SRT Hellcat Forum banner
  • Hey Everyone! Enter your ride HERE to be a part of this months Ride of the Month Challenge!
1 - 20 of 49 Posts

·
Registered
Challenger SRT 392
Joined
·
7,160 Posts
Discussion Starter · #1 ·



Sent from my SM-N960U using Tapatalk
 

·
Registered
Challenger SRT Hellcat Redeye Widebody Octane Red
Joined
·
1,506 Posts
Were they trying to hit top speed with that thing or what?
 

·
Registered
Challenger SRT Hellcat
Joined
·
2,115 Posts
Car looked nice before it came apart.....
 
  • Like
Reactions: snobrdrdan

·
Premium Member
2020 Challenger Hellcat Redeye Wide Body
Joined
·
9,876 Posts
And with no cooling fan out front. Not that it would have prevented that but still.
If you look close they have a small fan up front. A small one lol.
 

·
Premium Member
2020 Challenger Hellcat Redeye Wide Body
Joined
·
9,876 Posts
Having no real dyno experience I’m guessing running it through all the gears creates a heat issue without a ginormous fan?
 

·
Registered
2020 Challenger Hellraisin Scat Pack.
Joined
·
2,564 Posts
Based on YT videos nothing cuts short one's time with his hot rod than attending a cars/coffee gathering. Well, not the attending part the departing part.

Second is putting the vehicle on a portable dyno. If the car doesn't blow the dyno comes apart.
 

·
Registered
2020 Challenger Hellcat
Joined
·
904 Posts
The problem seen here can be caused a number of different ways. First, dynos generally have variable load settings dependent upon the vehicle's weight and HP rating. If running a pull at too high or too low of a load. If the load is calculated too high, it can stress the transmission and drivetrain similarly to the effect of pulling a load that's too heavy for the vehicle.This is my guess as to the root cause. The reason why they run them on a load is to account for simulated road friction/aero effects, and a dyno with no load can force over rev issues. Those rollers weigh in excess of 2,500lb, and that's a lot of rotational mass if they're not magnetically held back. Then, of course, maybe the guy's transmission was damaged or modified and it was just its time. But, more than likely, they ran the car through all 8 gears into overdrive and the overdrive gears can't handle the torque of the engine combined with the increased load on the dyno rollers. User error, 100%.

As others have mentioned, it's normal to do a pull in the single highest, non-overdrive gear when measuring torque/horsepower potential. My guess is they were trying to do a high speed run as part of some sort of dyno battle or some such.
 

·
Registered
Joined
·
422 Posts
IMO, if I were the owner of that car i'd sue the dyno operator for at least the new transmission part cost. The operator is clearly at fault here. I'm sure the owner is screwed, but the operator is just so clearly wrong here.

I've never seen anyone just run through gears like it's the drag strip like that. Even if it was a high speed run, you wouldn't just let the thing normally slam through gears to get there, and you normally wouldn't bother going into an overdrive gear either as you need the torque of 1:1.
 

·
Registered
Challenger SRT Hellcat
Joined
·
324 Posts
Never seen that kind of dyno pull before. Looks like the dyno operator didn't apply the brake to drum when the pull ended, and it was pushing the wheels/transmission when throttle was lifted. As mentioned earlier, the drum is very heavy and the car's engine braking or wheel brakes are not supposed to be used to slow it down.
 

·
Premium Member
2020 Challenger Hellcat Redeye Wide Body
Joined
·
9,876 Posts
The problem seen here can be caused a number of different ways. First, dynos generally have variable load settings dependent upon the vehicle's weight and HP rating. If running a pull at too high or too low of a load. If the load is calculated too high, it can stress the transmission and drivetrain similarly to the effect of pulling a load that's too heavy for the vehicle.This is my guess as to the root cause. The reason why they run them on a load is to account for simulated road friction/aero effects, and a dyno with no load can force over rev issues. Those rollers weigh in excess of 2,500lb, and that's a lot of rotational mass if they're not magnetically held back. Then, of course, maybe the guy's transmission was damaged or modified and it was just its time. But, more than likely, they ran the car through all 8 gears into overdrive and the overdrive gears can't handle the torque of the engine combined with the increased load on the dyno rollers. User error, 100%.

As others have mentioned, it's normal to do a pull in the single highest, non-overdrive gear when measuring torque/horsepower potential. My guess is they were trying to do a high speed run as part of some sort of dyno battle or some such.
Yeah was thinking about the load or maybe lack of it being a factor. More load I could see hurting things along with excessive heat. Less load with over rev but we have rev limiters so would over rev from too light of a load be sort of protected against or no?
 

·
Registered
2020 Challenger Hellcat
Joined
·
904 Posts
Yeah was thinking about the load or maybe lack of it being a factor. More load I could see hurting things along with excessive heat. Less load with over rev but we have rev limiters so would over rev from too light of a load be sort of protected against or no?
I'm not a transmission guy, so I apologize if I say something wrong here. But, overdrive gears are cruising gears. They're not bolstered for accepting high torque applications. If you look under the car on the dyno, you see all those transmission guts. It is my guesstimate that they were trying to run the car to 240mph or some such through 7th or 8th gear and it literally blew the trans apart. Normally under road conditions, there's less force being applied to the trans in overdrive gear(s). On a dyno, the load is fairly constant once the tester sets the magnetic load. IRL, if you put the car in manual mode in 8th gear at 65 mph, you accelerate very slowly and it feels like the engine is lagging a bit. On a dyno, the rotational mass of the cylinder is actually helping you turn the transmission in overdrive, and thus imparting a lot of that artificial load force directly into the transmission where it should not be. So, while Dodge says you can get max speed of 203mph or whatever in 6th, theoretically you can get more out of continuing to run it in 7th/8th in a test environment, like say with the wheels up on a lift. But, when you add in the artificial load (which is just as strong at 40mph on the Dyno as it is at 220mph), the more fragile 7th/8th overdrive gears probably couldn't take the stress and detonated something, which blew the entire pan off the trans and lord known what else in there.
 
1 - 20 of 49 Posts
Top