Prock "Auto Flow" (2 Viewers)

[parrotwhisperer]

Yesterday Tom Prock (Jimmy's Dad) posted on FB "Those in the know have Auto Flow". Auto flow is a new term to me. Is it a new clutch management system? Traction control? Does anyone know what it is and how it works?

 

[Treeshaker]

On a basic cannon system, there is fluid in the cannon that holds the throw out bearing in a predetermined position set prior to a run. This can be in a position that allows the car to leave only on the primary levers, or set to allow one or two secondary fingers to aid in the launch and then the clutch wear at the hit brings them back onto the throw out bearing. Then there is a timer system set from the hit of the throttle that opens a series of flow valves that allows the fluid in the cannon to transfer to an accumulator at a speed determined by the size of the orifices in the valve system. All preset prior to a run. Teams have stops on individual levers to release clutch pressure during a run in addition to the throw out bearing movement all preset before a run to create their preferred clutch graph profile. The pressure on the throw out bearing and movement is monitored by a pressure sensor and linear and is downloaded after a run for tuning purposes.

The Auto Flow system takes this pressure during a run and opens and closes the valves during a run with a set of parameters preset by the tuner. If the pressure on the throw out bearing is too great because of extra clutch wear it will speed up the cannon, and if the clutch isn't wearing enough it will slow down the cannon so that too much clutch pressure will not be applied. Traction control? You Bet.

A similar system was developed by Bob Otto when cannons were first starting to be used, but it worked off the G meter to control cannon movement. NHRA immediately banned the system. The Auto Flow has been around since that time but Prock and Medlin finally have it working to perfection in the last few events.

 

[flapjack]

On a basic cannon system, there is fluid in the cannon that holds the throw out bearing in a predetermined position set prior to a run. ...

Thanks for the nice explanation, Virgil.

 

[Jim]

Thanks Virgil (Though I always enjoy a good conspiracy story<G>)

A similar system was developed by Bob Otto when cannons were first starting to be used, but it worked off the G meter to control cannon movement. NHRA immediately banned the system. The Auto Flow has been around since that time but Prock and Medlin finally have it working to perfection in the last few events.

 

[CrewMan]

Wow...thanks Virgil....my head hurts now...but I get!

 

[mick]

hight commented on show last nite that their recent advantage was traction related.....also interesting to hear other DSR FC
crew chiefs know what they're doing but it would not work with their combinations....any way you slice it, absolutely amazing performance lately by the infinite hero FC, looking forward to watching them in 12 days.
thanks virgil.

 

[vegasnitro]

Great explanation Virgil. Every time I think I have a pretty good idea how these cars work, a post like this makes me realize I don't know squat LOL.

 

[flapjack]

Perhaps this is what Alan Johnson is experimenting with. that or a six disc clutch.

 

[Just Paul]

Perhaps this is what Alan Johnson is experimenting with. that or a six disc clutch.

Alan has been running a 6 for a couple years now. He was one of the first to do it. (If not the first)

 

[Usual password less 1]

Alan has been running a 6 for a couple years now. He was one of the first to do it. (If not the first)

Kalitta's were the first to get a real handle on it in Top Fuel and most of the others have followed

 

[T.Smith]

I've been suspecting this for years and it should be banned.

 

[Treeshaker]

The 6 disc clutch has been around a while. We had them in our cars for a while 12 years ago and we were not the first. You can obtain the same parameters with a 5 disc clutch by changing the floater thickness. I have seen floaters from .240" thick to .450" thick, and I am sure someone, sometime has tried thicker ones.

As for the Auto Flow being banned, I doubt if it will be. NHRA likes the excitement the numbers are bringing and it is only one of several methods of traction control being employed by some teams currently. I can remember Dell had it on his KSC cars way back when, and who was one of his tuners then and now working on the Beckman car? Coincidence? Not really, just the way technology gets spread around the pits.

 

[turbo ken]

As for the Auto Flow being banned, I doubt if it will be. NHRA likes the excitement the numbers are bringing and it is only one of several methods of traction control being employed by some teams currently. I can remember Dell had it on his KSC cars way back when, and who was one of his tuners then and now working on the Beckman car? Coincidence? Not really, just the way technology gets spread around the pits.

It maybe banned if they keep getting up to a 1/10th advantage over the rest of the cars.

 

[T.Smith]

The 6 disc clutch has been around a while. We had them in our cars for a while 12 years ago and we were not the first. You can obtain the same parameters with a 5 disc clutch by changing the floater thickness. I have seen floaters from .240" thick to .450" thick, and I am sure someone, sometime has tried thicker ones.

