just wondering if anyone knows of a good place to get a 4" dpf back exhaust for lmm van? thanks for the help

You need to use one from a truck. Alligator Performance is very good to deal with.

Ok so there the same from the truck to van? dont need to get it re bent or anything eh? Thanks

To have a cleaner looking install you could use a straight piece of pipe to connect to tailpipe or muffler is you planning on using one. The trucks have 1 piece of pipe that is bent to clear the transmission/transfer case support bracket that is not on the van.

Fill out your signature when you get a chance so we know exactly what vehicle you own.

Ok I talked to Jason at alligator performance Chad wasn't in. I think I'm goin to do it from the down pipe back , and get rid of the stupid dpf. Also use Idaho rob for the tune. Ok I will do that but I'm workin with a stock 07.5 ext lmm with a set of black 18's it also has 260k

If you stick with the DPF back (which is a waste) the DPF flange bolt patterns are different on a van than on a truck.

If you do a tune, make sure they know it is a van...your transmission will not handle the torque of a pickup tune (reliably).

He will know it is a van when he sends him the tune. There are a couple of tables that are different between trucks and van. You will be much happier without the DPF.

Ya going to go with the 4" dpf delete back also the tune is going to be dpf delete with 60 hp

You will be happy with that tune buddy. it will run nice and drastically increase your mpg

Ya they sure don't sound to good stock lol. That's what I was looking for I drive alot so it should pay it's self off in the first few mnths. Also they said it should lower the egt also because I haul about a 14-15k lbs toy hauler quiet a bit.

For sure. The DPF is a huge source of restriction in the exhaust system. Deleting that will make the exhaust flow much better lowering egts

You will be happy with that tune buddy. it will run nice and drastically increase your mpg
Exactly which tune is that? ...one that you sell for LMM vans?

Also, is there a 304 front pipe available?
Preferably one without any flanges on the back end, that look like this:
http://www.diamondeyeperformance.com/images/361001%20Down%20pipe.jpg
Is the riser on these front pipes long (tall) enough to reach the downpipe on a van?

GM oem LMM van front pipe has a taller riser than on a pickup, but it looks like it doesn't have to be.

That downpipe pictured is just the regular one that fits everything pre-dpf. You can cut that flange off or get the flange to pipe adapter. You are going to have to get a tape measure out and measure yourself since nobody makes any exhaust specific for vans. As for tunes, anyone with EFILive can tune your van or you could send your ECM to someone like Kennedy.

You will be happy with that tune buddy. it will run nice and drastically increase your mpg

Hey Jason,

Exactly which tune is that?
(i.e.: does it have a name and/or description of what changes are made compared to the oem tune)
Do you sell this van-specific LMM tune?

I already have EFILive and already know that not only a few tables, but the OS used in a LMM van ECM is different than the OS in an LMM pickup. Can't just change a few tables in a LMM pickup tune and expect it to run a van LMM.

Hey Jason,

Exactly which tune is that?
(i.e.: does it have a name and/or description of what changes are made compared to the oem tune)
Do you sell this van-specific LMM tune?

I already have EFILive and already know that not only a few tables, but the OS used in a LMM van ECM is different than the OS in an LMM pickup. Can't just change a few tables in a LMM pickup tune and expect it to run a van LMM.


Send your stock tune to someone that does EFILive tuning and they will modify it to what you what for a tune.

The pictures below show the reason I wondered whether or not the riser is long enough on a pickup truck front pipe (like the one pictured above).
Like I said, the oem van front pipe has a much taller riser (about 11" up from the bottom of the frame rail) than that Diamond Eye pipe.
I thought maybe the engine mounts on a van position the Duramax higher than on a pickup? (or not?)
But maybe it doesn't have to be; maybe it hangs down that low only to because of the way the cat is positioned. Looks like there's a lot of room above the pipe in the pictures below.

So I am wondering:
Who has actually used a pickup truck pipe like the Diamond Eye on a van, without lengthening the riser? (not concerned about modifications to the rear of it)
And if so, is a pickup truck front pipe available in 304SS or would I have to have one made?

Where they have it necked down is there room for 4" pipe to clear trans ? On the vans with 4L85E you have to dimple the pipe or cut the ear off the trans. I would check to make sure you would clearance in that area for 4" pipe. If there is you should be good to go. After that it should be a straight shot to the tailpipe. Aluminized steel pipe is cheaper and save you money. I have 150,000 with it so far and zero issues.

Where they have it necked down is there room for 4" pipe to clear trans ?
Should be no problem fitting a 4" diameter pipe as far as width in that area.

I'm still not convinced that 4" gains much if anything over 3.5" with the derated 250hp Duramax in a van. Probably gain more by replacing the restrictive turbo downpipe with a 3" mandrel bent pipe.

