Cylinder Head Flow Requirement Calculation: * good estimate for normally asperated performance engines rated at 28 inches hg.
Safe RPM Calculation:
* A good estimate for stock performance engines is 3,500 foot pounds per second; high performance should be rated at 4,000 fps or higher. To increase RPM capibilities, raise fps, which means higher quality pistons, rods, bolts, crank, etc.
Horsepower Required Use the chart below to see how much net horsepower is required to run the elapsed time you want. To obtain the rear wheel horsepower simply multiply the number by 0.85. Example: If your car weight is 3,000 pounds and you want to run a 12 flat, the required net horsepower is 343 or the rear wheel horsepower required is 343 x 0.85 = 292.
ET & SPEED
(seconds @ mph)
VEHICLE WEIGHT (pounds)
2400
2600
2800
3000
3200
3400
3600
3800
4000
4200
16.0 @ 85
116
125
135
145
154
164
174
183
193
203
15.5 @ 88
127
138
149
159
170
180
191
202
212
223
15.0 @ 91
141
152
164
176
187
199
211
223
234
246
14.5 @ 94
156
169
182
194
207
220
233
246
259
272
14.0 @ 97
173
187
202
216
230
245
259
274
288
303
13.5 @ 101
193
209
225
241
257
273
289
305
321
337
13.0 @ 105
216
234
252
270
288
306
324
342
360
378
12.5 @ 109
243
263
283
304
324
344
364
385
405
425
12.0 @ 114
275
297
320
343
366
389
412
435
458
480
11.5 @ 119
312
338
364
390
416
442
468
494
520
546
11.0 @ 124
356
386
416
445
475
505
535
564
594
624
10.5 @ 130
410
444
478
512
546
580
615
649
683
717
10.0 @ 136
474
514
553
593
632
672
712
751
791
830
9.5 @ 143
553
599
645
692
738
784
830
876
922
968
9.0 @ 151
651
705
759
813
868
922
976
1,030
1,084
1,139
8.5 @ 160
772
837
901
965
1,030
1,094
1,159
1,223
1,287
1,352
8.0 @ 170
926
1,004
1,081
1,158
1,235
1,312
1,390
1,467
1,544
1,621
1/8-MILE TO
1/4-MILE CONVERSION TABLE
The following table can be used to estimate what your car would run in the quarter-mile based on your 1/8-mile elapsed time. This table is useful for those of you who run on an 1/8-mile track and would like to know what this time equates to in the 1/4-mile.
NOTE: Please keep in mind that this table is only an estimate of what your 1/4-mile time would be. Different cars with different modifications, such as different rear end gears, will react differently. Your car may be a little quicker than this table shows, or a little slower. Again, this table is not exact, but simply a tool for estimating performance.
1/8-mile
ET
1/4-mile ET
1/8-mile ET
1/4-mile ET
1/8-mile ET
1/4-mile ET
1/8-mile ET
1/4-mile ET
5
7.80
6.8
10.61
8.55
13.34
10.3
16.07
5.05
7.88
6.85
10.69
8.6
13.42
10.35
16.15
5.1
7.96
6.9
10.76
8.65
13.49
10.4
16.22
5.15
8.03
6.95
10.84
8.7
13.57
10.45
16.30
5.2
8.11
7
10.92
8.75
13.65
10.5
16.38
5.25
8.19
7.05
11.00
8.8
13.73
10.55
16.46
5.3
8.27
7.1
11.08
8.85
13.81
10.6
16.54
5.35
8.35
7.15
11.15
8.9
13.88
10.65
16.61
5.4
8.42
7.2
11.23
8.95
13.96
10.7
16.69
5.45
8.50
7.25
11.31
9
14.04
10.75
16.77
5.5
8.58
7.3
11.39
9.05
14.12
10.8
16.85
5.55
8.66
7.35
11.47
9.1
14.20
10.85
16.93
5.6
8.74
7.4
11.54
9.15
14.27
10.9
17.00
5.65
8.81
7.45
11.62
9.2
14.35
10.95
17.08
5.7
8.89
7.5
11.70
9.25
14.43
11
17.16
5.75
8.97
7.55
11.78
9.3
14.51
11.05
17.24
5.8
9.05
7.6
11.86
9.35
14.59
11.1
17.32
5.85
9.13
7.65
11.93
9.4
14.66
11.15
17.39
5.9
9.20
7.7
12.01
9.45
14.74
11.2
17.47
5.95
9.28
7.75
12.09
9.5
14.82
11.25
17.55
6
9.36
7.8
12.17
9.55
14.90
11.3
17.63
6.05
9.44
7.85
12.25
9.6
14.98
11.35
17.71
6.1
9.52
7.9
12.32
9.65
15.05
11.4
17.78
6.15
9.59
7.95
12.40
9.7
15.13
11.45
17.86
6.2
9.67
8
12.48
9.75
15.21
11.5
17.94
6.25
9.75
8.05
12.56
9.8
15.29
11.55
18.02
6.3
9.83
8.1
12.64
9.85
15.37
11.6
18.10
6.35
9.91
8.15
12.71
9.9
15.44
11.65
18.17
6.4
9.98
8.2
12.79
9.95
15.52
11.7
18.25
6.45
10.06
8.25
12.87
10
15.60
11.75
18.33
6.5
10.14
8.3
12.95
10.05
15.68
11.8
18.41
6.55
10.22
8.35
13.03
10.1
15.76
11.85
18.49
6.6
10.30
8.4
13.10
10.15
15.83
11.9
18.56
6.65
10.37
8.45
13.18
10.2
15.91
11.95
18.64
6.7
10.45
8.5
13.26
10.25
15.99
12
18.72
6.75
10.53
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