fixnprsh

Ok, my Carrera is going back together soon and I'm trying to decide wether or not to leave the 50lbs of A/C and heater crap off the car and set it aside if I sell it.

The car will be used for weekend cruises, no daily driving, canyon runs and occasional track time. I can cope with no A/C or heat, but its the other half that will pester me on drives + I'm not sure if I want to go that drastic

Lets hear the arguments!

Peter Zimmermann

No argument, this is simple! Make the A/C and heat functional, or those weekend cruises will be in your Jetta or Tahoe! Ha!

Pete

KC911

OK, so I'm gonna disagree with Pete (that'll be a first, as I respect his opinion & expertise very much), and say ditch it! Of course, I don't live in/near the desert, but it does get hot here in NC, and I hadn't turned my A/C on in two years (I'm a windows down, top open kind of guy), so 'out the door she went' ! As far as heat goes, stock - my car could've roasted a turkey, so backdating still provides a more than adequate heat flow. It does make accessing everything so much easier....I like it !

Peter Zimmermann

LOL! So much for my one annual attempt at being a shrink!

Pete

RoninLB

your AC is no prize to begin with.

Can the AC and console controls. Backdate the heat. Replumb the dash AC vents to fresh air. Store tools and emergency parts in the smugglers box. Add a volt meter and a single CHT ga to the console.

KC911

Could you explain this a bit more? That's the first I've heard/read about doing that...what function do they provide? Thanks!

Keith

Dean Tanner

Explain "backdating". Sorry if I'm clueless.

KC911

"Backdating the heat" on the Carrera's refers to removing the heater blower and the plastic duct work in the engine compartment, and using the fan to push the air over the heat exchangers and on to the cabin of the car. If you compare the two pics I posted above, you can see this on the left hand side of the engine compartment. There are a few different ways to accomplish this, but I replaced the ductwork with a 'left hot air duct' from a 930 and a section of heater hose as is depicted in the picture below. When you remove the engine compartment heater blower, you will also lose functionality of the footwell blowers unless you get creative (like putting a resistor in place of the engine compartment blower). I'm going to remove my footwell blowers also, so obviously I didn't go that route. The fan will still push the heated air into the cabin, but the rate is porportional to your engine rpms. Hope this helps...

RoninLB

only downside is losing defroster at idle.

Otherwise it pushes just as much heat as before +- 2% est. For my yr there is a plastic [afaik] or metal left fan shroud to hose gizmo that sits rearward of the dizzy that has to be adjusted to clear the dizzy. I used the metal piece.

KC911

Hey Ronin, what about the volt meter and CHT...'splain?

Dean Tanner

Thanks KC911,
I have removed my A/C but had not heard of the backdating before. Your engine compartment looks great!

KC911

Thanks Dean! Obviously I spent a bit of time on this, but that's what can happen if you have the '911 sickness', and do a valve adjustment...one thing just led to another

Keith

RoninLB

A volt Meter will enable you to monitor your elec sys where as you really can't do that with an idiot light. The light won't let you know if the regulator crashes and you're now operating under high voltage. You may notice a brighter headlight or you may not. Frying your CDI or other electrics may eventually be the only sign that there is a prob. Hopefully it won't cost you 2 cd's to find out.

A CHT ga is a constant immediate indicator of engine loading and heat. Our oil cooling is usually marginal at best to perform its intended task. Oil temps take awhile to heat up and is a big pia timewise to cool down. Lets say your crossing a desert in the summer. Probably your highest speed is limited by your oil temps. You'll have an indicator of what your oil temps will climb to in 15min and can adjust speed before it happens. Lets say you're doing the Rocky Mts in the summer or even up-state Nevada and are crusing in 5th as you're climbing the mts. The CHT then noticably increases in 5th as a heads up on what's happening. If you do the climb in 4th at 3.4k rpm instead your CHT remains stable. A popular ride is coming into LA from up north in the summer, 90degF + ambiant. As you're hitting those mts at 60-65mph in 5th gearjust outside of LA metro your CHT will rise immediately letting you know what the future oil temp will be. If you then downshift to 4th the CHT drops and your oil stays cool.

fwiw I'll high idle my engine to about 175deg F CHT before taking off in order to avoid cold engine and carbs bs operation, especially in the winter. I also speculate that also helps not loading spark plugs with carbon. There is a few degrees difference among each cylinder head. It's not noticable as far as which single cylinder to use. There is also CHT and EGT x6 exotic monitoring that has become less expensive lately.

all above is a non-pro rant.

KC911

Thanks! I ASSumed that that what you were referring to was somehow related to backdating the heat...now I understand

Keith

RoninLB

yep.. dump the 2 AC controls and add gauges in its place.