Boost Issue's for Bracket Racin!!

[Robert Wilson]

Tony, you might try my technique for staging first.

Allways let the other car start their burnout first & pre stage first, then prestage your car. Let the other car stage. Now this takes some practice but you want to creep in a couple more inches past the pre stage beam. Now footbrake the car to 0-2psi or so, then engage the transbrake. Now you can throttle it to 10psi or whatever you want to launch at, let off the footbrake & the car will roll into the 2nd beam. You are staged & should be at your desired boost level and all you need to do is watch the lights & go.

It takes some practice but has worked very well for me yielding some good/consistant reaction times and the car runs consistant.

The tricky part is knowing where to stop in pre stage & how hard to footbrake it to get enough/not too much rollout when you let off the footbrake.

John

I like your idea cause it won't cost anything to try.

 

[Alky V6]

Can a person manually pulse a transbrake fast enough to creep into the light? I've never tried it, but it sounds like something worth playing with. That method has got to be a little hard on the T/C too. You're stalling the T/C for at least what, over 5 seconds?

 

[Tony Shoaff]

John that is a great idea staging deep. How will you ever get in the same place twice? I want to stage the car, set the brake ,go to 10-12lbs of boost and stop before the green is on and gnce off brake second stage goes to 25-30. Thats what I am lookin for Donnie is right. Why hold the car with brakes when you have a trans brake?

 

[Tony Shoaff]

Donnie I was told every second on the brake 100 degrees in the trans?

 

[Alky V6]

Donnie I was told every second on the brake 100 degrees in the trans?

No, it's not quite that bad, but you would be surprised at how fast the temp needle moves when stalling a T/C. Not to mention the tremendous load on the internal thrust washers inside the T/C.

 

[rtviper]

Isn't there an RPM that your engine reaches against a T-Brake that will produce your 10lbs boost? Stage early set brake and hold at the RPM that will only go to 10lbs boost. You mentioned stageing early but then you go over the 10 lbs boost. That must happen because you have pushed to far on the gas pedal. I installed a light that would come on at 3500 rpm and that gave me the boost I needed to launch the car. I staged early went to 3500 right away and held that rpm untill I released the T-Brake. Worked great for bracket racing
Was I just lucky or should the boost continue to climb while holding at a lower rpm?

 

[johnplogii]

Can a person manually pulse a transbrake fast enough to creep into the light? I've never tried it, but it sounds like something worth playing with. That method has got to be a little hard on the T/C too. You're stalling the T/C for at least what, over 5 seconds?

Donnie, I have seen this done and it was VERY violent. There is no creeping about it.

When I do it I let the car roll in between 5-10lbs boost. The reason I let the other person stage first is so the tree starts as soon as I stage. I think its more like 1 sec to start the tree then 1.5 secs worth of amber which is 2.5 total. I don't think I have ever stalled it for 5 seconds, that seems incredibly long, you just need to be concious of the time. I don't think I am too hard on my tranny, I made over 600 passes on a 2004r and when it went the sprague broke due to the ring & pinion breaking.

 

[Tony Shoaff]

Mr Wilson,
Are you using co2 for control of your set-up?

 

[johnplogii]

John that is a great idea staging deep. How will you ever get in the same place twice? I want to stage the car, set the brake ,go to 10-12lbs of boost and stop before the green is on and gnce off brake second stage goes to 25-30. Thats what I am lookin for Donnie is right. Why hold the car with brakes when you have a trans brake?

Tony, you don't deep stage. Like I said the tricky part is being in far enough past the first stage beam & not lighting the second stage beam. Then footbeaking so far before engaging the transbrake so you will have just enough rollout to fully stage when you let off the footbrake. When you hit that first stage light you want to creep 2-3 more inches, footbrake to just above 0psi, set transbrake, then go to launch boost & let off footbrake. very rarely would you go so far you deep stage, but your car could move more than mine too. If anything the car may not roll in far enough then you will have to start over and usually you are so close as soon as you release the tranbrake you stage even under minimal load. It is just something you need to practice, but it does work. I am no bracket racer, but of 10-12 bracket races I have entered I have placed in 4.

 

[Tony Shoaff]

John,
I do about the same thing now. I pre stage under a load, other guy pre-stages, I rollin and set my 2 stage light with more pedal. When the other guy gets staged I hit the button and go wot. I sit there until its time to go. What is not consistent is the lights and when I sit longer at times than others it changes my boost level and my et's change. I would rather have the same boost level every launch. My goal is to make this car as consistent as possible. I hope to win a bracket race whatever it takes.

 

[Tony Shoaff]

I am still wondering what I should buy to help control the boost better?? I guess the AMS500 and External gate?? I really hate wasting money though if its not needed.

