Launch Strategy Incorporating the BOV

[Otto J]

The way mine works is like this. I do the burn out and two foot
the car in two the stage lamp.Then i set the trans brake the
rpm trigger switch which is activated by the t brake turns on the
no2 at 3000rpm and off where i want usually 4000 rpm then the
two step takes over to control rpm while the gate controls boost
my problem is i cant dump enough boost due to waste gate size
now if i could bleed a little through the bov that would very nice.
A bigger waste gate is the solution but that means fabrication and more money.
i have the bov on the car already why not try to make it multi funtional.
controlling the bov will be the trick if i stray far from the proper spring size
it wont function as intended for initial purpose.

With a 2 step and an exteranl gate you cant control launch boost? what boost controller are you using? I am figuring the nitrous is off at the 2 step point.

With my XFI i was using the transbrake control,(was one of the first to test this back in 05 for F.A.S.T)
It ties your t-brake solenoid with a digital relay and the XFI has a PWM solenoid.
I would get into the first bulb,apply the brake,when i reached my 2 step, i would trigger the creep function and the car would simply roll into the second bulb with the transbrake applied.
It is a real nice feature,you can set it to creep as soon as you reach a certain KPA as to not creep to early also

 

[Alky V6]

With a 2 step and an exteranl gate you cant control launch boost? what boost controller are you using? I am figuring the nitrous is off at the 2 step point.

With my XFI i was using the transbrake control,(was one of the first to test this back in 05 for F.A.S.T)
It ties your t-brake solenoid with a digital relay and the XFI has a PWM solenoid.
I would get into the first bulb,apply the brake,when i reached my 2 step, i would trigger the creep function and the car would simply roll into the second bulb with the transbrake applied.
It is a real nice feature,you can set it to creep as soon as you reach a certain KPA as to not creep to early also

That is very cool.

 

[Otto J]

That is very cool.

I think someone makes a stand alone one. A digital relay is need with a pwm controller.
There are a few settings that you must play with to get it real smooth so its can be a bit tough on the convertor/trans, it will get hot spooling it on the brake to get it right.
When its set though it rolls smooth

 

[Alky V6]

I think someone makes a stand alone one. A digital relay is need with a pwm controller.
There are a few settings that you must play with to get it real smooth so its can be a bit tough on the convertor/trans, it will get hot spooling it on the brake to get it right.
When its set though it rolls smooth

I understand. What a great tool.
I already checked out the description of the feature on the XFI site. Very cool.
I was already wondering about a stand alone unit after your first post about the feature.

 

[Alky V6]

I've been searching around and there isn't much about stand alone transbrake creep controllers. I'm a little surprised about that. I would at least think that FAST would have come up with a unit. It just seems like the perfect product, and I can imagine there would be no shortage of customers for a unit like that. They're missing the boat big time on this one. There are a lot of people that really don't want to switch over their whole engine management system just so that they can have a transbrake creep feature. If FAST did have a stand alone transbrake creep unit, I would already have it on order.
Anyway, the principle of releasing a controlled amount of apply oil from the reverse and high clutch circuit is not a difficult matter. I'm already thinking up some ways to do this. Not nearly as sophisticated as the FAST system, but it would perform the same function.

 

[Alky V6]

It seems TCI and FAST are associated with the same mother company, yet even though TCI has a stand alone transmission controller, there is no mention of a transbrake control feature. Again, someone is missing the boat. If TCI were to incorporate a transbrake creep feature into their transmission controller that would give a person a reason to purchase the controller to be used on a non-computer controlled transmission, again, I'd already have the unit on order.
Dang! I need to work in the new product development departments for these companies. I'd have already earned my salary by now.
Otto. You seem to have an in with these people. Give them a clue, will ya!?

 

[cdsttype]

I understand. What a great tool.
I already checked out the description of the feature on the XFI site. Very cool.
I was already wondering about a stand alone unit after your first post about the feature.

I was building one for production but didn't finish it although i could.
When fast came out with theirs i stopped working on it.Once i put the nitrous in the need was gone.No need to cook the trans while creeping.

 

[cdsttype]

With a 2 step and an exteranl gate you cant control launch boost? what boost controller are you using? I am figuring the nitrous is off at the 2 step point.

With my XFI i was using the transbrake control,(was one of the first to test this back in 05 for F.A.S.T)
It ties your t-brake solenoid with a digital relay and the XFI has a PWM solenoid.
I would get into the first bulb,apply the brake,when i reached my 2 step, i would trigger the creep function and the car would simply roll into the second bulb with the transbrake applied.
It is a real nice feature,you can set it to creep as soon as you reach a certain KPA as to not creep to early also

msbc I have tuned the boost spikes out of it and the timer and ramp functions work as advertised.I do not have a
controller issue.I have too small a waste gate to run 275 drag radials.The
disclaimer of any boost controller is it only works as well as the system it is on.

 

[Dusty Bradford]

NLR had the stand alone creep box. I think they may have aborted the project or at least put it off until the AMS 2000 is rolled out.

 

[Alky V6]

NLR had the stand alone creep box. I think they may have aborted the project or at least put it off until the AMS 2000 is rolled out.

I'm going to contact them and ask about this. They would seem to be the perfect people to come out with such a system. Thanks, Dusty.

 

[Alky V6]

I was building one for production but didn't finish it although i could.
When fast came out with theirs i stopped working on it.Once i put the nitrous in the need was gone.No need to cook the trans while creeping.

