How free flowing should the XJ exhaust be?

[gradon]

I'm using Ubuntu as well, but might need windows to use the r4 software(split second psc-1) and logworks for the wideband o2. The ftc-1 is a good piggy-back for retarding the timing, so check it out as well.

 

[alex22]

If you have the money the F.A.S.T systems are really nice. We have built a few drag engines, supercharged and NA with NOS and used F.A.S.T. It works great, but its not cheap.
How well do you think the thin steel headers will support the weight of the turbo once it gets hot?

~Alex

 

[wolfpackjeeper]

not sure, there are a couple of extra stud mounts in the engine casting on that side, so I would probably fab a bracket up to hold it a little better. Header wrap and a turbo blanket will be pretty much mandatory

 

[Boostwerks.com]

I would like to run around 8-10 psi, and control it with a megasquirt setup. not sure on the exhaust yet, 2.5in at the least I think would be needed on the turbo setup.

I am also waiting on the programmers for megatunix to finish up the final program to control a megasquirt 2 setup from a linux based platform. I am one of those guys running a ubuntu/kubuntu setup and dont want to load windows just to run one tuning program.

Go with 3" at least. your engine/turbo setup will thank you. The larger the exhaust on a turbo setup, the better.

I personally can't beleive this thread is as long as it is lol :wow:

Exhaust is not that tough of a subject, but a lot of people get it wrong. It can be however, if you want to get into the complicated affect of tuned pulse scavenging (super trapp mufflers for example), but for most people it's as simple as this:

Velocity. N/A engines love exhaust velocity, as it will help scavenge the cylinder during the exhaust stroke. Note that I said "velocity" not "backpressure." This means that any engine will love a free flowing exhaust that keeps velocity high around it's natural peak torque output.

For the 4.0L this is the exhaust that I would build: mandrel bent 2.25" piping with minimal bends, and a straight through muffler (Dynomax ultraflow, magnaflow). I'm sure I'll take some hit for this, but the Flowmaster mufflers are not designed for power, but more for sound. The best muffler will do it's job without disrubting flow (straight through design). The small 2.25" piping will keep the velocity high, but the mandrel bends and straight through muffler increase flow.

 

[PurpleCherokee]

Go with 3" at least. your engine/turbo setup will thank you. The larger the exhaust on a turbo setup, the better.

I personally can't beleive this thread is as long as it is lol :wow:

Exhaust is not that tough of a subject, but a lot of people get it wrong. It can be however, if you want to get into the complicated affect of tuned pulse scavenging (super trapp mufflers for example), but for most people it's as simple as this:

Velocity. N/A engines love exhaust velocity, as it will help scavenge the cylinder during the exhaust stroke. Note that I said "velocity" not "backpressure." This means that any engine will love a free flowing exhaust that keeps velocity high around it's natural peak torque output.

For the 4.0L this is the exhaust that I would build: mandrel bent 2.25" piping with minimal bends, and a straight through muffler (Dynomax ultraflow, magnaflow). I'm sure I'll take some hit for this, but the Flowmaster mufflers are not designed for power, but more for sound. The best muffler will do it's job without disrubting flow (straight through design). The small 2.25" piping will keep the velocity high, but the mandrel bends and straight through muffler increase flow.

Amen brother :worship:

 

[BBeach]

Amen brother :worship:

Did you note it wasn't a dual exhaust and that everything he said we already stated. x2 on the magnaflow/straight through design. Ive got that now and I like it a lot. With the flowmasters, and stock for that matter that fluids gotta bounce around everywhere creating backpressure.

 

[PurpleCherokee]

Did you note it wasn't a dual exhaust and that everything he said we already stated. x2 on the magnaflow/straight through design. Ive got that now and I like it a lot. With the flowmasters, and stock for that matter that fluids gotta bounce around everywhere creating backpressure.

Who said anything about dual exhaust??? I amen'd him cause hse's got the right idea, there's a big difference between exhaust velocity and backpressure and a lot of people get mixed up. And he's right about the straight through mufflers too, everything else just creates more backpressure. So just let it the hell go. Those of us that actually know something will just ignore you.

 

[Boostwerks.com]

Did you note it wasn't a dual exhaust and that everything he said we already stated. x2 on the magnaflow/straight through design. Ive got that now and I like it a lot. With the flowmasters, and stock for that matter that fluids gotta bounce around everywhere creating backpressure.

Dual exhaust huh? Well let me give my input on that now that you've brought it up...

Dual exhausts belong on a:

- V8 where there are two headers

Thats all. If you don't have two headers you don't need dual exhaust. It's as simple as that.

Amen brother :worship:

Thanks! Lets just say that I've been around the "block" so to speak. :lecture:

 

[alex22]

And before we get back to the two piece header. It looks like Bryson meant two compleetly seperate headers, left side and right side, not front and back that just happen to have two outlets.

