FAQs about Exhaust Systems

Putting on a 2 1/2 inch exhaust system.

Date: Fri, 11 Sep 1992 08:46:17 PDT
From: Frank_Bov.Wbst311@xerox.com
Subject: Re: putting a 2 1/2 inch exhaust sys on my 242GT
To: swedishbricks@me.rochester.edu
Cc: cris@cm.deakin.oz.au

>1. Same as standard system but 2 1/2 inches. No, improve the mufflers, too.
>2. As above but with turbo mufflers (hear they are less flow restrictive). Yes, I've got a Flowmaster on the Bimmer and it's does improve power/torque
>3. Either of the above but made of stainless steel instead of steel. Stainless will cost more but last forever, or close to it. Use aluminized pipe at least
>4. 2 1/2 system with any of the above, but with extractors (have not looked to see if they came standard on my car). Extractors??
>5. other?

Look for a good bending shop. Some will be able to put on big pipe, but you lose if they crimp it too much when they bend it. Also, if you are removing the cat, most shops won't touch the car. If not, be careful how the do the interface to the cat.

>I dont desire a loud car, but I guess bigger exhaust/performance means a little more noise (hopefully not tooo loud).

Mine got louder, but not too much so. Flowmasters have an interesting design where it seems the muffler is quieter at higher RPM than at idle. I noticed an improvement in mid range torque (ability to climb hills in top gear at 3K RPM) and when I put the engine on a chassis dyno, the HP curve was flat from 5500 RPM up. Of course, this is a (slightly) worked-on BMW 1.8l , not a Volvo motor.

Frank

Date: Fri, 11 Sep 92 09:12:20 PDT
From: maj@m5.frame.com (Michael Jue)
To: cris@cm.deakin.oz.au
Subject: Re: I'm putting a 2 1/2 inch exhaust sys on my 242GT. ADVICE NEEDED.
Cc: maj@frame.com, swedishbricks@me.rochester.edu

While it may not be relevant to the 242GT, my experience with custom/aftermarket exhaust systems on non-turbo engines is that while you will attain some additional power, you may suffer some lowend power loss (particularly noticeable in your towing application.)

Side note: by increasing pipe diameters on a turbo car, you will quickly modify the torque characteristics in a more positive manner. That's another story...

In addition, if you do any kind of stop/go, city type driving, you may find that the resonance (note that I didn't say noise) will grow old pretty quickly. I had 2.5" exhaust on two cars, both 6 cylinder cars, and the incessant drone while stopped at traffic lights got to be pretty unbearable. So much so that I swapped the entire exhaust system out of one of my Datsun Z cars for a 2" system with a turbo muffler and up front and a SuperTrapp at the rear. Much better!!

If I were doing the exhaust setup on your particular car, I'd probably have it custom bent (as Mike Davis said) with 2" or maybe 2.25" piping with the FlowMaster. This seems to be a pretty hot setup these days what with the CHP getting all over motorists with non-standard exhaust...your area might be different...keep the gendarmes in mind as well.

Hope this helps!

Michael (maj@frame.com)

Date: Fri, 11 Sep 92 08:25:28 CDT
From: Mike Davis <MDAVIS@ua1vm.ua.edu>
Subject: Re: I'm putting a 2 1/2 inch exhaust sys on my 242GT.ADVICE NEEDED.
To: swedishbricks@me.rochester.edu

I would look into having a muffler shop custom bend a 2 1/2" system and put one Flowmaster muffler in the system. I have read good things about this muffler: excellent flow, good noise suppression. ipd sold them, but I don't know if they still do or not. I have seen them in the local hot rod shops also. ipd said that on a 240 turbo the Flowmaster made the car sound more like a Saab Turbo I don't know if this is good or not...

How can I fix a rattling exhaust system.

From: alfred@nyquist.bellcore.com (Alfred Kwan 21342)
Subject: Re: Rattling exhaust
To: maj@frame.com (Michael Jue)
Date: Tue, 18 May 1993 09:42:19 -0400 (EDT)
Cc: swedishbricks@me.rochester.edu

Michael:

> My '87 740T seems to have a rattling exhaust pipe or somesuch. Not having climbed
> underneath the car to check it out yet, I'm wondering if any other 740/760T owners have
> had anything like this. Might be something simple like and errant heat shield or flange but
> wondered > If anyone can pinpoint something for me.

My 86 745T has a lose Y-pipe heat shield. That is the pre-heat thing for cold start. The sound is coming from the front. If I tap the heat shield down with a piece of wood on the Y-pipe, the sound will go away for a few days. I really should take it out and reset everything.

