[Shawn]

Does anyone have that 2.5" 67-69 Camaro exhaust system that Summit sells for $329 ? It's got the 3 chamber delta flow 40 series mufflers from Flow Master and an "H" pipe. I was wondering how loud it is and if it's worth getting. I'm parting ways with my current 3" system, a little too much for a daily driver...

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Shawn Peterson
1969 Z28, 406SB

[Kevin]

I think that "loud" is a relative term. What's good for me may be too quiet for you or vice-versa. I do know of someone who was willing to sell me his 2 1/2" Flowmaster system for $75 because he thought it was way too loud for a daily driver.

[MikeDF80]

Does that system have the single transverse muffler, or dual mufflers? I have headers with a stock system now, and I want something a little louder. Not overboard though.

[Shawn]

The system I was looking at for the 69's is a dual system all the way back. It uses 2 of the Delta Flow 40 series mufflers which are 3 chambered. The normal 40 series are 2 chamber mufflers. I have the normal 40 series on my car right now, 3" all the way through. Cruising tone is tolerable but a little loud, stomp on it and it sounds like a NASCAR. Not a daily driver setup.

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Shawn Peterson
1969 Z28, 406SB

[CarlC]

I got a deal on the single transverse 2 1/2" Flowmaster system mentioned above that I thought I couldn't refuse. These pre-bent systems require a bunch of work to make them acceptable. There were several pieces that ended up in the trash because they did not fit correctly and could not be reworked. The single transverse muffler sounds great but it radiates a great amount of heat, so much so that the trunk becomes an oven. Heat shields, heat pads, insulation, the whole bit and it is OK, but if I had the choice again I'd take it to the muffler shop to have a full dual system installed for the same total cost.

[JimM]

Hey, timely topic!
I'll be putting a new exhuast system on my '68 convertible this winter. Non-originality is not an issue. I'd like a 2.5" system with full tailpipes and a good sound. I had a system years ago with 2.5" glasspacks, great sound, but too loud for me now. I don't like they sound of typical turbo style mufflers, too wheezy.

What do you guys recommend? Does anyone make something that fits and sounds good? I know I can fit dual 2.5's over the floorbrace in the ragtop, but will the prebent systems fit as well as custom bent pipe?

I see that Flowmaster offers 3 systems for firstgens, 1 with short tailpipes, 1 with transverse (according to summit it won't fit a ragtop) and 1 true dual full tailpipe system listed for a 69. Summit also shows a house brand system made by Borla. What about a repro chambered system from Rick's?

[CarlC]

JimM - please see my above posting.

I was hopeful that the pre-bent systems would fit without too much much hassle. I thought that with my trusty wire-feed welder and some patience I could do the job myself. It turned out to be a whole different story. The header-to-muffler pipes are generic and require bending and cutting to fit because of the wide variety of headers on the market. The short over-axle to muffler pipes were not bent correctly and because of their length could not be reworked. The muffler fit well but the heat is excessive especially on hot days in slow traffic. I ended up not running full tailpipes to the rear of the car but instead exited behind the rear tire. I just did not like the look of a 2 1/2" pipe sticking out the rear of the car. It took the muffler guy 4 hours to make this thing work correctly, about the same time ( and total cost) it would have taken him to make a full dual system. In your case with the extra convertible bracing, routing a 2 1/2" tube where normally a 2" would go seems to me to be a real stretch for a pre-bent system.

[Toby T.]

Exaust is a specific science and a balance of sound vs. performance. Edelbrock has a great web site that has lots of charts and advice. 3 inch systems are usually reserved for higher HP engines above 350 I believe and harder to find and install. For a 90 degree engine an h-pipe doesnt really do anything beacuse of the firing order and pipe pressures It does increase some low rmp torque but robs hp at high rmp. The best example for exaust systems is look into how the nascar boys design there systems. If you into a daily driver, keep it simple...use a factory aftermarket system like ones offered by Classic Industries.

[gheatly]

CarlC => thanks for the info. I was thinking of replacing my exhaust system with one of the Flowmaster kits. Sounds like it will be cheaper to buy the mufflers separately and have a muffler shop bend the pipes from scratch.

Speaking from experience, a 2.5 inch system with 40 series mufflers IS too loud.

