[big black nova]

We have been searching for issues we are having w/ driver/car reaction times. we are currently running a blown methanol/bruno drive in a door car. myself ,as the driver, gets the blame all the time for our poor pro tree average of .080 to.100.
we have recently installed a event sensor for the trans brake button so we now know exactly the lag between release of button and initial movement of driveshaft/tire. we are averaging .24 to .26 of lag. this seems excessive to me .
does anyone monitor this? how can we reduce this lag time?

 

[overkill69]

We run a BRT with a dedenbear adjustable button. Have run glides too with numerous buttons in several blown alcohol cars and my driver has always cut pretty good lights. Never had issues going red though...Recently a local guy switched from a clutch to a BRT and had to put a delay box on it. I've seen boxes in several lencodrive ADRL cars.
I wonder if staging has something to do with it.

 

[8.50 Express..]

make sure the trans brake is supplied with a clean power source & not running Thur any relays. Just my 2 cents. One last thing, what the bruno pressure filling the converter???

We have been searching for issues we are having w/ driver/car reaction times. we are currently running a blown methanol/Bruno drive in a door car. myself ,as the driver, gets the blame all the time for our poor pro tree average of .080 to.100.
we have recently installed a event sensor for the trans brake button so we now know exactly the lag between release of button and initial movement of drive shaft/tire. we are averaging .24 to .26 of lag. this seems excessive to me .
does anyone monitor this? how can we reduce this lag time?

 

[big black nova]

make sure the trans brake is supplied with a clean power source & not running Thur any relays. Just my 2 cents. One last thing, what the bruno pressure filling the converter???

we have rewired the seleniod to direct 12v from batterys
we did this awhile back hoping it would help
and we're charging w 200 pounds . i just read some posts before starting this thread about pressures set to 250 or even 300.
will this effect release time ??

 

[big black nova]

We run a BRT with a dedenbear adjustable button. Have run glides too with numerous buttons in several blown alcohol cars and my driver has always cut pretty good lights. Never had issues going red though...Recently a local guy switched from a clutch to a BRT and had to put a delay box on it. I've seen boxes in several lencodrive ADRL cars.
I wonder if staging has something to do with it.

we have tried every staging position including deep staging
but once we could chart the release of the trans brake buuton in the racepak that when it became clear . we see the release of the button then approx .25 seconds later we see our first bit of driveshaft speed. if we can reduce this delay i know our numbers will be where we need them. I have even attempted to practice with our practice tree with this much delay" dialed in" an cannot muster better than an .060 light but the average still hovers around .080 even on the practice tree! this much delay cannot be the norm!! i'm sick and tired of getting tree'd by literally every one we race

 

[Hutch]

If you have .24 between the time the button is released and the time the car moves YET you are still able to cut a .080-.100 light we have a major problem. Something is happening before the car gets there. This makes no sense.



Hutch

 

[big black nova]

If you have .24 between the time the button is released and the time the car moves YET you are still able to cut a .080-.100 light we have a major problem. Something is happening before the car gets there. This makes no sense.



Hutch

What you saying that this not possible?
i must admit most lights are worse but the question really is,
What might be causing this kind of lag
I have the graphs that show this delay
What is considered a normal amount of time?
Even my own team thinks I'm grasping at straws here!
Is it time to retire and let the young guys take over!!

 

[Hutch]

Im not saying its impossible but maybe the data is incorrect. Im just doing the math and it says if your car takes .240 to move then its impossible to cut a .080 light.


Hutch

 

[the358bansh]

Im not saying its impossible but maybe the data is incorrect. Im just doing the math and it says if your car takes .240 to move then its impossible to cut a .080 light.


Hutch

Or that means if Bob and Joe get their issue fixed, the next problem will -.160 red lights...

 

[Hutch]

Not quite. Its hard to tell how fast the car and driver will react but we have .400 to break the beams , I figure it takes the average guy .200 to react and most cars likely .200-.250 to leave the beams that would be .000-.050 light. If we say that them we have a car that takes .240 to start moving the driveshaft we would see .200+ reaction times. I may be all washed up here but its just my thought process.

There have been band self energizing problems with Bruno's and the way you can tell if its having trouble is when you let go of the button with the car idling you will feel a delay in release. Thats how you tell if the Bruno is acting up.


Hutch

 

[big black nova]

Or that means if Bob and Joe get their issue fixed, the next problem will -.160 red lights...

Evan
I should have know I'd find you here!
And I would kill for a red light some days
At least that's easy to fix!!!

 

[big black nova]

Not quite. Its hard to tell how fast the car and driver will react but we have .400 to break the beams , I figure it takes the average guy .200 to react and most cars likely .200-.250 to leave the beams that would be .000-.050 light. If we say that them we have a car that takes .240 to start moving the driveshaft we would see .200+ reaction times. I may be all washed up here but its just my thought process.

There have been band self energizing problems with Bruno's and the way you can tell if its having trouble is when you let go of the button with the car idling you will feel a delay in release. Thats how you tell if the Bruno is acting up.


Hutch

I appreciate the input about something we can check to resolve this issue
Also your math is correct even though we have cut lights as in the .100 range most are much worse. It,s like admitting a drinking problem when you have to claim a .200 average

Thanks again now maybe we have something we can do to fix this problem

 

[big black nova]

There have been band self energizing problems with Bruno's and the way you can tell if its having trouble is when you let go of the button with the car idling you will feel a delay in release. Thats how you tell if the Bruno is acting up.


Hutch

we have tried this and there does seem to be a noticable delay also checked all graphs the delay varies but is always there .
i have also tried to reach the manufacturer who is local, but head guy out of town, we hope to resolve for an upcoming 1/8 mile race this weekend.... any suggestions?

 

[Hutch]

The first thing to do it change the band. Thats quick and easy. See if that helps.


Hutch

 

[big black nova]

Thanks,
That will be the first thing we will try.
One other related question?
Does launch rpm effect this brake release issue?
The converter typically flashes to 6200 but we typically leave at 3500
Thanks again

 

[russ kelly]

When I ran a Bruno in my A/AP the car was very quick on launch---now it was an 1850lb car--that was one thing. However I always felt the Bruno had a very good release time. We have always done a lot of research on buttons and their release time--we generally need a slower release to keep from going red. I have tried every type of button and internal spring to find the slowest.

 

[jbersani]

I can tell when it's time to change the band in my Bruno as my reaction times go down the drain. When it's good I can go red almost anywhere. That's where the mega 400 comes in handy.

 

[Blownalky]

Any resolution on this issue?

 

[scot9055]

Hey fella just thought I would throw out there that if you are using a 2 magnet drive shaft sensor verses a 8 magnet thats where some of your lag time could be seen in drive shaft movement. In fact my car is the same but in real life the drive shaft is moving the computer just has to see the magnets pass by it a few times to start calculating it for you. My 2 cents worth.