But since an off-the-shelf front pipe like the Diamond Eye pipe would probably cost less than having one made (even though I already have a 304SS 3.5" 70° elbow), I might go that route, as long as the riser didn't have to be lengthened, which from your experience (I now see in your sig that you used the Diamond Eye pipe), it did not need to be.

I can get the 409SS version of the Diamond Eye pipe like the one pictured above for less than the cost of the aluminized version (even though the retail price of the SS version is higher).

ya i got the 4" down pipe back still have the cat but no dpf. The truck exhaust is suppose to work on the van so i hope it goes on fairly easy. We will see spose to have exhaust and ecm back tom. Try to get it on tom or tues. im leaving for sc on fri excited to see how it does on the mpg and cant waite to hear the turbo finally!

The downpipe is different on your 2010 than my 2006. The turbo direct pipe is also different if I am not mistaken.

Hey Jason,

Exactly which tune is that?
(i.e.: does it have a name and/or description of what changes are made compared to the oem tune)
Do you sell this van-specific LMM tune?

I already have EFILive and already know that not only a few tables, but the OS used in a LMM van ECM is different than the OS in an LMM pickup. Can't just change a few tables in a LMM pickup tune and expect it to run a van LMM.


I was refering to RamJam getting a 60hp tune for his van. Idaho Rob or Duramaxtuner Nick should be able to build you any tunes you need for your vans

Now I think I see why the oem front pipe seems to be have a taller riser than the Diamond Eye front pipe.
The oem pipe is made essentially the same way as this Corsa #25018 front pipe
(which they're calling a cat delete pipe since it has a rear flange):
http://www.corsaperformance.com/images/products/Zoom/25018/25018a.jpg

There is no reason for that taller riser & full 90° bend except for the way the cat is positioned.
Without a cat in place, it definitely does not need to be bent that way.
There is NO clearance issue in the area above that deeper bend in the oem pipe, or the Corsa pipe shown above.

I doubt that there's any way a pipe with a larger angle bend and an additional small angle bend flows better than the way the Diamond Eye #321001 / #361001 pipe is made,
http://www.diamondeyeperformance.com/images/361001%20Down%20pipe.jpg
which is similar to the red outline overlayed on the Corsa front pipe in the attached image.

Here's a diagram of their downpipe back exhaust system just sent to me by Tommy at ANSA. He said this diagram is an accurate representation of what their parts look like.

Looks like the ANSA front pipe (p/n CS101-1) is more like the Diamond Eye front pipe, without the extra bend that's in the oem pipe and the Corsa pipe.

Vans actually only need part number #1 and #10 shown on this diagram, plus a section straight 4" pipe, and whatever outlet tip & muffler you want.
BTW: the Quigley van 4WD conversion adds the same crossmember that the midpipe (#3) zig-zags around.

Yes, all you need is #1 and #10 and a straight piece of pipe to join them. That is how my van is done and it looks cleaner and flows better.

At least now the mystery of the ziggedy-zapped front pipe is solved. It doesn't need to be, and those that aren't (Diamond Eye, ANSA Silverline, etc.) work as well in a van as the oem front pipe or the Corsa pickup truck front pipe.

Yes, all you need is #1 and #10 and a straight piece of pipe to join them. That is how my van is done and it looks cleaner and flows better.
Here's a better picture of the ANSA Silverline downpipe back exhaust for a pickup truck, and it's easy to see that the front pipe is essentially the same shape as the Diamond Eye:
http://www.ocdiesel.com/v/vspfiles/photos/AS%20CS101-2.jpg
As you say, in a 2WD (non-Quigley) van, there's no need for the zig zag ahead of the muffler. Also, the muffler could be mounted farther forward, in what is the stock location for a van.

It does appear that a PRE-DPF exhaust will work. If you will be using a muffler leave it attached to the tailpipe then you should be able to get away with 1 piece of pipe from muffler forward. Then be prepared to maybe having to trim some material off of transmission bell housing or put a dimple in the pipe.

Ok got it all together! Sounds badass :D and you can deff feel the extra power its great! Went on pretty easy trimmed the housing and put a lil dimple in. I got the 4" mbrp down pipe back all the hangers ect lined up good. I had to cut the stock exhaust over the rear axle to get it out that was pretty much the only snag. Took me and a couple buddys like 4 hrs to do everything. Ill try and put up some pics here soon how do you post them?

Ill try and put up some pics here soon how do you post them?At the bottom, if you click on "Go Advanced" (instead of clicking on "Post Quick Reply") it will take you into an area with more options, including the ability to attach different types of files, including photos, via the "Manage Attachments" button.