rpm.
Torque reserve closes the supercharger's bypass valve to build boost, manages fuel flow to the cylinders, and varies spark timing. The change in exhaust tone is created by the engine controller briefly cutting fuel to certain cylinders in order to balance engine torque.

-There's no "spooling up" with a roots blower. It's always putting out some boost as long as it's turning. How much boost (and when it's applied) is controlled by a bypass valve...
 


Diboblo

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" The system effectively holds onto 8 psi of boost from the 2.7-liter supercharger by closing off the supercharger's bypass valve. The supercharger is always spinning at a rate that depends on engine rpm because it doesn't have a clutch disconnect. By closing off the bypass valve, the air is not recirculated and it's on reserve for a launch instead."

Read more, here:

https://www.motorauthority.com/news...eserve-work-on-the-dodge-challenger-srt-demon

Bob
Riverside, California
 


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Rollieman

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Thread Starter #4
Thank you all for the very much for detailed explanation.

To expand on this a bit; since the Red Eye does not have a transbrake then I assume the torque reserve feature only engages when the car is in launch control mode?

Apparently some folks seem to do better from a dig without launch control, thus I assume they receive no benefit from the torque reserve?
 


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BULL

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#5
Corrected thread title from "Reverse" to "Reserve"...


;)
 


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Rollieman

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Thread Starter #6
Corrected thread title from "Reverse" to "Reserve"...


;)
Thank you Bull !!!
 


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Just like our cars don't have the trans brake feature from the Demon, I don't believe they have the torque reserve feature either. Maybe it's incorporated in with the launch control, but I don't think so. I've never used launch control and really don't plan to. Let us know if you find the TR
 


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Just like our cars don't have the trans brake feature from the Demon, I don't believe they have the torque reserve feature either. Maybe it's incorporated in with the launch control, but I don't think so. I've never used launch control and really don't plan to. Let us know if you find the TR

It's there, in a limited, and undocumented fashion...
 


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#9
Sorry, for the REs
 


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#10
Just like our cars don't have the trans brake feature from the Demon, I don't believe they have the torque reserve feature either. Maybe it's incorporated in with the launch control, but I don't think so. I've never used launch control and really don't plan to. Let us know if you find the TR
Redeyes can build boost at the line using LC. However, I have not been able to put that boost down successfully on a 28" small tire
 


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It is my understanding that the quickest privately owned stock Demon (one seat- 9.71) was achieved by foot braking. I am not sure if anyone has had success with the transbrake, torque reserve or other launch options.
 


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#12
It is my understanding that the quickest privately owned stock Demon (one seat- 9.71) was achieved by foot braking. I am not sure if anyone has had success with the transbrake, torque reserve or other launch options.
But we are under the impression that Leah used both the TB and TR to get the 9.65, right?

FWIW - The Trackhawk has the Torque Reserve, and it doesn't have the 2.7 or the transbrake. The new Hellcats will also come with Torque Reserve... and the Redeye was advertised as having it by several publications. It's there, isn't it?
 


cole3986

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#13
But we are under the impression that Leah used both the TB and TR to get the 9.65, right?

FWIW - The Trackhawk has the Torque Reserve, and it doesn't have the 2.7 or the transbrake. The new Hellcats will also come with Torque Reserve... and the Redeye was advertised as having it by several publications. It's there, isn't it?
Jack,

I am not sure how Leah did it, based on my conversations with Ron his quickest passes were by foot braking it. Phasthemi has tried using it (his post is above).

The problem is that the supercharger makes soo much torque at low RPM that it very very difficult to get the tires too hook leaving at a high rpm (anything at or near 2,000 rpm). The stall on the Demon/RE is higher than on a hellcat, the stall on a Hellcat is 1,800 rpm or so.
 


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#14
Jack,

I am not sure how Leah did it, based on my conversations with Ron his quickest passes were by foot braking it. Phasthemi has tried using it (his post is above).

The problem is that the supercharger makes soo much torque at low RPM that it very very difficult to get the tires too hook leaving at a high rpm (anything at or near 2,000 rpm). The stall on the Demon/RE is higher than on a hellcat, the stall on a Hellcat is 1,800 rpm or so.
Redeyes have it on LC. We have datalogged it and know it is there. Even setting it to leave at 1100rpm, the car is traction challenged on a 305/45/17 radial. Better results can be obtained using it with a taller, wider tire like a 305/45/18 or 315/50/17.
 


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#15
I live in a fairly populated, busy suburban city. No places really, to practice Line Lock, Torque Reserve, Launch Control. For the most part, I would need to practice with that stuff on a Wednesday night grudge race where I can only get in about 3-4 practice runs. However, the starters are always rushing everybody up to the line to keep it moving, moving, moving. I don't have a big problem with launching off the brake. However, I'd much rather do my burn outs with the line lock. That would be a much cleaner, effective burn out without the wear and tear on the Brembos. I'm committed to practicing with the buttons for the line lock before my next trip to the track. I'm at about 10.67 and want to get down to at least 10.50 before the end of the season. That would be sweet!
 


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Trackhawk guys get better results from foot brake in sports over launch control as well FWIW.
 


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Dodge is doing some really ingenious stuff lately. It really is impressive what a bunch of engineers can do when a company quits handcuffing them.
 


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fubar569

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#18
My 18 charger has LC and TR. Both logged and observed.

Empty parking lot testing in Mexico...of course.
 




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