Sanden Compressor for AC

gr8vet

gr8vet

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After returning from the HRPT this year, it was HOT! The old GM compressor just could not keep up. Spoke with a couple of guys that had done nothing but replace the compressor and dryer with a Sanden 508, said it worked great and had to actually turn A/C down. Any of you guys done this? I really do not care to start replacing the entire setup.

thanks
tt
 
gr8vet said:
After returning from the HRPT this year, it was HOT! The old GM compressor just could not keep up. Spoke with a couple of guys that had done nothing but replace the compressor and dryer with a Sanden 508, said it worked great and had to actually turn A/C down. Any of you guys done this? I really do not care to start replacing the entire setup.

thanks
tt
Click to expand...

Had to get outta the house yesterday, went over to visit my welder buddy across the river....went to leave...it was 115f in the vette, top down....put on the HVAC, still top down, ambient at 110f anyway.....system on constant recirc, only option being a vert with all the crap sealed/removed...and so the discharge came down to 80f in the cab....still top down in the sun....

but I do wonder if I should pull it all apart and insulate hell outta the box on the inside, much less re orient the fans to blow back over the engine instead of downward from the radiator path....

:twitch::confused2::skeptic:
 
Things are alot different when you get on the road for a long time I found. If we stopped and let everything cool down, left the hood propped up with about a 1-2 inch gap in back, immediately cut the air on, windows up, run about 75 on Interstate, we would stay comfortable. Our feel like temp on Saturday coming home was 112 F. If we got into stop and go at red light traffic, screw it, it would get hot in cab fast. Water temp never made it over 115 even in traffic. It's serious "heat soak" of the firewall when not moving fast. Our warm weather came quickly this year.
 
gr8vet said:
Things are alot different when you get on the road for a long time I found. If we stopped and let everything cool down, left the hood propped up with about a 1-2 inch gap in back, immediately cut the air on, windows up, run about 75 on Interstate, we would stay comfortable. Our feel like temp on Saturday coming home was 112 F. If we got into stop and go at red light traffic, screw it, it would get hot in cab fast. Water temp never made it over 115 even in traffic. It's serious "heat soak" of the firewall when not moving fast. Our warm weather came quickly this year.
Click to expand...

Wife complains of the 'hot foot' syndrom, but I don't notice it much, used to it, I guess...I have done firewall insulation attempts and it should be almost as good as the factory shit, I would think....:amazed: but clearly something is missing....I wonder if maybe it's worth pulling the evap housing down again to insulate the inside of it...not done some years ago, last time around...

wonder what to wrap all this in....like on the camper/van project, the old dog house insulation is ragged, and so not really much missing, but what to put it back in place with?? almost same sort of issue....exhaust headers really close to the dog house, so need it be really high temp shit...but what GLUE will hold it without being a fire hazard???

:cussing:
 
mrvette said:
Wife complains of the 'hot foot' syndrom, but I don't notice it much, used to it, I guess...I have done firewall insulation attempts and it should be almost as good as the factory shit, I would think....:amazed: but clearly something is missing....I wonder if maybe it's worth pulling the evap housing down again to insulate the inside of it...not done some years ago, last time around...

wonder what to wrap all this in....like on the camper/van project, the old dog house insulation is ragged, and so not really much missing, but what to put it back in place with?? almost same sort of issue....exhaust headers really close to the dog house, so need it be really high temp shit...but what GLUE will hold it without being a fire hazard???

:cussing:
Click to expand...

That is funny about the feet, my wife put her feet in the seat and under her back side and I ask, " are your feet getting hot"? No, my A$$ is sweating! I'm trying to ventilate!" :clap:

What I have done: I figured out that I had a couple of holes in firewall, sealed them all up. I have three layers of dynamax in floor board. Two layers of same on exterior firewall, wrapped the fan/airbox with two layers. Two layers through tunnel to rear. Wrapped headers, and have side pipes. We both work together in our print shop so being hot is nothing new, just sux when you get all sweaty. I really believe if the Sanden compressor works out I should be good. I am told that the 134 needs more than the older GM compressors can produce to get a more effective cooling.
 
gr8vet said:
After returning from the HRPT this year, it was HOT! The old GM compressor just could not keep up. Spoke with a couple of guys that had done nothing but replace the compressor and dryer with a Sanden 508, said it worked great and had to actually turn A/C down. Any of you guys done this? I really do not care to start replacing the entire setup.

thanks
tt
Click to expand...

