Been driving it for a couple days now since I installed them, haven't done any WOT runs or anything but down low it sure does seem to go better and spoolup is definitely increased on the mileage tune which was already pretty good. I'm very pleased with the results so far, to me it seems like the gains are tripled or more over adding just the up pipes, that is all judged by what it "Feels" like though.

Also, even at part throttle I went down in drive pressure. Before at 40psi boost 1/2-3/4 throttle or so I was seeing 46psi drive pressure, now its down to ~43-44psi or so at the same boost pressure. My previous setup was ProFab up pipes combined with a BD manifold.

The 4" downpipe that I made off the S400 barely fit in there with the flange on the manifold to up pipe where it is located now, it is a mm or so from touching trying to keep it away from hitting the frame, I lucked out on that one for sure.

IMO these would work very good for anyone looking for better results towing as the gains down low seem to be greatly improved. I'd imagine that MPG would be improved as well but don't have any results to say for sure. I went with the larger 2" up pipes but there is also an option for smaller 1 7/8" tubing.

I know a few vendors on here sell them. Rick was very helpful and even answered questions after hours helping me with the install.
http://i721.photobucket.com/albums/ww213/sdhelpenstell/Profabcastflows1.jpg

Thank You!! It was my pleasure. :)

I've been monitoring EGT's closely while cruising before, and for a while after the install now, they seem to be down 50-100* across the board vs the profab up pipes and BD drivers manifold. So about 75-150* reduction from stock setup.

With the twins I've noticed the main drop in EGT's were at WOT so at part throttle speeds it should be similar reductions as what a stock turbo equiped truck would see.

Have you pulled anything with them on yet? Or do you know if they will make a big difference with EGT's and spool up while towing? Thanks

Nice! What's the price difference between the two sizes up pipes?

Thanks Dmax15 for the solid writeup!

They're nice parts, we're planning some back to back dyno comparo's soon. Your description of results jive well with what I've heard from other customers so far. We just need to put the numbers on paper :)

Nick

Thanks Dmax15 for the solid writeup!

They're nice parts, we're planning some back to back dyno comparo's soon. Your description of results jive well with what I've heard from other customers so far. We just need to put the numbers on paper :)

Nick

Cool, I'd like to see the results. Of course setups will play a big role in the results but it would be nice to see what a truck similar to mine would get for peak hp gains, its too hard to tell for sure at WOT just from driving it.

Remember too that peak is not the only place to see improvements. ;)

Nice! What's the price difference between the two sizes up pipes?

PM me or any of my dealers for info. :) Here's a list of them;

http://www.dmaxcentral.com/forum/showthread.php?t=2310

Remember too that peak is not the only place to see improvements. ;)

Driveability and power down low are definitely improved but I was just saying peak hp and power in the upper rpms have been hard to judge by seat of the pants.

It seems like there is definitely an increase in volume with these by looking at them, I would have thought they wouldn't give as good of results as I'm seeing at part throttle but I guess the smooth transitions and flow patterns does a good enough job to more than make up for it.