Imperial62

Performance Muffler Applications on Reattas

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Question - do the performance flow mufflers fit on Reattas?  I would think if one does, it would add 5 free horsepower fairly easy.  I am not talking about glass packs but the actual name of the manufacturer escapes me.  

 

My 1988 has an exhaust leak which I need to diagnose but I am pretty sure it's the muffler or tailpipe section.  If it's the muffler, then this would be an easy way to get a few more hp and let the engine exhale.  

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The link is a good place to start......the "Camaro" muffler is similar in that one end is a single and the other 2 outlets.   You flip the "Camaro" muffler for Reatta usage.

As stated in the link....check information in the muffler catalog....it should indicate that any port can be used as an INLET or OUTLET, if that is not stated the muffler could be too loud.

Also, most manufactures have several "Camaro" applications,  starting with STOCK sound, and progressing to performance, some are available in stainless.

I used the "Camaro" because the overall length is very close to the Reatta.

SAVE your outlet -pipes and install them on the replacement muffler.  The stock pipes are stainless and should last a long time.

 

Some owners have suggested the following mufflers.....I have not used any, I just collect the information.  If you find a manufacturer and part number you like let me know.

Walker  88-90 Camaro #18240  17" body 2 1/2 in  2" out

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Interesting notes. It sounds like - after reading - that the 1991 Reattas simply gained 5 hp by simple exhaust modifications. 

 

So, if 1991 exhaust manifolds were installed AND a freer flowing muffler - then you may gain 7 to 10 hp. 

 

There was no mention in Barneys Camaro muffler notes about the Camaro muffler being freer flowing, so is it or is it not a "performance" muffler? 

 

I will do more research tonight. 

 

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46 minutes ago, Imperial62 said:

Interesting notes. It sounds like - after reading - that the 1991 Reattas simply gained 5 hp by simple exhaust modifications. 

 

So, if 1991 exhaust manifolds were installed AND a freer flowing muffler - then you may gain 7 to 10 hp. 

 

There was no mention in Barneys Camaro muffler notes about the Camaro muffler being freer flowing, so is it or is it not a "performance" muffler? 

 

I will do more research tonight. 

 

It isn't as simple as that. While it is true the '91 has a 5hp greater rating, the entire exhaust system is larger diameter. More than that, it is an L27 engine and not the LN3. Essentially the same engine but uses a tuned port long runner manifold, different throttle body and a different camshaft. Just my opinion, but the 2.25" exhaust is adequate for a normally aspirated 3800. Remove the restriction in the rear manifold, replace the catalytic converter with a modern better flowing unit and install the muffler of your choice. Even if it isn't faster, it will sound like it is :)

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You could also look for an '88 block take the cam out of it and get 9.0 pistons and clean up the exhaust ports at the engine and the collector at the exhaust pipe and pick up about 30 HP...

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Well, I just had a Flowmaster Series 40 put on my Reatta, and as Dave said, it sure does sound faster. Haven't looked into if it actually gained a HP boost, but the whole job was about 340$ at my local Muffler shop, and they had it done in 2 hours. It gives it more of a growl. It shows the true colors of that GM 3800, but doesn't sound obnoxious. If I were you I'd definitely look into some things flowmaster puts out!  And shucks, I got a taillight out! :angry: Those are always a pain

20171005_003532.jpg

20171005_003503.jpg

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Thanks all. Yes - Flowmaster is the name I was thinking of. I finally remembered and saved their website but RetroJohnny has done exactly what I want to do and included the Flowmaster part #. 

 

This is the route I will be going.  

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Dual outlet looks great I agree.  Not sure how I will go since I am doing #105 as an archival type restoration since it represents the oldest surviving Reatta.  I am not sure I want to change a whole lot visually

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I did a little looking on muffler web sites and none are really helpful.

I sent a note to Walker and they came back with a little info, including this picture of the inside of their muffler for a Camaro.

On the Camaro the "IN" is the top right.  The Camaro tailpipes come out on each side.

If you used it on a Reatta, the LEFT pipe would be the "IN" and the right pipes would be "OUT"

That hump in the center would keep the sound from being straight thru.....it should work, the unknown is the sound level.

Walker part number is 12265

 

Capture327.png

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On the CARiD website- they have more exclusive diagrams and information. For my choice of muffler  https://www.carid.com/1990-chevy-camaro-exhaust-parts/walker-muffler-35449716.html   this is the generic diagram for their SS mufflers. According to the Walker fitment diagram I supplied earlier- the inlet is the "top right" and the two outlets are on the bottom, correctly fitting a Reatta.

 

Walker_SS_Muffler-diagram.thumb.png.5e91290cfb61c483190b4ff8b27af6a3.png

 

Exhaust-Diagram.thumb.png.f204a9e85b6fe2feb70efdb1e5f430cc.png

 

 

https://www.carid.com/walker/info/quiet-flow-muffler.html

Edited by 89RedDarkGrey (see edit history)

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For what its worth:

 

I've owned my '91 Reatta convertible since 2007, and it was purchased with approximately 107,000 miles on it.  Since the car is driven a couple thousand miles per year, it will never be a show car and I purchased the car not as an investment but as a pleasure vehicle to enjoy.  Therefore, when I decided to "upgrade" the exhaust, I was looking for the appearance of dual exhaust and the sound of an engine that was just a little louder/better than stock.  The photo's attached showed how the Camaro Flowmaster was installed and how the trim was adjusted to fit an outlet on the passenger side:

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ATT00044.jpg

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ATT00058.jpg

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Another possibility........AP Exhaust Technology (www.apemissions.com)

XS2265 is a stainless muffler 18" body 2 1`/2 in inlet and outlet, catalog says reversible, which means to me you can use any port as IN.

XS2268  same as above but IN port is centered

690514 is not stainless body is 14" long inlet and outlet are both 2 1/2 in IN port is centered

 

They list a header pipe for a Firebird (cat back to muffler) part number X6501 which could probably be modified for the Reatta, it has most of the correct bends but will be too long

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3 hours ago, Imperial62 said:

I would go Stainless although it's probably overkill.

 

After numerous heat cycles, weather conditions, road debris, etc. it will never rust out. Weren't all Reatta OEM exhaust components a "mild stainless"?

 

Funny- I did a magnet test to it all- and it stuck. My Mechanic friend then insisted it wasn't SS, and "no '80's GM car had factory SS exhaust" (even showing him various literature didn't sway his "opinion" because of his almighty magnet).

 

I guess to some people- if it's not rainbowed gleaming Harley Davidson mirror chrome- it's not stainless steel (forget trying to explain different grades to Sheeple)

 

ARTICLE #1        ARTICLE #2      ARTICLE #3

 

So- we can tell the magnet testers to shove their magnets.

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On ‎10‎/‎6‎/‎2017 at 5:57 PM, handmedownreatta said:

i would paint the muffler flat black.

 

On ‎10‎/‎6‎/‎2017 at 8:24 PM, 89RedDarkGrey said:

It would take some serious prep work- to successfully coat stainless steel.

 

http://homeguides.sfgate.com/painting-over-stainless-steel-41624.html

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None of my reatta are going to be driven enough to worry about replacing the mufflers once completed. The ss has a new Camaro muffler now. 

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