Exhaust single to dual on a tight budget - Then we get into some after issues

[Radiohead]

I'm running stock manifolds, and yes the air pump, pumps into the manifolds. Why do you ask?

To be honest at this very moment I'm a little pissed at myself for not waiting until I had $$ for the cats and just do it all at once, what with all the complications with the dual setup, I should have just spent the extra dollars and rebuilt the single setup.

For some reason I thought you had put on tube headers. Which made me wonder where you were putting the air, that's all.

 

[SirRobyn0]

A couple things I'm going to mention / play with. I'm not at all ecstatic with idle quality or sound of the exhaust with the ignition on ported vac. 4 DBTC is just not much and to some degree I've traded the smell of NOx for the smell of unburned fuel which is no surprise really. So tomorrow I have to drive the truck a bit and I may fiddle around with the mixture screws and try to lean it out some which of course risks bringing in NOx but if I can get rid of some of the unburned fuel smell I think it'll work.

If not I might set up a vacuum operated water "injection system". Basically the plan there would be to go back to manifold vacuum on the advance, and set up a crude water "injection system". Basically the system consists of a bottle, a hose to a manifold vacuum source with an adjustable valve inline. The get just enough water coming in to lower combustion temperatures, and NOx should drop off. I almost want to try the crude and simple water system just to see if it would accomplish that. @Ricko1966 wondering what you think if your up to thinking about it right now. I'd think the water system would have to come off when the cats go back on though.

 

[Ricko1966]

A couple things I'm going to mention / play with. I'm not at all ecstatic with idle quality or sound of the exhaust with the ignition on ported vac. 4 DBTC is just not much and to some degree I've traded the smell of NOx for the smell of unburned fuel which is no surprise really. So tomorrow I have to drive the truck a bit and I may fiddle around with the mixture screws and try to lean it out some which of course risks bringing in NOx but if I can get rid of some of the unburned fuel smell I think it'll work.

If not I might set up a vacuum operated water "injection system". Basically the plan there would be to go back to manifold vacuum on the advance, and set up a crude water "injection system". Basically the system consists of a bottle, a hose to a manifold vacuum source with an adjustable valve inline. The get just enough water coming in to lower combustion temperatures, and NOx should drop off. I almost want to try the crude and simple water system just to see if it would accomplish that. @Ricko1966 wondering what you think if your up to thinking about it right now. I'd think the water system would have to come off when the cats go back on though.

Yep water injection would bring down your nox emissions,and would probably keep you out of the knock sensor more often. It's funny because when I hit you back yesterday and told tuning was about all you had to work with,I almost suggested water injection but thought nah too much effort,too much babysitting for too little gain. But if you want to, your only byproduct is co2 I don't see how that hurt a cat.

 

[SirRobyn0]

Yep water injection would bring down your nox emissions,and would probably keep you out of the knock sensor more often. It's funny because when I hit you back yesterday and told tuning was about all you had to work with,I almost suggested water injection but thought nah too much effort,too much babysitting for too little gain. But if you want to, your only byproduct is co2 I don't see how that hurt a cat.

Ok I will think on it. To me a few bucks (or possibly just rummaging though my junk) to make a simple vacuum operated system to fool around with is one thing. Spending a couple hundred for a professionally made system is whole other ball of wax (and ain't happening). I don't think that water injection would hurt a cat, I just thought if I lowered combustion temps enough, it might keep the cat from getting up to temp. I guess if that were to happen the solution would be to dial back the water a touch. Thanks for a little reinforcement that my thinking is correct.

 

[Ricko1966]

Robyn here's some good reading for you.

https://www.sciencedirect.com/science/article/pii/S2352484721005643

 

[Ricko1966]

I made one before, I've seen people use engine vacuum as water injection ,that never made any sense to me,you have most vacuum at Idle and progressively less vacuum as you open the throttle,so the only way a system running off of engine vacuum could be correct would be at idle. I made one using an electric washer pump,the same washer bottle,drilled a hole in the air cleaner lid where a routed a piece of tubing,smashed flat and 2 small holes drilled in it,think of an upside down windshield squirter through the air cleaner lid. It was crude but did what I wanted. I'm smarter now I fully believe I could now vary the pump speed to make it progressive.
Here you go mount one of these upside down through the air cleaner top,pirate a washer pump and bottle from a parts car and your system almost assembles its self,you can probably use an aquarium valve as a limiter and jet drills to fine tune your shot.

