3.6 conversion update... Exhaust problems.

[Moses]

Maybe it was just a miscommunication. I received my GHL headers/cats setup today. Beautiful work. Problem: 1.5" ID tubing. Clearly inadequate. I called GHL and they said they would fabricate a set with 1.75" OD tubing. I noticed the GHL flanges are 2 bolt flanges. Aren't the 993 exhaust manifolds 3 bolts?

At any rate, I have the chance to just go with B&B headers with heat. That seems to be the most common approach.

My mechanic has done a TON of custom exhaust fabrication. He would like to hook up B&Bs to a huge 2-in 1-out catalytic converter. NO MUFFLER. He suggests we use this for smogging the car, then switch it out to a muffler fabricated to match up with the B&B headers for use in between smog checks.

I'm a novice at this. Will the smog guys pass a car with a huge cat but no muffler if it's not too loud?

I guess I really need to know if you would ask GHL to make some 1.75"OD headers with cats, or go with the B&B setup I described.

Thanks in advance for your help!

[pbs911]

Moses, I am listenting and learning.

Personally I would go with the B&B set up.
As far as the smog issues, unless it has received certification from CARB in CA, it will not be smog compliant. What did Thom do? His 3.6 transplant was subjected to the scrutiny of the CA smog nazis and came out with flying colors.

[Jack Olsen]

Modified 993 headers are by far the cheapest way to do this, without any real trade-off in performance.

GHL's offerings seem wildly overpriced, to me.

I have the B&B's, which are great. But you can get a pair of 993 headers for $250, and get them modified to fit (I've heard) for $100 or so.

[Bill Verburg]

I agree w/ Jack on this one the B&B is great but for the money the stock 993 manifolds w/ stock cats for smog, then some glasspack type muffler is the way to go.

The stock 993 plumbed to a "big ass" aftermarket cat will also work but not please the smog nazis

I don't think much of the GHL especially when price is factored in.

If smog isn't an issue then Steve Weiners solution(shown below) is the one I would shoot for, but w/ dual outs.


The 964/993 intakes are 3 bolt, the exhausts are standard long studs(x2). except the 993 which has its passenger side studs rotated 90&deg from all previous models. The passenger side studs will need to be tapped in the standard configuration for any exhaust except those specifically made for the 993, all 993 heads are pre-setup for this operation

[emcon5]

Originally posted by Moses

I'm a novice at this. Will the smog guys pass a car with a huge cat but no muffler if it's not too loud?

Before you spend $1000+ on a exhaust system, I would find out for sure what will pass smog.

Remember, this ain't Biff down at the Shell station, you will need to go to a Referee.

Tom

[Moses]

Jack,

I keep hearing that the 993 headers will not fit with the 915 tranny. Do you know if the mods you talk about are for a G50 or a 915?

Thanks!

[Joe Bob]

I am going to wait for the next batch of SSIs....rumor has it, they are testing 3.6 HEs right now.....

Until then I will put on a jacket and run headers.

[JonT]

I have the setup you are referring to. David Valliere aka. MIFINTIFIN was my supplier and modified the 993 headers to fit my 3.6L from an '89 Carerra. I also have the 993 cat which serves as a the muffler with 4" stainless tips welded on. The entire exhaust setup ran me around $600. Its loud and it sounds like a race car--a PORSCHE race car. I'll post some pics when I steal my digicam back from my brother.

I have working heat too.

[widebody911]

My car didn't require a cat because it's a '77. I had B&B fab me a set of cat tips, which I used during the smog process, although they really weren't necessary.

[Bill Verburg]

It's the stock 964 headers(I use the term loosely) that don't work w/ the 915(actually it's the clutch actuation arm that causes interference). SSI, B&B,993 or SC/Carrera will work fine though each poses other surmountable issues.