I have read in Hot Rod several times over the years that a 2.25 inch system will provide a significantly quieter system without much of a loss in performance. I guess that the sound level of a system is somehow related to the diameter of the pipe used.

[This message has been edited by gheatly (edited 12-17-99).]

[Shawn]

Carl- If you don't mind me asking, what did it cost to have the pipes custom bent at the muffler shop? What I'd really like to do is get a good fitting 2.5" dual exhaust, and then get a couple of the quieter series mufflers from flowmaster, maybe delta flow 50 series or something from Dynomax. I want some exhaust note, but would also like to be able to hold a conversation in the car without yelling. Stock is too quiet, and my 3" system is too loud. I have to think there is a happy medium in there somewhere.

FYI- Dynomax site has recorded some popular cars with various exhaust systems they sell. Somewhat useful because it gives you a idea how lod each of them is relative to each other, kind of cool...
http://www.dynomax.com/Sounds.htm


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Shawn Peterson
1969 Z28, 406SB


[This message has been edited by Shawn (edited 12-17-99).]

[CarlC]

Shawn,
$200 for four hours labor and parts. The only parts from the kit that had to be replaced were the over-axle pipes. The tailpipes I had cut short but when they put them in place for the initial mock-up they would have had to do some bending to make them come out the back straight. I had chrome tips added even though you can only see 1" of them. The system is fully welded. Like many things, it is sometimes easier to start from scratch than try to modify someting that someone else has done. If you need to have the whole system put in I'd reccommend heading down to your muffler shop and have them quote all new vs installing a pre-bent system. There are just too many variables involved.

I had a lenghty discussion with a Flowmaster field rep about exhaust systems. He stated that 2 1/2" (their full dual or single transverse muffler) system can support up to 400 hp. For best relults on street cars where some civility is requred, he reccommended (for me) a 2 1/2" system with 3-chamber mufflers, a crossover, and a minimum 18" long tailpipe. He also stated that tailpipe exit location was very important for passenger compartment comfort. Turn downs at the muffler are the loudest, while horizontal rear exit is the quietest given the same muffler. My exits are behind the rear tires, which is a compromise. The drawback to this exit location is that every time I back the car up the exhaust shoots up a cloud of whatever dust, dirt, etc. that is on the ground and it gets all over the back of the car. With matador red paint it is not something I appreciate very much.

As far as pipe diameter vs noise, muffler choice is the key, not pipe diameter. Factory 2" and simple 2 1/4" "turbo" muffler systems are usually pretty quiet, but 2 1/2" - 3" require the owner to do some homework on proper muffler selection. I thought the flowmaster single transverse muffler would be quieter than the 2 1/4" with turndowns at the muffler that I had temporarily installed on the car to get the car to the muffler shop. The muffler guy said that the Flowmaster muffler was going to be just as loud, if not louder than what I had on the car. I thought he was crazy, but he was right. Consult with your muffler man, if he is good he will know what you want and will make a good suggestion.

[gheatly]

CarlC,

I'm not sure what to think of your Flowmaster field rep. I have seen many cars making well over 400 hp with a 2.5 inch exhaust system. Personally, my supercharged 350 made 437 rear wheel horsepower on a chassis dyno (that's a tad over 500 hp measured at the flywheel). That was with SMALL tube headers, 2.5 inch pipes exiting from the stock location, and 40 series Flowmaster mufflers. In theory, the Flowmaster system would make even more power because the tubes are mandrel bent. My local muffler shop used a standard tube bender so I lost some pipe diameter in the bends.

[doug70]

(my 2-cents) when you start "modifying "exhaust from "standard" ie: headers,mufflers,h-pipe,etc)tends to make things "louder" experience has proven this to me as i took a standard dual exhaust and added headers and WOW! what a noise difference!(i'm 50/50 when it comes to headers)just like i was told, that "punch-out" a catalytic converter it'll make your car preform better ,no way! it only made it louder! this is just my opinion... (i guess you have to sacrafice noise for performance?).thanks and good-luck..

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70camaro(350)ground-up restification,350 slightly modified

[CarlC]

gheatly,

I belive that for most applications OEM's are going to lean toward a conservative approach in their products. Like yourself, I have seen big power in small packages, but from an OEM point of view (I work for a large OEM company) a conservative approach will likely not disappoint end-user down in terms of performance.