964 and 993 Heat Exchangers

[SRVYJM]

Do any of you fine knowledgeable folks out there know if the 964 and 993 heat exchangers are interchangeable at all on the 3.6? I have installed a set of FabSpeed headers/ exhaust system with the included heat exchangers that do not provide even close to adequate heat to the cabin (only 2 of the 3 pipes are even enclosed on either side) so I'd like to keep the system from the sport cats back to the dual exhaust- but replace the headers/heat exchangers with the dual 993 versions- the 964 has all the plumbing route to the drivers side and then back around because of the single passenger outlet (I assume that's why they did that) but when I look at 993 heat exchangers they seem to dump out to the sides individually- so it would be much easier for my muffler shop to plum those to the FabSpeed system then to try to use the 964's exchangers- but I'm not sure they fit the motor and cabin air tubes quite the same way. Does anyone know if they'll bolt up to my 3.6 heads just fine?

I'm thinking I could even get replacement cabinets flex tubes (whatever they're called) to reach the 993's to get some heat back in my car! I live in Colorado- it's a tough winter hear this season and the car's not getting as much road time that i would like because it just never warms up in the cabin. The left pic vs. the right pic- pretty different- but it seems the left would solve my problem if I can get my shop to customize the connection- Edit- I can't get the pics to load for some reason...

[964TargaC2]

993 headers will fit the 964 with modification (flipping the flange on one side)

Dan Pechtel at carsinc had a set on eBay , dont know if he still has them or not

[Bill Verburg]

Originally Posted by SRVYJM

Do any of you fine knowledgeable folks out there know if the 964 and 993 heat exchangers are interchangeable at all on the 3.6? I have installed a set of FabSpeed headers/ exhaust system with the included heat exchangers that do not provide even close to adequate heat to the cabin (only 2 of the 3 pipes are even enclosed on either side) so I'd like to keep the system from the sport cats back to the dual exhaust- but replace the headers/heat exchangers with the dual 993 versions- the 964 has all the plumbing route to the drivers side and then back around because of the single passenger outlet (I assume that's why they did that) but when I look at 993 heat exchangers they seem to dump out to the sides individually- so it would be much easier for my muffler shop to plum those to the FabSpeed system then to try to use the 964's exchangers- but I'm not sure they fit the motor and cabin air tubes quite the same way. Does anyone know if they'll bolt up to my 3.6 heads just fine?

I'm thinking I could even get replacement cabinets flex tubes (whatever they're called) to reach the 993's to get some heat back in my car! I live in Colorado- it's a tough winter hear this season and the car's not getting as much road time that i would like because it just never warms up in the cabin. The left pic vs. the right pic- pretty different- but it seems the left would solve my problem if I can get my shop to customize the connection- Edit- I can't get the pics to load for some reason...

Thru 964 all the headers are bolt on compatible, the 993 uses headers which have the passenger side flanges rotated 90 wrt the older design. That said 993 also have heads w/ threaded positions for both 993 and older style flanges

[Cobalt]

Seems like a bit of work for heat. Just curious but did you check the operation of the fans and or does your car have the rear blower motor removed. This might be a cheaper solution if not.

[SRVYJM]

Originally Posted by Cobalt

Seems like a bit of work for heat. Just curious but did you check the operation of the fans and or does your car have the rear blower motor removed. This might be a cheaper solution if not.

Yeah I've had it fully checked out- it is a lot of work for heat. And yes- I still have the rear blower motor and it's working fine. I get lots of air movement- just very little heat in that air. It's a poor, poor design by FabSpeed- just not enough surface area covering the exhaust pipes (only two are even covered) to heat up the air passing over them to heat the cabin by the time it gets there. It sucks- and I need heat to drive the car at all in the winter. I may go back to the stock system and just plumb it to the FabSpeed pipes just to get heat. Hell the car used to get warm within two blocks of driving with the OEM system- All the flaps and such have been checked out- everything is working- just a poor design.

[RedCoupe]

Yeah, with the stock system the 964 is an insta-bake oven!