SpeedCal Instructions

Dallas Mustang's SpeedCal is a highly flexible, easily adjustable electronic speedometer calibrator. With SpeedCal, you can maintain accurate speedometer readings with virtually any combination of rear tire size and gear ratio.

Time Required: Approximately 1 hour.

Tools Required: Basic hand tools, Multi-meter probe, Ratio Multiplier Table

Pre-installation Setup:

Using the Ratio Multiplier Table at the end of these instructions, or the DMP SpeedCal worksheet, determine the correct ratio multiplier and enter the binary code into the SpeedCal. Then, attach the cover using the supplied screws. The picture below shows the dipswitch settings of 1001001000 for a 3.27 to 3.73 gear swap.

Installation Steps:

Remove the vehicle negative battery cable.
Inside the vehicle passenger compartment, remove the shifter knob, outer shift boot, and inner shift boot. It is generally easier to disconnect the cigarette and traction control (if applicable) switches from the plastic housing and set the housing aside to facilitate installation. The outer boot is merely snapped in place and can be easily removed by grasping firmly on each side of the shifter and pulling straight up and away from the console. The inner boot uses four 8mm bolts for attachment.
Route the SpeedCal harness down the driver's side of the transmission and re-install the inner boot. Route the SpeedCal harness to the back of the inner boot.
Connect the Red wire of the SpeedCal to the cigarette lighter hot wire with the provided scotch lock. As an example, on a '99 and up late model Mustang this should be a Blue/White wire.
Center the SpeedCal ahead of the shifter and reinstall the outer boot and shifter knob.
Under the vehicle, locate and remove the VSS connector on the driver's side of the transmission.
Using and small flat bladed screwdriver or a thin punch, CAREFULLY remove the red contact lock inside the connector shell. CAREFULLY slide the screwdriver / punch down the side of each contact to disengage the contact retainer and remove both contacts from the connector shell.
Place the VSS connector shell removed in the previous step onto the SpeedCal Blue and Green wires. Keying is not critical.
Push the contacts into the connector shell until the contact retainers engage. Usually, a faint ÒclickÓ will be heard for each contact retainer engagement. Re-insert the red contact lock.
Reconnect the VSS connector that is now installed on the SpeedCal to the transmission.
In the vehicle harness VSS wire pair, determine which of the two wires is the ground wire. On a late '94-'98 model Mustang this should a Pink/Orange wire. On a '99 and up, this should be a Gray/Red wire.
Find the supplied connector shell in the SpeedCal installation kit. Using the connector shell keys as a guide, align the ground wire so it will mate with the SpeedCal Gray wire when the two connectors are mated.
Insert the remaining vehicle harness wire into the remaining connector location. Again, push the contacts into the connector shell until the contact retainers engage. A faint "click" should be heard upon engagement. Insert the supplied red key lock into the connector shell.
Connect the vehicle harness to the SpeedCal connector. Insure the contacts align per Step 13. Tie the excess wiring and cable harness with the supplied E-Z Ties.
Reconnect the battery terminal and drive the vehicle. Insure the vehicle speedometer is functional. If possible, pace the vehicle against a vehicle with a known reasonably accurate speedometer.

Notes:

If the vehicle speedometer ever malfunctions, disconnect the vehicle negative battery terminal, wait approximately 30 seconds, and reconnect the battery. This is required to Òcycle powerÓ to the SpeedCal as the cigarette lighter is and unswitched accessory outlet.
When wired per these instructions, the SpeedCal is always powered. The SpeedCal power consumption is minimal, however, and will not introduce noticeable vehicle battery power drain. It should be noted that portions of the Vehicle EEC are also connected in this fashion so this is not an unusual installation procedure. If the installer desires to use a switched accessory outlet, consult the shop manuals particular to the target vehicle and choose a switched accessory signal to tie into. The SpeedCal will perform just the same from switched power as from unswitched power.
The DMP SpeedCal is capable of speedometer adjustments in increments of 0.2% and will provide accurate vehicle speed data above the displayed speedometer value (160 mph for a late model Mustang Cobra). In order to retain this accuracy care should be taken in determining the correct binary code as the SpeedCal cannot provide accurate speedometer readouts with an incorrect ratio multiplier selection.
The supplied ratio table will provide reasonably accurate ratio settings for a typical gear swap. For more detailed settings, which also include tire size adjustments, refer to the DMP web site at www.dallasmustang.com and use the DMP SpeedCal worksheet to determine the desired ratio multiplier.

