Ok, my friend has a Starion (i know tis not a DSM but its still turbo) and it gets RED HOT! like glowing. I told him it was normal. Does this happen to you guys also?

If its red red then he's probably either way rich or has to little timing advance.

Or something in his exhaust is starting to clog.

I've seen air filters get plugged on equipment and the turbo get cherry red.
Makes them run rich like ncgalant said.

red hot is from a lean condition. I've seen it happen before say when you put 87 octane in a turbo car that's supposed to be running 92+.

The techs at work agreed, a lean condition would create heat (red hot condition) before a rich one ever would. Start running 92+ in that car to see if it helps. If not, retard the timing some and have someone knowledgeable with a timing light help. It won't run as strong but it'll be safer and you'll be able to extend the life of your motor. If it's possible, put a logger on it, I'd be willing to bet he's got plenty of knock.

retarding the timing will make it red. Try pulling timing and watch your EGT if there's a guage. I've heard of people running 1800 before. The car might be knocking like hell and pulling the timing out though. That would make the low octane idea make sense.

Think of it this way. A lean condition creates more than normal heat from the point of the chemical reaction. That heat has to travel out of the combustion chamber because of the natural equalization of pressure in the atmosphere. Now, when you run a higher octane fuel (on any gasoline engine) you have the ability to run a more advanced intake timing to make more power. Try running a timing curve set for 100 octane fuel while using 87 octane fuel. The engine will run lean and you will see much the same results. The stock timing on a turbo car is set up for 92/94 octane fuel and if you run 87 through it the results will be similar as well. Retarding the timing on the intake cam will "slow" the time between when the intake valve closes and when the exhaust valve opens. This offers a more gasoline efficient, safer, richer mixture because the reaction has more time to burn all the available fuel. Running a higher octane fuel compensates for it in this situation. Or.... as Larz said, this could be the result of an incredibly restrictive exhaust.

You are right on the lean condition making it hot. The air filter plugged will make it hot also but not because it is rich, just because the trubo is working harder to get enough air.

If your air passage was clogged and the computer did nothing to adjust for the condition, you'd have a rich mixture due to the air loss. The engine would probably die though...if it was clogged bad. If the turbo is red after a drive, this would mean most likely a leaner condition. Due to more air and less fuel in the mixture. Making it run hot. Lean is a condition you want to be careful with due to things starting to break at higher temps.(this being when "your engine blows up") Why do you think DSM's get such crappy mileage. Because Mits makes the ECU dump fuel like it is no ones business when on boost to keep things cool and under control. This is where a AFC, Reflash, chip or whatever form of engine management comes into play with making more HP. Leaning the factory mixture.

My DSM got pretty damn good gas mileage when it was stock. A helluva alot better than my Evo, that's for sure.

Turbohcar, ncgalant is referring to ignition timing. You are talking about valve timing. While somewhat related as far as engine performance they are two different, independent beasts. You're both on the right track anyway though.

Hot EGT's are usually attributed to retarded ignition timing, which in turn usually indicates a lean condition in the world of ECU's with knock detection/correction. Basically a lean condition causes knock, which is detected by the knock sensor, communicated to the ECU, the ECU therefore retards timing, sometimes enough to eventually cause the flame front to escape out the exhaust valves which then reads as a high EGT.

This same phenomenon can be seen in the anti-lag systems on rally cars, except in this case we don't have a lean condition. We have a stoichimetric to rich condition with super-retarded timing. Basically the fuel is still burning on its way out of the combustion chamber and in the turbine housing allowing it to use some of its stored energy to turn the turbine instead of compress the piston. This obviously will also read as a high EGT, except in this case we are running rich and hearing what sounds like backfire out the tailpipe. You can also almost hear the turbo screaming for its life, not to mention the exhuast manifold.

This is why EGT's can't always be trusted to tell the whole truth. They are usually a good indication of what's going on in the combustion chamber, but they can be wrong. Such as in a case of rich knock. We've seen and heard this on Spy's car quite a few times. Another reason why I think widebands are a tuner's best friend.