What to do for exhaust on a 3.5?

JP911 · JP911's Garage

I'm nearing completion on the build of a 3.5 twin plug from a 3.0 liter (100 P/Cs, 3.2 crank) and I'm not sure what to do for exhaust. I have a set of SSIs on my current 2.7 but have been told they will not be enough for a 3.5 and that 1 5/8 headers/HEs is the way to go. I've searched the forums on headers, GHL heat exchangers, B&B, etc. I would like to be able to use a Dansk dual in, dual out muffler. So what are my best options with and without heat?

asphaltgambler · 08-06-2005, 07:36 AM

MO is a cheap option is 964 stock headers / exhaust. To me the GHL's are a copy of the 964.

OR open up your wallet for a set of B&B's

Craig 930 RS · 08-06-2005, 07:37 AM

I'd do a B&B w/heat with Fabspeed partial stainless (Flowmaster) muffler

JP911 · JP911's Garage

964 setup is an option I had not considered. Is it a straight bolt-up?

Craig- do the B&Bs have spacing that is different than stock? In other words would a Dansk dual in, dual out bolt up to them?

Keep the ideas comin...

asphaltgambler · 08-06-2005, 07:45 AM

The 964 headers bolt up but I'm not sure of who or how many companies make aftermarket exhaust to go from the headpipes.

Craig 930 RS · 08-06-2005, 08:03 AM

The B&Bs won't bolt up to the Dansk.
Too bad, the Dansk is a great muffler - one with more hair and about 4-5 hp = the FLowmaster. But a LOT louder, I loved mine.

johnsjmc · 08-06-2005, 08:45 AM

Have you considered 993 HEs (rotate pass side flanges) and a Triad or MacNeil muffler?Lot,s of discussion on 3.6 exhaust should be relevant to a 3.5.

efhughes3 · efhughes3's Garage

Do a search for carrera3.5L here. You'll see what Ralph did on his 3.5L motor last year.

Bill Verburg · Bill Verburg's Garage

The best available off the shelf solution is the B&B, but as has been mentioned they use a non std. spacing between the collector ctrs. Most of us have used a Flowmaster X-flow muffler as a solution, it is loud but not unusably so.

Another issue is heat, even a track only car will want to be able to demist the windshield occasionally.

If you insist on using the Dansk, headers w/o heat are the only solution, in the 1 5/8" or bigger range, that I know of. Unless you modify the exhaust inlets.

993 headers would work but again the Dansk won't bolt up w/o modification to the muffler and headers.

If you have gone to the trouble of using some cams w/ some overlap then the 964 solution is not a good one. It would be fine for smog cams but not more agressive performance cams.

JP911 · JP911's Garage

I'm open to different mufflers. I've looked into Ralph's solution and the headers are certainly a good option, but no heat. Any opinions on the GHL heat exchangers? Do they use standard spacing? I am using 964 cams to remain smog compliant.

Bill Verburg · Bill Verburg's Garage

Here is a sound clip of the Flowmaster on my 3.8

JP911 · JP911's Garage

Wow! That is a great sound. Very aggressive but still 911. Thanks for posting that Bill.

Bill Verburg · Bill Verburg's Garage

I've been trying to get one accelerating and on the road, but I need a better mic setup. It really is a treat for an enthusiasts ears.

Craig 930 RS · 08-06-2005, 01:26 PM

B&B headers (for a 3.6)

B&B + Flaumeister

Check out the goods here:
http://www.instant-g.com/

Craig 930 RS · 08-06-2005, 01:34 PM

Here's a pic of Joe Fabiani

Bill Verburg · Bill Verburg's Garage

Craigs B&B appear to be the Carrera version, note the round heat inlets. If you want to use the Carrera heat tube that is the version you want.

I had mine(1 3/4") made w/ 964 heat inlets(oval) for use w/ the 964 heat tube. You can also have them made w/ the smaller 1 5/8" tube.

.

Joes kit is nice if expensive. The tips make it worth while, if you don't care about tips just get a couple of 2.5" ss Us and a flowmaster muffler. To tone it down a bit w/o building excessive backpressure Car Chemistry inserts are reported to work nicely.

Craigs also appears to be set up for US 993 dual O₂ sensors

Craig 930 RS · 08-06-2005, 02:36 PM

Correct on both counts

blue82coupe · 08-06-2005, 05:20 PM

Quote:

Originally posted by johnsjmc
Have you considered 993 HEs (rotate pass side flanges) and a Triad or MacNeil muffler?Lot,s of discussion on 3.6 exhaust should be relevant to a 3.5.

blue82coupe · 08-06-2005, 05:27 PM

Quote:

Originally posted by johnsjmc
Have you considered 993 HEs (rotate pass side flanges) and a Triad or MacNeil muffler?Lot,s of discussion on 3.6 exhaust should be relevant to a 3.5.

Sorry about the previous post. I have the 993 HE,s with the Timmons Happy Crab muffler.. couldn't be happier. The muffler is about $1200.00 .The HE,s about 500.00 used. Excellent bang for the buck.Dan

Carrera3.5L · Carrera3.5L's Garage

Jon,

Have you gone soft on us SoCal guys since you moved up north? Need heat?

Has Bert taken any pics of the motor for you along the way? When you come down, we'll hook up if you are interested and you can listen to my car and determine if the noise level is objectionable. I have a dansk dual-in dual out w/ 84mm tips at present but just bought a dual-in dual out Monty w/ 75mm tips.

The inlet flange i.d. on the Monty is 5mm larger than the Dansk and MAY be better suited for larger diameter headers. Planning on dyno'ing both back-to-back next week if possible to confirm.

Ralph