Has anybody dyno tested to see if turbo headers outperform stock manifolds? I have both but the stock manifolds may give me a better configuration for the hot side but not sure if there is a power cost and if so, how much.

 

You really need to do a lot more reading. The answers to your question could fill a book, but could mostly be summed up by saying either will work just fine. The specific details involve different areas under the power curve, material weight, packaging, and longevity. Every one of these details brings up a whole new set of potential compromises, which each could have another book written about them.

 

Here was my search criteria on this forum "Headers vs Stock Manifolds for Boost" and I got no hits.

 

Sounds like if you're asking this question, it's probably not going to be a max effort racing build. So let's assign a random power difference of 5% between the turbo headers and stock headers. That's probably a big amount for a T4 build but that's big enough for easy math. Is that 5% power worth the headaches you're going to create for yourself in the packaging/heat on this build? I'm going to assume this is an LS swap build as well, so it's probably not worth the pain on a street car.

The difference between 760HP and 800HP with a T76/75 on the street is going to be tough to feel most of the time unless you freeway roll. The occasional run at the track will be noticeable but you will have plenty of fun with either while you chop away at your 60' times with a home built street car.

Turbos, fuel and tuning make up for the minor imperfections caused by differences between manifolds and heads combinations.

 

Stock manifolds all day unless they physically dont fit or you need to run faster than 8's.

 

Either will do 1300whp.

 

I agree. Stock manifolds for cost, ease of installation, durability, heat retention, and plug access. They are hard to beat. The "cheap" manifolds dont insulate heat worth a damn and crack if wrapped most of the time. Decent collector style 14g SS manifolds won't be cheap. At the cost of roughly 1 additional pound of boost to make up the power difference, the choice is easy for me.

And a fun fact I was told... The "Ohio boys" made 2300hp on stock truck manifolds....

 

I agree with everything the guys have said here. I've run custom turbo headers, I've bought off the shelf turbo headers and I'm now using stock passenger side truck manifolds for my twin setup. Packaging becomes much more important to a street/strip car when you're trying to have fun, be able to change your plugs in under 3 hours and trying not to burn everything within proximity of your hotside. Plus, the longevity/durability, sealing, proven performance and relative quietness of cast factory manifolds, is really hard to beat.

 

People (Worm boy I believe) have taken stock manifolds into the 7’s iirc. That alone should answer this

 

May also mention you can get stamped SS OEM manifolds. As well as collector style VS log style OEM manifolds. All are very tough. I can literally remove/install a set of plugs in 8 minutes. And I've never burned a plug wire.

 

I have a header on one side and a manifold on the other. So I have the best of both worlds.

no seriously, it’s amazing how much power can be made with low flowing stuff in between the engine and turbo. It’s after the turbo that makes more difference. For the most part.

 

i'm building a rig right now with the cheapy ebay turbo log. I see no reason why it wouldnt perform as good as an other non divided hotside.

in my experience, if it seals, it'll make more power than you know what to do with

 

Because that's a crazy long search string to use.

 

Thanks for all the replys, I bought a pair of the headers thinking they would be a cleaner install, but it looks like the stock cast iron will make the intall a little tighter. Its worth a couple of horsepower it appears, this is a 69 Camaro pro touring build, 6.0, Precision CEA 76/75, Pro Flow, Tick Cam, mostly a street driver. Just wanted to make sure I wasn't making a huge mistake with the stock manifolds if I decide to got that route.

 

Stock truck manifolds have made 2000 hp, so unless you're planning on making more then that you should consider manifolds.
Stock Manifold Pros: Spark Plug Access, Low Cost/readily available, Longevity, superior heat retention
Cons: Weigh considerably more than iron, limited configurations, don't look cool.
Headers Pros: Look cool, optimized flow/velocity by design, lots of configurations, light weight, accommodates exhaust gas sensors
Cons: Cost, crack over time, can impede spark plug access, radiate heat unwrapped, wrapped still don't retain heat as well as iron
I'm sure there are some things I'm missing but these came to mind.

 

Put my stock manifold back on yesterday. couldnt tell no difference at all. the only thing I could tell is the car is much quieter. Power feels the same. Boost is the same.