I second this warning.

 

Doesn't wrapping the headers increase the cylinder head temps?

 

The head temp would remain constant because of the engine coolant flow and subsequent cooling that the radiator provides.

Let's review some things here...
header and testpipe are jethot coated inside and out
header wrap is catback
..... kills drone at source under the cockpit
..... eliminates center console cupholder heating
..... increase exhaust velocity because of restricted heat loss (scavenging)
exhaust is stock pipe with dual resonator-ectomy and magnaflows (low cost/great sound)
Maintain the monster WOT roar while enjoying a drone controlled drive

Cost to weight ratio
header wrap weight of 1/2 pound/50 ft roll with total of 3 rolls => 1.5 lbs.
top of line wrap is $25-30/roll => about $100 cost with incidentals.


Corrosion resistance provided by Boeshield prior to wrap and verified after 4 months of wettest winter on record in Calif.

 

`

 

lol you guys crack me up. You keep saying things that he has gone through over and over again. Read the entire thread before you type

 

I don't think 4 months is enough time to see if the pipes will be damaged from weather, it's also geographically influenced. It may be fine in Cali, but in WA it could be a completely different story. The good thing I suppose is that you have enough crap on there, if the metal eats away, you'll have a paper mache exhaust.

I think it's great that you're researching this on your own vehicle, more guts than I'd have and I'd like to keep hearing about the results.

Personally, the drone gets on my nerves but not as much as the center console heating up, its hell on a can on Copenhagen in the cup holder.

 

You can flow more cold air through a given size tube then hot air. It works the opposite of your theory. Cold air is denser. Warm air containing the same volume by weight requires far more space. With a given size exhaust you will flow less air if the air is warmer.

 

GeorgeP Posted on May 14 2006, 05:02 PM
What you say is correct but not why they want the gasses to stay hot/warm.
IMO you have to start looking at the engine => producing hot exhaust gasses.
Just thinking out loud:
Hot exhaust gasses enter the exhaust manifold, cool down, therefore shrink in volume (lose energy) and lose speed because of that, creating some kind of "cold air plug" at the end of the exhaust system (the silencer / damper)
So the hotter the gasses stay, the sooner they reach the end of the exhaust system and are free to go where they want to without blocking the ones coming right behind them.

 

Do you have a Wideband gauge ? Or have you checked your A/F


Having the forward O2 out of the exhaust flow is sending incorrect info to the ECU . I bet you are running rich .


The reason for having the after cat O2 out of the exhaust flow is to keeping the check light off .

Your car uses the forward for A/F , the second one is for emissions only. The car doesn't care what the second one is doing as long as it reads different from the front . But the front one is important .

 

When I was checking out how far the tip of the primary O2 sensor protruded into the exhaust flow, it literally blocked about 1/8 of the diameter of the header tube.
Backed out one drilled antifouler positions the O2 tip level to the interior header surface.

From a FLOW perspective, all the turbulence and blockage this represented was worth the risk of running rich. '01's run rich anyways. Lean would be more worisome. After 8k miles, I have had a recent opportunity to pull the sparkplugs and the electodes look perfect. The car doesn't run odd at all and I have the knowledge that I don't have a stick in the middle of the airflow.

I am close to putting in a AEM A/F dongle, then I will be able to monitor it more closely.