MarkC

I just changed out my stock intake to a 69 Z/28 intake and I used the intake gaskets with the intake exhaust port blocked off. I have a 66 L79 with sidepipes. As expected I got the exhaust flutter. It is worst than I was expecting so I am going to put the Nev Williams crossover on latter this week. So I was thinking about the 65 fuelie with sidepipes. Did it have the flutter or what?

Over the last couple of months I have changed my exhaust manifolds to ported 2 1/2 inch Brzezenski's, 3 inch vette packs ( 2 1/4 inch inside diameter ), Z/28 intake reskinned by McNeesh and a 650 AED carb. The power increase is significant. I plan to put it back on a dyno shortly. Here is a video.

MarkC

The video is not transferring.

biggd

I remember having a 69 Z28 Camaro with chambered exhaust and that flutter was normal. What I would give to experience the flutter of that car again right now.

MikeM

All the C2 fuelie's had that "flutter". I never knew it was a problem until I started getting on Corvette forums. I didn't know anyone else that even noticed the different sound.

I always liked that distinctive sound they made.

1965fuelie

My '65 fuelie has sidepipes and I think it sounds fantastic with more "pop" in the exhaust note than other cars. I believed it was from the 11:1 compression and the 2.5" pipes.
What do you guys mean with "flutter"?

MasterDave

The crossover will get rid of the flutter.

MikeM

Probably the same thing you mean with "pop".

I used to describe that same exhaust note as "flappy" and I don't think that's even an English word.

MarkC

Let me back up here, I had the very restrictive sidepipes with 2 inch manifolds. The first bend leaving the manifold was 1 7/8" so the inside dia. was about 1 5/8". I did not want headers, I decided to go with the 2 1/2 " ported manifolds which I have had ceramic coated. The pipes are manderal bent going into the vette packs which are very open. I did the exhaust before doing the intake and I felt the sound and power increase was great. You could really feel it over 4000 rpm's. then I changed the intake and used the gaskets that block the exhaust. That's when this fluttering showed up. Once you get over 2500 it disappears but is very noticeable at idle and when you let off the gas. I did some research on this and found the Nev Williams crossover which I plan to do. I don't know how noticeable this flutter would be with under car exhaust or the factory sidepipes. I have heard plenty of fuelies and never noticed tha flutter. My theory is the vettepacks or so open that you hear it. Nev Williams installed vettepacks on his car andthe car was too loud plus the flutter. He fixed both of those issues with the crossover. Here is a picture. My video is too long so I'll try a shorter one.

MarkC

My theory is the vettepacks make it more noticeable. I tried to get it on a video but the phone doesn't pick it up.

MarkC

I have a short 20 second vid and it still exceeds the max allowed. Sorry.

Vettrocious

I don't believe I've ever seen a 65 fuelie with original sidepipes. They must have been pretty scarce...

6T5RUSH

Hey Mark,

Go to YOUTUBE.com and just upload the video. Make it public so all can see. Then copy the browser link into your next post here.



Jim
In God We Trust!

6T5RUSH

Here ya' go MarkC:




Jim
In God We Trust!

MarkC

Thanks Jim, that vid does not really capture the flutter. I'll send you another one that does. Mark

wmf62

geez... flutter.. must be a slow day on the florum....

next it's gonna get sidetracked to a discussion of what is a 'correct' "Flutternutter"....

https://en.wikipedia.org/wiki/Fluffernutter

Bill

6T5RUSH

Ok MarkC, here's your latest video:

https://www.youtube.com/watch?v=x3FF...ature=youtu.be

Jim
In God We Trust!

MarkC

Thanks again Jim, when I let off the gas you can hear the flutter.

aaronz28

Here's the thing... that sound is just typical exhaust scavenging or a lean moment as you close the throttle.

Its ONLY noticeable on FI cars because the intake does not have a crossover tube for the divorced choke setup. Block off any intake crossover on any engine with a decent amount of overlap in the cam and you'll hear it. FIs and 69z28s have the OE 30-30 cam which has a ****-TON of overlap.

The less restrictive the exhaust, the more noticeable it is.

I have N11 on my Fuelie, and Chambered Exhaust on my 69Z. You can hear it as more of a POP or Crackle on the rev down in the Camaro.... I have my intake crossover blocked to reduce intake heat as I have no need for the choke when i drive that car. Sometime ago, (with another chambered exhaust setup) I had a balance tube installed on my Camaro and it really reduced the crackle, or raspy-ness.

Installing a small exhaust balance tube in the exhaust will change the exhaust note of your sidepipes or any exhaust system for that matter - it may also create an unwanted drone - so be prepared - you may not like it. MAny say that it adds a few ft/lbs and can aid in fuel economy - i never noticed anyting other than the change in tone.

Cheers.
A

MarkC

I took the car in yesterday for the crossover and will get it back today. I am hoping for the same sound I had before the intake swap.

65tripleblack

A crossover pipe only increases torque if the pipe is very short, large diameter and close to the exhaust valves. If I were adding one to a C2 I'd use an oval shaped 4" diameter tube as close to the engine as I could get it.

An X-pipe absolutely adds torque.