I have built an exhaust system to meet 5 objectives 1. To keep heat out of the engine bay 2. To keep heat away from the transmission 3. to keep heat away from the front passenger side 4. To increase flow 5. Having real cooled air induce in to the cold air filter (more power) 6. To keep water off of the header 7. To help keep down the exhaust noise (the wrap). There is a lot more noise coming from the tubes of your header then you think
I started with a good header; I have “toque tubes” by Banks. I painted them with spray paint that can withstand high heat, I cured them in my oven, in 3 fazes (The wife loved that ). I raped them and socked the wrap with the same paint, I also cured it again. This alone will solve 3 things, (I hope) 1. To keep heat in the header and out of the engine bay, increased exhaust flow, to keep water from the header, and to reduce noise. I guess that’s 4 things.
After the header; I have 2.5-inch pipe all the way to the end of the system I painted the pipe with the same paint I did for the header. No, I did not cure the pipe, the oven is not big enough . I wrapped the pipe; I socked the wrap with the same paint used for the header. The tip at the end of the tail pipe is a 30-degree bend with a 70-degree angle slice pointing rearward.
I am trying to understand the laws of thermodynamics and how it may apply to my exhaust. This is what I think I know. Heat moves faster than cold, and the speed of the exhaust will increase as the differences between the 2 temperatures (hot and cold) increased.
I am also creating a small vacuum pocket at the tip of the exhaust pipe by using a 30-degree bend and a 70-degree slice on the stinger pointing rearward. This will create a low pressure that will also help with the flow rate
All this to get 3 or 4 present more power. That does not sound like much but if you are putting out 250 all ready then you could gain 7.5 H.P. or maybe even more.
So, I have not seen anyone do this before (maybe there is a reason for that) it’s a lot of work. but it’s fun, doing research, trying to making something work better than it did before (I hope).
I welcome any input into this subject
exhaust flow
-
- Making Progress
- Posts: 54
- Joined: June 2nd, 2021, 1:36 pm
- Stroker Displacement: 4.6
- Vehicle Year: 1998
- Vehicle Make: jeep
- Vehicle Model: xj
-
- Making Progress
- Posts: 74
- Joined: November 16th, 2010, 2:58 pm
- Stroker Displacement: 4.7
- Vehicle Year: 1992
- Vehicle Make: Jeep
- Vehicle Model: XJ
Re: exhaust flow
Lots of deep science for exhaust tuning. You've def done some homework and put in the work Hard to truly quantify results without before and after dyno numbers.
You certainly will have gained some heat-soak prevention with all the paint & wrapping. So if it sounds good and feels faster, I'd say you succeeded!
You certainly will have gained some heat-soak prevention with all the paint & wrapping. So if it sounds good and feels faster, I'd say you succeeded!
-
- Making Progress
- Posts: 54
- Joined: June 2nd, 2021, 1:36 pm
- Stroker Displacement: 4.6
- Vehicle Year: 1998
- Vehicle Make: jeep
- Vehicle Model: xj
Re: exhaust flow
I love learning and I want to know how to make something better. I don't mind being wrong but I what and why I am wrong. that is what learning is all about. yes I did do a lot of research and a lot of work but I am 70 and I have the time, for anyone else it's not worth the time or money for the little return you may get from this. for me, well call me crazy but I thing it is fun doing and talking about. I was hopping someone would say I was wrong and why. the only dyno I have is the seat of my pants.
-
- Making Progress
- Posts: 75
- Joined: February 4th, 2020, 8:48 pm
- Stroker Displacement: 4.7
- Vehicle Year: 1985
- Vehicle Make: AMC
- Vehicle Model: CJ-7
- Location: NC
Re: exhaust flow
I’m planning on having my Banks SS header ceramic coated by Jet Hot, and the down pipe between the header and the cat as well. My goal is to have less heat under the hood, by keeping more heat inside the exhaust. I also want to lessen any heat under the drivers side floor.
