1967 Corvette 427-435 factory side exhaust had no gain in Performance

[Patrick H.]

Re: 1967 Corvette 427-435 factory side exhaust had no gain in Performance

The undercar chambered exhaust gives you the sound without the drone at your ear.
Allen's, MidAmerica, etc offer this as an option.

[Michael J.]

Re: 1967 Corvette 427-435 factory side exhaust had no gain in Performance

Hello michael..the trim tag identified the plant the body was made in..only st louis was able to install side exhaust..or was it ????????????? Peter...

Yes, but it contains no identifiers specifically for side exhaust. Even if you have a St. Louis body, it may or may not have had side exhaust. It means nothing.

[Patrick H.]

Re: 1967 Corvette 427-435 factory side exhaust had no gain in Performance

Yes, but it contains no identifiers specifically for side exhaust. Even if you have a St. Louis body, it may or may not have had side exhaust. It means nothing.

Conversely, if it's an AO Smith body, it could not have had side exhaust.
I think that's what Peter was getting at.

[Michael J.]

Re: 1967 Corvette 427-435 factory side exhaust had no gain in Performance

Conversely, if it's an AO Smith body, it could not have had side exhaust.
I think that's what Peter was getting at.

That is the conventional wisdom. However, I remember at a regional in 2010, I was having my '66 with side exhaust judged (first time it had ever been judged), and since it was outdoors, on an asphalt parking lot, as a fellow chassis judge, I told the chassis team I had an AO Smith car, so no need to examine the side exhaust. Roy Sinor heard about that and said they had to check, because even if it is the accepted conventional wisdom, all cars should be examined as there could be one out there that was an AO Smith side exhaust car and he didn't want it missed..........

[Guest]

Re: 1967 Corvette 427-435 factory side exhaust had no gain in Performance

A none factory side pipe Corvette being judge NCRS is about 80 point hit I believe

[Gene M.]

Re: 1967 Corvette 427-435 factory side exhaust had no gain in Performance

There are two thoughts on the NCRS correct or not. Some want it NCRS correct while others could care less. The new concourse class is for the care less crowd or anyone that is not into the NCSR correct flight judging but still has a nice car.

[Joe L.]

Re: 1967 Corvette 427-435 factory side exhaust had no gain in Performance

As I've said many times before, if I were to ever acquire a Corvette with side exhaust, original or not, the very first thing I would do is to remove it and replace it with undercar exhaust. In my opinion, side exhaust is an abomination on a street-driven Corvette.

[Bill M.]

Re: 1967 Corvette 427-435 factory side exhaust had no gain in Performance

I have to disagree with you on that. In my opinion they look great. But I guess that is why they were an option.

[Michael J.]

Re: 1967 Corvette 427-435 factory side exhaust had no gain in Performance

I would agree they are not something one would want on a daily driven Corvette, too loud and too dangerous from the heat as you get out of the door and a lack of clearance on the sides. But on an occasionally driven, frequently displayed show type car, they are dynamite.

[Jeff B.]

Re: 1967 Corvette 427-435 factory side exhaust had no gain in Performance

I once had a side-pipe 66 while in college in 1969. One of my girlfriends always complained about having to "step over" the sidepipes. She didn't last long.

[Michael F.]

Re: 1967 Corvette 427-435 factory side exhaust had no gain in Performance

all a matter of opinion, back in day my first corvette had side exhaust which I loved but for performance I put under car pipes and left side covers etc. on for looks so I, in my opinion, had best of both worlds

[Mark E.]

Re: 1967 Corvette 427-435 factory side exhaust had no gain in Performance

I once had a side-pipe 66 while in college in 1969. One of my girlfriends always complained about having to "step over" the sidepipes. She didn't last long.

Sounds like college life was good to you, Jeff... A three year old Corvette and multiple girlfriends. :-)

[Jim D.]

Re: 1967 Corvette 427-435 factory side exhaust had no gain in Performance

After hearing about the performance loss with side exhaust but wanting to keep them on my 65 big block, I did some research. I cut my OEM pipes open and it's obvious why they hurt performance so much, especially with a big block. The flow path is 1 1/2". That would be like trying to run a marathon breathing through a plastic straw. The solution, for me and several others, was to build my own using Classic Chambered VettePack mufflers. Not original I know but the performance difference is worth it to me. Joe Ciaravino, RIP, put them on his modified 65 with headers and electric cut-outs. His dyno results were impressive. Back to back runs resulted in 414 RWHP with the headers open, 408 RWHP through the side exhaust. They are a little louder than OEM pipes but sound a lot deeper. Here's a pic. of my OEM pipes cut open.

[Guest]

Re: 1967 Corvette 427-435 factory side exhaust had no gain in Performance

Wow what a different from 2 1/2" like I said before back in 67 you wanted Performance and Horse power your running against the big boys back then on the street, I still think 427-435 is more valuable Corvette with a factory N11 exhaust system

[Daniel S.]

Re: 1967 Corvette 427-435 factory side exhaust had no gain in Performance

Agreed, while N11 will probably perform a little better it does not have the appeal with collectors that a true side exhaust car has. The sound and looks of a side exhaust car is intoxicating.

/thread.

Dan