Cracking The Hellcat Code: How The DiabloSport Redeye Runs 9’s

Some cars break records, hearts, and parts. Impressive – yes. But, then some cars obliterate any memory of speed you had before them. I’m talking about the kind of car that doesn’t simply push you back into the seat – it stuffs your stomach into the deepest, darkest cavern of the Earth’s core while the rest of your body is launched into the stratosphere. I like to call these, “face-melters.”

Not only is the car before you a face-melter, but it didn’t take very many modifications to get it there – at least, not by today’s standards, anyway. Sure, the modern Hellcat Redeye produces an eye-watering 797 horsepower from the factory, but moderation is for the weak, as they say. The adrenaline junkies at DiabloSport sought to stretch the demonic feline’s legs a bit to see what it could do with a few mild upgrades.

The crew at Diablosport even took it a step further by challenging themselves to make more power while still maintaining factory emissions. Now, they’re no strangers to optimizing tunes for drivability and performance, so it comes as no surprise they took on the challenge. With a goal in mind and the knowledge that supercharged Gen-III Hemi motors paired with eight-speed automatic transmissions leave tons of power on the table, the mad scientists got to work on the tuning portion.

To start, the crew optimized the Redeye to run on 93-octane fuel using their Trinity 2 tuner and CMR (Chip Master Revolution) custom tuning software. That alone unleashed an extra 54 horsepower and 42 lb-ft of torque to the tires. They even took some time to make some shift improvements while they were at it.

Keep in mind – this is only a tune – no hardware was replaced, modified, or even needed to make such a robust power increase. That’s pretty wild when you stop and think about it! This thing is still wearing the factory exhaust system – including the catalytic converters.

Like any real car enthusiasts, the crew didn’t just want to see the Redeye make dyno pulls and crazy horsepower numbers. They wanted to see what their Hellcat creation could do on the racetrack, too. But, before they could, they had to make sure all that power could be put to the pavement efficiently. So, they wrapped some Weld SR71 bead-lock rear wheels in Mickey Thompson ET Street R drag radials and slapped on some Alumastars in the front.

A snarling engine and sticky rubber make a great combination, but they mean nothing if you’re risking it all every time you launch the thing. So, the team wisely installed a Per4mance differential brace, lest they fall victim to the notorious cracking that plagues Chrysler rearends.

The first trip to the track proved the work to be fruitful. With the baseline/stock tune loaded up, the car was consistently hitting 10.91-second quarter-mile times at 125mph. Once the team loaded the Diablo tune and ran the Redeye on 93-octane, the 54hp increase afforded them almost a half-second on the quarter-mile ET, finishing at 10.56 at 128mph. Yes, that’s an extremely impressive gain to be had on only a tune, but…it’s not exactly deserving of “face-melter” status.

Of course, if faster is better, why not take things a step further? Well, the answer most enthusiasts give at this point is, “I don’t want to break something.” Newsflash: that’s a risk you run if you’re consistently beating on your ride on the track and the street. Still, there are things you can do to hedge your bets. Among them are the modifications mentioned earlier.

For the gang at DiabloSport, it meant teaming up with the tuning specialists at Drag-On Resources. With Trinity 2 hardware in-hand and DiabloSport’s CMR custom tuning software loaded up, the real fun began.

They upped the amount of boost around 3psi by swapping the factory supercharger pulley for a smaller 2.75-inch unit. They also upgraded the injectors to Injector Dynamic ID1050X sprayers. Although, Matt Barker of DiabloSport told us the injector change was performed primarily to accompany future upgrades. The smaller pulley and pump-gas currently in-place didn’t necessitate it.

All told, the upgrades increased the Redeye’s rear-wheel horsepower to the tune of 820hp. That’s a gain of almost 100 horsepower with nothing more than a tuning change and smaller supercharger pulley with the factory catalytic converters still intact.

