What exactly is "Off Road" exhaust?

Sams '66 · 09-11-03, 08:58 PM

Sounds like something I might add to my Jeep.......

LoL

Sam

67HEAVEN · 09-11-03, 09:20 PM

Off Road Exhaust was Chevy's way of implying louder than normal, and those naughty boys ordering same should be sure to race their cars "off the road" on race tracks.

Sams '66 · 09-11-03, 09:28 PM

ahhh Haaaa
So .......it is more open? and lots louder?
Or chambered just for the noise?

Sam

SebringBill · 09-11-03, 11:04 PM

For my 57 (and through 62) the mufflers were round instead of oval. I believe that the "off road exhaust was less restrictive, hence louder. I like the sound of mine both at idle and at speed.

Dave65 · 09-12-03, 07:44 AM

The mufflers had three baffles rather than the five on the normal mufflers. Otherwise they looked identical.

Dave

396 RAT · 09-15-03, 09:55 PM

I have never had 'em, but I thought off road exhaust was a chambered system that exited out the rear?

bossvette · 09-15-03, 10:05 PM

I had "off road exhaust " on a 69 z-28 and they were chambered pipes that exited from the rear.

Sams '66 · 09-15-03, 10:15 PM

Sounds like it is an exsaust system that is louder and more restictive??
Reduces performance?.....like side pipes?

Sam

78SilvAnniv · 09-15-03, 10:42 PM

Quote:

Originally posted by Sams '66
Sounds like it is an exsaust system that is louder and more restictive??
Reduces performance?.....like side pipes?
Sam

Nah...more like louder, less restrictive and more performance.
That is what I experienced with my switch to chambered exhaust which is termed "for off road use only".

I think FORUO is a legal term that absolves the manufacturers/providers of responsiblity towards smog changes to on-road vehicles, since legally (Federal) we are not supposed to change any emissions on our vehicles.
Heidi

Tom Bryant · 09-16-03, 01:42 AM

As Dave said the off road mufflers for the midyears looked just like the standard mufflers but were less restrictive. Sounded great too. This was option code N11. Side mounted exhaust was chambered and was option code N14. The off road mufflers for the solid axles were round and had 2 smaller tubes straight through with no baffles. They didn't have a seperate option number but came as standard equipment on the high horse fuelies.

The chambered exhaust used on Camaros and 442s and maybe other GM muscle cars was made up of the same chambered type pipe sections as the Corvette sidepipes (midyears). This was developed by Walker and they still sell it in replacement muffler configuration under the brand name Walker Turbo Tubes (also NAPA). Off road refers to 2 different type of systems here. As a matter of fact N14 Side Mounted Exhaust was footnoted in the parts manual as off road use only also.

Tom

78SilvAnniv · 09-16-03, 09:18 AM

Tom,
Is the For Off Road Use Only exhaust you are discussing different from what I am thinking it is?

It seems from your comments that FORUO exhaust could be ordered for the early vettes, but by today's definition (my understanding) we are not supposed to change anything about the emissions and companies who sell the exhaust use FORUO as a disclaimer?
So...you used to be able to have FORUO installed at the factory, and now you must use-at-your-own-risk according to the disclaimer?
Heidi

Tom Bryant · 09-16-03, 10:36 AM

That's about it Heidi. Pre-emission era cars used the off road disclaimer mostly because they were kind of loud. Now it can mean that the exhaust is louder lthan is commonly accepted by law enforcment and also that it isn't emissions certified.

Tom

78SilvAnniv · 09-16-03, 12:20 PM

Thank you!

I see that I was on a TOTALLY different page than everyone else...but I learned something new.
Heidi

bossvette · 09-16-03, 02:27 PM

Back in the good ole days us old f***ts remember It was like Tom said you could order "Off Road" exhaust and other go fast parts from the manufacturer, which simply meant they were louder and or more performance orientated not for normal street driving. The first Corvette I ever had a ride was a 65 396 Big Block with the 425 HP engine and had side pipes(off road) and 4.56 rear gears(gas was $.30 a gallon for high test) It would pin you back in the seat thru most of third gear.
As emissions laws took over the term "Off road use only" came to be a disclaimer that aftermarket manufacturers used so they could sell their "illegal equipment" The larger companies have the resources to become "50 state legal" while the smaller ones don't.
the 69 z-28 I had was equipped with "off road" exhaust, camshaft and had dealer installed headers with 4.11 gears beyond the standard z-28 package. As long as you kept it under 3000 rpm it drove like your grandmas 6 cylinder after 3000 was a different story.

wallyknoch · 09-18-03, 01:17 PM

Off road exhaust was included with the fuel injection at no extra cost for the 1962 Vettes. Look close to seventh line down, which reads, 441A off road exhaust. cost $00.00. Close to 3000 cars were so equiped and that probably included some or all of the 340 cars too. This is a true copy of my dealer invoice that I found in my old law school notes about a week ago. I have been looking for it for years and if I still had it, the notes were a logical place to look and I finally got lucky.