Headers lowering HP?

[Eagle Kammback]

My buddy has an 87 GN, heavily modified, And he was telling me that headers would decrease horsepower on her. is there any way that it would? And how?

 

[my1stgn]

Depends on the mods but it your engine doesnt flow enough air (ie intake and exhuast) then the exhuast air coming from the heads to the headers may slow down some and cause slower turbo spool. Basically the exhuast gases will slow down and not spool it up as much or as fast.

 

[Eagle Kammback]

Oooohhhh, That makes sense, thanks

 

[Nick Micale]

Actually none of this makes sense?

The GN comes with factory headers, something in your buddy's conversation must have been mixed up in the translation.

 

[QUIP'6']

Only Hooker Headers Will Slow Down Your Car. Because They Were Poorly Designed

 

[gmpower]

Yep hooker headers will slow down a stock car! I tried them before and learned from it.

 

[Fab Shop]

Hooker headers

It depends on the mods. I just made over 600rwhp and I have hooker headers with a very safe tune. see sig for mods.

 

[QUIP'6']

it will slow a stocker down to a highly modded car. did you try and see what your car will make on stockers. with your setup you should see more at that tune.

 

[meanchicken]

A wise old Turbo Buick guru once told me that unless you have nothing else to spend your money on, leave the stock headers on the car. The stockers...aside from a tendancy to crack here and there, are a good design and flow well enough for most street/strip cars.

Money will be better spent on
Other things to free up more power.

Alky, Cold breathing open element Inlet track, IC, turbo, down pipe, cat and cat back, ...and a good set of heads if none of the above get you going fast "enough".

 

[my1stgn]

Okay so let me re-phrase my statement. If you get bigger headers, it may slow down the exhuast gases cause you a lose of power from not spooling your turbo fast enough on a basic set-up. Even moded engines will see no big gains from bigger headers unless you are flowing enough air that your stock headers are restrictive..... hope that makes sense

 

[Eagle Kammback]

I get it, less backpressure means the exhaust is moving slower

 

[SouthernCal GN]

Okay so let me re-phrase my statement. If you get bigger headers, it may slow down the exhuast gases cause you a lose of power from not spooling your turbo fast enough on a basic set-up. Even moded engines will see no big gains from bigger headers unless you are flowing enough air that your stock headers are restrictive..... hope that makes sense

I get it, less backpressure means the exhaust is moving slower

Guys, you're thinking normally aspirated.

You have a huge restriction already in the exhaust tract- the turbo! Even with the largest diameter piping available, you still smash all that exhaust into the turbo. The converter has more to do with getting the turbo spooled than the headers.

Stock headers are fine for any street driven car. Theu've been proven to the 10 second range, so in evertday driving, they are more than adequate.

More free flowing behind the turbo is great.

 

[bison]

Hooker headers will require nitrus or a looser converter or they will give up a lot of spool. I dont know about hp though. I doubt they will cause a loss though. Even though it will feel like it with the slower spool

 

[my1stgn]

I think it makes more sense if you picture "air" flow as something we could see like "water" flow. If you have the same amount of flow but increase the "hose" (ie header diameter) the amount of flow would be about the same but the "pressure" would decrease. So less pressure I would assume the turbo would not spool as fast as with the stock diameter headers. Maybe it wont make a huge difference to where you feel it and mabe you wont even lose power, but unless it flows the exhuast faster, I wouldnt worry about upgrading yet. Now Im confused!