TH400 Switchable stall results

[turbobitt]

As some may know, I been building my own version of a TH400 switchable stall.
http://www.turbobuick.com/forums/threads/where-has-all-the-th400-tech-gone.405180/

I have the design just about perfected and installed it in my own car for vehicle testing. So far the very preliminary results looks unbelievable. Once I get the data organized I will try and post some graphs.

Basically I was able to go from idle to 5000 RPM in 1.53-2.14 seconds vs. 4.32. Time to get to 10 psi boost was reduced from 4.95s to 3.37-3.54.
Data range was taken from about 6 logs. Once I get the wiring complete I can get some better data logs.

Allan G.

 

[norbs]

Looks like you stumbled on to something that you could market, congrats! Will this be available in a kit?

 

[turbobitt]

Norbs,
I can easily make a kit but it won't be cheap. I did a cost analysis and know what it will cost. Kit will include modified pump, modified CK valve body, and deep aluminum pan.
AG

 

[turbobitt]

Here are some preliminary results,

 

[rag231]

Cheap? That word has been wiped out of my vocabulary. Interested! Is this product horsepower limited? I wonder could it be used on the.400 pro tree?

 

[turbobitt]

Cheap? That word has been wiped out of my vocabulary. Interested! Is this product horsepower limited? I wonder could it be used on the.400 pro tree?

I would not say this is hp limited. It is limited to the turbo being used. So if your turbo is capable of spooling in less than 3 seconds than there is no benefit to using this device. A small block or big block engine with a lot more torque would probably not benefit. Small displacement big turbo applications would see the most out of this.
Launching from a pro tree is very possible in my opinion and is only limited to the release of the brake. Since the CK brake has very short passages and a hydraulic assist on the release I would say no problem. Like everything else, the control strategy of the device is very important. In conjunction with the XFI creep function this can be a very useful device.

Allan G.

 

[Alky V6]

The time you will have available with a pro light tree from the moment you become fully staged will be 1 to 1.4 seconds, recalling from my experiences, and depending greatly on the generosity of the starter. Usually, when the starter sees that you're a turbo car, they cut it as short as possible. A-holes.
What sort of staging strategy are you suggesting with this system? The times that you're giving are an eternity at the starting line.

 

[Alky V6]

Correct me if I'm wrong. I see a full recovery of converter charge in over 2 seconds.
The only way I see this working with a pro light is if you do most of your boost building before final staging. You will need to be able to creep in anticipating no more than 1 to 1.4 seconds, on occasion even less, before the amber comes down. Develop your system and staging strategy accordingly.

 

[turbobitt]

Correct me if I'm wrong. I see a full recovery of converter charge in over 2 seconds.
The only way I see this working with a pro light is if you do most of your boost building before final staging. You will need to be able to creep in anticipating no more than 1 to 1.4 seconds, on occasion even less, before the amber comes down. Develop your system and staging strategy accordingly.

You are correct in your assumption. This process would have to be done at the pre stage level. I would want to allow for at least 2 seconds recovery before launch. But like I was eluding to, the strategy become vey important and the time can be cut down by simply shutting the device off before hitting the 2 step. Basically building in the 2 second recovery time in the boost building event. I still need to play with the unit and dial in the details but very optimistic that I can make this work.
Allan G.

 

[Alky V6]

What does the converter fluid temp rise vs time look like with the system? It will be very advantageous to keep total time of building to launch boost and final staging in under 3 to 4 seconds, with an anticipated wait for the amber of around under 1 second to 1.2-1.4 seconds. This would keep temps in the torque converter reasonable by the time you will need to launch the car. It is generally understood that you will see a fluid temp rise of 50 degrees per second at full converter stall speed. Has that been your finding with your tests?
God forbid you take 4 to 5 seconds to build boost and creep into final staging at full launching power and stall speed. Then your opponent decides to burn you down for about 4-5 seconds before he finally decides to final stage. Then the starter delays the amber for another 2-3 seconds. You'll have a fried converter and trans with all that time piled together.

 

[Alky V6]

That is the big problem with depending on having to build boost to launch level before you final stage. You are at the mercy of your opponent AND the starter if you happen to stage first.
I watched a guy burn his trans down in 7 seconds because his opponent decided to burn him down. Then the starter waited forever!

 

[Alky V6]

The best way to not be at the mercy of your opponent is to be able to stage the car, and when both cars are finally staged together, start to build boost and have it to launch ready level before the amber comes down. That will mean you will need to move from engine idle, or thereabouts, to launch ready in about one second for a pro tree. With most starters, even less than one second.

 

[Alky V6]

The one individual that I mentioned earlier figured out a way to prevent being burned down at the line by his opponent. Last I heard this method was effective.
He ran his trans cooler lines through an ice box. Like one would do with icing his intercooler. This gave him more head room with the trans fluid temperature in case he got into a burn down scenario with his opponent and/or starter.

 

[Alky V6]

I would also suggest that you will need to be at around 5700 rpm or higher at launch time to make most combinations work the best.

 

[Alky V6]

OK. Done throwing monkey wrenches into your thought process, for now

 

[turbobitt]

That's OK, Need to get out there and gather more data. Need to start somewhere.
Allan G.

 

[Dusty Bradford]

The best way to not be at the mercy of your opponent is to be able to stage the car, and when both cars are finally staged together, start to build boost and have it to launch ready level before the amber comes down. That will mean you will need to move from engine idle, or thereabouts, to launch ready in about one second for a pro tree. With most starters, even less than one second.

If this was the case we would all need to be racing supercharged cars. Turbo cars can take 5-7 seconds to stage and have no issues with heat, even without a trans cooler. Having a trans cooler in the ice tank does help. I have never witnessed a turbo car be able to roll in at a high idle and be on the 2 step with full launch boost in 1 second. It just isn't necessary.


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[Dusty Bradford]

Where I see the benefit of this system is in the pre stage beam. I would activate the system, stab the gas and once the rpm reached 3800-4000 rpm or a 3-4 psi boost limit was reached, turn the system off. What this allows you to do is get the converter over the hump which is usually around 3000-3400 rpm right before the boost starts coming on quickly. Set a 3 step at something like 4200 rpm activated by the brake switch so you can use this as a limiter while rolling into full stage.

Staging procedure would be just like any other heads up turbo car except you will have the ability to get over the converter hump more easily.


Posted from the TurboBuick.Com mobile app

 

[turbobitt]

Where I see the benefit of this system is in the pre stage beam. I would activate the system, stab the gas and once the rpm reached 3800-4000 rpm or a 3-4 psi boost limit was reached, turn the system off. What this allows you to do is get the converter over the hump which is usually around 3000-3400 rpm right before the boost starts coming on quickly. Set a 3 step at something like 4200 rpm activated by the brake switch so you can use this as a limiter while rolling into full stage.

Staging procedure would be just like any other heads up turbo car except you will have the ability to get over the converter hump more easily.


Posted from the TurboBuick.Com mobile app

Thanks Dusty for the input. This is exactly the point I been trying to make. Its all about how the system is used to get the maximum benefit. With the way I have the converter charge not only being stopped and dumped, the system responds very fast. I have the charge pressure a little on the low side so if pressure is increased the recharge time will only get better.

Allan G.

 

[turbobitt]

Looking at the data logs taken on Saturday, I did 5 consecutive pulls on the brake within 10 minutes. The maximum trans sump temp was 214 degrees at the end of the last pull.

Allan G.