Rock Guard for 08 GM Diesel

Just upgraded to a 3/4 ton Chevy Diesel, had these rock guards on the 1/2 ton, but don't think that they'll hold up behind the bazooka exhaust out the back. Any other ideas?

you might want to cut a hole the size of the exhaust pipe. i'm not sure that if the exhaust hitting the rubber would bounce back enough to cause any exhaust back presure. i know that at our shop when we install trolling plates on the IO's when have to cut a 2 inch hole in them because the exhaust hitting it was causing exhaust back presure and causing the little 4cyl motors to run really crappy.

honestly..change that crappy looking exhaust

I've thought about cutting a hole, but will do that as a last resort, I know of one guy that has already melted a set and don't want to find melted rubber on the boat.

Jonny-I would but GM is really cracking down on warentee claims...just came out saying that ANY mods to the exhaust (even putting a cat back) would void the warentee. Don't want to push it yet.

You can buy a filter back exhaust that won't void the warranty. I put one on my 3/4 ton chevy and it looks so much better. Sound didn't really change and that is with removing the muffler. Kind of tells you how much restriction is in the cat and DPF.

Why not just bolt on a piece of Alumnium sheet in the area that could hit the muffler so the rubber won't melt?

I would assume the rock guard is not permanent?

The aluminum isn't a bad idea, could replace both sides and hinge it at the top. The guard is clamped to the hitch so I can remove the whole thing when it when not needed...it is pretty ugly when the boat isn't in tow.

My customers cannot change out their exhaust without risking a void in their warranty. With the new emission's standards these exhaust are set up to handle very high temperatures in order to burn of particulate in the particulate filter they then dissipate the heat very quickly so you don't melt the paint off the car next to you. I don't know why GM went with that mega phone looking pipe but ours doesen't look bad at all. We had an after market tuner company come in who had switched out exhaust and they were unable to get any improvement in power their tuner on the other hand was very impressive.

why not just go to a muffler shop and have them cut 10" off it (by the looks of it) and then just add a bend so that it's side exit rather than rear. That should fix the problem, shouldn't do anything adverse to the warranty, and would look 100% better.

The end of the exhaust is designed to cool the super heated exhaust thats why it's shaped the way it is.

Someone else posted this on WW a while back and I love the look of it. I think he made it him self.

Ben-I was looking for that pic and hoping someone would post it. I like the idea, would have to work out the details on how to build it.

Mike-I'm going to go by a muffler shop and see if they can bend it out w/o creasing the pipe.

Also found a way to polish it so it doesn't have that galvanized look.

Right now nothing is off the table, keep them coming.

Hey Ben, that is my setup there. it's actually a kit that you can buy, and just bolt right onto the trailer. I'llh have to get the manufacturer and phone number for you guys that are interested. it's a great setup.

PWORK,
I built a similar one last year for my 2006 HD, and it works OK, but not great. The problem is the gap at the top between the bumper and the guard. The guard will keep the rocks from chipping the boat, but I still get small rocks and assphalt in the boat sometimes. I still have the stock small tires also. I plan to modify mine in the next couple weeks, and add a guard piece that closes that gap.

Ryan-I'd like the info if you can dig it up. Darin, the above pic is pretty bad, but the material sticks up above the bar ~2" which filled in the gap you speak of on my 00 1/2 ton. Dad has also used pipe insulation placed over the top to fill that gap and it worked well.

super heated exhaust?get outta town

i call BS!

no BS, exhaust is heated up to approx 1250 degrees to "regen" the particulate filter. takes about 20 minutes and kills your mileage because extra fuel is dumped in the engine after the power stroke to cause this regen. mileage is a tradeoff for clean exhaust and thus no black stuff on boat

The exhaust thing is only what we're seeing on the end of the tailpipe? If so, it's snake oil. I'd love to be proven wrong with some real-world test results, though.

No, there is a DFP up stream of the tail pipe, think of it as a exhaust filter, which is really what it is. When the ecm sees a certain pressure differential pre and post DFP it dumps extra fuel into the cylinder during the exhaust stroke which bumps up the temp per shane's comment and cleans it out. The exhaust tip is designed to mix with ambient air to lower the exhaust output temp, however, I'm worried that the exhaust temp is still high enough and pointed directly at my rock guard that it will melt it. The new Ford's have this system as well, and I believe Dodge's do too.

(Message edited by siuski on February 20, 2008)

(Message edited by siuski on February 20, 2008)

the end of the tailpipe is to allow air to mix with the hot exhaust so it is cooler by the time it reaches the tip. The actual particulate filer (DPF) is before the muffler and after the cat (DOC).

RYAN-- I'm interested in that product. Thanks.