 

[SirRobyn0]

@Ricko1966 I'll read the article you linked, but also want to say this. Part of the attraction to a vacuum draw system is it's super quick and simple to set up. One bottle, one vacuum line, one valve. Adjust valve open until NOx is reduced (would really be nice to have an exhaust gas analyzer!) but I'd just have to do what my nose tells me. Remember my primary purpose, at least at first is controlling idle emissions not WOT pinging. Perhaps the ESC computer would need to pull less timing at light throttle, under ping likely conditions like light acceleration in OD. And perhaps I'd be able to run a little more vacuum advance from the can as well, without getting into pumps and nozzles. I think that's putting the cart before the horse. Right now I just want to see what I can do for idle emissions and go from there. Like I said I could likely build the vacuum draw system from stuff I've already got in what maybe 15 minutes just to see if it has the desired effect seems like the thing to do vs building a more complex system if I find I'm unhappy with the results.

 

[SirRobyn0]

Well I fiddled around with the idle mixture screws this morning and settled with them a little more than a 1/4 turn leaner. No equipment was used set my ear and feel. Well that made a hell of a big difference. (Shaking head at myself), I should have known going to ported vac would require a leaner idle mixture to make it right. Well it idles a bit better like that and even the sound is a bit better but most importantly the smell is much better. Not as clean as with a cat of course, but certainly back to an acceptable level, and my drive this morning did not set off my asthma! That's a good thing for sure. I even went though a drive through where I had a wall up against the truck and my window down, of course I did smell exhaust then, but it was well within tolerable. With that I should be fine until I get cats back on it, then I'll have to decide if I want to continue to run it like this, or if I want to go back to manifold vacuum.... My mechanic side says leave it like this with the vac. advance on ported, it obviously burns cleaner. My other side says, but I like the idle better with manifold vacuum, so I guess we will just see. I think it'll depend on how I feel about the current setup over time.

 

[Radiohead]

Well I fiddled around with the idle mixture screws this morning and settled with them a little more than a 1/4 turn leaner. No equipment was used set my ear and feel. Well that made a hell of a big difference. (Shaking head at myself), I should have known going to ported vac would require a leaner idle mixture to make it right. Well it idles a bit better like that and even the sound is a bit better but most importantly the smell is much better. Not as clean as with a cat of course, but certainly back to an acceptable level, and my drive this morning did not set off my asthma! That's a good thing for sure. I even went though a drive through where I had a wall up against the truck and my window down, of course I did smell exhaust then, but it was well within tolerable. With that I should be fine until I get cats back on it, then I'll have to decide if I want to continue to run it like this, or if I want to go back to manifold vacuum.... My mechanic side says leave it like this with the vac. advance on ported, it obviously burns cleaner. My other side says, but I like the idle better with manifold vacuum, so I guess we will just see. I think it'll depend on how I feel about the current setup over time.

Rig up a bypass system so you can switch it from the dash. Lol

 

[SirRobyn0]

Rig up a bypass system so you can switch it from the dash. Lol

That would be possible to do but there are to many complications. At minimum I need to add a idle kicker as the idle speeds would be different. I know your joking though. I hauled a second load this afternoon and all was well she idled well enough, drove good and sounded fine. Which I really haven't talked about until this smell thing came up.

Sound. Like others advised me I would not consider the thrush turbos to be loud, but I wouldn't consider them quiet either. Take my comments from someone coming from a single exhaust truck. So when I'm rolling down the road like at cruse depending on the speed they are either barely audible or cannot be hear at all, but as soon as you step into it you can hear them, but not terribly loud. The only time I'd consider them loudish is like climbing a hill loaded. At idle with the window up they are totally fine, but with the window down they are pretty noticeable. When I leave the farm in the morning to go to the shop it seems like they are loud, but the farm is pretty quiet at 6:30am. In reality the exhaust sound is more noticeable at lower speeds when there is less drive train noise to drowned it out. Conversations can be had inside the truck at all speeds and RPMs at a normal volume, in other words you do NOT have to try to talk over the exhaust. Conversations at idle with the window down can be had at normal volumes. I did NOT have to shut the truck off to hear when I was in the before mentioned drive though. I'm quite sure I could run the truck all day long down the road loaded or empty and the exhaust sound would not be bothersome, which was a big concern of mine. I would say that the tone (not volume) is mellow, they are neither raspy nor bassy, just a pleasant mid range tone. They do give my truck that nice old school V8 sound, which goes well with the nice old school work truck image the truck portrays and lives. Would I prefer the Walker FX's.... honestly probably a little bit. But unless these mufflers start to annoy me over time, which I doubt they will, they'll be fine. And right now the cost savings of spending $40 for a pair of muffler vs $120 for the Walkers is more important than my nit picky complaints.

