Geoff H

Finally got around to fitting my sidepipes on my 69 b/b vert roadster, as they were removed and sold off by a previous owner.
Car has a built 427, did it my self, an honest 450 hp, and was fun to drive.
removed old headers and horrible old exhaust system, not factory, and i seem to have dropped 150 hp or so.
Runs ok, timing is good, carb seems ok, new 800 holley, but just gutless.
Any ideas??

lsorense

With reverse flow mufflers you will loose at lot of power - 150 HK with a 450 HK could be right - have tried these on my 600 HP 427 - lost all top-end power - did not like to go above 4000 RPM. Use glasspack for more power, or best JCL turbo spirals for most power (and noise). With JCL spirals installed, lost only 6 HP compared to free exhaust measured on a dyno.

SmokedTires

Did you replace with Hooker style 4 into 1 sidepipes of the factory style sidepipes under the covers? If using the Hooker style, then I'd recommend the Spiral Turbo Specialties baffles if you're concerned about HP lost.

norvalwilhelm

Maybe it just seems like you lost all the power because they are so noisy. All the exhuast is dumped right beside your ear. I had a set for about 3 or 4 months and then got rid of them because I was having problems with the phone the next day after driving with them.
You can push a quiet exhuast harder and it feels like the car is not working as much as a loud exhuast.

Geoff H

Removed hedman type headers, and replaced with aftermarket cast exhaust manifolds from Corvette central, into a complete Corvette Central side pipe kit, all fittings, pipes etc, by passed the heat riser butterfly on r/h manifold with a straight thru piece.
Definetly low on power, but going to dyno her today, and probably slit my wrists or have a good cry :-(
Pretty disappointed if the power loss is due to the exhaust change.
Love the look of factory sidepipes but not going to sacrifice looks for grunt.
havent made up mind about the noise yet either!

Biggus Blockus

Factory repro side exhausts are very restrictive. OD may be 2.5 inches, ID more like 1 5/8 inches.

I think it's a restriction issue. I put 4" OD, 3.25" ID sidepipes on my 65 from stainless-works and the sound and hp are incredible. They are very loud, however. That's the trade off with sidepipes.

Corey_68

One of the drawbacks of the '69 OEM pipes LACK of power. This is why many go w/ the Hooker side mounts, though I think the OEM looks better.

67tripwr

I have Hooker side exhaust on my 67 427/400, and I know there choking this engine to death! The mufflers in these from Hooker are horrible! These will hit the floor soon!

I am going with side exhaust headers, and 2.5" chambered side tubes

Check out these guys for a cure! http://www.sweet-thunder.com/corvett...pes_68_74.html

I had manifolds, and factory 69 side exhaust on my 68 427, and it was a screamer! Of course after never running for 15 years will cause the garage to fill with rust smoke!


http://forums.corvetteforum.com/show....php?t=1069116

73 LS-4

Hooker makes a high flow muffler now for their sidepipes. I have them installed on mine. These just came out this year, they are very loud though but sound good on my Rat. They made these becouse they knew their old mufflers were restrictive.


Pat Kunz

bobs77vet

my brother is driving a supercharged jaguar which is fast as crap.. and handles like a dream.....however the kids in my passenger seat grin in my t top vette going around a cloverleaf at half the speed....its all about noise...