I see your point completely. If I were using a smaller turbo my problems would be pretty well solved.
Even with my involved nitrous system, my choice of turbo still needs about 2 seconds on the nitrous to get to my launch targets. I know pro lights can come down quicker than 2 seconds. That's why I'm looking at every possible tool to put together something that will help me work a pro light in even the most extreme situation. That would be a situation where the light comes down real quick after final staging.
Or, another would be where a competitor attempts to burn you down at the lights. I've seen that happen to a fella I know and what happened to his transmission and converter was not pretty.

 

[Dusty Bradford]

I'm going to contact them and ask about this. They would seem to be the perfect people to come out with such a system. Thanks, Dusty.

It worked very well in testing.

 

[cdsttype]

I see your point completely. If I were using a smaller turbo my problems would be pretty well solved.
Even with my involved nitrous system, my choice of turbo still needs about 2 seconds on the nitrous to get to my launch targets. I know pro lights can come down quicker than 2 seconds. That's why I'm looking at every possible tool to put together something that will help me work a pro light in even the most extreme situation. That would be a situation where the light comes down real quick after final staging.
Or, another would be where a competitor attempts to burn you down at the lights. I've seen that happen to a fella I know and what happened to his transmission and converter was not pretty.

i got my 80mm ball bearing
turbo down to .8 sec with out much tuning effort school is out on my gt4788
i will let you know how fast i can spool that on my 274 cu inch

 

[Alky V6]

i got my 80mm ball bearing
turbo down to .8 sec with out much tuning effort school is out on my gt4788
i will let you know how fast i can spool that on my 274 cu inch

So you're switching from an 80mm to the gt4788?

 

[HighPSI]

I did the prototype testing for FAST on the transbrake creep back when I was running a Classic FAST. I still have the stand alone unit. I'm not sure if I can get rid of it since it has "Engineering Prototype" written on it. Since I was the one pushing for it, they also wrote "Calvinator" on it :biggrin: If they say it's ok, you're welcome to try it. It's not nearly as refined as the one in the XFI

 

[Alky V6]

I did the prototype testing for FAST on the transbrake creep back when I was running a Classic FAST. I still have the stand alone unit. I'm not sure if I can get rid of it since it has "Engineering Prototype" written on it. Since I was the one pushing for it, they also wrote "Calvinator" on it :biggrin: If they say it's ok, you're welcome to try it. It's not nearly as refined as the one in the XFI

I greatly appreciate the offer, Cal. I'm going to first see if there is a finished product that I can get. If I strike out, I may take you up on your generous offer. Thanks.

 

[Alky V6]

[Thinking out loud]
How would a pro light launch routine go?
I would pre-stage. Bring the rpm up as high as the brakes will allow me to get away with. Roll into stage, then set the transbrake and go WOT.
I would need to have the nitrous activate with the setting of the transbrake and going WOT.
The BOV would also open getting its signal from the wastegate control pressure line (teed into) via the 3-way valve. The 3-way valve would be activated to allow flow from the wastegate line to the BOV when the transbrake button is pressed. When the transbrake button is released, the 3-way valve will switch to flow from the intake plenum to the BOV. That way the BOV can act as it normally would for the rest of the run.
The BOV should only be allowed to open enough to maintain a certain rpm and launch boost level. Launch rpm and boost level could be finely tuned by how the BOV is set, adjuster screw and control pressure wise.
A turbine speed sensor might become useful for the tuning and monitoring of this launch routine.
The nitrous system would need to time out at some point, or leave it on until the release of the transbrake? Or, leave it on threw the first part of the launch and shut it down at 176 kPa. That would depend on how controllable the rpm and boost level becomes at the target launch values. The AB level could be adjusted to help with this, maybe.
A problem is, I've found a good launch boost level that is right in the middle of my aux fueling activation transition point. Not really a point. It's more of a MAP range. How to make that work. Move the transition range higher? That would be the best way to handle it, if I have enough range left in the VE table to allow it.

I have looked at the VE table and there is plenty of range to move the aux fueling transition point. I even have the proper pressure switch in stock to move the range well out of the map range that I want to play with for the launch.

 

[Alky V6]

The switching solenoid is in place. I've decided to abort trying to incorporate the spool valve into the launch routine and freed up the aux channel on the boost controller to use for controlling the BOV. I came to realize that I would probably need a different pressure for the BOV than what I would be needing on the wastegate. Being able to control the wastegate and BOV with their own separate control pressures should allow a better chance of controlling the staging rpm and boost level.

 

[Alky V6]

I'm going to leave the aux fueling activation at the low setting I've been using all along. I'm figuring it would be better to get the aux fueling online through the nitrous activation and have that transition all done with before launching the car. This will mean that I will need to launch the car with no less than 182 kPa MAP. I now believe I should be able to use the nitrous to achieve a certain rpm and boost level, shut down the nitrous and have the engine alone maintain a target launch rpm and boost level. The launch rpm and boost level would be controlled by a combination of wastegate and BOV CO2 control pressures.
Some preliminary rack tests show that after the nitrous shuts down and the timing comes back in, the rpm and map want to continue to climb, even while on the transbrake. There is no question the engine will be able to maintain a target rpm and map level while on the transbrake, without the nitrous.

 

[Alky V6]

The nitrous is no longer on a delay box. Basically, it will controlled by a WOT switch and will be shut down by a 175 kPa MAP switch. Other controls are a master arming switch and the minimum rpm and map enabling is controlled by a GPO channel of the ECM.