So, back to the racetrack they went, with a goal of 9-seconds in mind…

At Orlando Speed World, the Redeye burned up the quarter-mile, not only meeting the goal but exceeding it – on pump-gas no less. Matt told us, “Our first pass on the improved tune with the smaller pulley got us a 10.2 at 130mph, and that was so close to our goal that we knew we’d make it happen. On our third pull, we hit a 9.92 at 132mph. We’re thrilled to see that, with simple modifications and expert tuning, you can get a Hellcat Redeye into the 9’s with emissions intact on pump-gas alone.”

When I spoke with Matt, I knew our readers would want to know how they can achieve the same results. So, I asked him to go into more detail about how the process works for customers.

“The customer provides us a VIN (vehicle identification number) and calibration I.D., and we program a PCM (powertrain control module) optimized for their build. The customer then uninstalls the factory PCM, installs the new unlocked PCM we’ve supplied, and sends the old one back to us. That means no downtime, so customers won’t be without their ride for any amount of time.”

“Our goal with this whole project was simply to show that with experienced tuning, small hardware upgrades, and a well-designed tuning platform, you can reach impressive new e.t.’s for not a lot of money.”

While I doubt any Redeye owner is going to quibble over the cost of a few upgrades, it perks my ears for all the people with standard Hellcat Challengers and Chargers. The performance trickle-down effect, if you will…

This is important because, during our conversation, Matt pointed out this truth –  “the fastest Hellcat isn’t a Demon or a Redeye. And, if you look at the records, many of the cars in the running are Diablo Tuned.”

Who knows? Perhaps DiabloSport’s Redeye will be knocking on that door soon. As you can see in the video below, they went back for more. The crew put those larger injectors to use by filling the tank with E85 and recalibrating the tune once more. The new setup inches them closer to the 8-second mark, by quite a bit. The Redeye ran a 9.29 in the quarter at 146mph, and that’s right off of the trailer!

Unfortunately, gratuitous horsepower tends to break things. Such was the case for the heroes of our story. So, while they were able to crack off an insane ET, they also found the limits of a stock axle when they were met with some track surface issues. But, what’s more metal than that? Axle snapping power and single-second quarter-mile times from a relatively unmolested production car? Now that’s worthy of being called a “face-melter”!

We have no doubt they’ll get the broken axle taken care of soon and be back on the track in no time. For now, the video of the 9.29 pass will have to hold you over. If you’re interested in finding out more about everything DiabloSport has to offer, or how you can take your Demon, Redeye, or Hellcat to new performance heights, check out DiabloSport.com.

About the author

Vinny Costa

Fast cars, motorcycles, and loud music are what get Vinny’s blood pumping. Catch him behind the wheel of his ’68 Firebird. Chances are, Black Sabbath will be playing in the background.
Read My Articles

Hot Rods and Muscle Cars in your inbox.

Build your own custom newsletter with the content you love from Street Muscle, directly to your inbox, absolutely FREE!

Free WordPress Themes
Street Muscle NEWSLETTER - SIGN UP FREE!

We will safeguard your e-mail and only send content you request.

Street Muscle - The Ultimate Muscle Car Magazine

We'll send you the most interesting Street Muscle articles, news, car features, and videos every week.

Street Muscle - The Ultimate Muscle Car Magazine

Street Muscle NEWSLETTER - SIGN UP FREE!

We will safeguard your e-mail and only send content you request.

Street Muscle - The Ultimate Muscle Car Magazine

Thank you for your subscription.

Subscribe to more FREE Online Magazines!

We think you might like...



Classic Ford Performance

Street Rods

Classic Chevy Magazine

Street Muscle - The Ultimate Muscle Car Magazine

Thank you for your subscription.

Subscribe to more FREE Online Magazines!

We think you might like...

  • Classic Ford Performance
  • Street Rods
  • Classic Chevy Magazine

Street Muscle - The Ultimate Muscle Car Magazine

Thank you for your subscription.

Thank you for your subscription.

Street Muscle - The Ultimate Muscle Car Magazine

Thank you for your subscription.

Thank you for your subscription.

Loading