As for the Auto Flow being banned, I doubt if it will be. NHRA likes the excitement the numbers are bringing and it is only one of several methods of traction control being employed by some teams currently. I can remember Dell had it on his KSC cars way back when, and who was one of his tuners then and now working on the Beckman car? Coincidence? Not really, just the way technology gets spread around the pits.

Of course it's not, but it should be.

 

[Nobody]

As for the Auto Flow being banned, I doubt if it will be. NHRA likes the excitement the numbers are bringing and it is only one of several methods of traction control being employed by some teams currently. I can remember Dell had it on his KSC cars way back when, and who was one of his tuners then and now working on the Beckman car? Coincidence? Not really, just the way technology gets spread around the pits.

So Virgil, following this line of thought, do you think it would be OK to run a pressure regulated flow valve keyed off of boost to "manage" fuel flow when boost comes up (ohhh like when tires start to loose traction). I suppose it's already been done/tried.....
Was jus' lookin' round the scrap parts bin thinkin' out loud....

 

[Treeshaker]

So Virgil, following this line of thought, do you think it would be OK to run a pressure regulated flow valve keyed off of boost to "manage" fuel flow when boost comes up (ohhh like when tires start to loose traction). I suppose it's already been done/tried.....
Was jus' lookin' round the scrap parts bin thinkin' out loud....

Nitro is load sensitive so when you smoke the tires you take the load off the motor and it goes rich, stay on it and it goes very rich. Now when you drop cylinders the boost spikes in the other cylinders and they go very lean usually burning a piston or torching a head gasket.

When you smoke your tires during a run, you can whack the throttle quickly hoping the tires will grab and the motor will drive thru the clutch again. But for this to work the driver has to feel it happening before the spectators/crew actually see much smoke from the tires, or you can get off the throttle and let the car settle and then squeeze the throttle back on never getting to full throttle so that the timing/fuel system timers are reset and there will be less fuel volume.

To limit overall fuel pressure on a run they use what is called a BDK valve that is adjustable and usually preset prior to a run. It will open at a set pressure and close when the pressure drops, basically what you are describing. A sensor could come off several computer inputs to change this pressure when different events take place during a run.

I have seen a type of waste gate/valve installed on intake manifolds to limit blower pressure. Sid Waterman was working on this many, many years ago when NHRA was considering ways to slow the nitro cars down and has been used on cars since at times.

 

[FABMAN]

Virgil, in your opinion since this is a process to control your traction should it be allowed in competition.

 

[Mike]

It is not a process to control traction directly! Everything we do is an attempt to control traction. It helps control the amount of clutch wear which will make the car more forgiving. It IS NOT slowing or speeding the driveshaft (to control traction) based upon an RPM curve or otherwise. They can do that in certain Pro-Mod classes though. Per NHRA rules, you CAN have a pre-programmed automatic control of a pressure. You can only directly control the pressure of the sensored device with the pre-programmed pressure curve. You CANNOT, for example, control the pressure of a device based upon the status, position, speed, pressure, temperature, etc. of another sensored device (feedback control). You ARE NOT changing the pressure based upon some other input. You ARE adjusting the pressure to what you wanted it to be at a certain time increment of the run. Everything else (in the can) has to be perfect for this to work properly and be an advantage. They have worked very hard at getting this to work and they are currently reaping the benefits of it. I was against this type of control when it first came out several years ago and have my letter to NHRA to prove it. NHRA's rule at the time was no computer (feedback) control and I felt this was in direct conflict with that rule. They said as long as you are not controlling one device with the input from another it was legal. It must be pre-programmed and cannot change once the run has begun.

 

[my friends call me Zappy]

I've been suspecting this for years and it should be banned.

Just curious, why do you feel this should be banned ?? Isn't eliminating "smoke-a-thons" a good thing ??

 

[Just Paul]

It's not going to eliminate "smoke-a-thons". Not even close. If you are over center, you are over center and this will not help you too much. If you get it right, the tuning window does open up. If you are off on your projected wear it can help one way or the other. Aside from that, I can see this as a benefit if you are needing to work in some new disks that have slightly different characteristics than what you are used to.

If you flat miss the set up, and the car is going to smoke the tires, this will not stop that.
Also, this will not make a 4.01 car into a 3.91 car like some magic box.
Who's to say it's not all smoke and mirrors anyway.