Boost Issue's for Bracket Racin!!

[Tony Shoaff]

Patrick??? Talk to me

 

[DR BOOST]

I wish I could use a 2 step with my factory ignition. That would be of great help.

MSD DIS4

any good electonic boost controller has a programable launch boost setting

 

[Robert Wilson]

I need some help in this issue I need a way to stage my car, Set the trans brake, build 10lbs.boost and stop in less than 3sec, Launch the car, build boost to 25-30 lbs and stop@ WOT. What does it take to achieve this control?? My combo is in the Sig. I need some honest help here? Anyone/Everyone welcome and If you don't know do not reply please! Thanks.

I am using an AMS 500 with a homemade wastegate actuator to do what you are asking. Attached is a data log of boost.
I prestage and bring the boost up to 0~2psi on the foot brake. I roll in until the stage light comes on, grab the transbrake (this activates stage one on the controller) and mat the accelerator. Boost goes to about 16psi and levels out. When the last amber lights, I release the transbrake button and boost goes to about 27psi. The spike you see in the graph above 27 psi is cause because I have no ramp in timer set between stage 1 and stage 2. Of course, stage one and 2 can be adjusted to whatever you want to set it to.

 

[Tony Shoaff]

Homemade internal or external wastegate? Whats up Dr Boost? I know the MSD 4 can work but I have heard alot of them were junk and I do not have time for issues of that sort. I am liking what Robert is saying. What is your combo though compared to mine??

 

[Tony Shoaff]

Hello Bob. I am sure you are tired of me asking this question too but I have no choice I have to do something to get this car more consistent? I am ordering a Tial 44 external and some kind of boost controller. I really do not want NOS unless I have to because I am trying to keep this car for bracket racing without spending alot more money on it and buying another car for Heads up racing.

 

[Robert Wilson]

Homemade internal or external wastegate? Whats up Dr Boost? I know the MSD 4 can work but I have heard alot of them were junk and I do not have time for issues of that sort. I am liking what Robert is saying. What is your combo though compared to mine??

Internal Gate with THDP.

For the rest of the combo:
T64 P trim turbo
stock headers
ported iron heads
218 flat tappet cam
400 trans with brake

Here are a couple of pics of the wastegate actuator setup.

 

[Tony Shoaff]

What is the difference between factory and yours?? Does yours have two inlets for boost control lines maybe? How many extras do you have or can you build me one? I would like to try it.

 

[Robert Wilson]

Yes, the difference is 2 inlets and the spring I am using will let the boost be turned down to 8psi.
For an AMS style boost controller to be used, you need to be able to apply pressure to both sides of the actuator diaphragm or piston in the case of the cylinder I am using.

Do you already have a boost controller? The actuator will do you know good without a boost controller and CO2 source.

I do not have a spare actuator currently.

Here is a link to larger photos.

turbowilson/wastegate actuator - Photobucket - Video and Image Hosting

 

[Tony Shoaff]

I will buy the external gate and a AMS 500 boost controller and see what happens??/ Should be the same set-up different wastegate. Right? Does the AMS controller need C02?

 

[Robert Wilson]

Yes, an external gate will work the same.
I set up a AMS 500 with a Tial V44 external gate on my uncle's GN. We have a 7lb spring in the gate so the boost can go down to to about 7 psi for the first stage.
At first, I used boost to control the gate but could only go to about 23 or 24 psi on the second stage.
CO2 gives you more adjustment range by letting you apply more pressure to the gate.

 

[Tony Shoaff]

Is that because of the highside spring psi though? I'm am listening.

 

[Robert Wilson]

Read the following information about boost controllers. Especially the CO2 section.

boost controller comparison

 

[ct67_72]

I skimmed the last couple posts but I believe you can just use a multi stage boost controller. depending on what you have for engine management. We ran up to 6 different boost stages on the fwd drag cars with an aem ems. you can do similar with other products, an aem trueboost I believe will do it. I use one in another fwd drag car. I stage with one setting which at the moment is 7 psi, set the lights, when the clutch switch closes the controller goes into scramble mode wich is set to 20 psi. I have also used the cruise switch to active the high boost setting, you could wire it to go into a different mode with the release of the t-brake, or even use a delay or have it come up progressive to prevent tire spin.
that way you can be full throttle staging and not have to worry about boost as long as the wastegate is set lower or the same as the lowest boost you want. if you leave on 10 the wastegate has to be set for 10 max.
I beleive this is what you are trying to do anyway

 

[Alky V6]

This talk about boost controllers is all fine and dandy, but how does a boost controller get the turbo spooled up quicker? I'm assuming his existing wastegate is not creeping open prematurely. It seems to me that the first problem that needs to be addressed is getting the turbo to spool up quick enough so that he doesn't end up being late on the light. Remember, this fello is going to be bracket racing.

 

[ct67_72]

if i understand correctly its not the speed but the consistency of it, if you start building boost on the first yellow, and creep in as you make full boost on the low setting of the boost controller, or even creep in on full launch boost and set the brake youre all ready to go, it doesnt need to be fast to come on as its consistent, as I understand to be the problem. now its too early, to much boost, to late and not enough. youll be on the wastegate staging already so it wont matter

 

[Alky V6]

Then I guess we need to discuss what braking system to use on a GN that would allow creeping into the staging light with launch boost. Even I would like to know the answer to that. That could solve some of my own current problems.

 

[Robert Wilson]

I agree it doesn't help the turbo spool quicker but I was answering his very first post.

Another approach would be to use a transbrake "creep" feature like the FAST XFI has. With this feature, you pre-stage, get the car up on your first stage of boost, activate the creep which pulses the tranbrake solenoid a programmed amount allowing the car to "creep" forward into the stage lights.

 

[johnplogii]

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

 

[Tony Shoaff]

I am still here. I will always have time to do it once. I never have time to do it again. Thats all. Keep it goin I am listening. I just need your help in the issue guys no wars please. Thanks Again.

 

[Tony Shoaff]

I will get back on the board in a little bit. Gotta go for now.