Hey guys,

I'm about to place an order with Riff Raff and have a few questions. First off, I need to replace the leaking up-pipes in my E99 F350. That's the basis for the upcoming work. So, that leads me to my first question. Riff Raff offers ceramic coating for their up-pipes for an extra $150 ($459 vs $609). Is this necessary? Worth it? I'm leaning towards saving my money for other things.

Since winter is coming and I have two glow plugs out (at least last time I checked a couple of months ago), I plan on swapping all of them out for Motorcraft plugs. Should I do UVCHs also while I'm in there? They are currently working fine. I hate swapping out good working parts, especially to the tune of $120 if I don't need to replace them. Would a good inspection suffice? I do plan on re-torquing everything while I'm under the valve covers.

Other work I will be performing while I'm "in there" will be: a new EBP sensor, new CAC boots and clamps, and a new fuel bowl heater and filter. The current EBP sensor is aftermarket (I know, I know - that's why I'm replacing it -it never has read right on Torque Pro). The CAC boots are original and look to be on their last legs. The clamps have been leaking in a couple spots despite different torque settings (yes, I know about not torquing down the spring clamps, but one of them leaks no matter what I do). The fuel bowl heater went out last winter, and I never got around to replacing it until now. I know it's not "necessary", but I like knowing that things are working like Ford intended. I'm kind of **** that way. And I'm due for a fuel filter anyway.

My final question is, what else should I do? I've had the truck for about a year and a half and 15,000 miles. It's running well with no codes or hiccups. Details are in my signature, but basically, I've added a Hydra and canned PHP tunes, an S&B intake, a 4" MBRP exhaust, hutch and harpoon, gauges (EGT, Boost and Trans temp), and Torque Pro monitoring. As far as I know, everything else is original under the hood. I believe the PO used my truck to haul a 5th wheel for the first 135K miles. I've thought about fuel and HPOP lines, but I kind of wanted to inspect them first before I bought new ones - again, I hate replacing things that are still working, but I don't want to be stranded either.

Any and all suggestions are appreciated! Thanks!

And since everyone likes pics, here's a pic from this summer from Eastern Oregon during my family's Solar Eclipse camping trip (in the path of totality ).




Kyle

 

Those UVCH's are getting old and I expect you'll get feedback for both sides of that argument. I'd take a good look at them and if they are still intact and supple I'm with you, don't fix it if it's not broke. The $.50 mod for it would be in order at the minimum though. Coated up pipes or non coated? That is the question. I went coated but I'm not sure it is/was necessary. What does the coating do? It keeps the heat in. Is letting it out out a problem? I'd like to hear about that because I feel like the more heat lost from the exhaust system the better. I don't see how more heat through the turbo would be good. Addressing the bracket on the fuel line where it attaches to the passenger's side head would be a good move. New HPO lines could save you a messy problem down the road.

 

I've heard you can wrap your up pipes in exhaust wrap, figured that'd be cheaper too.

 

I'm still not sure I see the benefit of coating or wrapping them. Maybe call up Riff Raff and ask Clay. If you still have the original stainless braided HPOP lines, replace them for sure. They are 18 years old, subject to pressures in excess of 3000 psi, and when they suddenly fail they spray everything under the hood in oil and leave you stuck on the side of the road. I didn't replace my UVCH or valve cover gaskets either. They looked fine so I just saved the money and put them back in. Good call on the boots and clamps, the new hardware is much better. Nice FJ40 too!

 

I spoke with Clay about it and he said that coating helps keep heat in, like it's a good thing. I don't see any advantages and would need someone to enlighten me. Unless having it that close to the firewall is a problem.

 

Keeping the heat in pre-turbo also keeps the velocity of the exhaust gasses higher. The turbo needs high velocity exhaust gas to spin the turbine. Coated or wrapped manifolds, pipes, and exhaust housing increase performance. That's why racers do it.

 

If you still have the factory stainless steel braided HPO lines, CHANGE THEM! Nothing will put you on the side of the road with a mess for a mile and an undercoated truck faster. My blew around 135k miles.
Change the rubber lines on your front brakes too. You didn't ask about it but it's always a good idea if they're original. The rubber breaks down on the inside making them act as a check valve.