Good Luck

Alfred

Date: Tue, 17 Aug 93 14:28:29 EDT
From: nick@meaddata.com (Nick Gough)
To: swedishbricks@me.rochester.edu, nathanso@umdnj.edu
Subject: Re: front exhaust pipe

Yep, heat sheilds rattle. And, no I haven't had to replace the pipe... no need to, yet. It appears to be common on 700's & maybe (I dunno) 200's as well.

If a weld breaks, just re-weld it. That pipe should last a helluva long time, since it gets very hot & any moisture that may be present, after being parked, is usually evaporated away very quickly. Plus, I believe that it's stainless steel, but I may be wrong. No need to replace it if only a weld is broken on the heat shield, IMHO... unless something else is wrong.

Phibe away...

Nick

> From nathanso@umdnj.edu Tue Aug 17 13:54:19 1993

> From: Mark Nathanson <nathanso@umdnj.edu>

> Subject: front exhaust pipe

> To: swedishbricks@me.rochester.edu > Date: Tue, 17 Aug 1993 12:30:23 -0500 (EDT)

> It is interesting to see how many other people have the same
> problems with their bricks. For example, the recent talk of the
> front exhaust pipe. My pipe has rattling heat shields and probably
> a cracked weld to boot as the exhaust noise has risen recently.

Should I replace the muffler with an OEM?

Date: Tue, 25 May 1993 04:54:19 PDT
From: damouth@wrc.xerox.com (David E. Damouth)
To: jtembulk@spica.cv.com
Subject: Re: Muffler replacement.....

is ipd a good alternative ? Or one of these Midas, Monroe, etc.?

I've gotten frustrated, over the years with the Midas, Monroe, etc, muffler systems. They indeed honor the lifetime warranty on the muffler, but the pipes die too, often sooner than the muffler, and they are *not* guaranteed. It's a hassle to have some piece of exhaust system falling off every couple of years (I`m in the rust belt -perhaps you don't have the same problem).

The OEM Volvo exhaust system was a real revelation. I replaced it a few months ago, at six years and 100,000 miles. So I was quite happy to have a complete new OEM system installed by the dealer for $350 or so.

It was tempting to build a custom low backpressure system around a FlowMaster and get another few horsepower, but in the end, I took the easy way out.

Some local independent shops are advertising that they bend their own pipe, using high quality aluminized pipe, which ought to last (the OEM Volvo pipes were aluminized steel). I doubt if it's significantly cheaper than OEM.

How do I replace the exhaust gaskets on a B230FT?

From: alfred@nyquist.bellcore.com (Alfred Kwan 21342)
Subject: Re: Exh Manifold Gaskets Replacement
To: KCHANCE@acc.haverford.edu (SALAD SPINNER)
Date: Wed, 30 Jun 1993 11:15:48 -0400 (EDT)

Douglas:

[replacing the exhaust gaskets on a B230FT]

No, I am not chuckling. Anytime I have to deal with the exhaust side, there are always some rusted out bolts or seized out nuts that I can't get out.

I remembered that I had to use all my small wrenches and sockets (1/4" drive for the real hard to reach nuts) to remove the exhaust manifold nuts. Some of them are real pain to get at.

I don't know if you can move the exhaust manifold back enough to install new gaskets without disconnecting the turbo oil lines and exhaust pipe/catalytic converter. I was pulling the dead engine out. I just took everything out. Double check this, If you have to do both, you might want to disconnect the exhaust pipe/catalytic converter to turbo connection first. Don't forget to support the catalytic converter, it's heavy.

Remove the 2 oil lines. After the 2 turbo oil lines are out; plug all the holes so junks can't get in. I would get new gaskets and the rubber seal ring for the oil lines.

Remove the manifold nuts. The manifold/turbo unit is heavy, real heavy, be careful not to drop it on the fender.

I used anti-seize on all the exhaust hardware.

Good Luck

Alfred

> Howdy Volvovians!

> I have decided to try and replace all the gaskets and bolts/nuts involved
> on the exhaust manifold/turbo side of my '88 760t (100k miles) hoping that
> doing this will solve my 'push lawnmower' sound eminating from the rear of the
> engine.
> I have never taken on such a procedure and though I have no doubts that I can
> do it, I am worried that I won't be able to do it 'right' the FIRST time.
> do I hear chuckles from the group? huh? If anyone would be gracious to briefly state any items that they have learned from experience I would be very
> gratefull. I have the Haynes manual and it seems to be quite cut and dry
> I just want to know WHERE and WHEN I should but ANTI-SEIZE *or* ANTI-LOCK
> fluids... and if I should replace anything else particular at the same time?
> I'm also worried that i'll need some special crow-foot wrenches or something else?
> unfortunately I'm at work and must go now...