If there is enough charge for the compressor to cycle, I doubt just changing the compressor will have any effect.
I ran R-12 in the 81, had it converted to 134, then switched it back. It works better with R12.
As explained to me, The "system" is designed around the refridgerent.
R-134 uses a different design of condenser, and does not interchange well.
I found with the later cars, R12 with a C-4 fan, and good insulation is the ticket. Heat shielding under the floor pans helps alot.
The classic air system works well too, as it moves the plenum out of the engine compartment. A stupid idea to begin with.
Good luck.
 
big2bird said:
gr8vet said:
After returning from the HRPT this year, it was HOT! The old GM compressor just could not keep up. Spoke with a couple of guys that had done nothing but replace the compressor and dryer with a Sanden 508, said it worked great and had to actually turn A/C down. Any of you guys done this? I really do not care to start replacing the entire setup.

thanks
tt
Click to expand...

If there is enough charge for the compressor to cycle, I doubt just changing the compressor will have any effect.
I ran R-12 in the 81, had it converted to 134, then switched it back. It works better with R12.
As explained to me, The "system" is designed around the refridgerent.
R-134 uses a different design of condenser, and does not interchange well.
I found with the later cars, R12 with a C-4 fan, and good insulation is the ticket. Heat shielding under the floor pans helps alot.
The classic air system works well too, as it moves the plenum out of the engine compartment. A stupid idea to begin with.
Good luck.
Click to expand...

I"m still wondering about remounting the Spals to blow straight backwards over the engine, instead of down towards the balancer/crank....

anyone with any experiences on that??
 
gr8vet said:
After returning from the HRPT this year, it was HOT! The old GM compressor just could not keep up. Spoke with a couple of guys that had done nothing but replace the compressor and dryer with a Sanden 508, said it worked great and had to actually turn A/C down. Any of you guys done this? I really do not care to start replacing the entire setup.

thanks
tt
Click to expand...

There is nothing magical about the Sandens.
I agree with your friends, but in the vast majority of cases the old compressor is just worn out and any new compressor will give better results. Remember too, that the original A6 has a much higher displacement than the 508 so it is impossible for the 508 to perform better in that case. Also the reason people feel they lug the engine less.

To insulate the evap box,
You can try this foil peel and stick, but it works best on the outside directly reflecting the heat.
http://www.bestmaterials.com/detail.aspx?ID=14791

You can also add ceramic to ANY liquid coating including any paint and resin. Here is a sample but not thee cheapest supplier.

http://www.hytechsales.com/insulating_paint_additives.html

As mentioned heat shields with air space behind them will help too.
The biggest single plus for 134 is to change to a parallel flow condenser to dump the heat, same as using a good alum radiator vs brass, more efficient.
 
Good deal! Thanks for the info. I did add another can of 134 and things really cooled down. I also found that I had sealed off the return air vent to system from cab, so my airflow was dang near nothing. It blows like a hurricane now. More and more I read, I agree 100%, the trick is the condenser to help the 134, that would be the best thing to swap out first. Also, the consensus is NEVER use a rebuilt compressor due to possible inferior parts. I have a rebuilt compressor, built specifically for GM, sold by a GM dealer. Good or bad??? Seems to working much better now.

I am running about 45 psi on low side but the system does not cycle. Should I add more freon? No clue where things are at now as far as quantity. Wondering if I should empty system and just add specified total weight?

Thanks gain for all the input!
tt
 
010752 said:
You can also add ceramic to ANY liquid coating including any paint and resin. Here is a sample but not thee cheapest supplier.

http://www.hytechsales.com/insulating_paint_additives.html
Click to expand...

Cool - yep that was intended!
Have you used this additive? Tried it on headers? Thoughts?
Seems like there are engine paints out there that meet the high temp - POR-15 etc that are brushable - and this might be a great option.
Sorry for the diversion!

Cheers Jim
 
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