silfox

Do any of you straight axle guys have the off road mufflers? If so, how do you like them and where did you get them? I've got the standard oval mufflers and they are far too quiet so I'm looking for something to make the old 59 sound more like a Vette! :D

solidaxles&elkys

hey silfox,
i have the "off road exhaust" on my 62 and it sounds great. i am constantly getting compliments on the sound. i am trying to find who i got the set up from, it was a while back. it is all stainless from the manifolds back with a crossover pipe. very nice quality, i will chime in when i figure out what company i ordered it from. any questions e-mail me elky207@yahoo.com
eddie

DZAUTO

I DID have the round, offroad mufflers on the 56 several yrs ago. I myself cannot hardly believe that they were too loud for me, but they were. I have the 62-5 style 2 1/2in manifolds with Zierden stainless all the way back. When I removed the offroad mufflers, I installed stainless stock mufflers and they blew out with the engine that was in the car (strong 350). I now have aluminized turbo mufflers from the local muffler shop with a lifetime guarantee.
ALSO, I really dislike the stainless because it expands and contracts WAY too much and causes frequent rattles. Unlike Eddie's 62 which has the tailpipe exiting at the rear wheel, my tail pipes go through the tunnels next to the trunk and it is just impossible to get them adjusted so that they don't rattle at some time or another. I am seriously considering removing the stainless and have a 2 1/2 alum system made up and have the tailpipes exit like a 61-2. If and when I do that, I will go with 2 1/2in turbos.

I also have a dear friend who has a 57 FI 283 that had the offroad mufflers. They were too loud for him and his neighbors (nothing like peer pressure). He brought it to me to take to the muffler shop that I use to get turbo mufflers installed. He is now very happy.

Ron04,02,96,64

Yes, have them on my 57 and like them. No expansion or other problems. Got all the parts from Paragon.

Fairly loud under throttle but not as bad as some side pipes I've heard plus since they're headed out the back not really aproblem while driving and really not very noisy at cruise speeds.

cdwilson13

Whatever happened to Hush Thrush mufflers. That's what's on my 62's 250 hp 327 and I have always liked the sound. Not too loud, but not too tame. Since it's been about a hundred years since I bought them, and since until recently, my corvette hobbying was dormant for most of the last 10 years, I'm out of touch. Anyone know if they're still around. If not, is there something similar? If so, I would; a) recommend them and; b) like to know where to get them since my are in need of replacement.

claf

Most all the bigger after market suppliers have them ie: Ecklers, Corvette Central etc. I'm using Smitties on my '62 (stock 250 hp, NO crossover) and I have never heard a better sound, except maybe my 67 435 with sidepipes!

silfox

Eddie, Tom, Ron, et al,
Want to thank all of you for taking the time to send the info on the off road exhausts. Sure appreciate it. :)

62fuelie

I put a set from Corvette Central on my 61 a couple of years back. I was sort of disappointed. They were a little louder than the oval "silent" mufflers, but not a lot. Didn't really sound like a Vette. Engine was a 2X4 283. :(

JCL

silfox. Do you have any dimensions on the area that the muffler goes. Or better yet a picture. Might be able to come up with a shorter BAFFLE like the ones i have for the 4" sidepipes !!! Let me know. Thanks, JCL :cool: :chevy

JohnZ

I have a Paragon stainless system with the round off-road mufflers on my '57 270, and it's terrific - nice "rap" when you get on it, otherwise nice, classic Chevy sound. It's a mite loud inside with the top up (resonates), but that only happens if I get caught in the rain (twice in 4 years). I don't buy the expansion argument at all; I set mine up carefully, adjusting hangers and clamps for about four hours to get everything hanging with proper clearances and no stresses when I installed it four years and 4,000 miles ago, and I've never had a single rattle anywhere since. My tailpipe tips grow about 3/8" from cold to hot, and my neighbor's '59 with an aluminized system grows exactly the same amount - measured both of them one day last summer. 304 stainless has a smaller coefficient of thermal expansion than plain steel does; there's no way it can expand more than a similar plain steel system that's installed the same way. I like the sound - sweet, but authoritative :) .

