I am looking at a couple options for exhaust systems, originally I was going to use the Jegs kit (highly recommended on this forum) and add the mufflers. But the price of doing it that way exceeds what you can buy the complete Flowmaster American Thunder kit 17119 for @ Summit which also includes the h-pipe. I read alot of people dont like the Super 40 mufflers because of the interior resonance (sp?). One question I have is will you get the same resonance with a convertable? I typically drive with the top down 90% of the time :hurray: so I thought that may reduce it some.For the last 19 years I have had Walker glasspacks with pipes out the rear and I am pretty comfortable with that sound level,I wouldn't mind maybe 1 notch quieter,but dont want any louder, will the 40 series be comparable or should I look for the 50's or something else.

I know you're interested in price and sound, but the mandrel bend systems by flowmaster look a lot nicer then some of these that you can see the pipe bender stretch marks in them. I don't know if they last any longer, but they don't look like a muffler shop special.

Rob

I love the AT sound. It is a bit agressive but with the stereo turned up ....

My wife says there is no way I can sneak up on the house when i come home though :D .

I am very happy with my At system. Very easy to install, 2-3 hrs. Except for my collector connection which I measured and took to the muffler shop to have it expanded for a slip fit.

My only issue is that I have had to replace several hangers because the rubber keeps splitting and breaking. Been on the car about 4 years.

The finish has held up very nice too.

I am very happy with my At system. Very easy to install, 2-3 hrs. Except for my collector connection which I measured and took to the muffler shop to have it expanded for a slip fit.

My only issue is that I have had to replace several hangers because the rubber keeps splitting and breaking. Been on the car about 4 years.

The finish has held up very nice too.

I see on the Flowmaster website it says NOW with super 40 series mufflers http://www.flowmastermufflers.com/products/index.php?main_page=product_info&products_id=3703 So I wonder what did they use to come with, and are super 40's quiter or louder?

I have the American Thunder system on my wife's coupe, sounds great and looks good. I did the same as ss1970chev454 and expanded the pipe to fit over the header collector for a neat clean look and good fit.

Rich.

Another user of the American Thunder system but I'm replacing the muffs with Ultraflows for more power and flow. :hurray:

I did the same as ss1970chev454 and expanded the pipe to fit over the header collector for a neat clean look and good fit.

Rich.



I thought that was how it should fit to begin with,no?

Have you looked at Magnaflow's American Muscle Car systems, they are a header back system, mandrel bent with x pipe design, pipes are stainless steel comes with polished stainless mufflers, 3 different tailpipe designs and chrome tips includes all the hangers and clamps. Magnaflow used my son's Chevelle for a fitment session and gave him a complete system, (the orange Chevelle on Magnaflows web site when you select Chevorlet Chevelle link)when we built the car we installed Flowmasters A-T system but was just to uncomfortable to drive any distance due to interior resn. The car is much quieter at cruising speeds and still has that nice muscle sound under acceleration. The car runs much better with the Magnaflows, better off idle acceleration, broader power band. I installed the same system on a buddies 71 SS with stock 402 and 4 speed, greatly improved the performance, and loves the sound. Took about an hour and a half to install. I'm currently have another complete system waiting to go under my 67 Chevelle. 67 currently undergoing a complete frame up build just finished completely going though the rear axle, re-assembling the chassis right now.

I see on the Flowmaster website it says NOW with super 40 series mufflers http://www.flowmastermufflers.com/products/index.php?main_page=product_info&products_id=3703 So I wonder what did they use to come with, and are super 40's quiter or louder?

I think they used to come with the Delta Flow 40's but here's the wierd part.....if I'm not mistaken the Deltas are supposed to sound mellow at cruise and wicked at WOT....

...the mufflers that came with my kit are longer than the traditional 40 series....and mine sound EXACTLY like the regular 40 series.....loud all the time....

If I were home I could tell you the part number of the muffs that came in my kit, I remember the nuber started off with either a 94 or a 95....it's in my install kit.....gives part numbers of all the pipes and the muffs too...

I have Magnaflow's American Muscle Car system on my 69 velle and it sounds great when you get on it but no too loud you cant have a conversation on the highway. I noticed an improvement in the power and I really like the full stainless with the polished mufflers. You cant beat the price of 450 for the kit.

I see on the Flowmaster website it says NOW with super 40 series mufflers http://www.flowmastermufflers.com/products/index.php?main_page=product_info&products_id=3703 So I wonder what did they use to come with, and are super 40's quiter or louder?

I installed my AT kit about 5 years ago. It came with 30 series mufflers. I've never really figured out how they are different than the 40's or 50's. They do have a pretty big case.

Edit: I just looked them up, PN 52533

I thought that was how it should fit to begin with,no?

Yes.... but the kit comes with extra long, ,un-expanded head pipes. You have to line them up, ,and trim them to fit your particular header and collector combination. I too expanded the pipe to slip over the collector.

