Well my Megamouth downpipe came in today, and I have to say, its an impressive piece! I'll start at the beginning though, for those who don't know why I bought this pipe. My downpipe hanger had broken off from the pipe, causing stress to be placed on the turbo flange, which cracked. The piece that broke off was long gone out the exhaust, and the flange is cast, so welding wasn't an option. To get a replacement flange, a new turbo is necessary, $1200 from the dealer! I could have purchased an aftermarket turbo for less, or purchased a used one on ebay with unknown mileage and wear. Then I found out the Megamouth downpipe includes the flange! The pipe wasn't cheap at $329 for the 3.5" version and $354 for the 4" version. They also had just the flange and elbow available for $199, but I would have still needed a downpipe. I went with the 4" full pipe, figuring for the extra few bucks, I'll be prepared in case I ever get the bombing bug. Pic of the cracked flange below:


A word of caution for those ordering these pipes: the shipping was pretty slow, at exactly 3 weeks from the day I ordered it. But that included sending it out for coating and shipping it down from Canada. I hear they are working on faster shipping options, so hopefully they will have it worked out by the time someone else orders one. I guess I was one of the first people to order one of these, so things will probably pick up as they do more. Here is a pic of the new pipe:


The ad for the pipe says that welding may be required. The place I had to weld was for the front hanger, ironically the one that had broken off my original downpipe. The Megamouth isn't as long as the original downpipe, and stops just about where the front hanger is, so it doesn't include the hanger. It just happened that the hanger lines up where the clamp goes for the 4" pipe I attached, so I used the piece of the original hanger and welded it to the clamp. This should give a good, strong hanger. Since my whole exhaust only consists of the downpipe and a 4' long section of 4" pipe, I also welded a hanger to the rear of the 4' pipe.

I have to apologize for not being able to give the info most people want...EGT numbers. I don't have gauges yet, and I didn't buy this pipe specifically for performance or to lower temps, so I can't compare before and after numbers. But I can give some seat-of-the-pants info. First off, the sound is awesome! Going from my 3" straight pipe to a 4" and the Megamouth really improved the tone! Its much deeper and more like a larger diesel. I don't think it got a whole lot louder, just deeper and different. When I went for a test drive, the first thing I noticed is that my throottle response seems to have improved. I could be wrong about this, but it sure seems like the engine increases speed quicker when I hit the throttle. When I got to a hill, I could REALLY hear the turbo now! It seems to come on a bit quicker and pull a bit better on the hills. I'm not saying it has a lot more power, just that it seems to be a little noticable. I think the real benefit would be if I had other mods to take full advantage of the flow of this pipe.

More pics are in my gallery, and I'll post a couple more when they are approved.

Jim

 

Here is the Megamouth next to the factory downpipe. The Megamouth looks like its 3.5" coming down off the turbo, then flares up to 4" for the horizontal section. You can just make out the piece of factory hanger on the factory pipe where the Megamouth stops. I heated the factory hanger, which had about a 110 degree bend, and bent it to 90 degrees so that it lined up with the new clamp.



Here you can see the length difference between the two pipes:


Jim

 

Wow looks good Jim

Thanks for the report and keep smiling!

 

Nice to see some info on this unit. I didn't realize it flared to 4", good to know, I thought they would try to get 4" up near the elbow. Probably wouldn't have made any difference. I'd love to have one when I get a 4" exhaust, seems like a nice mod for stocker turbo's. Nice to see it's getting you some small power increases too! Enjoy!

 

Better sound, responsiveness, quicker spool- sounds like a good bomb=P

 

I already made the decision to get a fuel plate ordered this week. I just need to decide which one. I'm bouncing around between 3 different ones...#6 for safety with my transmission, #5 and use a little caution until I get my 5-speed installed, or #10 and really be careful, but boy would I be happy once I get the transmission swapped. I hate to spend the money twice...now, then again when the tranny can handle it. I'm leaning for either the 5, since I won't be towing much for a while and the trans should hold up better with that plate and no towing, or the 10 and figure if I toast the trans, I get to buy the 5-speed sooner. Regardless, the exhaust should help keep the temps down for any of them.

Jim

 

Well here is a little update. Back when the pipe came in, it didn't come with a gasket, even though its shown with one in a picture, and it says it comes with a stainless gasket. I was told it shouldn't need one. Well after driving it for a week, I found out that it indeed SHOULD have a gasket. This thing is leaking around the flange to turbo housing connection, and is leaking some fumes into the cab again. After spending over $350 on this pipe, I would have expected NO leaks. I thought about reusing the original gasket, but its not cut out like the Megamouth, so it would restrict the flow, and the thin gasket looks like it would be tricky to cut out to the right shape. I think I'm going to have to buy some material and do my best to make my own. The rest of the pipe is impressive, but I just can't keep driving it like this, especially since I may be starting a new job that would have me driving 80 miles a day round trip.

On a good note, I managed to get a new rear bumper fabbed up today, since it was 60 degrees up here. i have a bit left to finish on it, but the main part is installed and welded up.

Jim

 

You can take a tin snips to the original gasket- they're MUCH stronger than it would appear.

brandon.

 

A Cummins distributor ought to be able to get you a new gasket within a week or so. I would not be surprised if the old gasket does not seal perfectly, but I have reused them successfully myself.

 

Well I just got an e-mail back from Greg at Cooleeze, and he said it should have come with a gasket, and he's sending one right out to me. Its great to have service like this.

Jim