Backdate / Modify Heat on Turbo Carrera

polizei · 04:57 AM

Hello All,

I'm tying up the loose ends from the turbo project on my '87 Carrera, and I was hoping some of you could pass on your advice regarding how to modify the heating system for my setup.

This past winter, I didn't get any heat coming out of the vents on the dash, and, from what I've read, that is usually due to the heater blower in the engine malfunctioning. The foot-well heat proved effective enough to carry me through the winter, so I am entirely comfortable with removing the rear blower system and tweaking the system to allow for the continued operation of the foot-well blowers (Help! Does anyone understand the footwell blower circuit?).

I understand that what would typically be suggested in my case is to pick up the 930 heater duct (http://rennlight.com/duct/) and run a hose to the Y-pipe which comes up through the engine tin next to the distributor, ultimately connecting to the heat exchangers. However, I have two issues:

1. I'll be running the 2-head 964 twin-plug distributor which gets in the way of this Y-pipe.
2. The charge pipe coming up from the turbo will be snaked around the distributor.

I've seen a lot of setups in which hoses are run down the side of the engine to each heat exchanger, but I don't believe the Carrera engine tin would allow for that.

Any suggestions?

spence88mph · 06-30-2008, 05:33 AM

I'm sorting heat right now on my car too, I have headers without heat so I'm going to get the protomotive heater shroud that goes over the engine mounted oil cooler and relies on the footwell blowers to draw the heat in. I've heard they're nothing on the stock heat exchangers in terms of efficiency but I could never have the heater on 1 for much more than 2 minutes without cooking.

polizei · 06-30-2008, 05:39 AM

Quote:

Originally Posted by spence88mph

I'm sorting heat right now on my car too, I have headers without heat so I'm going to get the protomotive heater shroud that goes over the engine mounted oil cooler and relies on the footwell blowers to draw the heat in. I've heard they're nothing on the stock heat exchangers in terms of efficiency but I could never have the heater on 1 for much more than 2 minutes without cooking.

Thanks for the info Spence. I didn't know that was a possibility. Since the foot-well blowers would suck the air in, could I just cap the heat exchangers? I assume this would result in the same amount of heat that I am accustomed to, since my rear heater blower has never worked.

spence88mph · 06-30-2008, 05:57 AM

Well many people in the past have removed the engine bay blower, it usually requires you to jumper a relay as the footwell blowers don't work without the engine bay blower connected. Do a search on this or the other forum and you'll find how to do it. Also you can increase the efficiency of the footwell blowers with a simple modification if they don't perform well enough, I know someone explains this on the other forum, it looks quite easy and costs nothing. Finally, capping off the exchangers could plug up the airflow... If you leave them open you will likely suck in some exhaust smell into the cabin. Some hoses running off the exchanges directed to the front of the car may help? You seem to be going to a lot of trouble with twin dizzy, 3.3 cylinders etc to then be using the stock exchangers...

polizei · 06-30-2008, 06:08 AM

Is this the thread you're referring to: http://forums.pelicanparts.com/showt...+blower&page=3

If so, I agree - it looks really simple. I understood your point about the heat exchangers being an odd fit with the rest of the components I've chosen. It really all comes down to $$. I want to retain heat, and quality heads with heat are easily an extra grand. I had to draw the line somewhere :-/

polizei · 06-30-2008, 06:08 AM

Is this the thread you're referring to: http://forums.pelicanparts.com/showt...+blower&page=3

If so, I agree - it looks really simple. I understood your point about the heat exchangers being an odd fit with the rest of the components I've chosen. It really all comes down to $$. I want to retain heat, and quality heads with heat are easily an extra grand. I had to draw the line somewhere :-/

spence88mph · 06-30-2008, 06:13 AM

hmmm I can't see that thread.

I know what you mean about the budget creeping! It will seriously haul either way, believe me, you'll be happy! Are you intercooling? how much boost will be running, using the AFM?

jbrinkley · 06:29 AM

if you want that rennlight, widebody911 fiberglass left hand heat duct I have one sitting here. But I suggest the footwell thing even if you leave the Boxes themselves open underneath the car. Connect your HE boxes to the flappers and let the footwells do the work. block the left and right sides in the bay. Screens over the openings with clamps will keep the bugs and stuff out of the openings under the car.
For it to work right the blowers need to work and the flappers need to be leak free. otherwise you'll get heat passing by in the summer. Also during the summer you can just pull the relay for the footwells so they don't spin.

polizei · 06-30-2008, 06:30 AM

It chopped the link when I pasted it. Try this:

Help! Does anyone understand the footwell blower circuit?

No, I won't be intercooling initially. I'll be running .7 BAR with 8.0:1 compression. Ben @ M&K and Todd @ Protomotive both said I should be fine at that level, so long as I don't exceed it. Intercooling along with brakes is on my list of follow-up projects. I'm just aiming for a street car, so I have no track expectations. Yes, I will be running the AFM.

jbrinkley · 06-30-2008, 06:39 AM

make sure your oil cooler fan works also. where you're returning the oil from the turbo will also affect when/how fast the fan turns on.
cam cover = fan runs every drive
sump = fan runs occasionally.
intercooled = never ran

polizei · 06-30-2008, 06:49 AM

Quote:

Originally Posted by jbrinkley

make sure your oil cooler fan works also. where you're returning the oil from the turbo will also affect when/how fast the fan turns on.
cam cover = fan runs every drive
sump = fan runs occasionally.
intercooled = never ran

Thanks for the info Jerry. I am planning on returning the oil to the sump. I still need to place the order with Bat Inc! I noticed on your pics that your heat exchangers were bent where the line made a 90 degree turn to connect to the oil drain hole. Was that bend necessary to fit the fittings from Bat?

jbrinkley · 08:52 AM

yup, even if you use a hard 90 like on phil's car

could be different with 930 or stock 3.2 exhaust though

911st · 06-30-2008, 11:24 AM

Promotive system the recovers heat from the motor oil cooler sounds very interesting. Do you have any picture of the components and or the install?