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TH400 Switchable stall results

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They have a new turbo on it with a T6 turbine side. Don't remember much more about the turbo.
The boost was surpassing 200 kPa in the initial stall testing on the transbrake with the nitrous. I had them tame it down a bit, but when we started launch testing they sounded like they wanted more as the driver got used to the car. I guess their new car will handle it.
That is your converter they have in it now, right?
The converter is holding stall at 6250 rpm with 200 kPa MAP. I think the stall could stand to be lower. What do you think? If I remember correctly the duration is around 230s @ .050. I don't expect them to be turning big rpm numbers with this combination. 7000-7500 at the most.
It took 1.3 sec. to reach that rpm and MAP level with a T6 turbine side.
5200 rpm @ 150 MAP within exactly one second.
TC is stalling at 2500 rpm with no boost, no nitrous.

The new chassis should handle some power. It is the same converter we had behind the other car. Ultimately we'll have to get some passes on it with some boost thrown at it and see slip% and rpm drop to make a decision on stall adjustment. The good thing about using nitrous is that it takes the worrying about spool up out of the equation. We can go anywhere we need with the stall.


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Go ahead, The trans forum has been dead with tech for some time. So fat is good to chew on.

Allan G,
 
Is what you're trying to do based on the old switch pitch technology of the 60's or is this totally different???
 
Is what you're trying to do based on the old switch pitch technology of the 60's or is this totally different???
Totally different. What I'm doing requires no special torque converter. Basically manipulating charge pressure to raise the stall. I'm not the first to do this and there are other designs out there, and have not been able to get any detailed information on the other systems or there performance. This is what drove me to develop my own. I designed features into this set-up that I thought would give me the most optimal results while remaining integrated into the factory iron valve body and pump. From what little I know, mine is unique in the way I used the valving and existing valve body features to contain the system. For now, I'm keeping the details to myself and a select few until I decide how to present this system. It may be added to Chris new TH400 book s I don't want to undermine his effort.
Allan G.
 
I'd be glad to test it but I'm not using the stock valve body. I've swapped to the 2 speed Griner from Proformance.
 
I'd be glad to test it but I'm not using the stock valve body. I've swapped to the 2 speed Griner from Proformance.
I'm using Chris's (CK performance) trans brake RMVB body as the donor. I like the short 3rd gear passages and simply trans brake circuit. Plus it leaves me with a lot of opportunity to manipulate the unused passages for my device. I'm building a spare unit and would like to get one out to a high profile racer that could do some testing and constructive feedback. It would require changing the pump, and valvebody and separator plate as well as the external solenoid/TB valve.
AG.
 
A TSO racer would be a good fit for it. Maybe put it in the TSO section and see if you have anyone who can test it.
 
I played around today and have more data to share. This time I have the device wired into the XFI so that it switches OFF at 4000 RPM. What I found was that the unit can refill in time to launch by the time the car gets up to boost. The interesting thing to note is that the converter charge increases to full charge faster than if the unit wasn't ever activated.
With these results, I can now start to increase the RPM shut off threshold to get up on RPM quicker and move the refill point to the right since there is some margin to play with.
The "SS" label is the switchable stall results.

Have some more fine tuning to do but results are looking more promising and starting to come around.

Stall.jpg
 
Dude that's a huge difference! Subscribed.

Posted from the TurboBuick.Com mobile app
 
I have more results to share. Today I raised the shut-off point to 4200 RPM. The improvement is getting better. I'm thinking I could go 4400-4600 shut off and still have time to charge before launch ready.

Stall_4200_off.jpg
 
Took the car out for a little ride and decided to take another data point with the switchable stall. This time raising the shut-off point at 4400 RPM. RPM's came up faster but it appears there wasn't enough load to build boost faster. With 5000 RPM as the 2-step rev limit it looks like 4200 RPM will yield the best results.
May need to raise the 2-step and do another data sweep through the RPM range and see what that yields.

Stall_4400_off.jpg
 
Saw some action at the track today with some testing done on this prototype unit . Tripped the 60' beam with the rear tires.

AG
 
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