> thanks again... -douglas dibella

Date: Wed, 30 Jun 1993 09:53:27 PDT
From: werner.wbst311@xerox.com
Subject: Re: Manifold Gaskets Replacement
To: KCHANCE@acc.haverford.edu

Be very careful with the manifold studs. The extreme heat cycling from the turbo tends to make these very brittle and easily broken. Be sure to replace them all. It is a lot cheaper to replace them then to pull the head so you can drill an old one out.

Also, when putting stuff back together, use a high temperature "copper" grease. Local auto parts stores should have it. It is designed to work at extreme temperatures and is a copper color. I have used it in all of the head swaping I have done, and have never had any problems with stuck bolts.

Can I increase performance when changing my exhaust system?

Date: Fri, 9 Jul 1993 05:16:20 PDT
From: werner.wbst311@xerox.com
Subject: Re: performing exhaust for 240 ? (long, see note at bottom)
To: walowitz@acsu.buffalo.edu

>It is time for some work on the exhaust system of our 1980 244.
>But, can i do something here that will better performance (by
>decreasing back pressure) ? I mean, does anyone have any facts on this ?

Yes, but how loud are you willing to put up with.

The first thought that comes to mind is the free flow exhaust IPD sells. I really do not known what the characteristics of it are.

There are some people who suggest just using the resonator and going with pipe the rest of the way. I don't think I have ever heard a car setup like this, but it still may be reasonably quiet.

Another suggestion is to run a straight pipe from the resonator to a Super-Trap muffler. The Supper-Trap is a tunable glass-pack. You can then start tuning the back pressure to what you want. In theory, you could actually get the car as quiet, or even quieter then stock. You could also, on-the-fly, retune it if you decided you wanted more power and less quieting.

Many AutoXers have used just a Super-Trap muffler with no resonator. I have never heard it on a 240, but it can have a nice sound on a VW GTI 16V.

BTW: The presence or lack of a catalitic converter can make a _big_differenence in the amount of sound.

If you have a cat, you may be able to get away with just a simple straight pipe. It can be very loud though.

My personal favorite these days is a FlowMaster Muffer. It is a very simple, low restriction design that uses a series of baffles. (IPD has a good picture of the insides of one in their catalog, but you can do better on price.) They make 2 and 3 chamber designs. The 2 chambers are the least restrictive, but they also provide the least quietting. I use a 2 chamber on my 740T and loved the sound. I also have a 2 chamber on my rally car ('70 145 with 2.1 liter B20, IPD Street Performance Cam and 2.25" exhaust). At first, I thought it did not do that much because the car was (is) still very loud. I then disconnected the exhaust at the end of the down pipes. The flow master takes away a lot of the sound, especially the high frequency noise.

The one caviet I have found is that I have reduced the back pressure so much that the stock carburation became too lean. With reduced back pressure and a reasonable amount of valve overlap, you end up pumping a fair amount of the air/fuel mixture out the exhaust before it burns. This is especially noticable at low RPMS. If you have a Lambda-Son equiped car, the FI computer should compensate.

_IMPORANT_NOTE_: Most states, including NY, are starting to actually check the tailpipe emmissions of cars. Playing with exhaust systems is a good way to muck up your emmissions. Before you spend the money, make sure that either your car/state does not require testing, or the exhaust system is C.A.R.B. (or similarly) approvable. (C.A.R.B. is the California Air Research Board - The are the defacto standard setters for emissions and testing policies for many states in the US.)

I'm raising my care 1-1.5", will this cause my exhaust pipe to touch the axle?

On Tue, 28 Nov 1995, Paul R Demeo wrote:

> Well, I'm finally getting to the point where i'm going to raise the rear
> end of my brick (1980 244dl) with springs off a wagon.
> My question is this: My tailpipe, between the first and second mufflers,
> goes under (between the pavement and:) the rear axle. I've taken to
> looking at other passing bricks of my vintage, and this appears to be the
> stock setup. Problem is: I'm afraid that lifting the car even 1-1.5
> inches will cause the pipe to be touching the axle. I'm not real fond of

FWIW, I've never had this problem. I run wagon springs and pipe under the axle (a stock pipe this time, it was a chewing gum and bailing wire setup for a long time). I'm pretty sure the suspension reaches the end of it's travel before the axle bumps the pipe-try jacking up both sides of the rear end to see how much rebound there is in the rear suspension.

Jim, 82 244DL B21A M46 308K km / 191K miles