02-19-2019, 01:46 PM | #161 |
Mugwump
Join Date: Oct 2003
Carmudgeonly Ride: E46 330i, Chevy Colorado, Tesla Model 3
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That is all just frigging awesome.
I want a Haltech. |
02-19-2019, 01:53 PM | #162 |
No more BMWs
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Carmudgeonly Ride: Ram, MS3, CX-5, RX-8
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02-19-2019, 02:41 PM | #163 | |
Alphanumeric
Join Date: Aug 2005
Carmudgeonly Ride: 981S, 340i
Posts: 9,585
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You mentioned launch/traction earlier. Isn't that more than the ECU? So you will incorporate the ABS sensors as well. I assume no yaw, that's left to the old gray matter. |
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02-19-2019, 02:49 PM | #164 | |
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Yes, the ECU ties into the CAN bus so it should technically be able to read wheel speed from the ABS system. I don't desire yaw control, only for the computer to manage front-rear wheel speed differential with a method that doesn't create a bunch of turbo lag. |
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02-19-2019, 03:45 PM | #165 | |
Alphanumeric
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02-19-2019, 09:00 PM | #166 |
No more BMWs
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I expect the tuning of all this to be much more difficult and time consuming than the wiring, which is fairly formulaic and rote.
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02-21-2019, 09:46 PM | #167 |
No more BMWs
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I'd like to go on a diversion called "fun with electricity" for a moment if I may.
There are a lot of similarities between the RX-8 and the MX-5 and this includes the way the cars are wired but if you look closely there are some differences that can trip you up. Example: the thermostatically controlled fans. Here are two wiring diagrams, first from the MX-5 and second from the RX-8. Background: I installed the radiator from the MX-5 as well as the fan from the MX-5 into my RX-8. The fuse / relay box is from the RX-8. At first glance, everything looks okay. Both cars have three fan relays and both cars have four total connections to the fans (i.e. there are two motors, each with a power and a ground). But upon closer inspection they work slightly differently. It took me a while to understand what was going on here but here goes. The MX-5 first. There are three fan speeds. Low has half of the windings powered with +12V switched through Relay 1 and the fixed ground wire. Medium is the same, +12V switched through relay 1, but relay 3 is also energized, shorting the second set of windings (presumably higher current) to ground. High energizes all three relays, so Relays 1 and 2 energize the high-side windings and relay 3 grounds the low side winding. Blue is "low", green is "medium" and red is "high" Looking at the RX-8 diagram, it's a bit different. Relay 3 is actually a SPDT relay. Just wiring in the MX-5 fans with this configuration won't work, because if you look closely, just energizing relay 1 won't give motor 1 a path to ground. Well there is one, but it's in series with motor 2. Follow the green wire from the low side of motor 1 and it goes to the high side of relays 2 and 3. Relay 3's low side connects to the second cooling fan motor. You'll also notice that the RX-8 only has two control wires going to the relays, whereas the MX-5 has three. I really didn't want to add a control wire, and I didn't need to. What I did was actually very simple. I cut the green wire where it exited the fan motor and connected it to ground. This means when relay 1 is energized, it will drive the first set of windings and run the motor on low speed. Then when Relay 3 is energized, the second set of windings will be powered and the motor will run on high. I've lost the medium speed setting, but I don't see this being a problem. |
02-21-2019, 10:42 PM | #168 | |
Relic
Join Date: Oct 2003
Location: Bethesda, MD
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__________________
2011 M3 2006 Sierra 2500HD 4WD LBZ/Allison 2004 X5 3.0i 6MT 1995 M3 S50B32 1990 325is 1989 M3 S54B32 Hers: 1989 325iX 1996 911 Turbo |
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02-21-2019, 11:13 PM | #169 |
Mugwump
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Can you explain the non-insulated part? Don't you need to then insulate them?
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02-22-2019, 07:12 AM | #170 |
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Yes, you insulate them with shrink wrap.
The reason I don't like the ones that have plastic surrounding them (i.e. insulated butt splices) is they're too fat and as a result make the harness bulky. These are hardly bigger than the insulated wire, even after shrink wrapping them. |
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