True Downpipe

[Burner]

Who makes a "down pipe" for our 6.6? I've seen different pipes but nothing from the Turbo down? Who makes a down pipe? :( --------


----- How much should a Stainless down pipe cost?


Burner---------> :D

[DinoMax]

Burner, no one makes a true down pipe for our trucks. From what I've seen & read, it is a clearance issue. A 4" down pipe will just not fit. IIRC, from another thread, Tomac was going to try and fab up a 3 1/2" down pipe with a flange to connect to 4" system. Don't know if he has yet. Maybe he will chime in & let us know. DinoMax :D :D

[Mark Bajus]

Is this not the pipe that connects to the turbo?

https://www.rpmoutlet.com/ezRetail/search/view.php?msg_id=1457

part of this exhaust system, advertised as "4 inch turbo back".

https://www.rpmoutlet.com/duraexhaustm.htm

[ 09-24-2003, 03:07 PM: Message edited by: Mark Bajus ]

[DalDMax]

Mark,
That is the pipe that connects to the downpipe. They aren't really being truthful when calling it a downpipe.

[Mark Bajus]

no truth in advertising? Oh, my guilded view of the world has been shattered!!!

Someone needs to do a "Y" pipe right off the back of the turbo into dual 3" pipes side by side into dual exhaust...

[Cheavyduty]

In talking with Banks engineering awhile back I asked about a downpipe. I was told the downpipe they developed was only negligibly better than stock. Therefore the price would be not worth the improvement.

[BlueOx03]

But would it make more noise like those big buck air boxes? :D :D :D That would make it well worth it! :eek: :eek:

[ 09-24-2003, 04:50 PM: Message edited by: BlueOx03 ]

[Kennedy]

CPMac has a custom one on his truck, but the problem is quantifying the results. A guy almost needs an engine dyno first, and then a chassis dyno, and then a strip test as well...

I believe his gut instinct said it helped, but just like my compressor wheel, we haven't dyno tested without delay/variables...

[Burner]

Cost? How much would that short pipe cost?

[Jomar]

On a true downpipe connected to the turbo, I think it would take some very technical testing to determine any difference between a 3 1/2" pipe and a 4" pipe especially with a low restriction exhaust system -- IMHO.


Jomar

[Phil B.]

There was a similar post a couple of weeks ago where I posted the RPM outlet link and we had this same discussion. Michael Tomac said it would be nearly impossible to increase the diameter of the downpipe without first modifying the oil dipstick tube. I went and checked and I think he is correct. The dipstick tube runs right up against the downpipe.


Phil B.

[mtomac]

CPmac has a bigger downpipe on his 6speed truck. He's making one to fit an Allison equipped truck but wants to try it on a truck locally before sending one my way and have it not fit right. Yes, the steel tranny dipstick tube is in the way of a bigger downpipe but a flexible tube could be used for the dipstick on the Allison equipped trucks. When the downpipe restriction is taken care of the turbo will be next.

[mackin]

Never looked myself .....

What's in the way to use the drivers side dipstick port in the Allison ??

Mac :confused:

[Kennedy]

I think the key here will be LABOR to install it...

[dmaxalliTech]

Originally posted by kennedy:
I think the key here will be LABOR to install it... Yup

[Jomar]

I just got a new Summit catalog yesterday and it shows a Turbo back exhaust system for the Duramax. I called them this morning and Eric verified that it does hook up to the turbo. You can get the 4" aluminized set or 4" stainless.


Jomar

[mtomac]

I doubt it hooks to the turbo. It probably just hooks to the downpipe.