Spirit R/T Exhaust Q&A
On another note, the exhaust system on the R/T needs replacement and I was
wondering if you had any ideas about things I could do. Do you know anything
about availability and obtaining high performance mufflers, pipes, etc.
Does the exhaust make any difference? Are there any advantages of aftermarket
systems vs. a Dodge factory replacement?
The stock exhaust system is adequate, but tuned more for sound control
than all-out performance (as you might expect). The cat is probably the
largest single restriction. As delivered, the system comes out of the
turbo and goes into the cat at 2.5", comes out of the cat 2.25", necks
down to 1-7/8" just before the rear wheel, and finishes its run through
the muffler at 1-7/8''.
The popular replacement system has been installed on several of our
vehicles at Lou's Custom Exhaust off Main Street in North Reading.
He cuts off the whole system before the cat, puts on an Arvin hi-capacity
cat (2.5'' in/out), custom bends the required 2.5'' pipe out to the muffler
area, then attaches your muffler of choice. I can highly recommend just
about any Dynomax muffler: Super Turbo, CVX, Boss Turbo or Ultraflow. The
Super/Boss Turbo have good sound control and good flow. The CVX is a bit
louder, but has much better flow. The Ultraflow is essentially the same
as a CVX, but in stainless steel and more expensive. If you choose the
Super/Boss Turbo or CVX, expect the whole job to run $200-$250. If you
choose the Ultraflow, you'll be well over $300. DO NOT allow them to
install a Flowmaster ANYTHING - they are loud and obnoxious on 4-cylinders.
Most other mufflers designed for V8s are loud and boomy on Mopar turbos.
SuperTraps make good power, but have an unpleasant exhaust note (and are
Expect as much as an extra 2 pounds of peak boost from a full aftermarket
system of this type (you already have a Fuel Rich/Lean gauge installed,
RIGHT?) :-) as well as a slight rise in MPG. Expect 1/4 mile times to
drop almost half a second! Expect much less if you just replace the
muffler and pipes, and leave the stock cat in place.
One last comment - Lou's gets all his Dynomax mufflers from a local parts
shop that stocks Dynomax. Several times, Lou has ordered us 2.5''-2.5''
Super Turbo mufflers, only to have those jokers send him 2.25''-2.25''.
You might want to pick up your muffler of choice and haul it down to the
muffler shop yourself. Stay away from muffler chains unless you want
exactly the same thing that is on the car now, that's all they will do.
You can pretty much ignore the tight-fit and added expense of 3'' pipes,
since you are not planning on making over 250 horsepower. Also note that
the EPA mandates OEM cat unless the car has over 50,000 miles on it,
because the EPA mandates 50,000 miles (unlimited time) warranty by the
manufacturer on all factory cats. If you are close, most muffler shops
will fudge the mileage for you, otherwise, you might get a hassle -
From Wes Grueninger :
When I needed a replacement for the internally rotted original muffler
on my first '91, I tried calling several parts stores and had the muffler
looked up by application. Everybody, from cheapo brands like 'Silver
Knight' all the way up to Walker, listed the Turbo III as having the smaller
diameter muffler. The smaller diameter muffler fits all of the naturally
aspirated 2.2 and 2.5L K-derivates.
When matching the replacements up to the original, however, I noticed
how much larger the OE muffler was. I finally called one of the parts
stores I sell starters and alternators to. They looked the application up
in their AP Muffler catalog, and a different number was listed for the Turbo
III. (Note that sometimes this is listed in catalogs just as 'w/
intercooler' and 'wo/ intercooler' - there were two different turbo engines
available in 1991!) When they delivered the muffler and I matched it up to
the original, it was a perfect match.
Just for grins, I had the counterman look up the part number in his
application guide. It fit all 3.0L-equipped K-derivates, as well as the
Turbo III-equipped cars.
Surely, though, you're aware that "fits" doesn't mean "matches". The T3
muffler is a special low-restriction item which very well may have the
same inlet and outlet diameters (and certainly has the same mounting and
external dimensions) as the 3-litre piece. Aftermarket parts makers LOVE
to consolidate whenever they can...it saves them big $$$$. If I wanted a
factory-type muffler, this is one app where I'd probably get a genuine
Sorry I didn't clarify this. I am not sure that the internal baffling
should be or is the same between the 3.0L and the Turbo III muffler.
However, I am positive that this muffler will have less backpressure than
running through the dinky naturally aspirated muffler. In my case, I had
the exhaust ripped off the car and had to have it reinstalled that day so I
could make it to Chryslers@Carlisle in '95.
If you REALLY want to do it right, then get the factory item. But if
you need it fast and cheap, then the 3.0L exhaust (which was designed to
handle the exhaust output of .8 more liters and two more cylinders) will be
better than nothing.
I thought that I might jump into this great muffler debate and offer some
factory parts info. The orignal part number muffler for the 91 & 92 R/T's is
4427635 and was unique to these cars only. That muffler is no longer available
from Chrysler and is replaced by the following Walker (Chryslers replacement
exhaust supplier) numbers. Muffler;E0022554, Spout;E0041422, Pipe;E0043130.
This also happens to be the same part numbers that the 89-91 3.0 A-bodies use.
The part number for the 92-95 3.0 A-body muffler is 4427747 and this piece is
still available from Chrysler. And on a sad note for us Spirit R/T owners the
muffler for the IROC R/T is still a good number and available for less than
$100 list at any Chrysler dealer. So from the stand point of it looks orignial
you cant beat the 92-95 3.0 muffler because all the replacements are 3 piece
and the orignal is only one. And as a final note I have run the orignal part
number for the R/T muffler on Chryslers parts locater and this also turned up
no mufflers. Oh yes the price on the late 3.0 muffler is around $120. list.
Cliff & Lorraine Ramsdell
The Spirit R/T Club
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