Backdate heat on a 930

[freesaints]

I've read a lot of threads on the benefits of backdating the heat (cleans up the engine bay, less weight), but most of the examples were cars other than Turbos. I have heat exchangers on my BB headers/exhaust. Footwell blowers are pretty much inop. My car is a 1987 930 so I have the 10 stage dial between the seats. As is, I only really get heat in the cabin when I switch the knob to 10 and it feels like it leaks in. Don't get me started on the HVAC controls. Is this a thing the people do on 930's?

I'm not that familiar with the plumbing to know what can be gotten rid of, what's kept, etc, and how to go about doing this project. Also, as a newb wrencher, not sure if this is something I can do myself (screwing/tightening/removing/rerouting) or if I'd need a more experienced hand to help (dropping engine, etc). Also, do you keep the HVAC controls the same?

Side note, I've got aftermarket AC (I am in TX) and will need keep that.

[RarlyL8]

930's already have the backdated heat configuration. Most likely your problem is the electronic garbage knob between the seats or stuck heater flap valves.

[David]

I removed the electronic stuff between the seats and installed a simple rubber cover over the hand brake and heat lever. Then I freed up the cable. I had previously removed the blower on the engine and installed a proper block off cover. It’s the first time in 15 years of ownership that I have proper heat.

[freesaints]

Thanks Brian. One of the things I was excited about was getting rid of all the various blower motors and fans but it looks like ours is already simplified?

Has anyone tried an electric unit like a DC Thermal unit? I was talking to another forum member who had gone that route and seems to work for him in a fairly mild climate (as mine is in TX). Seems like it doesn't draw too much current, sits in the smugglers box and ports directly to the center vents with an on/off switch with heat adjustment. Seems like you could remove all the motors, fans and knobs.

Or I could just keep my system and tweak it and let it continue being a rats nest of several different components clogging up the engine bay

[David]

I don’t think you need anymore heat than what the engine fan and exhaust heat exchangers provide especially being in the south.

[timc]

Originally Posted by David

I don’t think you need anymore heat than what the engine fan and exhaust heat exchangers provide especially being in the south.

Agreed, Removed my blower motors in the footwell, all I have is the engine cooling fan blowing air thru B&B Headers, and into the car. Heat runs me out of the car in the winter, including winter drives in the mountains. I can't imagine why you would need the footwell blower's.

[freesaints]

Agreed, I don't need much heat at all. So, you just removed the footwell blowers on both driver and passenger sides? Anything else get removed? I'm assuming all the HVAC controls remained the same?

Still interested if anyone has used a low power electric heater and then just remove all blowers and fans.

[spuggy]

Originally Posted by freesaints

heat exchangers on my BB headers/exhaust. Footwell blowers are pretty much inop.

Maybe your heat control doesn't work right, or the flapper valves stick. That won't help.

That said, factory heat exchangers would have 1/4" ice on the windscreen steaming/melting within 2-3 minutes of starting on a winter's day. You'd have to turn the heat down or open a window after driving for 10 minutes.

GHLs, in comparison, could barely keep the screen from misting up if it rained and you closed the driver's window so as not to get wet - and that in full defrost mode.

And other performance headers are no better. I drove through an arctic storm - and literally stopped at every rest stop for 60 miles to stomp around to get feeling back in my toes.

You know how with old sealed beam headlights in murky conditions, you think the headlights are so bad they're not working, so you switch them off to see the difference? That's the heat with performance headers in 14F ambients. You open the window to check that, yeh, it is actually warmer in the cabin than outside. But, as it turns out, not by much...

I'm pinning my hopes on Classic Retrofit actually packaging the electric heat system they developed with Ruf for other 911s... Unfortunately, they don't seem to be in hurry to do this...

[baloo]

For those with water cooled turbos, wonder whether it's too complicated to run a hose with cutoff valve up into the cabin with a simple heater box/fan assembly adapted out of some other small car?
Hah, I remember turning on my heater in summer in my old Dodge was a way to cool the engine down.
Maybe there already is a kit that can be adapted to the P car?
However, certainly is worth first trying to make the original system work.