Because I ended up hauling horse manure (you'd think a chicken farmer would have plenty of compost, but chicken poo is terrible for your garden) I haven't had the time with the bed empty so I could lift it and do the shielding for the bed pump. Hopefully I'll get to that during the week at the shop. If not I'll do it over the long weekend at the farm. I'll be sure to post pics of the shielding.

 

[GTX63]

I've installed 3 or 4 of the Dynomax systems, usually the 89003s. Yes, they are way cheaper than OEM or custom bent pipes. I have seen prices vary from $140 to almost $300 for basically the same kit, depending on who the seller is.
I believe they manufacture them for the long beds and you either cut them down or not use the mid length extensions for a short bed.
That said, they are not always as simple as hang and clamp and go. My first impression was that the pipes wouldn't last very long, but it has been 4 years on the first install and it is doing just fine. The clamps and hangers they send with the kits are absolute chinesium garbage, so for others reading this, know ahead of time that you may need to make a run to the parts house mid install.
What you are getting for your money are pipes that are close enough to fit; everything else included may or may not work.
I'm not complaining, just saying. I'm happy to have a cheap source of squarebody exhaust.

 

[SirRobyn0]

@GTX63 you echo my thoughts. So I used 89006 kit which is listed for the C trucks, where as the 89003 is listed for the K trucks, though I'm sure you could put a "3" kit on a C truck though.

There is an extension pipe used on the between the tailpipe and muffler for the long beds like mine.

I'm not sure if I mentioned this but I used the Thrush version of the recommended Dynoflow mufflers. Despite that when I installed the left pipes I noticed that the tail pipe was bent so the back part of the pipe was much closer to the axle than the front part of the pipe. When I went to install the right side tailpipe it hit. So I ended up purchasing a $9 piece of pipe to extended the pipe between the muffler and the tailpipe another 6" which put the bent right in the middle and kicked the tailpipe out so it exits more straight out from the body than the left side does.

I agree the hardware is not the best. I'd bought extra hangers and clamps figured I'd return them if I didn't need them, but instead I used the ones I'd purchased and I guess I'll hang on to the cheap stuff out of the kit for use at another time.

I considered purchasing universal pipe pieces to run new pipes from the manifold back, installing mufflers, and 90 degreeing the pipe out in front of the rear tires (which I hate BTW but looking at doing this as cheap as possible), well the kit was cheaper than trying to cobble something together and tailpipes exit where they should.
For the price paid I'm totally fine with the little issues that have to be over come to install the kit.

 

[SirRobyn0]

Ok so I started on shielding for the hydraulic pump for the bed dump. Specifically all I have done is wrapped the bit of tail pipe that the hydraulic hose is close to. And wrapped the hydraulic hose with heat resistant tape. I did this Wednesday at the shop, and that's as far as I've made it. So after work I drove the truck for about two hours and the smell of the wrap doing it's curing process from the heat of the exhaust was not pleasant. I don't have a lot of experience with header wrap. You'd think with all the classic work we do at the shop that someone would want a wrap, but no.

So my point to this is how long would you expect the header wrap to smell for? And will it smell bad later if I were to get the exhaust hotter than normal, like towing the trailer up a hill? This is just an inexpensive fiberglass wrap that has been hanging around in the shop, so I no longer remember the manufacture.

I'm going to work on the muffler and the pipe that is below the fuel tank valve either tomorrow morning or Sunday morning. I'm about 1/2 temped to cut the wrap off I've already done, and just make a long shield, but I was going to wrap a short bit of the pipe nearest the tank valve, and possibly the muffler, or I might make a metal shield for the muffler. Anyhow if someone with header wrap experience can give me an idea of how long it takes to stop stinking would be great. Thanks.

And yes I will take pictures!

 

[bucket]

It's been years, but I don't remember any smell. What type of wrap did you use exactly?

 

[SirRobyn0]

It's been years, but I don't remember any smell. What type of wrap did you use exactly?

I really have no idea, it's been hanging around the shop for around 5 years. It was in a plastic bag with a label that said "Fiberglass header wrap". Nothing else. I know at one time it was in a cardboard box with a sheet of paper which likely had info on it but that disappeared at some point. I will probably just see how it goes next week and if the smell stops.