Pre-Production 80 Exhaust by EMS Powered (1 Viewer)

Joined
Oct 3, 2006
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Medford, OR
So I picked up my truck today (finally!). Nice to see her again after almost two weeks.


First off, let me say that it's been nothing but a pleasure working with baktasht. He's stood behind everything he's told me, and has bent over backwards to support my needs and requirements. He's one of those folks that would rather fork over the extra cash for top of the line gear than get by on something that "works."


First, some exhaust pr0n. I didn't get any complete (or even semi-complete) shots off the exhaust off the truck, so you're stuck with what's on the truck (except a Y pipe pic I shamelessly stole).

For larger pics: http://picasaweb.google.com/ebagola/Exhaust#


ypipe1.jpg


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DSC_0241.jpg


undercar1.jpg


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DSC_0251.jpg


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As you can see, the exhaust is routed very close to the OEM location. Here's some of my thoughts on it.


Rock Crawling:

Everything is very well tucked up. The OEM muffler as we all know hangs down way low, with this one it's all nice and tucked up in there.

The over-the-frame bend is well done, and there's plenty of room between the rear heater lines and the exhaust (a concern of mine, that it'd be too close and toast 'em).

The cat is in approximately the same location as the OEM cats, if you cut and turned them. This is a bit of a limitation as the goal was to be able to have a cat-back system available, so unless additional bends were added, the cat location was pre-determined. Even still, you don't have that second cat hanging way back, so I think it's going to be difficult to whack on a rock.

Here's a comparison between my truck and the :princess: rig. Keep in mind that my truck has a 1" body lift on it, which means you'll see an extra inch of the cat that a rig without the body lift won't have.

DSC_0254.jpg


DSC_0253.jpg




Temperature:

After driving 5 hours home (both my truck and the :princess: rig), I felt the two common hot spots, the passenger foot well and underneath the passenger side center row seat (which was not tumbled forward on the drive home).

Unfortunately, the passenger foot well doesn't feel any cooler. This isn't really that big a surprise as if anything the aftermarket cat is slightly farther forward than the OEM cat, to give more room to go over the frame. I was hoping for a drop, but I'm okay with it staying the same.

Under the passenger side center row seat, the temperature difference was noticeable. I'm attributing this mostly to not having that second cat further back toasting the floor boards. Considering how warm that spot can get, this was a pleasant surprise.

Pretty much everything else was about the same.


Noise:

First, let me say that I love the way it sounds. With one caveat. The OEM resonator was removed, and a new one was not put on. So that infamous whistling we all hear with the stock exhaust is there, and in spades. It's not so bad I can't stand it (or drown it out with music), but definitely there, and a lot worse than my old OEM system with a cracked open muffler.

baktasht and I are talking about adding a resonator and seeing if it reduces/eliminates that whistling. I have a feeling it will. Once that's added, the sound is...well....I'll have to get some sound clips to add here at some point. :p

The exhaust sounds almost muscle car like, which is the closest I can relate it to. Kinda like the offspring of a classic old American truck and a muscle car. It's a very nice deep rumbling sound, much deeper than the OEM setup (which I always thought was kinda high pitched and a bit whiny).

I'm pretty sure the muffler is smaller than OEM (would need to measure to be sure), so it's no real surprise that it's a bit louder than OEM. I'm willing to put up with the extra noise to have it so well tucked up however, and the muffler does an excellent job for the size. I doubt you could get one that tucked up and have any better result, without getting real expensive.

Here's a breakdown.

Startup: You definitely hear it starting up. I like.

Idle: It's hard to say if it's actually quieter than OEM in volume, but I can guarantee you it's harder to hear. Very quiet idle, a nice low rumble. Sounds like a real truck.

Cruising: A bit louder than OEM in volume, but a deeper sound, so it kinda balances itself out (it feels about the same). No whine at all.

Mild Acceleration: Volume increases slightly, and so does pitch. The whine is present, so it's difficult to tell how much of that pitch is due to whine and how much is just natural.

Medium Acceleration: IMHO has a very nice sound to it, though I wouldn't call it "deep" anymore. Not as high pitched as OEM, but headed in that direction. The whine is very present.

Heavy Acceleration: Sounds a lot like OEM when the skinny pedal is to the floor. But if you cut off the resonator.

For comparison, here's some sound clips:
:princess: Truck - Outside
My Truck - Outside
:princess: Truck - Cruising
My Truck - Cruising

The first two are recorded outside the cab, right next to the exhaust exit. These are the best two for sound/volume comparison.

The second two are recorded while inside the cab. A quick run down of events (so you can get an idea of what was happening):
Turning onto the street.
Turning onto the freeway.
Accelerating on the on ramp (on mine I had to slow down as there were two cops right there).
Cruising on the freeway.

Now this is not a fair comparison. On the :princess: truck I have added some sound dampening to her truck. I'm absolutely amazed at the difference a single gallon of Second Skin Spectrum made, I always notice a difference but it's always more pronounced when I drive each rig back to back, and even more so listening to the audio of it. So don't use the cruising MP3's for volume comparison, the :princess: truck has an unfair advantage over mine!

For both cruising MP3's, the recording device is sitting on top of the steering wheel. So this is pretty close to what the driver would hear.

It's not the best audio, but it should give you an idea.


Power:

Now, this is all seat of the pants, and I haven't dyno'd it, but here's my impressions.

Feels more responsive and it does feel like there's slightly more power there. It's hard to tell how much of that is real, and how much is because I want it to be there.

I can tell you something I noticed, and that is that I consistently cruised about 500 RPM less on the way home than I normally do. This is a trip that I've made quite often, so it's something that was noticeably different.






Unfortunately, not everything was all fun and games. Can you spot what's wrong in this picture?


under.jpg
 
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Joined
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Medford, OR
Nope, it's not this.