Years ago I had a CJ-7 on stock suspension and 31’s. After installing 2.5” lift and 33’s my drivers side floor was
noticeably hotter on my feet.
My current CJ-7 is on stock suspension with 31’s, but I am planning a SOA YJ leaf spring conversation in the future. I know the lift changes the airflow under the Jeep, and I am hoping the ceramic coating will help in this regard.
Years ago I had a CJ-7 on stock suspension and 31’s. After installing 2.5” lift and 33’s my drivers side floor was
noticeably hotter on my feet.
My current CJ-7 is on stock suspension with 31’s, but I am planning a SOA YJ leaf spring conversation in the future. I know the lift changes the airflow under the Jeep, and I am hoping the ceramic coating will help in this regard.
-
- Strong Poster
- Posts: 896
- Joined: August 15th, 2009, 1:27 am
- Stroker Displacement: 4.7
- Vehicle Year: 2000
- Vehicle Make: Jeep
- Vehicle Model: Cherokee
Re: exhaust flow
I’ve had bad experiences wrapping a header on a street application.
What happens is the header wrap holds moisture and typically will reduce the life of the header and usually voids any warranty from the header manufacture.
Not trying to undermine the benefits and effort that you’re putting into your project but just wanted to share my experiences with the group.
What happens is the header wrap holds moisture and typically will reduce the life of the header and usually voids any warranty from the header manufacture.
Not trying to undermine the benefits and effort that you’re putting into your project but just wanted to share my experiences with the group.
-
- I made it to triple digits!
- Posts: 172
- Joined: March 28th, 2010, 9:31 am
- Stroker Displacement: 4.2
- Vehicle Year: 1987
- Vehicle Make: jeep
- Vehicle Model: wrangler
Re: exhaust flow
I've been following David Vizard's Chrysler 2.2 cylinder head project for Richard Holdener's turbo build. In addition to enormous V-8 experience, David got his start racing Mini's in the UK years ago. The head on the Mini has the same Reverse Flow (intake and exhaust on same side of head; non-crossflow) design as a Jeep head. One thing he mentioned in the very beginning was that the intake tract is directly exposed to the heat of the exhaust tract which is undesirable. He mentioned coatings inside the tracts to help shield this. He hasn't got that far yet, but I'm watching to learn.
OP may be interested in this based on his undertakings so far!
OP may be interested in this based on his undertakings so far!
-
- Making Progress
- Posts: 54
- Joined: June 2nd, 2021, 1:36 pm
- Stroker Displacement: 4.6
- Vehicle Year: 1998
- Vehicle Make: jeep
- Vehicle Model: xj
Re: exhaust flow
you know, I never thought about how a lift would change the air flow under the jeep that much to cause a problem with the hot foot on the passenger side.
I am hoping the paint will seal out any water but then there are other factures at play that will allow water to get to the header too. I am wondering if I may be keeping to much heat in the headers that will cause premature failure, but I am ok with that. I'll just keep an eye on it.
for me I think the benefit's out way the risk. if something fails then I'll just replace it, but I want to document why it failed. I always want more power and I think this will provide me with that, and there is so much heat in that engine bay that sometimes I cant even lift the hood with out gloves, a real pain. I really cant see how all the other stuff in the bay survived so far. O yes, keeping my wires feet happy keeps me happy too
after all of this work, its going to be fun to see what benefits I will gain and how much.
I am hoping the paint will seal out any water but then there are other factures at play that will allow water to get to the header too. I am wondering if I may be keeping to much heat in the headers that will cause premature failure, but I am ok with that. I'll just keep an eye on it.
for me I think the benefit's out way the risk. if something fails then I'll just replace it, but I want to document why it failed. I always want more power and I think this will provide me with that, and there is so much heat in that engine bay that sometimes I cant even lift the hood with out gloves, a real pain. I really cant see how all the other stuff in the bay survived so far. O yes, keeping my wires feet happy keeps me happy too
after all of this work, its going to be fun to see what benefits I will gain and how much.
Who is online
Users browsing this forum: Google [Bot] and 29 guests