~Alex

 

[BBeach]

Dual exhaust huh? Well let me give my input on that now that you've brought it up...

Dual exhausts belong on a:

- V8 where there are two headers

Thats all. If you don't have two headers you don't need dual exhaust. It's as simple as that.



Thanks! Lets just say that I've been around the "block" so to speak. :lecture:

Before you start pointing fingers, read the past couple of pages of this thread and realize that purplecherokee has been arguing how get his dual exhaust system is. Seriously, read my position on the matter, and then you'll realize i completely agreed with you in the first place.

 

[BBeach]

Who said anything about dual exhaust??? I amen'd him cause hse's got the right idea, there's a big difference between exhaust velocity and backpressure and a lot of people get mixed up. And he's right about the straight through mufflers too, everything else just creates more backpressure. So just let it the hell go. Those of us that actually know something will just ignore you.

Im saying something about dual exhaust. Bryson said:

"For the 4.0L this is the exhaust that I would build: mandrel bent 2.25" piping with minimal bends, and a straight through muffler (Dynomax ultraflow, magnaflow). I'm sure I'll take some hit for this, but the Flowmaster mufflers are not designed for power, but more for sound. The best muffler will do it's job without disrubting flow (straight through design). The small 2.25" piping will keep the velocity high, but the mandrel bends and straight through muffler increase flow."

I could only assume that he believes 2.25" is the best system with one single pipe. Im assuming this because of his later statement on V8's
"Dual exhausts belong on a:

- V8 where there are two headers

Thats all. If you don't have two headers you don't need dual exhaust. It's as simple as that. "

Any thoughts on that?

 

[BBeach]

And he's right about the straight through mufflers too, everything else just creates more backpressure. So just let it the hell go. Those of us that actually know something will just ignore you.

And thats why I've had one on my jeep for the past two years. I wont even comment on your last line.

 

[Boostwerks.com]

Before you start pointing fingers, read the past couple of pages of this thread and realize that purplecherokee has been arguing how get his dual exhaust system is. Seriously, read my position on the matter, and then you'll realize i completely agreed with you in the first place.

I'm not arguing. Simply adding some experience and knowledge to whats being said. I don't come onto forums to stir up e-fights, but simply "answer the question". :beer:

 

[Kittrell]

Not to hi-jack. But what ever happened with that turbo?

 

[PurpleCherokee]

Im saying something about dual exhaust. Bryson said:

"For the 4.0L this is the exhaust that I would build: mandrel bent 2.25" piping with minimal bends, and a straight through muffler (Dynomax ultraflow, magnaflow). I'm sure I'll take some hit for this, but the Flowmaster mufflers are not designed for power, but more for sound. The best muffler will do it's job without disrubting flow (straight through design). The small 2.25" piping will keep the velocity high, but the mandrel bends and straight through muffler increase flow."

I could only assume that he believes 2.25" is the best system with one single pipe. Im assuming this because of his later statement on V8's
"Dual exhausts belong on a:

- V8 where there are two headers

Thats all. If you don't have two headers you don't need dual exhaust. It's as simple as that. "

Any thoughts on that?

Ya, he's right about the backpressure thing and wrong about the dual exhaust being useless on a six-cylinder thing. Simple as that

 

[Boostwerks.com]

Not to hi-jack. But what ever happened with that turbo?

It's still on man! I've just decided to completely change up the design. The manifold simply did not turn out how I'd like, so I've decided to develop a remote mount kit. I should have some pics here soon actually.

Some highlights:

- CNC'd 1/2" flanges
- 16ga 304 mandrel bent stainless tube
- designed to work with the factory front pipe
- Turbo/WG are held up with adjustable heim links
- Can fit up to a Garrett GT40 (600ft/lbs possible)
- Will allow use of an aftermarket belly pan (protection)
- 3" down pipe (extra)
- charge pipinng kit (extra)
- External or Internal WG options

I am selling the kit in parts, which will allow someone to get exactly what they need to get a turbo on the rig, It'll be inexpensive, but no doubt the highest quality power adder for the XJ out there.

 

[wolfpackjeeper]

where are you remote mounting it. I have been looking at it and was planning on right under the manifold, but i am gonna have to hack up a manifold something special. everywhere other than right there was gonna interefere with effective wheeling.

 

[Boostwerks.com]

Right behind the transfer case. It's actually working out to be the perfect spot.

I'm also working on a flexible intake tube that would keep water crossings possible.

 

[wolfpackjeeper]

I was not worred so much about water injestion but as to what cold water would do to the turbine housing. I was gonna shield the hell out of it and hope for the best, but I dunno..

 

[Boostwerks.com]

I was not worred so much about water injestion but as to what cold water would do to the turbine housing. I was gonna shield the hell out of it and hope for the best, but I dunno..

You might want to get it ceramic coated, but I honestly don't think you'll have a problem. It's not like your going to get it red hot, and then dive into a river. At least I hope your not