I fit up the whole system myself, trimming, and expanding where necessary. If you do it yourself, make sure you get a GOOD expander. I don't know what those pipes are made out of (aluminized steel?), but it was a lot of work to stretch the pipes with a manual expander - even with an impact wrench on it. The impact runied the threads on the first cheap expander.... anyway, after fitting it up, I installed it with clamps, and for $100, I had a muffler shop weld it up, and I removed the clamps at home.

Have you looked at Magnaflow's American Muscle Car systems


More $$ than I budgeted, but stainless sure would be sweet


If I were home I could tell you the part number of the muffs that came in my kit, I remember the nuber started off with either a 94 or a 95....it's in my install kit.....gives part numbers of all the pipes and the muffs too...

mufflers starting with p/n 94xxxx are delta flow 40's
mufflers starting with p/n 95xxxx are super 40's

Summit has Flomaster pipes only and I used Dynomax super turbos 2.5 Interior is quiet outback is loud I have seen other team members say they like the combo

I just picked up a Chevelle application 3" Summit system from them less mufflers on Friday. It's good lookin' stuff and hard to beat for the price. (less than 200 bucks for the whole thing minus mufflers which is cheap for 3" mandrell bent) I'm actually modifying it to use on my 427 Biscayne or I would have bought the stainless Magnaflow system from them. It's the best lookin' bolt on stuff I ever saw, but the floor pan in the Biscayne is enough different that the Chevelle stuff wouldn't be modifyable to work.

I just finished ordering the 2.5" AT system from Summit, It should be here by Wed or Thurs. I sure hope it sounds good

I wouldnt bring my car to a muffler shop if they were offering thier services for free. Nor would I have them install a pre-bent system. Im not a big fan of having a system bent for you.

The system i took off wasn't very old (except the glasspacks) I had it bent from scratch at a local shop and I thought they did a decent job until I removed it and found the top side of the tailpipe was 1/2 way collapsed over the axle on one side

Gravy D,

I have the 40's with my system. I don't know if you would consider them loud but they are definitely not quite. You get that typical FM rumble. Ultimately that was the sound I was after anyways. When I'm cruisn' down the road, I like to hear it, feel it, and smell it. No radio in my car.

I hate doing exhaust work. laying on your back trying to lift stuff in place, trying to get it all adjusted to look right, crap falling in your eyes. But I'll tell you as far installation, it was...no pun intended..."gravy".

If you like the FM sound I think you'll be happy. Just keep an extra supply of hangers on hand. I now keep a couple in my trunk.

Check out pypesexhaust.com They have 3 different mufflers to choose from that will suite your needs for power and sounds. Also they are offered in 409 and polished 304 stainless!

Gravy D,

I have the 40's with my system. I don't know if you would consider them loud but they are definitely not quite. You get that typical FM rumble. Ultimately that was the sound I was after anyways. When I'm cruisn' down the road, I like to hear it, feel it, and smell it. No radio in my car.

I hate doing exhaust work. laying on your back trying to lift stuff in place, trying to get it all adjusted to look right, crap falling in your eyes. But I'll tell you as far installation, it was...no pun intended..."gravy".

If you like the FM sound I think you'll be happy. Just keep an extra supply of hangers on hand. I now keep a couple in my trunk.

The muffs I had on there were quite loud before,so I dont expect these to be any louder which is ok,I love to hear it as well (along with my kids who always are yelling "make it growl dad"):thumbsup:

I'm not a fan of rusty exhuast work either,but since I still have the body off the frame,I dont expect it to be too bad. I'm just going to get it hung and not overtighten the clamps until the body does go back on in the next couple weeks

If you do it yourself, make sure you get a GOOD expander. I don't know what those pipes are made out of (aluminized steel?), but it was a lot of work to stretch the pipes with a manual expander - even with an impact wrench on it.

As bulb122 stated those front pipes are tough to expand by hand. I used a bluepoint pipe expander with an internal roller bearing and it was still tough. Take your time and be carefull if using air impact gun with a cheap expander.

Rich.

As bulb122 stated those front pipes are tough to expand by hand. I used a bluepoint pipe expander with an internal roller bearing and it was still tough. Take your time and be carefull if using air impact gun with a cheap expander.

Rich.

Thanks for the heads up, we have either a Bluepoint or Snap-on at work that I wil use, if it still gives me much trouble theres a muffler shop across the street we sometimes use that will do it for little or nothing

Just keep an extra supply of hangers on hand. I now keep a couple in my trunk.

It arrived this evening so I started to get it all hung, I see what you mean on the hangers, the muffler hangers seem to have alot on tension on them the way they are mounted. When they brake are you replacing them with the same style hanger or just the universal type? Also any idea the purpose of the heavy plate that goes in between that hanger and the clamp?