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Old 01-13-2016, 07:10 PM   #34
picklito
Registered User
 
Join Date: Sep 2013
Location: Vacaville CA
Posts: 510
Re: 4L80E & TH400 Tech.

Quote:
Originally Posted by clinebarger View Post
A Boost Valve & enlarging the feed holes will work, And....You are correct, Do not block Accumulators with a stock to 2800 stall converter.


For Non-Performance-Stock converter transmission orifice sizing, Do Not go bigger than a 50% "Area" increase over the Stock diameter! Shifts will get pretty rough if you do.

Stock 10% 20% 30% 40% 50%
0.040 0.042 0.044 0.046 0.047 0.049
0.045 0.047 0.049 0.051 0.053 0.055
0.050 0.052 0.055 0.057 0.059 0.061
0.055 0.058 0.060 0.063 0.065 0.067
0.060 0.063 0.066 0.068 0.071 0.073
0.065 0.068 0.071 0.074 0.077 0.080
0.070 0.073 0.077 0.080 0.083 0.086
0.075 0.079 0.082 0.086 0.089 0.092
0.080 0.084 0.088 0.091 0.095 0.098
0.085 0.089 0.093 0.097 0.101 0.104
0.090 0.094 0.099 0.103 0.106 0.110
0.095 0.100 0.104 0.108 0.112 0.116
0.100 0.105 0.110 0.114 0.118 0.122
0.105 0.110 0.115 0.120 0.124 0.129
0.110 0.115 0.120 0.125 0.130 0.135
0.115 0.121 0.126 0.131 0.136 0.141
0.120 0.126 0.131 0.137 0.142 0.147
0.125 0.131 0.137 0.143 0.148 0.153

**I have the chart spaced correctly in my reply, But the site will NOT take it without spacing it funny? I hope you can read it.....***
Your chart came through well. Thanks. Some stock data if it's helpful:

2003 Yukon XL 2500 8.1/4L85E/4.1
1-2: .070"
2-3: .075"
3-4: .050"

The holes are so much smaller than I expected, I'm not quite sure what to do. Might just use your recommended .085/.093/.085.
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