K2

Respectfully disagree with you John on the thermal expansion coefficients of 304 stainless vs carbon steel. Actually 304 stainless has a thermal expansion co-efficient 29% greater than carbon steel. I believe some stainless exhaust systems are made from a ferritic 400 grade of stainless which has a lower thermal coefficient of expansion than that of 304 SS and therefore the amount of expansion you notice may be neglegible.

Do you know if Paragon will make their mufflers with larger inlets and outlets as I am looking for some to fit on 2 1/2" dia. pipes. I really liked the sound of my original off road mufflers but a few years ago I bought some replacements and they sounded terrible. Took them off and put on turbos but they are a little to quiet for my liking. :sleep:


[Modified by K2, 6:00 PM 11/21/2001]

magicv8

DZAUTO - I have 2.5" stainless exhaust pipes from Allen. I slotted the flarred ends so that the clamps didn't need to dent the pipes to get a good bite on the inserted pipe ends. Over the years, I have removed and replaced the exhausts several times (clutches, synchros, engines, rear ends) and the pipes always come apart easy and do not come loose. Neither do they grow with heat to the extent that the hangers can't keep the tips centered in my rear valence panel bezels - which is a real feat with 2.5" TIPS coming through the bezel instead of the wimpy stock ones. I am using stainless Borla turbo mufflers (that you can see through), 2.5" in and out - hung at the back only with a cheapo ($2) muffler hanger. The only other support is at the trans (motor) mount.

Set the pipes up carefully (I had to trim the left exhaust pipe .375 and the right .125 before I slotted the outer collars) and the stainless pipes should work like aluminized. The coefficient of expansion of the two materials isn't that different.

Sorry to interrupt this thread.


PS Please check my math: The coefficient of thermal expansion for 304 is 1.8x10-2 mm/m/ºC, so for a 3m long exhaust pipe the result is .054mm/ºC - then for a 200F/90ºC change, growth will be 4.8mm instead of 3.2mm. I don't think the extra 1.6mm will be noticed. A 30% difference is still not a lot of growth. Make the temp change 300F and you still only get a 2.4mm difference. :boxing


[Modified by magicmachines, 9:31 PM 11/21/2001]

SebringBill

Got a stainless system with the offroad mufflers for my 57 from Zierden in 1995. Looked, fit and sounded great. Still does. Unfortunately, Zierden sold their business to MOFOCO a while ago and while MOFOCO did finally honor the lifetime warranty (outlet pipe on the rt muffler broke loose) it wasn't without a fight. I really liked the Zierden company and products but cannot recommend MOFOCO and still sleep well at night.

My 57 has had the pipes ending a la 61-2 since before 61...it seems that the original owner (I bought the car from his widow in 1991) got it when he was 24 years old. (Stock oval system) Took his mother for a ride...she said "I don't like the sound of that car. Fix it or get rid of it!", so he turned the pipes down behind the wheels and actually fiberglassed over the access holes in the rear end kickup area of the body. That's also why I still have the original exhaust bezels with the original chrome!

The original owner soon after delivery in May, 1957:

silfox

SebringBill,
Cool! :cool:

Big Block 60

How about taking the '65-67 side exhaust mufflers (chambered), fit them along side between the body and the frame rail. You'll need to fabricate a bracket at both ends to bolt to the frame. Measure how long of a pipe you'll need to match up to your headers. Cut off what you don't need on the chambers, weld in a pipe and collector and you're done. I've got block hugger headers and this was a piece of cake.

abdo

When I bought my '57 245 HP, it had oval mufflers and they were too quiet. I put on a complete exhaust system last winter and installed off road round mufflers from Corvette Central. They are only a little louder than the ovals, except when you put your foot in it. They sound good.