Stock Ratio	New Ratio	Mult. Value	Hexadecimal Value	Switch Settings	Count Value	Intermed. Value
3.27	6.33	1.936	0F8	0011111000	248	248
3.27	6.20	1.896	0F3	0011110011	243	243
3.27	6.14	1.878	0F0	0011110000	240	240
3.27	6.00	1.835	0EB	0011101011	235	235
3.27	5.83	1.783	0E4	0011100100	228	228
3.27	5.67	1.734	0DE	0011011110	222	222
3.27	5.57	1.703	0DA	0011011010	218	218
3.27	5.50	1.682	0D7	0011010111	215	215
3.27	5.43	1.661	0D5	0011010101	213	213
3.27	5.30	1.621	0CF	0011001111	207	207
3.27	5.29	1.618	0CF	0011001111	207	207
3.27	5.25	1.606	0CE	0011001110	206	206
3.27	5.14	1.572	0C9	0011001001	201	201
3.27	4.88	1.492	0BF	0010111111	191	191
3.27	4.86	1.486	0BE	0010111110	190	190
3.27	4.78	1.462	0BB	0010111011	187	187
3.27	4.71	1.440	0B8	0010111000	184	184
3.27	4.57	1.398	0B3	0010110011	179	179
3.27	4.56	1.394	0B2	0010110010	178	178
3.27	4.50	1.376	0B0	0010110000	176	176
3.27	4.44	1.358	0AE	0010101110	174	174
3.27	4.30	1.315	0A8	0010101000	168	168
3.27	4.22	1.291	0A5	0010100101	165	165
3.27	4.11	1.257	0A1	0010100001	161	161
3.27	4.10	1.254	0A0	0010100000	160	160
3.27	4.00	1.223	09D	0010011101	157	157
3.27	3.91	1.196	099	0010011001	153	153
3.27	3.89	1.190	098	0010011000	152	152
3.27	3.80	1.162	095	0010010101	149	149
3.27	3.75	1.147	093	0010010011	147	147
3.27	3.73	1.141	092	0010010010	146	146
3.27	3.70	1.131	091	0010010001	145	145
3.27	3.64	1.113	08E	0010001110	142	142
3.27	3.56	1.089	08B	0010001011	139	139
3.27	3.55	1.086	08B	0010001011	139	139
3.27	3.50	1.070	089	0010001001	137	137
3.27	3.27	1.000	080	0010000000	128	128
3.27	3.10	0.948	079	0001111001	121	121
3.27	3.08	0.942	079	0001111001	121	121
3.27	2.73	0.835	06B	0001101011	107	107
Stock Ratio	New Ratio	Mult. Value	Hexadecimal Value	Switch Settings	Count Value	Intermed. Value
3.08	6.33	2.055	107	0100000111	263	263
3.08	6.20	2.013	102	0100000010	258	258
3.08	6.14	1.994	0FF	0011111111	255	255
3.08	6.00	1.948	0F9	0011111001	249	249
3.08	5.83	1.893	0F2	0011110010	242	242
3.08	5.67	1.841	0EC	0011101100	236	236
3.08	5.57	1.808	0E7	0011100111	231	231
3.08	5.50	1.786	0E5	0011100101	229	229
3.08	5.43	1.763	0E2	0011100010	226	226
3.08	5.30	1.721	0DC	0011011100	220	220
3.08	5.29	1.718	0DC	0011011100	220	220
3.08	5.25	1.705	0DA	0011011010	218	218
3.08	5.14	1.669	0D6	0011010110	214	214
3.08	4.88	1.584	0CB	0011001011	203	203
3.08	4.86	1.578	0CA	0011001010	202	202
