MR2 SpyderChat banner

1 - 6 of 6 Posts

Registered
Joined
2 Posts
Discussion Starter #1
So first to everyone here(and who reads this) Hello new to the forum and this is my second MR2-S. So thats out of the way so please HELP!!!!!

So my 2001 has 53500 on it I just did the whole exhaust swap to include midpipe as originals flex pipes were fubar(precats were in perfect shape). I cannot find the noise in this video Sorry the video isn't the greatest.


I have checked all three gaskets on the header and the donut from midpipe to muffler no air coming from any of them. I am sure someone here is going to have the answer and make me feel stupid 馃ぎ馃ぎ for overlooking something simple but I can take it as long as I can figure out this thing...
 

Registered
Joined
557 Posts
If it were me, i would take a dead blow hammer and with reasonable impact, see if I can locate the vibration. It sounds like metal heat shield versus sub-frame.
 

Registered
Joined
869 Posts
So your theory is that the headers got too hot and got a hole thru them?
When an engine is running near full-power, the exhaust temperature is in the region of 1600 - 1700F (red-hot). At these temperatures the material strength of even a good grade of Stainless Steel is pretty low. At the same time the headers are stressed due to thermal expansion and vibrations. So if you do a lot of running at high load you can expect to get close to the fatigue life of some part of the headers (or turbo-housing) and a crack will start. If you can get cooling air to the outside of these red-hot tubes the average temperature comes down a lot and the material strength goes up. Ask any engineer that has spent a lot of time running engines for performance on an dyno (where we might run continually at full-load) and we can tell you that the life of headers (cast or fabricated) goes down to hours if you don't place big powerful fans blowing air directly on them. We often even remove the factory heat shields just to get the temps down. The reason OEM's use heat shields on exhaust systems is that the shield blocks the radiated heat from burning or melting stuff, but allows cool air to get to the pipes. Many years of running engines for performance on dynos has taught us that you don't even consider doing a run without blowing ambient air directly at the headers. From this point-of-view, wrapping headers is unthinkable.
For normal street-driving you can probably get away whit wrapping headers because you spend very little time at near full-power, but for open-track or racing use you can expect your wrapped headers to eventually crack, and you can expect the header manufacturer to blame you for wrapping the product. It is much better to add shielding (or wrapping) to any plastic, rubber, or painted surfaces that are within about 1 foot distance from the header tubes.

Dave
 

Registered
Joined
91 Posts
I picked up an extra exhaust from Phat recently and plan to have the entire exhaust system ceramic coated. I鈥檓 thinking about doing the heat shielding as well. Ceramic coating is the best way to keep heat out of the engine bay. I鈥檝e grabbed headers five minutes after running a car two hundred miles and they were Luke warm. That sold me.
 
1 - 6 of 6 Posts
Top