exhaust recos for 90 964

[dhsu1]

hi all,
have a1988 carrera w/ 90 964 transplant, just wonder all's opinion on exhaust upgrade w/ heat exchanger for greater sound and perhaps a gain of hp for track days. budget has to be considered. thanks

[schubee]

I have the GHL full exhaust system on my 964. It's a little on the loud side since I'm not running their dual cats. I get a little resonance (sp?) around 4K. However, I'm very satisfied with the product and their customer service is great. The price of the entire system (headers/exhaust) may be out of your price range if you're on a tight budget. I think I paid under $2K about a year ago.

[Bill Verburg]

Option 1
SSI w/ the muffler of your choice, homemade heat ducts


Option 2
B&B, w/ Flowmaster type crossflow muff, oem 964 heat duct

Option 3
Instant Gs headers Steve Timmins stuff


Option4
993 headers/ w adaptersas installed by Rennsport Systems

[plain fan]

Bill,
Could you elaborate on option 1 - SSI w/ DIY heater sysem?
Thanks

[Bill Verburg]

Could you elaborate on option 1 - SSI w/ DIY heater sysem?

When I had a 964 engine in my Carrera I used the pictured setup for a while. It works ok for a street car but is too restrictive at high rpm for max. performance.

To hook up heat all you need is to modify the 964 heat tube just after it drops below the tin work as pictured here


just use ~2.5" hole saw to drill a hole in the side of the stock tube, size the hole so that the duct fits snuggly in the hole, run this duct to the left side ssi heat inlet. I used a silicon sleeve, from the stock 964 heat, to clamp in place on the ssi.

The reducer at the bottom is a std. aluminum dryer vent piece which connects to some ss or galvanized 2.5" flex tube.

The flex tube crosse to the other side where the final 180&deg bend is again made w/ more flexible duct, claped on w/ the silicoon sleeve.

it was a while ago so take the posted sizes w/ a grain of salt.

Worked great.

[Bill Verburg]

Oh, the SSI's also needed a spacer to push the muffler back a bit.

[plain fan]

Thanks Bill, I was thinking that the SSIs would be too restrictive. What are you running now?

[Bill Verburg]

What are you running now?

Option 2, just not on that engine

[plain fan]

So B&B headers with DIY flowmaster type of muffler.

[Bill Verburg]

I've found that combination to work well. It's a bit on the rowdy side, but I can live with it easily.


Timmins/Mcneil kit has gotten some good reviews sound wise.

[project935]

If anyone is interested I'll be posting the following for sale soon ... send me a PM/e-mail if you want more info/pics.

* new/never used B&B 964 headers - will need a dual-in muffler added to it to complete the system. Approx 22RWHP gain and 45-50lbs lighter and OEM system.

* new/never used B&B 964 single-in/dual-out muffler for OEM headers/cat. Approx 10RWHP gain and 34lbs lighter than OEM muffler(s).

[dhsu1]

Hi Bill,
thanks always for great infos, but i thought SSI does not have a header/ heater box system for 964 C2 3.6 engines. your option 2 is exactly what I was leaning towards. best regards, DH

[Bill Verburg]

i thought SSI does not have a header/ heater box system for 964 C2 3.6 engines

They don't specifically, but a little ingenuity goes a long way. The hard part is adapting the heat connections.

[jc964rs]

Who have tried 993 headers on 964s ? Some say they are really more efficient
The only problem with them is that 2 pipes have to bo turned