gear/tire size vs rpm ?

[dumpycapri85]

So I got a new car that will be a track mostly beater (we will call it the dumpyGT) , and I have a question about what rpm I can exspect to see thru the traps in the 1/8 . Its an 85 fox and has a built rear with 5.13 gears . With a c4 , tight converter and 28" tires whats the aprox rpm you think I would see . Anybody with a like combo please chime in . Blast away .

[mustangguy289]

Depends on how much power it is making.

[mustangguy289]

But probably 15k rpm

[Doug Hatton]

Trap Speed 5.13
60 3694.6
61 3756.2
62 3817.8
63 3879.4
64 3940.9
65 4002.5
66 4064.1
67 4125.7
68 4187.3
69 4248.8
70 4310.4
71 4372.0
72 4433.6
73 4495.1
74 4556.7
75 4618.3
76 4679.9
77 4741.5
78 4803.0
79 4864.6
80 4926.2
81 4987.8
82 5049.3
83 5110.9
84 5172.5
85 5234.1
86 5295.6
87 5357.2
88 5418.8
89 5480.4
90 5542.0
91 5603.5
92 5665.1
93 5726.7
94 5788.3
95 5849.8
96 5911.4
97 5973.0

[Doug Hatton]

That's with a 28" tall tire, in 3rd gear (1:1) with 5.13's. MPH shown on left, RPM on right.

[dumpycapri85]

Thats not to bad . I gues I will have to put it together and test it . Its a 351 with 1 kit for now .