Heat Shield - removal

[kration]

I asked in a previous post about rattling from underneath my car at certain revs - and the replies correctly identified problems with the heat shield (tho the cat is blowing as well :/ )<P>To fix this, the bloke at the garage has simply removed the heat shield from the middle pipe of the exhaust.<P>He says that this will be OK, and the rattling has now gone . But if it is OK to remove the heat shield, why is it there in the first place?<P>I hope that this will not damage my car, and I would appreciate your comments on this.

[David Coleman]

The heat shield is there to keep the heat in the exhaust piping. This makes it less dense, therefore lighter, therefore easier to push, therefore having higher velocity. So you probably lost some HP from doing that, as well as increasing underhood temps.<P>------------------<BR><B><I>David Coleman</B></I><BR><A HREF="http://www.PinkMX-3.com" TARGET=_blank>1993 Mazda MX-3 GS Special Edition</A><BR><B><A HREF="http://www.highlandsun.com/hyc/sae920677/" TARGET=_blank><I>V6 engine info</I></A> | <A HREF="http://www.bradbury.cwc.net/probemx/index.htm" TARGET=_blank>KL FAQ</A> | <I><A HREF="http://www.brownsword.ca/Probe.html" TARGET=_blank>ECU reprogramming</A></I> | <A HREF="http://members.home.net/tekguy/" TARGET=_blank>K series Image cache</A> | <I><A HREF="http://archive.probetalk.com/cgi-bin/se ... tion=intro" TARGET=_blank>Probetalk Archive Search</A></I></B><BR><B>Support OPEC: Buy an SUV</B>

[pelado]

Normally I agree with Mr. Coleman's posts but I don't here. <BR>I doubt seriously if you lost any HP at all. If heat shields were that effective, wouldn't they be used on race cars?<BR>I'm not an automotive designer but I'm guessing this particular shield is there because it's the lowest mounted portion of the exhaust, closest to the grass, and therefore the most likely to start a fire.<BR>I could be 100% wrong but I'm not buying the argument that they're there to increase performance.

[kration]

Hi, thanks for the responses.<P>David Coleman may be right, as the heatshield was placed on top of the middle pipe, rather than beneath it.<P>There is a rubber (?) bush/joint or something on the cars undertray above where the heat shield used to be, and I thought the shield may have been there to protect that. But again the bloke at the garage said that it would not be affected.<P>Again, your comments would be appreciated.<P>kration

[David Coleman]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by pelado:<BR><B>Normally I agree with Mr. Coleman's posts but I don't here. <BR>I doubt seriously if you lost any HP at all. If heat shields were that effective, wouldn't they be used on race cars?<BR>I'm not an automotive designer but I'm guessing this particular shield is there because it's the lowest mounted portion of the exhaust, closest to the grass, and therefore the most likely to start a fire.<BR>I could be 100% wrong but I'm not buying the argument that they're there to increase performance.</B><HR></BLOCKQUOTE><P>You can always disagree with me. But PV=nRT is a law; can't argue with that. <P>If you have ever seen the lower exh manifolds [I had mine in my garage for 6 months this last year ] you will notice all piping after the cast iron collectors have heat sheilding. I know my underhood temps are already hot enough, without heatshields more heat will be kept in there. <P>You ever see ceramic coated headers? Same principle, but prettier. They don't double the price cause its <B>just</B> shinier <P>------------------<BR><B><I>David Coleman</B></I><BR><A HREF="http://www.PinkMX-3.com" TARGET=_blank>1993 Mazda MX-3 GS Special Edition</A><BR><B><A HREF="http://www.highlandsun.com/hyc/sae920677/" TARGET=_blank><I>V6 engine info</I></A> | <A HREF="http://www.bradbury.cwc.net/probemx/index.htm" TARGET=_blank>KL FAQ</A> | <I><A HREF="http://www.brownsword.ca/Probe.html" TARGET=_blank>ECU reprogramming</A></I> | <A HREF="http://members.home.net/tekguy/" TARGET=_blank>K series Image cache</A> | <I><A HREF="http://archive.probetalk.com/cgi-bin/se ... tion=intro" TARGET=_blank>Probetalk Archive Search</A></I></B><BR><B>Support OPEC: Buy an SUV</B>