Headder wrap on turbo down pipe.

[94turbo-]

My new turbo back 4" exhaust should arrive any day, should I wrap the 3" turbo down pipe with header exhaust tape? Does this make a difference in temps, performance, and mileage?
How about the crossover pipe? Thanks!

 

[WarWagon]

Depends on how you plan to abuse it. (I tow heavy and EGT's do not bother me till the gauge is about to peg. And that is only because I am running out of numbers on the gauge.)

The downpipe heat burned the paint on both sides of the floorboard on my 1993. Found it when I was removing the carpet after the elk encounter.

Heater hose life, even new, was not very good without wrap. IMO it helps things stay cooler around the exhaust - stuff that is 3" or more away.

I use the expensive copper colored stuff and lots of stainless ties. I then paint it afterwards with the special wrap paint to harden it and seal it.

You will need 6-9 ties for the crossover alone. More if you have furry things and other road debris banging around under the vehicle as this tends to tear the wrap off. 3 on each side and 3 across on the 'bottom' of the pipe.

Turbo's are supposed to run off heat. So keeping the manifolds hotter and the crossover hotter gives you more heat to the turbo. It also keeps this heat out of the engine compartment. This lower heat helps keep the floorboard cooler esp. if the firewall insulation has fallen off. Floorboard means your feet get hot and you run bi-level on the AC.

Others can chime in about the downside of keeping these parts hotter and the effect of road salt with header wrap. Other than the manifolds the exhaust parts are fairly cheap.

 

[guybb3]

Others can chime in about the downside of keeping these parts hotter and the effect of road salt with header wrap. Other than the manifolds the exhaust parts are fairly cheap.

I have witnessed, personally, how wrapping an exhaust pipe on my truck rotted it much faster than everything else in the exhaust system. That being said, I'm still going to wrap my new downpipe (bought a spare with my new exhaust) and when it rots I'll just replace it.

 

[mug23]

What I did was I painted the downpipe and the rest of the exhaust when it was brand new with high temp exhaust paint. Wait till it all dries up and then wrap the downpipe with the exhaust warp. This way, the paint will help the trapped moisture from touch or getting onto the metal. I think this way works best for me.

 

[racedaymechanic]

I have witnessed, personally, how wrapping an exhaust pipe on my truck rotted it much faster than everything else in the exhaust system. That being said, I'm still going to wrap my new downpipe (bought a spare with my new exhaust) and when it rots I'll just replace it.

If your exhaust is rotting out you need to Move.......South

 

[94turbo-]

Well my new exhaust system arrived...What I ordered was the 4" exhaust pipe kit, what I got was the Lincoln Tunnel....Man that thing is huge! (makings of a good joke)! I'm gona havta wrap it in a sleeping bag!

 

[guybb3]

If your exhaust is rotting out you need to Move.......South

Brother, isn't that the truth. I live in Mass. (don't tell anyone) and when my daughter and I go to TKD tournaments, the big joke is that we are honorary Texans.

 

[94turbo-]

Now that I feel better and healthier, I took the pipe out of the box....

OK this is no joke......, I laid out the pipe to have a looksee.... my wife sees the pipe asks me if I can teach our little dog to go through the twisty tunnel!!! :rof I was going to post here "how I keep the stray cats from curling up in there and giving birth!")...... Or...... Now I have to worry..What if BATMAN has too much BATPUNCH and gets BATDRUNK and mistakes it for the entrance to the BATCAVE...:yikes:... Or......watch out for Cpt Jack Sparrow to hide his :hijacked: treasure in that cave!

 

[Twisted Steel Performance]

If you want a real answer, I would have it ceramic coated inside & out, Tech Line TLHB inside & turbo X outside, the inside will be coated with a ceramic thermal barrier , outside is a ceramic coat that is also a heat barrier/ corrosion stop, then you don't need anything else, you could spend the extra money and do it this way or wrap it and replace it when it rots out. Unless you have a blaster & 700deg oven to cur it, you would need to send it off and have it done. But it would last forever and would stop heat soak better than the wrap and a lot less trouble, and by the time you add up the cost of the good rap & ties, it will be about the same only look much better.

 

[racedaymechanic]

If you want a real answer, I would have it ceramic coated inside & out, Tech Line TLHB inside & turbo X outside, the inside will be coated with a ceramic thermal barrier , outside is a ceramic coat that is also a heat barrier/ corrosion stop, then you don't need anything else, you could spend the extra money and do it this way or wrap it and replace it when it rots out. Unless you have a blaster & 700deg oven to cur it, you would need to send it off and have it done. But it would last forever and would stop heat soak better than the wrap and a lot less trouble, and by the time you add up the cost of the good rap & ties, it will be about the same only look much better.

I have used both The Header wrap and Ceramic on race cars and as far as Heat is concerned the wrap wins hands down, its not even close, you can touch a wrapped header the minuite the car pulls off the track But not for long, the coated one instant 3rd degree burn

 

[Twisted Steel Performance]

You are right about that, but you half to admit that coating both the inside & outside + wrap would be about as good as it could get, the ceramic would prevent rust build up under the wrap.

 

[94turbo-]

EXHAUST in! NICE but I have some boost questions...

Thanks for the info guys, my local stores didn't have the tape, so I just installed the pipe. The 4" looks great and sounds great on the truck, I had thought it may look huge! but really it looks just right. I can hear some turbo whistle with the windows down against the concrete barrier, but with a lot more V8 rumble. This must be a tight turbo compared to my others for it to be so quiet. It has very little play, but it does spin freely. I expect it is a GM-4? It spools up to 13psi very quickly and at about 2400 rpm it starts dropping and flattens out at about 9 psi. I expect the computer is doing that. Would this EFI truck go better above 2500 rpm if the boost was there, or do I need to look at changing out the chip for that? All my other diesels used aneroids, fuel screws, and pressure regulators for tweeking. It is an OB1 being a 1994

 

[Koots]

Now you just need a bigger turbo to make use of that big exhaust

 

[great white]

...I expect the computer is doing that...

Yup.

The PCM looks at the %TPS you set with your right foot and then adjusts the fuel an boost. There's a bit more to it than that, but that's it in a nutshell.

As you get up to speed you start letting off the throttle, we do it without thinking. That's where your %TPS comes from.

I can command 25 psi at idle (0% TPS) in the program if I want. Heck, I can command 50 psi if I want.

You won't get it, but you can command it.

You won't get that 25 psi at idle either, not enough drive pressure for the turbine at low fuel rates even with the wastegate closed.

 

[great white]

Ooopps, my mistake.

I was thinking of something else when I said %TPS (IE: fueling):

Boost is fuel and RPM dependent:

Which is also a roundabout way of saying it's %TPS dependent.......

Sharp eyes will notice where the boost table tops out and remember the BW/IHI compressor map limits for the rhc6 (closest thing you'll find for an accurate "compressor map" for a GMx)



Well, I don't want to get in too deep here and make this a complete thread hijack so I'll stop...........