Optimum rpm stall converter
09-02-2011, 09:39 PM
#1
Optimum rpm stall converter If the the car is making peak torque@5k and peak power@6900-7000 rpm on a chassis dyno, how high a stall is needed for the best in 1/4 mile? I was thinking about 4400 or so. Drag racers please advise. Thanks.
Trans is a built 4L60E and 4.10 gearing in the rear, running on 28" tires
Trans is a built 4L60E and 4.10 gearing in the rear, running on 28" tires 
09-02-2011, 10:34 PM
#2
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I have always heard you want about 1k below peak torque. But, that may be a little on the conservative side. I see you say peak power at 6900 but where do you plan on shifting? That effects which converter you want as well. From the looks of it I would say a PT4400 would fit your combo very nicely.
09-02-2011, 11:13 PM
#3
I have always heard you want about 1k below peak torque. But, that may be a little on the conservative side. I see you say peak power at 6900 but where do you plan on shifting? That effects which converter you want as well. From the looks of it I would say a PT4400 would fit your combo very nicely.
09-02-2011, 11:23 PM
#4
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Honestly, I have always thought shifts should be when the power is starting to fall off. So if your power flatlines then you want to keep going. When its starts to nose over on the graph is when you want to go to the next gear and let the rpms drop. Sounds like you have a top end screamer.....I spoke to Dave at Yank a while back. I had only run my SS4k a few hundred miles but was pulling the trans and considered going PT4k or PT4400. I briefly went over my combo with him and he asked me where I shifted, to which I responded about 6400. He then asked me where I dropped back to. I told him I didn't know but suspected the low 5s. He stopped me at that point and told me the SS4k was what my combo needed. He explained that with my shift rpm a PT4 or 4400 would not work as their shift extension would be even less on my combo and that 1k rpm drop after shifts is needed for it to perform correctly. He said the PT series is for cars turning higher rpm then what I was. So, I stuck with the SS4k. And, that is why I simply don't recommend the PT converters to most people. But with your combo, it seems perfect.
09-04-2011, 06:41 AM
#5
If track performance is your primary concern, I would go with a CircleD Specialties
230mm in a 4800-5200 stall range. You can give Chris a call and he can spec it out for you. It's really a guess without having additional info such as race weight, cubic inches, cam and/or a dyno sheet. The 230mm will work well and be very efficient in your set up. We ran one in our 4L60E running high 9s/low 10s. We now run a 230mm in our glide and race almost every weekend. It works!
G/L
230mm in a 4800-5200 stall range. You can give Chris a call and he can spec it out for you. It's really a guess without having additional info such as race weight, cubic inches, cam and/or a dyno sheet. The 230mm will work well and be very efficient in your set up. We ran one in our 4L60E running high 9s/low 10s. We now run a 230mm in our glide and race almost every weekend. It works!
G/L
