I'm thinking of installing an Allen Chambered Exhaust on my '68 327 Roadster with 4 speed.
Is there a performance gain or decrease with using the chambered exhaust?

I put one on my previous '74 with a 350 and 4 speed but did not have it long enough after the install to notice any gain or loss of power. Did sound awesome though. Even set off some car alarms when passing by

 

The chambered exhaust will offer you more exhaust flow vs the stock muffler so yes there will be an increase in power.

Oh... I carry Mike's systems and wholesale them too Give Tommy a call at 812-288-7103.

Willcox

 

Hello there,
I have two Corvettes and both of them have Chambered exhaust systems on them. On my 1968 BB it sounds like side pipes but the noise is behind you instead of next to your door. It sounds very nice but I can't say whether it helped or hurt my power output.

On my C4, a 1988 Coupe with the stock L98 It helped my mileage on the highway a bit. I was able to break the 30 mpg barrier with my new exhaust system. Again, no way to verify but it certainly doesn't sound like a stock L98 out back of the car. There is not enough of the dreaded "Drone" that some aftermarket systems have.

I bought both of my systems from Allens Stainless Exhaust from Indiana I believe. I was able to buy them at Corvettes @ Carlisle and saved more than a few bucks and had no shipping to contend with.

Both of my systems are now 20+ years old and are still sounding great. I was very happy with the quality and fitment of the parts from Allens Stainless. I still love just listening to the car when on a highway with jersey barriers or any embankment to reflect some of the music back to me.

I am very happy with the systems and have had no trouble getting through the emissions inspection station or on safety inspections. Some inspectors notice the total lack of mufflers but have not made it an issue.

Good Luck and I hope my .02 cents helps!

 

I just ordered one from them today. Hope it's not too loud.
We'll see.

 

I like mine.
Found if you turn up the volume on the radio it helps. OK sorry for being a smart ****.

 

I have it on my 72 and I have some videos of both the chambered and the stage II exhaust on Youtube.

Here are the two systems we offer... The stage II is probably our most popular system too.. It sounds great with a beater camshaft and it sounds great with a stock one. Either system can be ordered for a car with or without headers as well. Keep in mind the 1972 in the second video has a huge camshaft... so it's a bit deceiving... The engine will play a huge roll in how the systems sound.

Personally.. I like the stage II system which is the 69 side pipes split into two sections, one as a resonator and the rear as a muffler. That's what is on the video in the lower section.

But the chambered system below is mellow and sounds way better than the the stock exhaust...

Willcox


Small block 72 with chambered.

http://willcoxcorvette.com/product_i...ducts_id=27260




Hefty small block with Stage II

http://willcoxcorvette.com/product_i...ducts_id=27267



Chambered: https://willcoxcorvette.com/corvette...uminized-25565

Stage II https://willcoxcorvette.com/corvette...-79-aluminized

 

I had a bone stock 427/400 three years ago and put a Wilcox chambered system on it......the stock system was 2"......yes 2".........the 2 1/2" that I installed flowed so much better that I had to drop the idle like 300 rpm......
Plus it sounded great.....and fit perfect.
Stock exhaust is a joke at best on these......absolute garbage.....if I had a 100 point car....it would get this system.....they just do not run right as GM intended......corked up to much.

Jebby

 

I will be going to this system when I replace mine
Marshal

 

I had Summit # 630125 mufflers on my modded "75 L48, 4 speed with full length 2 1/2 inch system. These muffs had a nice tone but severe cabin drone at 35 to 55 mph. I went to Flow Tech Terminator dual chamber muffs and the drone all but disappeared but I couldn't say the car had any more go power. In the spring of this year I added Tri 5 short tube headers and the drone is gone completely. Without track numbers to go by I couldn't confirm any performance gains but seat of the pants feel is much better and the tone is great. I can rattle the neighbors windows and bark the tires in 2nd and 3rd with a smile on my face.
Good luck with your project; Jerry

 

Back when these cars were new I drove quite a few of them. The big block cars always felt like they had a cork up their @ss. The small block cars felt like they ran much better and would rev, which makes sense as they ran basically the same exhaust on a much smaller engine.

Mike

 

It is not NOISE, It is music to the ears of we the mechanical few!

This type of sound belongs with a Corvette! It would sound "out of place" on a Chevette.

If you are using a carburetor be sure to check your plug readings after switching to a free (r) flowing exhaust like the Chambered Systems. Mine required a change to one size larger main jets.

Best wishes for a great sounding engine!

 

Sounds nice. I have a 69 427/390....it came from factory with rear exhaust and the previous owner installed Hooker side pipes. I will be removing my Hooker side pipes and installing exhaust out the rear again.

Would you say the Stage II or chambered is louder?

I like the sound of both in your video....

 

They are great ,you will love them . They sound good and the noise is behind you . Not to loud either. Runs a lot better too!

 

If you have ever owned or built performance motorcycles you know that the slightest upgrade in any component makes a huge difference in performance. One of the biggest performance gains is achieved aby installing a good chambered exhaust system.
Noise doesn't mean performance but the proper system matched with any other upgrades makes all the difference.
I'll be installing a chambered exhaust system as part of my resto mod and the ones sold through Wilcox have been rated very well.