Crash Dummy

For your knowledge....

Sweet Thunder is (for now) no longer offering complete chambered exhaust systems and are only making the actual chambered muffler. I spoke to Allen's Stainless Exhaust this A.M. and they are building me a *dual* chambered under vette exhaust system with 2 1/4" I.D. They say the dual chambered system gives the same length chambered effect of the '66-'69 sidepipes and that "loud" was in the ear of the beholder. But, he said that the single chambered system was probably louder.

And ordered the 360# rear monospring and Bilstein shocks. VBP agreed that Bilstein performance shocks should be used with the 360# spring and not the KYB's that are on this '71 now.

Toys, toys, toys! :cheers: (And work, work, work!)

OHSIXX

I have Allen's side pipe mufflers. Very good quality and the sound is just right.!

Crash Dummy

OHSIXX,

Mike was really helpful with trying to find something that might breathe better on the 454. He was upfront that the '71 exhaust system they have is hindered by the 2" exit pipe that hooks to the rectangle chrome exhaust tip that came on '71's and suggested I go with the '73 set-up that is 2 3/4" O.D. and 2 1/4" thru. Go figure it that the '73 exhaust was better flowing with less HP. The only difference is that he's supplying me with a center mounted '73 tip(instead of the offset in the earlier years) and linkage to adapt to the centered exhaust. And he said they should be able to put it all together and ship by tomorrow. By the way... if anyone is wondering, the dual chambered exhaust has about 32" of chambered muffler under the vette before the cross member and then another 14" at the rear. Looking forward to it. I'll take some mpgs of the before sound and the after. :cheers:

OHSIXX

I think you will be happy with his product. After talking with him, I decided to put the BB Mufflers on my SB. It is loud, I guess! But strangely at 75-80 mph it seems quieter than at lower speeds.

Maybe when I get 3.70 gears all that will change. :)

Phil Zell

I have a set of the stage two exhaust on my 75 from Allen's 2.5" and it is sweet.
Very well constructed product.

Crash Dummy

Phil,

It's amazing what you can find in the archives on this forum. I've read about the hinderances of chambered exhaust for flow and that's why I was actually looking to buy Sweet Thunder's 2 1/2" exhaust when I started calling this morning. And when that didn't pan out I just accepted that I really didn't need it anyway with my stock set-up, so nothing was lost going to Allen's 2" set-up(I didn't know about the 2 1/4" alternative until talking to them). It is unbelievable the help I get when I call looking for parts and tell them that I have a '71 Vette with a 454. I'm sure Mike at Allen's helps everyone, but I consider it real service to not just sell me something that is on their site that is the stock part and may not be the best for my application.

Tex71BB

I had the exact same experience with Allen's. On their recommendation, I went with the '73 setup on my '71 LS-5. Quality and fit are very good. When you're driving, you definitely know you ain't in a Lexus, but it's really not that loud. Since the exhaust is coming out the back, you don't hear it as much as sidepipes. Go under an overpass or through a parking garage, though, and you will REALLY hear it!!! When I drive the car to work and park in the garage, I typically set off between 2 and 6 car alarms. Sometimes, I even blip the throttle a little to set off a couple more! It's great fun - you'll enjoy the pipes.

Stewart's74

:iagree:
Pass someone at WOT on the freeway and watch their face :eek: Priceless.

kanzawa

I have a 79 Corvette with Hooker Header side pipes 50735HKR with the reverse flow insert quiet mufflers 21003HKR. Was wondering if anyone has the Sweet thunder muffler inserts from Ecklers 25-251528-1(2 inch inside diameter core) or the 25-251534-1 (2.25 inch inside diameter core) installed on their car and can compare how much louder they are to the 21003 mufflers? They claim these sweet thunders are loud and aggressive on the outside of the car but quiet inside the car (cabin). Main concern is that at highway cruising speed at 75 MPH, my engine tachs at 3500 rpm and did not want excessive noise at that speed for a long vacation trip.