I have an exhaust leak under the intake so I have to take it off to repair. Since I'm in there, is a turbo blanket worth it to install on a 87 running 15lb boost?

Tom
1987 951

 

yYu bet it is worth it. I can literally put my bare hands on my intake and associated hardware immediately after driving. Without the blanket way too hot. I would also recommend wrapping the crossover and the downpipe. For what it is worth, the wraps actually improve the efficiency of the turbo. I personally don't know for sure, but; I definitely notice the lower underhood temps. It is worthwhile!

 

If you can put a blanket without removing the turbo from its mount then my hat is off to you - I spent an hour trying to put one while I was there, to no avail.

As for wrapping the rest of the (stock) exhaust I'm not convinced it's good idea since it's double walled, and if heat cannot dissipate headers may crack and the inner wall of the cross pipe may collapse.

 

My oppinion would be no on a turbo blanket. Early turbos did not last long due to heat. center section bearings would fail due to the oil "coking". Water cooled center sections and turbo water pumps with timers were added to prevent early bearing failures. I personally do not see the upside. You want to retain the heat energy to the turbo, but once in the turbo heat becomes something that needs to be dissapated safety.

 

Good point. i never thought of that.

 

... and under normal running condition air flows through the intake fast enough not to be "too much" affected by the heat below the intake manifold.

By the time we stop our cars, raise the hood and put our hands on the intake, heat will have radiated plenty on the intake.

 

It is my understanding that all 951s came with a water cooled center section. I know that my 87 has one since I've had to repair the turbo water pump. My goal is to reduce the heat load of the intake. After a hard run you can't touch mine now without burning your hand.

 

Heat is why the 951 turbo is located on the side of the engine opposite the exhaust. The 924 turbo was located on the exhaust side. This is best for performance, but it led to the turbos early demise. So Porsche moved it to a cooler spot. My EGT sensor located 1" off the head in #4 tube routinely see's 1,500 degrees. Aluminum melts at 1,200 degrees.

 

Unless you do not mind replacing turbos on a regular basis, I would suggest that you do not touch things like intake manifolds, engine blocks or exhaust headers and do not worry so much about under hood temps.

 

What about putting them on an after-market water cooled turbo?

 

Easy answer is NO!!!!!

 

What about Jet Hot/Swaintech/some other thermal coating?

 

You do not want to retain heat in the turbo period. It will cook the oil and the bearing will fail. No blankets, no coatings, no , no, no!

 

Now that's interesting.... would covering the underside of the intake manifold with some of that heat reflective gold foil possibly help reduce intake manifold temp? And, would there be any real benefit to that?

At least the turbo would still be able to dissipate heat like normal, and at the same time the gold foil would prevent the manifold from reaching such high temps... Or so it would seem.

 

bump, any opinions? ^