mike229

Stock manifold and straight back chambered is on there now, is pretty friggin loud and mean.

As Ive mentioned, I want to go to the Hooker system w JCL Spirals

Will I gain or lose performance and will it be louder or more quiet?

Thanks!

mike229

anyone?

GTR1999

Chambered pipes are restrictive, stock 2.5" exhaust is better but not as loud.
I would think the Hooker system is better but I'm not familar with it. I have chambered pipes and headers and don't like them too much. For the money they cost I'd would go with a 2.5" and performance mufflers.
Gary

mike229

Thanks Gary - that answers the perfomance question pretty firmly..

I still wonder if the Hooker/JCL will be louder than stock manifold/chambered pipes because Im not sure I can take it any louder :)

69ttop502

Mike, I am one of the first guys that ran the Hookers with the JCL's and also one of the people that dyno tested them and I can say enequivically that the Hookers with JCL's is your best horsepower configuration other than headers and a good straight back system which should be close. However with the Hookers and JCL's you get a cooler cockpit, better ground clearance, and an easier setup to work on the car. As for noise the fully capped JCL's will most likely be quieter than your chambered pipes, however they are tunable by drilling holes or totally removing the cap to get the sound you want. Now my car is a big block but the results should be similar. Jim (JCL) is a great guy to work with as well. I love my setup and am sure you will too if you decide to go this way. Something about the Hookers and sidepipes heighten the whole Vette experience for me. Any other questions just ask.
Bill.

Chuck Harmon

I am running a L88 clone in my 69. I know two others with L88's that compared open pipes behind factory iron exhaust manifold against open headers. They both lost about 75 horsepower at the crank compared to open headers. Adding mufflers would take a bit more hp off that depending on how restrictive they are.

I am running Hooker sidepipes on the L88. With the JCL's capped, I made 45hp less than uncapped. Uncapped I made 6 horsepower less than open headers on a chassis dyno. That's 477rwhp vs. 483rwhp. You're not going to get much better than that!

Regarding noise, there are numerous decibel measurements taken using the same model Radio Shack digital sound meter verifying the sound levels. My setup is in the low 80 db's at idle standing 15 feet to the side. At 2500rpm free revvs it is at or just below 90 db's. I don't believe that a chambered exhaust would be any less noisy, only more restrictive.

Chuck