3 knob HVAC control upgrade
09-09-2015, 03:43 PM
#46
Rennlist Member
I dunno why they picked 5spd, as it's a severe minority of the vehicles available for them to sell into.
IMHO, replace the upper trans cooler fitting to the radiator with a straight fitting like the bottom hose, and just run the radiator cooler.
Cars with much more HP run only the 1 cooler with no issues...little chance that I will be pouring long term heaps of WOT Autobahn energy into the transmission in my lifetime, or anyone else...even in Germany anymore...
It's not even that efficient of a cooler either.
Then your Rogerbox can fit the 5spd condenser just fine.
09-29-2015, 10:35 PM
#47
Rennlist Member
Yep, I said wouldn't do it, but I find myself going through the steps of making a newer 3 **** hvac control work with the 928 system. I'm using a 2010-12 Nissan Sentra control because the **** styling works with my louvers, they feel nice, and they fit in the width between the console side rails. These are cheap and plentiful on ebay. I did look at using Arduino to be the interface between this and the 928, but that involves programming, and the size would be limited to the base unit plus shields required. I wanted something that could fit within the same profile as the 928 hvac head so it could work with my 2X DIN stereo mount design. Just checked, and these ***** are slightly larger dia than the face profile of the slider hvac. I wasn't thinking of just replacing the stock with this only, but it might be possible with an adapter bracket - this might be ideal for a printed plastic part. So, the plan is to use this control (or possibly others, as long as it fits the space, and the circuit traces can be figured out), and have it feed through a new circuit board with outputs to the 928, or possibly other cars that use solenoids to control the vac pots. This has PWM for the fan speed, so the PWM fan amplifier will need to be installed into the airflow after the blower fan. I hope to use all the functions on this control, including the rear defrost button. So far, the board design is about 90% done, and getting ready to order my first kit of parts and proto boards, and I have the Sentra board tapped for the circuits I need. It originally uses CanBus to control the airflow motors, with a control logic on this board. I'm using the Sentra logic, just tapping into various outputs on the hardware which will go to my new board. This is not ready for prime time yet, but I think the design is valid, and it has some flexibility for different mixing of airflows, plus a small user customizing area on the board. I just need to prove it works! Teaser pics included.....
I
10-12-2015, 09:38 PM
#49
Rennlist Member
10-13-2015, 10:20 AM
#51
Pro
Thread Starter
There has been progress! Currently waiting for first version circuit boards to arrive here, plus several sets of *****/buttons - hopefully late this week for both. With these plus a few more Digikey parts, I'll be able to assemble a real test unit, and verify my Arduino code, then trial it in my car. Once the board is proven, then will design a housing for it, and hoping to design a front facia that will allow it to directly replace a stock slider head, in the stock location. Realistically, these first units will probably not be allowed into the field as they will be testing for me only, and the fixes will be applied to the V2 design - that will be for production (I hope!). Of course, this will work with my 2X DIN stereo bracket, but only for the one designed for these rotary ***** - not sure if it will work with older brackets I have made - need to look at that. So, plenty done, but still more to do.....
10-17-2015, 10:47 AM
#52
Pro
Thread Starter
Got my first circuit boards - first time I have designed one of these - and had a big grin when all the parts fit! Still need to assemble and test to prove my circuits, but things are moving forward....
10-17-2015, 02:10 PM
#56
Rennlist Member
Great!
10-17-2015, 08:10 PM
#58
Pro
Thread Starter
Not sure yet if it will fit the 2X DIN brackets already made. The 3 ***** have an OD just slightly larger than the height of the stock slider unit opening, so facing that challenge. Will be working on that next after the board assembly is proven.