Exhaust for 3.6IB (with B+B headers)

[EVO575]

Would appreciate some advice guys.Got a 3.6 in my SC .Project 98% complete except for a few nigglies.Problem is with the exhaust.I got a Magnaflow 2 in 2 out made up (headers are B+B) but it's horrible-sets off the neighbours alarms and just plain too loud and drones to drive.

What are my options? - I want to use the car for occasional drives and weekends away.Needs to be more sociable than it is now and I'm not looking for every last HP , although I don't want to strangle the 3.6 either.

i am in NI so won't be able to bring the car to any of the renowned U.K. Based custom makers.

Options:

-Buy a B+B muffler? - has anyone any experience?

-Modify a proven muffler to suit the B+ B headers? - this could work? If so what proven muffler

-Get a custom exhaust made on the car using a proven configuration- but it would need to be proven as I wouldn't want to go through this and end up too noisy again.

Also.do I need 2 outlets ? Would a single outlet strangle the engine?

Would be very interested in hearing your thoughts and indeed anything suitable that you may have for sale( even if needing modified)

 

thanks.Paul.

[Richard Bernau]

You have covered most of the options yourself.  As you know, B&B headers are a different spacing so off the shelf options are limited.

My experience is that US mufflers are loud, so B&B may not be a solution - though that is your only off the shelf.

Taking a step back, the only way to gain "quiet" is to get a larger silencer in place.  Nick Moss has used stacked silencers. meaning one for each bank oriented across the back but stacked one on top of the other and each exiting to the side (left bank exits RHS etc).  I think Turbo Thomas has done a B&B compatible system, but he is limited in size by the oval casings he uses, however, with the wide spacing of the headers you could have a wider muffler.  If you leave your car with him, he will build something, but doing it remotely is fraught with potential for error.

The only other variable I can think of is to limit the exit pipe diameters (which is one effect of a single pipe).  I don't know what you have now, but going to smaller exit pipes makes a big difference in sound while seeming to have a limited performance detriment.  That would be the first thing I would try.  Make sure the tailpipes are no larger than the inlet pipes and preferably a little smaller.  It forces the muffler to muffle by making the exhaust gases and sound waves expand through the perforated pieces rather than kind of pass straight through.  Not a great analogy, but best I can think of.  I have permanent welded inserts in my tailpipes making them about 8mm narrower internally and that takes the edge off the noise.  Have a look at new cars with huge tail pipes - invariably the real exhaust is much narrower even in high power cars.

[ALEX P]

Is it the 14" Magnaflow that you've got fitted? If so then yes, they are loud. I did put a pair of inserts in mine to get on a 105db track day and it does make a difference albeit at the noticeable expense of a few hp.

2 out are louder than a single exit and no you do not need 2 out - 964's only had single pipe.

There are so many options and variables it all gets a bit subjective but it really depends on what you want to spend and what you are prepared to sacrifice. By that I mean heat, noise, cost, looks, weight, power etc etc. There isn't really a perfect solution that suits everyone.

Andy Perks made a 21" Magnaflow fit and that was supposed to be a lot quieter but to do that he had to cut the ends off his headers to achieve the bend into the box.

[Chris T]

Maybe as Alex suggests, cut the ends off the B+B headers and get somebody to re-make them at standard 2 in width, thus making a heap of silencers available (I may even have one if you twisted my arm). I can vouch that 2 in 1 out is way quieter than 2 in 2 out!

 

Chris.

 

 

 

[EVO575]

Thanks for the replies guys.The exhaust (14" Magnaflow)is off the car now so may look at installing the smaller bore tailpipes as an experiment.

Chris- what type of silencer do you have that may be available? Pm me if you prefer.although I think I'd like to keep the B+B standard if possible.

[Leicestershire]

The B+B single exit silencer is not excessively loud. The exit is on the wrong side to IB cars.

Prepfab sell a stacked silencer (made by Tube Engineers). These tend to be very loud and owners don't keep them long on road cars.

A 2 in dansk silencer could be modified to suit the BB spacing. 

[EVO575]

Hi,

Yes a modified 2 in 1 out Dansk would probably be my preferred option - I will check under the car to see what modifications are needed.

[SilverWT]

10 hours ago, EVO575 said:

I will check under the car to see what modifications are needed.

Success will depend on what rear engine console/hanger was used in the 3.6 conversion.

If a 3.2 type of console and hanger were used a Dansk 2 in designed for a 3.2 will physically fit (one for and earlier car will not have the cut out "notch" to fit around the console).

If the 3.6 console and modified hanger (hanger ends bent forward to fit) were used there will not be enough space for the diameter of the Dansk, "notch" or not. You would have to cut a long way into the silencer and then plate it up to make it physically fit and this would interfere with the internal piping in a big way.

 

Mark

[SilverWT]

A further comment, if you have a 964 engine you will not have the option of using the 3.2 console/hanger and retaining your harmonic balancer bottom pulley. If it a 993 engine you can fit a single RS style bottom pulley to work OK with a 3.2 console/hanger.

 

Mark

[EVO575]

Thanks for the advice Mark.Its a 964.Will have a look at the options and let you know how I progress