Im looking at that same truck right now and I told the dealer of that "special" exhaust is the only option it could really be a deal breaker for me and my dealer said it could be switched out for a nice chrome tipped one with no problem. They even had a couple at the dealer with it already done. I would check with the dealer again.

so you are burning more fuel to lower the emissions? the emissions from diesels are less then conventional gasoline engines... makes no sense and it would be the 1st thing that would be taken off on the truck is that. As far as voiding warranty, i call BS again!

yes, burning a lot more fuel to decrease emmisions. knocks my tank mileage down a couple of mpgs every time it goes into regen, which is about once a tank. for it to void warranty the dealer would have to prove that removal of the dpf caused the problem. it would be hard to prove that a more free flowing exhaust caused engine problems. diesels like to breath, i would guess that an identically tuned engine without the dpf would last longer than one with one. (and get much better mileage and a little more power). wasting more fuel to get marginally more clean exhaust sounds like bad logic to me, but that is probably why i don't work in government!

http://www.trailer-rockguard.com/

sorry for the delay. here's the site to get the setup. they might have a dealer closer to you. another idea I'm prob going to do is a member on here (brevin i believe) had some sunbrella material extrend from bow cover down to the trailer front to completely protect the trailer. I ordered some material off ebay, and hopefully get something done before the season hits up here.

about the dpf and regen cycle on the 08's. I'm looking at an 08 as well. the diesel particulate fileter traps all the soot, and when truck goes into regen cycle, it burns off all the soot that is trapped. wakebaordvegas, it don't make alot of sense. they are keeping the air cleaner, but burning more fuel in the process. It's a ballsy move, but I'm half thinking about doing a dpf delete and adding turbo back exhaust. dieselplace.com is a great place to do your homework. there's been a few guys on there that have done this already.

I use a towtector for mine, works great and fairly inexpensive.

Here is another one
http://strombergcarlson.com/store/products.php?categoryParentName=Other+RV+Accessori es&categoryName=Louvered+Tow+Guard

Remember, YOU WILL HAVE TO HAVE A TUNER of some kind to delete your DPF. It's not as simple as removing your exhaust. You will trigger a CEL, which will stop your ability to use the factory Remote start (if you have it), and it will eventually put you into limp mode.

Currently on the GM models you can go w/ PPE (my personal favorite), EFI or HP.
Quadzilla is the cheapest route by far, but their tunes have caused some problems for some folks. If you want just the DPF delete but no tune, then the Quad is def. your best bet.

If you try running a bigger tune, and tow w/ your DPF on, you will clog your DPF and trigger a CEL w/ the code 244B, which will put you into limp mode.

Basically, removing the DPF has nothing but benefits for your vehicle You'll be essentially turning your LMM motor into a LBZ.

Tanner, I am looking into the PPE hot, did you go 4" or 5" I just towed for the first time yesterday.

Bryan, you will not really see a benefit w/ a 5" exhaust. You MAY see a SLIGHT benefit in EGT drop w/ the 5" but not really anything significant. Unless you were hard into racing I wouldn't recommend a 5".

DO NOT run the race tune unless you have built your tranny. It will shred your T/C. You'll have to buy the tune in order to get the DPF delete obviously, but I wouldn't go above lvl. 4 unless you want your tranny to live. Give Dan at PPE a call... he'll set you straight.

All you guys on the west coast are lucky as you have the go to guy for Built Allisons (Mike at Inglewood Tranny's) in case you do blow it up

Its getting even better I hear Mike is moving close to Dan @ PPE in OC

He is.... he is ;)

You should see what I got cooking under the hood on an LMM ;) ...well.... in design phase right now.

Try and dig out of Dan what Joe has going on over there .... lets just say Nasty Girl in an LMM Version

Tanner, we want more info. I would love to get an 08 and do dpf delete with tuner, just trying to grow a set and hope to heck that I dont' need warranty. the 05 is working so well right now, and my mileage seems to be very decent for the 05's. still on the fence.

Well I'm building a set a custom set of twins ;)

As for what PPE is doing.... give em a call

Warranty is something that can go either way. GM has recently revealed that the ECM is now storing the last 5 programs that were in it. However 99% of techs will never access this info as usually only the engineers or sales reps do in the incident of a blown motor, or toasted turbo, etc.

I actually went in and talked w/ the Service Manager at my dealer about what I wanted to do w/ the DPF. He asked why would you want to do that. I told him -25* degrees of timing during regen is one reason... and mpg is the other. I made the argument that I would be essentially turning the motor into an LBZ at that point. He thought about it and agreed. I told him how I was gonna do it and what I would have to do. He told me no worries, do what u gotta do. He said hang on to the DPF just in case we ever had a problem that we had to get the sales rep out there.

Of course all that is going out the window the second we get that second turbo on there ;)

(Message edited by Tanner on March 09, 2008)