After nearly 5yrs since I made my turbo kit and wrapped my hot side.Things have frayed and come apart but with the boost levels steadily increased over time..the heat that would come off the turbo was disgusting.Ive made cuts into the t/a hood to make the vents functional and aid with feeding fresh air to the engine bay with small effect. My hot side was never coated originally so i decided to take off the downpipe and try a few products on a budget. I had originally wrapped the hot side with DEI lava wrap and was happy with it.Now that things have been on/off a few times..become brittle ,the heat is affecting performance and my cooling.

I started with the downpipe and coated it with 3 layers of black vht header flameproof paint,then used cheap amazon "lava" titanium wrap, ontop of that i used a copper based exhaust wrap paint that claims to reduce heat and extend exhaust wrap life. I sprayed a few other things with the left over paint that I could get to in the engine bay. That being said i got some interesting results. I got my desired result of much lower underhood temps ..200+ degree reduction. It has also changed how the turbo spool up. As much as heat isnt radiating out..its retained throughout the piping so the turbo spools damn quick,which does throw off the tune slightly.I can easily get flames out of the exhaust from free revving the engine at will. Before hand I would have to hit the 2 step and build some boost. Heres a quick video of how it turned out.I do like how it appears under the hood with the copper spray i must admit.

 

Interesting. Makes you realize just how good the "hot v" concept is that the Germans are doing.

Just a little fun fact... Exhaust is a compressible fluid, and compressible fluids have odd behaviors. The heat loss through the exhaust pipe is actually being stolen away from the kinetic energy of the exhaust, meaning the velocity of the exhaust goes down. So keeping the heat in the exhaust produces higher velocity and that is spooling the turbo quicker.

Compressible flow was one of my favorite engineering courses in grad school. I forgot 99% of it but I remember it was some cool stuff!

 

Yea i expected the spool up to be quicker but not to the extent its giving me.I didnt think the unburnt gasses would really become present just from mainly treating the downpipe, the flames are cool at times but makes it hard to keep a sleeper status.

Im sure having things properly ceramic coated is ideal..but can be expensive..it may last longer than what ive done but for less than $50 bucks i got nothing to complain about with cooler underhood and iat temps

 

I bought a slightly used ‘89 IROC a long time ago. It ran way too hot even while driving down the highway. I noticed that it was missing a plastic air deflector underneath. Once I found a parts guy that cared at the Chevy dealer, I bought a replacement for under $50. I bolted it on, and the problem was solved. I don’t know how the Trans Am gets engine airflow, though. Maybe you can get more airflow with something like the IROC deflector.

 

Firebird and Trans Am have similar plastic air deflector underneath.

 

I do have my airdam on but all the does is to help airflow for the radiator in keeping the coolant temps under control. Im talking in regards to reducing engine bay heat. I removed the hood insulator because it was soo old and falling off and burning on my hot side piping. I thought about applying heat reflective tape to the underside of the hood and also to the coldside piping just to see if it will reduce iats some more.

 

I don't know all that much about turbos, but I have heard from the diesel guys that those short cone air filters are a restriction to the intake. You might want to consider a longer filter to gain some air flow

 

Since you mentioned this, I was told by somebody a long time ago that an exhaust system should get larger (and less restrictive) from the front to back because the exhaust pulses stack. Any thoughts on this?

 

Filters can be a slight restriction for a turbo.it really depends on the material used and its overall size. For the street I run a filter and due to location i cannot physically fit anything bigger than what i run currently.my catch can is plumbed to the filter. At the track Id remove the filter for a pass. but for the power level having the filter on and off showed no real gain of 10whp. I do want to shield off the as best i can the intake ait from the rest of the engine bay to further reduce iats.

 

I dont know much on the best way to get exhaust pulses perfect to produce the most power but having a larger exhaust does make it easier for an engine..or air pump to effortlessly make power.You would see alot of n/a guys running stepped headers or equal length headers being keys ways to manipulate performance. Having some backpressure can also give you some lowend torque.What your doing is playing with powerbands and where things will peak..and fall off.There is alot more to an exhaust than just slapping on the biggest pipe you can

 

I always knew of this factoid but never knew that exhaust is actually a fluid! Thank you Qwik I really do love learning new things every day.

 

I think this makes sense if you are losing heat through the kinetic energy of going through the pipe. the pulses stack as they slow down from the heat loss so you won't need a bigger pipe to get them out. If you can maintain the heat in the pipe the gasses(fluid) maintain their velocity through the system and therefor you will benefit from a larger pipe all the way through.

VHT Flameproof header paint is some really good stuff. I have been using it for awhile now and have never had it burn off, ever! It also has silica ceramic in it to help with keeping the heat in, a real DIY ceramic coat IMHO. As the OP said use 3 good coats. I will be using this on my entire exhaust system, those mannies I got from you are already 3 coated.

 

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I was thoroughly more impressed with the Thermotech stuff than the VHT. Ive seen VHT stuff fade and flak off on other vehicles before but who knows how well it was prepped and applied.The bronze coating from the Thermotech stuff on bare metal and on my existing wrap gives it a interesting texture. I can touch my turbo downpipe after a pull and its not going to melt my skin instantly. I really want to pull off all my other hot side components and treat them aswell now in the exact some manner. 3 coats black vht header paint as much as I can inside the pipes/manifolds and then 3 coats of the bronze header wrap stuff. Especially near the lug wires this is critical to not cooking them even though they have sleeves on them,its tight between the plug wires and direct contact on the manifolds in some spots.

 

I have been afraid of coating the inside, of it flaking and clogging the muffler. Can you spray that Thermotech right on the VHT without using the wrap? Might give my whole exhaust system a cool look.

 

I dont have cat so im not afraid of it flaking off from the inside pipe, Im runing a gmmg muffler which is pretty straight through design. I did spray the thermotech stuff directly ontop the vht on some parts that had no exhaust wrap and it does look cool and still reduces the heat drastically. Give it a try and post it up