As far as coating goes that's up to you. If you live in a place they put salt on the road it's a good idea. Yes, it keeps heat in... because that's what you're worried about most... From the factory they are not coated and do just fine. It's your money though. As someone else said you can just wrap them. It's something you will never see a difference with and I would save the money. I live in Michigan where they salt the roads like crazy and I would opt for the coating over the wrapping.

 

Keep the heat IN! ... Maybe!... It depends!

Physics (thermodynamics) says that there is a benefit. Here's why. Hotter gases entering the exhaust side of the turbo will be more expanded in volume in comparison to the same quantity (mass) of gas at a cooler temperature). These expanding gases will try to consume more volume, and the result (for our system) will be a faster velocity through the pipe (because the end of our system -- tailpipe -- is OPEN). Therefore, as the gases expand with increased temperature, the gases will evacuate from the system faster.... higher velocity in the pipe.... and we all know what that means... it will spin the turbo's exhaust wheel faster than the same mass of gas flowing at a lower temperature. If the exhaust inlet wheel turns faster, the intake wheel will suck in more air, and you already know the rest of that story.

The next question becomes, "Is the higher velocity significantly beneficial?" Good question, and it's the one initially asked, but the problem is in estimating how much difference the wrapping/coating really makes. I do not have an estimate for the volume of exhaust at, say 1000°F exhaust temperature, so I cannot calculate the difference in velocity as temperature increases. The increased velocity WILL take place. It probably will not be significant for "running around town" conditions. However, pushing the engine hard for moderate to heavy towing conditions (or racing), I suspect that the increase would be beneficial.

The next and real bottom line question becomes, "How often do you really put your engine under moderate to heavy loaded conditions?" Only YOU know that answer, and it will be somewhat different for every individual.

The final question which has also been asked is, "Will the extra heat hurt anything?" Another excellent question, and my answer of "No, it won't hurt anything" is based on my knowledge of science and equipment design factors... and a little bit of faith in the turbo charger designers/builders and engine manufacturer covering their own butts with conservative design factors. These exhaust systems and turbos are all built with safety factors in terms of wheel speed and heat tolerances. On average, the increased heat you get from coating or wrapping will not create overheat conditions for your system. If you were to assume that heavy towing or racing conditions make up 70% of the actual engine run time, I would say that you are probably still within the design limitations for both the turbo and piping. After all, once the velocity is higher and the turbo is spinning faster, it will be exhausting these hotter gases at a faster rate. Additionally, the coating and wrapping will reduce the ambient temperatures around components which are near the piping. The turbo casing will get a little hotter, but you can also wrap the turbo if you need to protect anything adjacent to it. However I do not believe that will be necessary unless your only running the truck for races.

 

I'll add a little more Pete. To see any difference in flow or speed of exhaust gasses you must touch other choke points in your exhaust system. Have you even seen the inside of a cylinder head on a 7.3? It leaves a lot to be desired to say the least. This is all the more reason if you do not live where they salt the roads to not bother. You won't see a difference

 

Thanks, John. I'm sure that you have good reasoning, but I don't follow the connection with salted roads. Can you explain a little more?

 

Southerners.

This is what a truck looks like after ~10 years of driving on salted roads in the winter (notice the door was replaced, probably because the rot got too bad):



They use salt because it lowers the freezing point of water so ice doesn't form on the roads as easily. It's usually mixed with cinders, gravel, or some other kind of traction aid as well.

 

^^^ I thought floor ventilation was a standard feature on Chevys ...

 

On the issue of salt...how much salt spray do you figure gets up there? I wouldn't expect too much but don't know. When I replaced my up pipes the old ones didn't look like they had seen much water.

 

I can't help it that the first picture of a rusted out truck I found with a google search was a chevy...

 

Thanks everyone for all the input! They don't salt the roads here in the NW just yet. And living in the Portland OR area, we don't see much snow or ice on average - maybe a week or two each winter. While I believe you guys that there may be some small benefit to coating the up-pipes, I think I might be better off spending my money on things that will really help. Like new HPOP lines. I just went out and checked, and they do look like the originals. I'll go ahead and order those up when I call Riff Raff. I'd love to do more, but I already have almost $1200 in parts in my basket. That money tree in the backyard just didn't produce like it should have this year. I'll update this thread when I start installing everything.

Thanks again!