Ok, I know everyone talks about buying a downpipe from Rip, but I haven't got the money to spend on just a down pipe.I have a complete shop and good help to install my own exhaust. I can get 10' of four inch stock for only $60. Add a 3 to 4 adapter for $20 and all I need then is a stack in the bed. My problem is finding anyone that can bend 4". Has anyone ever found an exhaust shop that can bend four inch? I know I can buy 90 and 45 elbows, but there are some slight bends to route through everything. It just seems like with the pipe being cheap, I could do this system fairly inexpensively if I could find someone with the ablity to bend it. Even if you aren't close to central KY, I'd like to hear if there is any shops that do it.

 

The problem is bending, most all 4" exaust are mandrel bent to keep it from colapsing. most exaust shops don't work with 4" pipe. The equiptment is expencive. If you find someone to mandrel bend your pipe it will cost ya, no one will do it for free and if you find some one to bend it for ya for free I would bend as many as I could at all angles I could think of.

Greg

 

I think that is the problem with 4" pipe. That's why you have to purchase the systems banks and other performance vendors have on the market. I have never been able to find a muffler shop that could bend 4" pipe. I have a good friend who owns a muffler shop and he told me that the benders they have will only go up to 3". That's how those guys get their dough. But maybe someone wiser than me will chime in here and get you on the right track.

 

Another option would be to find a big metal fabrication shop as they would have a mandrel bender with larger than 3" dies.

 

thought u might be interested in this site... They have all sorts of stainless, aluminum, and carbon steel tubing in all sorts of sizes with great prices.

Here's a link for elbow bends, you can change OD, and bend degree, $13.
http://www.globaltecheng.com/Product...terLineRadius=

 

they don't show prices for carbon steel tubing straight stock, but i'm assuming it's even alot cheaper than the aluminum which is pretty cheap as is. I think there's a $10 cutting charge for length shorter than 20' in straight stock, still really good. You could make a full 4" exhaust for cheap.

I linked those elbows in 4" OD, you can get them up to 8" wide. But I don't think 8" exhaust would do much good, lol, unless someone in a honda civic wants to look bad a&&

 

I used only 2 90 deg. and 2 45 deg. in the whole system turbo back and there is no flex anywhere. By using only 90 's and 45's I was able to just buy the elbows from a truck supply place. I used a 3"-4" adapter and welded it on to the stock down pipe as soon as it was turned down. So essentially I just left a 3" elbow. You won't be disappointed your cummins will love the 4".

 

I got mine from Rips soooo I cant help tooo much, BUT, if you have access to a welder and a cutting saw, you could probably fabricate your own, it may not be an exact science but thats why guys like Rip get $150 for a downpipe. They have all the R&D to get it right.

Finding guys to bend 4" isnt easy by anymeans. With some knowledge, and money to burn u can take 90's and 45's and cut em and weld em to fit.

I believe trial and error is just as expencive as buying from the guys that have already been and done that.

 

I remember in shop that if you put sand in the tubing and weld the ends shut, heat up the pip and bend it the bend is real smooth and doesn't crunch down.

 

Go to a truck wrecker and get everything you need there for peanuts. theyll probly trade it all for a twelve pack.

 

there is a shop down in el paso texas that bends 4 inch, but only slight bends??
and p.s.
that 4 inch downpipe is def. worth every penny i dotn have one yet but you can ask just about anyone that knows anything, the downpipe is where your egts really matter, it helps.
just a suggestion.
good luck!

 

oh and another suggestion...FLEXPIPE super cheap works great, all the big rigs use it, you can buy 4 inch at most truck shops as long as you want it, best option for a stack, super easy, keep in touch and show some pics i'd like to see the finished product!!!

 

Local shop here bends 4". I need to give em a call to see how much. Might be worth the drive.

 

I got my 4'' from J Jardine in Dubois WY cost me 235$ and a lot less headaches, If times is money It looks like a wash JMHO.

 

I did talk to a welding shop close by. They can bend thick wall pipe but said they would probably smash exhaust if they tried to bend that.I'm really interested to try the cut and bend method, but I would need my current pipe for a template and my truck is a daily driver. Of course i know where there is a first gen parts truck that I could get the exhaust off of...
I'm really starting to think Rip downpipe, flexpipe, stack. Then over time, slowly replace the flex with pre-formed 90s and 45s. The other problem I find is that pre made bends cost around $30 each, so by the time you make something your pretty close to buying a system. Thanks guys.