header question - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

docrice · 01-20-2003, 11:42 AM

Ok, i know a lot of guys that drag race Trans Ams, Stangs, etc. and some of them use header wraps because it usually keeps the temps lower under the hood and is supposed to help exhaust flow better (?) and i was wondering if you think it would affect the 240sx, either with stock headers or aftermarket ceramic ones like hotshots, etc. thanks for the input.

Rice

*Jeff240sx* · 01-20-2003, 11:59 AM

Header wrap solely keeps heat from the engine bay. The colder the intake air is, the more power you get. Also, by keeping the block cooler, you eliminate the metal expansion due to heat, which will keep closer tolerances, giving you better compression and sealing.
Header wrap will work on anything you put on it. Just don't confuse eliminating heat with keeping in heat. The heat goes somewhere, so make sure that whatever the wrap is on can deal with the absorbed heat constantly. (That is the main reason I will never wrap my turbo. The heat will stay in the turbo/wrap, and coke oil faster.)
-Jeff

kandyflip445 · 01-20-2003, 12:05 PM

I thought that the wrap keeping in air also help due to keeping the exhaust gases warmer and by keeping the gases hotter, keeping the velocity of the gases higher also?

*Jeff240sx* · 01-20-2003, 12:13 PM

Well. The gas law (PV=nRT) states that as temperature goes up and all else is constant, then either pressure is increased (which can't happen in an exhaust system), volume is increased (yes) or both increase (not possible). So Volume increases, but nowhere does it state that the velocity would be higher.
Also.. don't put it on your intake piping.
-Jeff

docrice · 01-20-2003, 06:07 PM

well the turbo idea makes sense, but do you think that a set of ceramic aftermarket headers (hotshots or equivalent, not that Greddy nonsense) would be alright wrapped? i know that it would have a minimal effect on the engine as far as the exhaust goes, but if i can keep underhood temps down for a few bucks then why not? i know i certainly don't care if it looks stupid...

AKADriver · 01-20-2003, 07:15 PM

It's pointless on a ceramic coated header. That's what the ceramic coating is for.

01-20-2003, 11:42 AM	#1
docrice Zilvia Junkie Join Date: Jan 2003 Location: central PA Age: 40 Posts: 416 Trader Rating: (0) Feedback Score: 0 reviews	header question Ok, i know a lot of guys that drag race Trans Ams, Stangs, etc. and some of them use header wraps because it usually keeps the temps lower under the hood and is supposed to help exhaust flow better (?) and i was wondering if you think it would affect the 240sx, either with stock headers or aftermarket ceramic ones like hotshots, etc. thanks for the input. Rice

01-20-2003, 11:59 AM	#2
Jeff240sx I hate you too... Join Date: Jul 2001 Location: Tampa, FL Age: 42 Posts: 5,828 Trader Rating: (0) Rides Gallery: Jeff240sx Feedback Score: 0 reviews	Header wrap solely keeps heat from the engine bay. The colder the intake air is, the more power you get. Also, by keeping the block cooler, you eliminate the metal expansion due to heat, which will keep closer tolerances, giving you better compression and sealing. Header wrap will work on anything you put on it. Just don't confuse eliminating heat with keeping in heat. The heat goes somewhere, so make sure that whatever the wrap is on can deal with the absorbed heat constantly. (That is the main reason I will never wrap my turbo. The heat will stay in the turbo/wrap, and coke oil faster.) -Jeff __________________ Whatup?

01-20-2003, 12:13 PM	#4
Jeff240sx I hate you too... Join Date: Jul 2001 Location: Tampa, FL Age: 42 Posts: 5,828 Trader Rating: (0) Rides Gallery: Jeff240sx Feedback Score: 0 reviews	Well. The gas law (PV=nRT) states that as temperature goes up and all else is constant, then either pressure is increased (which can't happen in an exhaust system), volume is increased (yes) or both increase (not possible). So Volume increases, but nowhere does it state that the velocity would be higher. Also.. don't put it on your intake piping. -Jeff __________________ Whatup?

01-20-2003, 12:05 PM	#3
kandyflip445 Post Whore! Join Date: Sep 2002 Location: Arden, NC Age: 40 Posts: 4,460 Trader Rating: (1) Rides Gallery: kandyflip445 Feedback Score: 1 reviews	I thought that the wrap keeping in air also help due to keeping the exhaust gases warmer and by keeping the gases hotter, keeping the velocity of the gases higher also?

01-20-2003, 06:07 PM	#5
docrice Zilvia Junkie Join Date: Jan 2003 Location: central PA Age: 40 Posts: 416 Trader Rating: (0) Feedback Score: 0 reviews	well the turbo idea makes sense, but do you think that a set of ceramic aftermarket headers (hotshots or equivalent, not that Greddy nonsense) would be alright wrapped? i know that it would have a minimal effect on the engine as far as the exhaust goes, but if i can keep underhood temps down for a few bucks then why not? i know i certainly don't care if it looks stupid...

01-20-2003, 07:15 PM	#6
AKADriver Post Whore! Join Date: May 2002 Location: Springfield, VA Age: 43 Posts: 3,517 Trader Rating: (1) Feedback Score: 1 reviews	It's pointless on a ceramic coated header. That's what the ceramic coating is for.