3.08	4.78	1.552	0C7	0011000111	199	199
3.08	4.71	1.529	0C4	0011000100	196	196
3.08	4.57	1.484	0BE	0010111110	190	190
3.08	4.56	1.481	0BE	0010111110	190	190
3.08	4.50	1.461	0BB	0010111011	187	187
3.08	4.44	1.442	0B9	0010111001	185	185
3.08	4.30	1.396	0B3	0010110011	179	179
3.08	4.22	1.370	0AF	0010101111	175	175
3.08	4.11	1.334	0AB	0010101011	171	171
3.08	4.10	1.331	0AA	0010101010	170	170
3.08	4.00	1.299	0A6	0010100110	166	166
3.08	3.91	1.269	0A2	0010100010	162	162
3.08	3.89	1.263	0A2	0010100010	162	162
3.08	3.80	1.234	09E	0010011110	158	158
3.08	3.75	1.218	09C	0010011100	156	156
3.08	3.73	1.211	09B	0010011011	155	155
3.08	3.70	1.201	09A	0010011010	154	154
3.08	3.64	1.182	097	0010010111	151	151
3.08	3.56	1.156	094	0010010100	148	148
3.08	3.55	1.153	094	0010010100	148	148
3.08	3.50	1.136	091	0010010001	145	145
3.08	3.27	1.062	088	0010001000	136	136
3.08	3.10	1.006	081	0010000001	129	129
3.08	3.08	1.000	080	0010000000	128	128
3.08	2.73	0.886	071	0001110001	113	113
Stock Ratio	New Ratio	Mult. Value	Hexadecimal Value	Switch Settings	Count Value	Intermed. Value
2.73	6.33	2.319	129	0100101001
2.73	6.20	2.271	123	0100100011
2.73	6.14	2.249	120	0100100000
2.73	6.00	2.198	119	0100011001
2.73	5.83	2.136	111	0100010001
2.73	5.67	2.077	10A	0100001010
2.73	5.57	2.040	105	0100000101
2.73	5.50	2.015	102	0100000010
2.73	5.43	1.989	0FF	0011111111
2.73	5.30	1.941	0F8	0011111000
2.73	5.29	1.938	0F8	0011111000
2.73	5.25	1.923	0F6	0011110110
2.73	5.14	1.883	0F1	0011110001
2.73	4.88	1.788	0E5	0011100101
2.73	4.86	1.780	0E4	0011100100
2.73	4.78	1.751	0E0	0011100000
2.73	4.71	1.725	0DD	0011011101
2.73	4.57	1.674	0D6	0011010110
2.73	4.56	1.670	0D6	0011010110
2.73	4.50	1.648	0D3	0011010011
2.73	4.44	1.626	0D0	0011010000
2.73	4.30	1.575	0CA	0011001010
2.73	4.22	1.546	0C6	0011000110
2.73	4.11	1.505	0C1	0011000001
2.73	4.10	1.502	0C0	0011000000
2.73	4.00	1.465	0BC	0010111100
2.73	3.91	1.432	0B7	0010110111
2.73	3.89	1.425	0B6	0010110110
2.73	3.80	1.392	0B2	0010110010
2.73	3.75	1.374	0B0	0010110000
2.73	3.73	1.366	0AF	0010101111
2.73	3.70	1.355	0AD	0010101101
2.73	3.64	1.333	0AB	0010101011
2.73	3.56	1.304	0A7	0010100111
2.73	3.55	1.300	0A6	0010100110
2.73	3.50	1.282	0A4	0010100100
2.73	3.27	1.198	099	0010011001
2.73	3.10	1.136	091	0010010001
2.73	3.08	1.128	090	0010010000
2.73	2.73	1.000	080	0010000000