 

[Robert Wilson]

I am still wondering what I should buy to help control the boost better?? I guess the AMS500 and External gate?? I really hate wasting money though if its not needed.

If you want to control your launch boost then I would look to purchase a boost controller with at least 2 stages such as the AMS 500.

What I like about using the boost controller to stage is that I can put the accelerator on the floor and know the boost will go only to my set level. I don't have to watch the boost gauge and adjust the throttle to reach a certain level.
Also, in my case, the launch RPM is around 4600 RPM at the 16psi without using a 2 step rev limiter. Of course this would vary depending on your convertor and power you are making.

To answer your previous question, I do use CO2.

 

[Tony Shoaff]

Where did you get the co2 kit? I am leaning towards the ams 500 and tial 44 with co2 for now. I will use nos if needed. I don't think i have a problem with spool though. I just cannot control the psi at this time before launching.

 

[Robert Wilson]

Here is the cheapest source I found for a CO2 kit.
Biondo Racing - Shopping
I purchased the BK80E model and had it filled at a local paintball gun place.
The boost control system uses very little CO2 so the 10oz. bottle will last several trips to the track.

 

[Tony Shoaff]

Mr. Wilson,
Did you figure a price for a internal wastegate like yours for me?

 

[Alky V6]

Tony. You want to final stage, then go WOT to build boost to a launch level of 10 psi. That is how I've read your requirements. Taking the reaction time of the car into account and your reaction time after lighting the final stage bulb, you have around .6 to .8 second to accomplish this before it's time to release the transbrake button, assuming a worse case scenario where the tree comes down immediately after you've final staged.

With that being the case, how long, exactly, does it take for your combination to reach your target launch boost of 10 psi? I'm looking for an exact number. If you don't know it, you need to time it. Which way you go at this point will hinge on that one answer.

I'm not down playing the need for a good boost controller, in fact, I have an AMS1000 and a CO2 kit sitting on my desk that I plan to play with when it becomes absolutely necessary. But, up to this point I have been able to get by with just changing the springs in the wastegate and adjusting the preload bolt. If your combination will build the target launch psi in less than .6 to .8 seconds, then by all means take measures to control your boost better. If you can't reach the 10 psi within .6 to .8 seconds, then high tech boost control, at this point, seems like a waste of money.

It may turn out that you need to take measures to quicken the boost rise, and once that has been done, then you will need better boost control. But,... first things first. Can you attain 10 psi in the required time?

 

[Tony Shoaff]

Donnie what kind of wastegate are you using. All I have is the factory style. And no I really don't know if I reach 10 lbs or not before I launch. I say no because there is not enough time and I cannot sit any longer than when the 3rd yellow lights up. How do you keep from building to much boost before you launch also? Thanks.

 

[Alky V6]

Donnie what kind of wastegate are you using. All I have is the factory style. And no I really don't know if I reach 10 lbs or not before I launch. I say no because there is not enough time and I cannot sit any longer than when the 3rd yellow lights up. How do you keep from building to much boost before you launch also? Thanks.

You must know the answer to that before moving on. You don't have to be at the track to test this. Warm the car up at a safe place, apply the transbrake, and stab the throttle. Time how long it takes to get to 10 psi while on the transbrake. Very simple. Make sure the front and rear of the car are clear, in case you have a transbrake failure of some sort.

I control the boost at launch by adjusting the delay timer setting. If I want minimum boost, I delay the activation of the nitrous right up until the transbrake timer is set to release the transbrake. I can adjust the nitrous delay timer all the way to a point where the nitrous would activate .001 second after the release of the transbrake button on the first amber. The nitrous would have close to one second to work the boost up before the transbrake delay timer released the transbrake. In that case, way too much boost will have built up by then. It would be over 16 psi and the nitrous would already have been shut off before the release of the transbrake. The timers are adjustable to .001 of a second, allowing very precise tuning of the launch attitude. The one variable that comes into play is the nitrous bottle pressure at the time of launch. There is equipment that can be used to stabilize the bootle pressure.

My launch is not controlled by boost controllers, 2 step rev limiters, precise throttle angle, precise staging techniques. It is controlled by the simple change of a delay timer. All I have to do is stage, and I could do this at an idle if I chose, set the transbrake and go WOT, and finally release the transbrake button on the first amber. Then of course, wait for the fireworks!

I'm using a HKS 60mm wastegate.

And yes, sometimes I do red light. Imagine a turbo car staging at an idle and redlighting with the wheels in the air.

 

[Tony Shoaff]

I will find out today and let you know.

 

[Robert Wilson]

Mr. Wilson,
Did you figure a price for a internal wastegate like yours for me?

I will figure it out tonight and let you know.