5" Exhaust

**crzycowboy** · 11-22-2006, 09:39 AM

Grand Rock is looking at offering a 5" systems for the GM's. We've been getting alot of calls for 5" systems for the Dodge boys, and got me thinkin' how many if any Duramax's are in need for these. Now our kits now have a mid-pipe that goes up and over the cross-member, is there room there for a 5" pipe? Or would we have to go 5" after that pipe? What do you guys and gals think? Is this something the Duramax's are needing, or is the 4" systems out there good enough? Thanks for your guys feed back!!

**05_LLY** · 11-22-2006, 02:38 PM

IMO Bigger is usually better in most cases

(like exhaust). And yes a 5" pipe will fit over the axle!!!!!

**TurboBeagleBuggy** · 11-22-2006, 06:53 PM

General Concensus was that a 5" is beneficial to a Dmax when it goes over 500+ hp.

**crzycowboy** · 11-27-2006, 04:22 AM

Ok, cool. I already knew the 5" tail pipe would fit over the axel, but we have a mid pipe that goes over the cross member, will a 5" pipe fit there, or will we have to stick with a 4" pipe, and go 5" after that point?

duramaxdavid · 11-27-2006, 05:20 AM

5" will work from the front pipe back. Smokeshow has one.

duramaxdavid · 11-27-2006, 05:25 AM

Use installing it on his truck. Thats a 5" front pipe.

SmokeShow · 11-27-2006, 07:32 PM

Apparently David's memory is lacking a bit. It has a 4" front pipe then flares to a 5". The 5" mid-pipe goes UNDER my cross member and is the only thing I really don't like about it cause its just a tad lower than the frame and can slightly be seen from a distance.

No worries though, stacks are coming soon!!

C-ya

**crzycowboy** · 11-28-2006, 05:20 AM

Quote:

Originally Posted by SmokeShow

Apparently David's memory is lacking a bit. It has a 4" front pipe then flares to a 5". The 5" mid-pipe goes UNDER my cross member and is the only thing I really don't like about it cause its just a tad lower than the frame and can slightly be seen from a distance.

No worries though, stacks are coming soon!!

C-ya

So would you rather see a system that is 4" until after the cross member, then turn to 5".

SmokeShow · 11-28-2006, 06:53 AM

I think it would be better if it could be made to have the 5" go over the cross member.

IF thats not possible, its a toss up on waiting to go 5" after the cross member or going 5" right after the front pipe. Would depend on what the majority of customers wanted, more 5" or less showing from underneath. I haven't heard any other complaints of the 5" going under the crossmember and looking bad and I've never had anyone comment about it on my truck. Its just my observation (I'm a bit of a perfectionist

).

My $.02, go 5" as long as possible. Its up to you to determine how long is possible.

I will add this though, the Grand Rock stack setups are the best manufactured setups I have personally ever seen (seen a custom setup that was built the same way but coated that looked sweet!) and if money were no object, I'd have a set. Congrats on those. I really just want/need everything except the stacks for a 6" setup. Wanna trade me a "y" pipe et al for my 5" to use as a guide to design your own 5" system and improve upon it?

C-ya

**crzycowboy** · 11-28-2006, 07:12 AM

Quote:

Originally Posted by SmokeShow

I think it would be better if it could be made to have the 5" go over the cross member.

IF thats not possible, its a toss up on waiting to go 5" after the cross member or going 5" right after the front pipe. Would depend on what the majority of customers wanted, more 5" or less showing from underneath. I haven't heard any other complaints of the 5" going under the crossmember and looking bad and I've never had anyone comment about it on my truck. Its just my observation (I'm a bit of a perfectionist

).

My $.02, go 5" as long as possible. Its up to you to determine how long is possible.

I will add this though, the Grand Rock stack setups are the best manufactured setups I have personally ever seen (seen a custom setup that was built the same way but coated that looked sweet!) and if money were no object, I'd have a set. Congrats on those. I really just want/need everything except the stacks for a 6" setup. Wanna trade me a "y" pipe et al for my 5" to use as a guide to design your own 5" system and improve upon it?

C-ya

LOL thanks for the compliment on our system. I can hook you up with a good distributor if nothing else...... We have two different no 3 different kits we offer for this truck. One is a 4" inlet system, one is a 5" inlet system, then the other is a complete system 4" to the y-pipe in the truck bed.

I have an Idea, what if on the 5" system we were to flatten the section fo pipe that you see showing? You will still keep a 5" flow, but you wont see the pipe? How much of te 5" pipe do you see under the truck? Got any pictures?