Muffler comparison

[BobCGT]

Im looking to upgrade the exhaust system on my GT.

Currently I have the stock system and I will be going to the 2" dia.

After reading the threads on this subject, it appears that a lot of folks are using the #11365 MagnaFlow. How would this compare to,say a 60 series Flowmaster? Performancewise similar or just sound difference?
Bob

[BQS4]

Bob;
I have had good luck with MIDAS off the shelf muffler, that way, as long as you own the car, they'll replace it free!!

[ungermm]

I have heard from a member here that Dynamax #17777 gives a great sound. Jerry

[Paul]

Here's what I recently used on the GT.

DynoMax Thrush Turbo muffler. Reason low cost, decent flow, and hopefully somewhat less of a drone between 2000-2500rpms than what I used on the Manta

Headman Single Resonator Chrome tips: Reason take the edge off the noise level, but be less restrictive than a second muffler.

My daughter wanted something louder than stock. I wanted something not so loud that you couldn't hear the stereo AND without the drone. Since its hard to tell what a muffler will sound like before its installed, low cost was a factor. As in, if I don't like it, I won't have wasted lots of money on something that's thrown in the trash.

The result was actually suprisingly good. It has enough of a deep raspy note to hear in the parking lot... but mostly from OUTSIDE the car. With the windows rolled down it can be heard and sounds good. With the windows rolled up, its NOT heard (much).

I'm sure, as the engine modifications begin to add up, the noise level increase as well...

PS I purchased the Muffler from Summit for ~$25 and the tips were ~$20 each Summit Racing - High Performance Car and Truck Parts | 800-230-3030

[Lindsay]

Originally Posted by BQS4 Bob; I have had good luck with MIDAS off the shelf muffler, that way, as long as you own the car, they'll replace it free!!

1983 or 1984, Midas completed entire 1973 GT exhaust system for approx. $350. I already had a custom trailer hitch to tow 220 lb. utility trailer. Rear resonator would "bang" inside trailer hitch cradle and eventually crack weld joints of the two chrome tips to resonator. Midas would constantly repair welds, add stiffeners, then replace resonator. I went to another trailer hitch shop and had hitch cradle lowered a few inches.

Sure got my money's worth out of Midas Muffler. Do they still have GT mufflers?

[BQS4]

Originally Posted by Lindsay 1983 or 1984, Midas completed entire 1973 GT exhaust system for approx. $350. I already had a custom trailer hitch to tow 220 lb. utility trailer. Rear resonator would "bang" inside trailer hitch cradle and eventually crack weld joints of the two chrome tips to resonator. Midas would constantly repair welds, add stiffeners, then replace resonator. I went to another trailer hitch shop and had hitch cradle lowered a few inches. Sure got my money's worth out of Midas Muffler. Do they still have GT mufflers?

Lindsay;
It's not a GT specific MIDAS muffler, it's more like one of their gold "turbo" style mufflers that's real small to fit the Opels. I have one on my GT that was installed going on over 20 so odd years ago, and it has NEVER given me any problems. I have had this same style muffler and system added to all the Opels I have bought and not one has ever had to go back for ANYTHING.

[wrench459]

I was behind one of BQS4 many Opels while at Snellville this year.
That muffler is very quiet BUT has a mean rumble to it
like..."are you sure you want to mess with me?"

[RallyBob]

I've used the Dynomax mufflers, Magnaflow mufflers, and Simons mufflers...all with good results. Of all these I mentioned, the Dynomax are the cheapest to purchase, sound good, make good power, but rust out the quickest.

The Simons sound the best to my ears, and make great power, but are not readily available in this country (they're Swedish made, and sold under the name of Jetex in the UK and at some US distributors). The exchange rate makes them a bit pricey too.

The Magnaflow last a long time, make great power, sound nice (but a bit noisier), and are reasonably priced. The stainless Magnaflows cost a bit more, but last virtually forever. Acoustically, stainless steel is louder by nature. More 'tinny'.

