How much horsepower do you actually gain switching from exhaust manifolds to headers on a GM 4.3 V6?

Question

JBA cat4ward stainless steel headers. cost $465.95 plus tax and freight. i'm hearing anywhere from 5 to 15 hp gains. are they REALLY worth the cost and hassle to install?

Answer 1

The only true way to tell you an accurate number is running the vehicle on a Dyno before and after. But, in my experience, you will only gain marginal horsepower. Maybe 5 to 9. There is a lot of drawbacks though, melting spark plug wires, extreme heat under the hood, You can actually create so much heat under the hood with headers that it hurts performance. You are better off spending your money on a good Air Intake and Cat Back Exhaust.

Answer 2

Manifolds are factory equipment, or an after market version of the factory part. Its to connect the exhaust ports of the engine to the exhaust pipes as quickly as possible, with the easiest route available. They usually feed the ports into a pipe that runs parallel to the engine and then into the exhaust. Headers are an after market version of an exhaust manifold, but they are made so there is less or no restriction from the ports to the pipes. they are designed for a power gain as the exhaust gases are able to move more freely and unrestricted from the engine to the pipes. Headers use a seperiate pipe all the way back to where they will meet up to the exhaust, and then meet up in a part known as a collector. With Headers each exhaust port will have its own pipe that is made to allow as little restriction as possible to the point where all pipes will collect. The manifold will have a pipe from each port to a common pipe.

Answer 3

the actual gain from them is 12 horse power ,i got them on my truck now,and we put it on a Dino and tested it,i gained 12 horse power ,but went up about 3 miles to the gallon at least.and mines a 4 wheel drive,they do help it,i used stainless steel with a ceramic coating,and they helped some,good luck with it.

Answer 4

10-25 HP depending on the ones you choose.

Exual length with a 3" collector would be best

Answer 5

Headers only? Maybe 5 HP max..... you need to go with high flow catalytic converters and high flowing mufflers as well.

Answer 6

Depends on the headers and their design. they only way to know for sure is to check with the manufacturer of the headers.

Answer 7

It breaths better at higher RPM so you might lose some of your low end not good Read some forums on GM an see what others have experimented with use there money testing>?

Answer 8

i would guess an honest 10, maybe 15 hp. dont believe the crazy 40 or 50 hp claims....

Answer 9

not enough to bother...10 to 20 tops...the real problem with 4.3 is the heads dont flow...i have a 99 s10 and looked into hopping it up and gave up.next truck is a v8