[timc]

Originally Posted by freesaints

Agreed, I don't need much heat at all. So, you just removed the footwell blowers on both driver and passenger sides? Anything else get removed?

Nope. Just make sure the following work properly:
1: The slide controls on the dash, to direct heat to Upper Dash or Floor
2: Fresh Air Slide - I use this to help control the heat, as it really gets to hot.
3: Heater Control Between seat properly operates the heater flaps under the car.
4: Hoses between Heat Exhanger and Heater flaps are in good condition and they are secure.
5: Hoses between Fan Shroud and Heat Exchangers.

If the above work, I can't imagine you need more living in the south.

[freesaints]

Oh yeah, no need for more heat on my end. What I've got works fine even with some parts inop. I'm trying to figure out if I can remove some of those components, simplify the schematics and clean up the engine bay and yet retain the adequate heat that I already get.

[flightlead404]

It seems fairly simple for someone with a modicum of electrics skill to make a drop-in replacement solution for the auto-heat that would work well and look stock. A cheap arduino and a couple of stepper motors and a thermister would be all that was needed.

[baloo]

Originally Posted by flightlead404

It seems fairly simple for someone with a modicum of electrics skill to make a drop-in replacement solution for the auto-heat that would work well and look stock. A cheap arduino and a couple of stepper motors and a thermister would be all that was needed.

Are you talking about making an electric heater replacement, or a better heat control mechanism?
Either way, let us know when you've done it. (Anyone who knows what an "auduino" is, MUST know how to do this, right?)

[freesaints]

Keyword being "modicum of electrical skills", which still exceeds my electrical skills. fwiw, I spoke to another Pelican member who used one of the DC Thermal setups and he says it's been great. He too is in a fairly mild climate so the heater needs are minimal (as are mine) and for that, it's been an adequate heat output. He's got his in the smugglers box with two hoses going to the cabin with two switches (on/off and fan speed) tucked under the dash. Looks like it replaces the whole stock setup. Trying to see other solutions to cleaning up the archaic heating setup in these old cars with all the blowers, relays, motors, etc.

[baloo]

Originally Posted by freesaints

Keyword being "modicum of electrical skills", which still exceeds my electrical skills. fwiw, I spoke to another Pelican member who used one of the DC Thermal setups and he says it's been great. He too is in a fairly mild climate so the heater needs are minimal (as are mine) and for that, it's been an adequate heat output. He's got his in the smugglers box with two hoses going to the cabin with two switches (on/off and fan speed) tucked under the dash. Looks like it replaces the whole stock setup. Trying to see other solutions to cleaning up the archaic heating setup in these old cars with all the blowers, relays, motors, etc.

FreeSaints - what is a "DC Thermal setup"? Do you have a brand or a pic of what this looks like or how to search for one.
Thanks.

[freesaints]

This is the setup he runs. http://dcthermal.com/product/sa12-5000-12-volt-brushless-cab-heater/

To his admission, it's only enough to knock the fog off the front windshield and provide a minimum of heat, which is all he needs. Car is not very airtight too. Runs directly off the battery and he said he's run it for 3 hours straight no problem. There's also beefier units if more heat is required but not sure about the power draw from the battery if you go bigger and what that might entail.

[David]

Here's few pics of my set up. The only blower is the main engine fan. The only heat is to the front windshield defroster vents but it provides plenty of heat for me in Texas. Granted I don't drive when temps are below freezing or even close to freezing. I've also attached a pic of the rubber cover that replaced the heater controls between the seats.

[flightlead404]

Originally Posted by baloo

Are you talking about making an electric heater replacement, or a better heat control mechanism?
Either way, let us know when you've done it. (Anyone who knows what an "auduino" is, MUST know how to do this, right?)

I better heat control mechanism.

I could certainly do it, but I have a few projects ahead of it and my auto-heat works perfectly