- Joined
- May 27, 2001
- Messages
- 10,866
How much rpm drop should I get on the shift?
I am seeing 400-500 on the Datalog.
Thanks in advance!
I am seeing 400-500 on the Datalog.
Thanks in advance!
T-400 Converter ?
- Thread starter John Wilde
- Start date
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- Joined
- May 27, 2001
- Messages
- 10,866
Thanks I think we are going to try a 10 inch pro mod converter.
- Joined
- May 27, 2001
- Messages
- 10,866
8 inch Art Carr:
- 8800 through the traps @ 167 MPH
- 3.89 Gears 29.5 inch tall tire
- shifts at 8600 ish and rpm drops to about 8200
-Flashing around 7000
9 inch ATI Pro Mod:
- 8400 through the traps @ 166
- 3.89 Gears 29.5 inch tall tire
-rpm dropping about 800 to 1000 on shifts
-Flashing about 6700RPM
- 8800 through the traps @ 167 MPH
- 3.89 Gears 29.5 inch tall tire
- shifts at 8600 ish and rpm drops to about 8200
-Flashing around 7000
9 inch ATI Pro Mod:
- 8400 through the traps @ 166
- 3.89 Gears 29.5 inch tall tire
-rpm dropping about 800 to 1000 on shifts
-Flashing about 6700RPM
John,
I calculated both converters using 2 different methods. The 8" comes out to aprox 15-16% slip. The 9" comes out to aprox 11-12.5% slip. The second isnt too bad for using an 88 turbo (whats listed in your sig). If you could stand some less stall/spool on the line obvioulsy you will pick up on the big end with a tighter converter. Unless the current ones you listed are being pushed through on the big end then maybe a larger dia 10" will hold better and hopefully keep your existing stall on the line.
I calculated both converters using 2 different methods. The 8" comes out to aprox 15-16% slip. The 9" comes out to aprox 11-12.5% slip. The second isnt too bad for using an 88 turbo (whats listed in your sig). If you could stand some less stall/spool on the line obvioulsy you will pick up on the big end with a tighter converter. Unless the current ones you listed are being pushed through on the big end then maybe a larger dia 10" will hold better and hopefully keep your existing stall on the line.
- Joined
- May 27, 2001
- Messages
- 10,866
Thanks for your help.
This is not for my junk, which does not run yet
This is for a friend's car with a twin 76mm SBC.
We are driving through the converter.
A couple converter builders told me that a rule of
thumb is that a T-400 Converter should drop to
about 200-400PRM above the flash stall point on the
shift.
What I think we will be trying is a 10 Neal Chance
that will stall about 5500RPM. In that case we will
shift aroung 8800 and the rpm should drop to about
5900. This will allow us to use the power band of the motor
and not just a narrow peak.
We are also going to a 3.60 pro gear to help slip the car out of the hole. Our MPH should go up to the 170s at low boost.
This is not for my junk, which does not run yet
This is for a friend's car with a twin 76mm SBC.
We are driving through the converter.
A couple converter builders told me that a rule of
thumb is that a T-400 Converter should drop to
about 200-400PRM above the flash stall point on the
shift.
What I think we will be trying is a 10 Neal Chance
that will stall about 5500RPM. In that case we will
shift aroung 8800 and the rpm should drop to about
5900. This will allow us to use the power band of the motor
and not just a narrow peak.
We are also going to a 3.60 pro gear to help slip the car out of the hole. Our MPH should go up to the 170s at low boost.
