Mike Murphy

OK, thanks, I'll try that. Just so you know, I don't have the automatic heating. I only have the 4-position switch and 2 red levers. I'll give it a shot and let you know how it goes

KC911

Have you considedered 'backdating the heat', and getting rid of all of that crap...you'll still get PLENTY of heat. It was 20 degrees on the drive in to work this morning, and I only raised my center levers a bit to be comfortable. Here's a link to what I did:

http://forums.pelicanparts.com/showt...light=backdate

Keith
'88 CE coupe

Mike Murphy

Yes, you're the 3rd person to have mentioned this to me, but I guess I'm still a bit unclear that it is worth the change. I am under the impression that to get it to really work well, you have should backdate the heat exchangers or go to new ones (from SSI). Granted, if someone already had to purchase new heat exchangers because the existing ones were failing, I would lean toward doing this. It is clear that the footwell blowers are a generally a joke in terms of reliability. And with all 3 blowers, 4 fuses, 2 relays and a resistor pack, one would save weight and complexity if removed. But if the heat exchanges need to be replaced, you're talking about a lot of money and work just for a little more heat? And then there is the issue of leaving a stock car stock.

KC911

Threre's a reason it's continually mentioned ! On a Carrera, you simply remove the blower in the engine compartment, install a "left side hot air duct" (a 930 part works great, see my pic), and a tube to connect to the rest of the 'stock' system'. Removing the front footwell blowers is optional, and all of this could be returned to stock with minimal effort. You will still get PLENTY of heat, trust me....

Keith
'88 CE coupe

Mike Murphy

So you're saying that there is no need to change the heat exchangers? That would be ideal. Then the only difference is the rear engine compartment blower? Correct me if I'm wrong, but if I remove the rear blower, the front blowers will not turn on. Also, if you attempt to run the front blowers without the rear blower, by bypassing the electronics, I've heard you could fry them (they were not meant to be run independent of the rear blower). So if the rear blower were removed, the front footwell blowers should not be used and might as well be removed. Again, I'm not seeing the added benefit if all I'm removing is the rear blower and duct work. Unless you're talking about a beautiful engine compartment - in that case, it's mandatory!

KC911

I think you've got it now. No changes to the heat exchangers for a Carrera. Yes, if you remove the engine compartment blower, the footwell blowers will be inoperable unless you follow Mysterytrain's (or other's) solution for a workaround (I personally haven't heard of any being fried). In my case, stock heat (with all blowers working) was WAY too effective, and very much overkill. Like I posted earlier, I drove to work in 20 degree weather this morning, and I was still 'toasty' with my backdated setup. That being said, I really did my backdate in order to 'clean up' the engine compartment, and it was part of a 'diet' that I put my Carrera on (losing about 200lbs total). That was the real reason for me

Keith
'88 CE coupe

Mike Murphy

200 lbs?!! Holy...what else did you do? I hope this just wasn't the components we're talking about here. Spare tire removal? What else?

KC911

200 might be pushing it (haven't had her on scales yet) but I'm real close. Heat backdate, total a/c system removal, engine sound deadening pad, spare tire/jack removal, lighter battery, windshield cleaner system removed, stereo system removed, and a few other things here & there....it all adds up. My 'Carrera pig' isn't quite as plump anymore, and it makes a BIG difference

Mike Murphy

I might replace that spare tire with an AAA membership as well...

der Mond

Just one caveat - if the engine overheats the rear blower is set up to auto-run in reverse to help cool things down. Anyone know how much that helps, or hurts to not have it?

KC911

I've never heard of such a thing, and that doesn't make sense to me. If the blower does indeed reverse flow, it's going to pull HOT air from the heat exchangers back inside the engine compartment...not good imo.

Mike Murphy

The rear blower will indeed come on if the engine temperature is too high. It will stuck cold air from the intake/fan area and push it through the heat exchangers. I believe the engine compartment relay circuitry does this. It does this regardless of the positioning of the exhaust valves.

griffiths

Lancaster911

Hey I just found out that my heat DOESN'T work. 20F now. Wish I had your problem now, LOL

J. Brinkley

a couple years and a whole lot of people worked out the footwell work around without the rear blower. It works well. I use one footwell for heat and thats it. Both sides of shroud on the engine are blocked off and my ssi's are open ended. I use the footwell to pull from the rear and push into the cabin on one heat exchanger, Plenty of heat.
There isn't a reverse on the engine compartment blower, but it does come on, or did when new in high heat situations. The footwell blowers in stock configuration with the rear blowers run full time in an idle (very slow) speed. which translates into mild heat in the cabin IF your flappers or levers are not in good working condition. The fuses on the footwell blowers are needed for fire prevention, there are a some stock ones out there that didn't come with a fused link from the factory. They will catch fire, as does the condensor blower next to the battery if not fused.
IF your rear blower is shot, NO heat is the result.
imcarthur has great info on his rennlist site