I've never run the Flowmasters, but my friend Bjorn Anvedh in Sweden has dyno tested them, and they consistantly lost 8 hp over the Simons mufflers on his engine dyno. That was on a 221 hp engine however.

JMTCW,
Bob

[oldopelguy]

Hooker Aerochamber.

You know the nice rumble Flowmasers ahve down low before they get all raspy when you rev them up? The Aerochambers sound that way all the way up.

Good stuff.

[madhatterpdc]

I've spent some time with an exhaust system that consists of a resonator, then a Simons muffler, then a 2.5 inch over axle, then a second resonator.

The sound is great! Not at all too loud or raspy, but you definitely know this motor is healthy (2.0, ported head, cam, etc.). It runs strong and breathes easy. Can't say the same about the owner though.

The Simons muffler has an added benefit of being small in size too, great for the restricted space requirements that we are limited to.

I can't say that I have ever seen a Dynomax muffler last longer than a year on a car that is driven more than ocassionally. It's been a while since I heard an Aerochamber, and that was on a built mouse motor, haven't heard it on an Opel, but I recently have been considering trying it due to the small size.

[BobCGT]

Thank you all for the replies.This gives me lots to think about.

So far all I have decided on is a 2" dia. system,I do want a nice deep sound but not a farty one like the "tuners" seem to be fond of.

Improved breathing over stock is my first concern, then a healthy note, but not so loud that John Law will want to give me an "award"

[wrench459]

Originally Posted by BobCGT Improved breathing over stock is my first concern, then a healthy note, but not so loud that John Law will want to give me an "award"

now this will blow your mind
go after the intake side first then the exhaust
if you want a free breathing CIH engine

[Paul]

Here's in interesting technical article to read up on about mufflers....... Lets see if the link works...

Auto Exhaust Science

[tekenaar]

Originally Posted by oldopelguy Hooker Aerochamber. You know the nice rumble Flowmasers ahve down low before they get all raspy when you rev them up? The Aerochambers sound that way all the way up. Good stuff.

. . . yeah, those ol' "Flomasers" will do that to you!

[sugg578]

Come on, I like Flomasers too.

[RallyBob]

Here's in interesting technical article to read up on about mufflers....... Lets see if the link works... Auto Exhaust Science

I noticed they didn't care too much for the flow characteristics of the Flowmasters in that article either. Hard to believe that two 2.5" Flowmasters only offer unrestricted power up 'til 265 hp. So that's what, 132 hp on a single 2.5" Flowmaster?

[tekenaar]

I've been using JCW's Cherry Bomb "Turbo" mufflers as the primary, front mufflers in many of my Opels for some years now in either 2" or 2.25" size, depending primarily on engine displacement and modifications, and either with or without resonators.

Made by Walker, sound good, last well and, most importantly, . . . LOW PRICE! M2CW anyway.

[Paul]

Originally Posted by RallyBob I noticed they didn't care too much for the flow characteristics of the Flowmasters in that article either. Hard to believe that two 2.5" Flowmasters only offer unrestricted power up 'til 265 hp. So that's what, 132 hp on a single 2.5" Flowmaster?

I noticed that too. I was interested in what they said about resonator boxes and their thoughts on the Aero Chamber and the Dynomax Turbo muffler.

However, most of the discussion centers around V-8s which have two places in the foring order where 2 cylinders fire with 90* of each other, so that the exhaust system "sees" it as one "big" pulse. This kinda skews things compared to our 4 bangers.......

[Lindsay]

Galaxie Gazette - Company Profile - Spintech Mufflers
Spin Tech Mufflers

Seen Spin Tech booth at a few car shows, but no car to listen to. Not many applications with 2" inlet/ outlets sizes, but several 2.25". I don't see any or many application info for sports compact or small vehicles. Cost is slightly expensive!

Had some fun listening to exhaust sounds on their link (YouTube).

[opel kid]

i've noticed at Auto zone online they have exhaust pieces ,anyone try to buy from them???