DSC_0262.jpg


(baktasht, you owe me a new bolt. :p )












For those of you who caught the front arm on the lift.....where were you when they were putting it up there? :mad:


Damage:

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It's hard to tell from the pic, but it is significantly bent. I have a suspicion that someone may have bent it back some, as well. There's some yellow flakes embedded in there from the arm, and plenty of bare steel.

For comparison, this is off the :princess: truck.

DSC_0255.jpg



Let me clarify two things here.

1) This is absolutely not baktasht fault in any way/shape/form. For those who aren't aware, this isn't his shop that had my truck but a contractor of his. (And in Portland, OR, while he's in Texas, none-the-less.)

2) When I was up there last weekend, I went in because I saw some early pics and noticed that they lifted it the same way. I explicitly told the guy there (who said he was the one who lifted it, he was one of two guys actually working on the exhaust) not to lift it off the body. At that time I did not see any damage, other than maybe a slightly bent pinch weld. This damage happened after I warned them.


The passenger side is the worst, but the drivers side is bent some too.

So for all you guru's out there, anything I need to worry about? It doesn't look like the rocker is dented or anything, just that inside panel, but I'm not sure what connects to what, and what to keep an eye on.
 
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Joined
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Sorry to see the damage, I'd be pissed about that.

I can tell you something I noticed, and that is that I consistently cruised about 500 RPM less on the way home than I normally do. This is a trip that I've made quite often, so it's something that was noticeably different.

Trying to fully understand your statement here. If your traveling the same speed as before your RPM should be the same. Unless you are saying that your torque converter is remaining locked more often? The only way I could see a constant 500RPM drop, is if you trip is all uphill and your TQ was always unlocked before. Just trying to clarify.
 
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Trying to fully understand your statement here. If your traveling the same speed as before your RPM should be the same. Unless you are saying that your torque converter is remaining locked more often? The only way I could see a constant 500RPM drop, is if you trip is all uphill and your TQ was always unlocked before. Just trying to clarify.

Not necessarily true. If I'm pulling a load, I'll have consistently higher RPM's because the engine has to work harder to maintain the same speed.

My thinking is that with the more free flowing exhaust, the engine is producing more power and/or working easier than with the OEM exhaust, and thus isn't working as hard.

Another option is that my muffler was pretty seriously split open, so it's possible that was causing the motor to work harder (either causing turbulence and restricting flow, or making it too free flowing).

A third option is that the ECU is still learning how to deal with the new exhaust. When I started the truck this morning, it wanted to idle between 200 and 400 RPM for a while. After driving around for a bit, the idle went back to normal(ish). (It was still running 500 RPM's less while cruising after the idle was normal however.)

A fourth option is that the rear O2 sensor was moved from the OEM location. Since the second O2 sensor is used for long term fuel trim, this could cause the engine to run (slightly) differently.




500 RPM isn't really enough to make a significant difference. I'll probably get slightly better gas mileage on the freeway, but that's about it. Assuming it stays that way.
 
Joined
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Correct me if I'm wrong as I do not claim to be an automatic transmission expert. But once your torque converter locks up are your final gear ratios not fixed just like they would be in a manual? Therefore the relationship between engine RPM and speed would be a constant.

When my TQ locks in 3rd or 4th gear my RPM normally drops 500 RPM +/-. So it does make sense to me that if your truck is now producing a little more power you may achieve lockout more often.
 
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Well, neither am I, but I know that I cruise right even with the line, and when the TC locks it drops down to the next one. (I don't remember off hand exactly which one it is.)

Now it's halfway between.

So unless someone changed my gearing or tire size slightly.....

I'm on 35's with stock gearing, so mine's going to be a bit different than yours I think.
 

fzjconvert

one hand, two ducks
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Not necessarily true. If I'm pulling a load, I'll have consistently higher RPM's because the engine has to work harder to maintain the same speed.

My thinking is that with the more free flowing exhaust, the engine is producing more power and/or working easier than with the OEM exhaust, and thus isn't working as hard.

Another option is that my muffler was pretty seriously split open, so it's possible that was causing the motor to work harder (either causing turbulence and restricting flow, or making it too free flowing).

A third option is that the ECU is still learning how to deal with the new exhaust. When I started the truck this morning, it wanted to idle between 200 and 400 RPM for a while. After driving around for a bit, the idle went back to normal(ish). (It was still running 500 RPM's less while cruising after the idle was normal however.)

A fourth option is that the rear O2 sensor was moved from the OEM location. Since the second O2 sensor is used for long term fuel trim, this could cause the engine to run (slightly) differently.




500 RPM isn't really enough to make a significant difference. I'll probably get slightly better gas mileage on the freeway, but that's about it. Assuming it stays that way.

I must have missed it. Why was the rear O2 sensor moved from the stock location again?
 
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Fit likely. Since it's going over the frame rail instead of under, and in a different location, it would have been relatively difficult to add it to the exact same spot.

It's not very far off from where it was before, but it is slightly different.

Something else I just thought of is that having one cat instead of 2 may be changing things slightly as well.....
 
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Looking good Gabe. I'll get that bolt for ya ;) no worries.

The O2 sensor was moved for fitment mainly, a few other reasons as well, but mainly fitment.

What was your total investment for the project? And what type CAT did you end up using?

The system on Gabe's truck is the very first prototype. We will be doing some more beta-testing along with some changes along the way if/when necessary and will have the exhaust setup available for sale to the community soon. The CAT is a Magnaflow/Schwartz high flow oversized OEM replacement unit. The muffler is an Aero Turbine long body, high flow truck muffler. All piping is 2.5" mandrel bent to spec. It's designed for maximum ground clearance with piping going over the frame rails.
 

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