[layinbody31]

Here's my dilemma: I'm designing a body-dropless chassis (SFBD), and I'm really hurting for room for my exhaust. I want to run it all the way to the back of the truck, but I don't have much room under the cab area. I have to have room under there for the trans, driveshaft, possibly part of a fuel cell, and body mounts, etc. I don't want to have to cut the cab for anything other than the trans tunnel. I'm planning on running a smallblock v8 with 3" outlet headers. I want to run dual 3" pipes all the way to the back behind the axle where I want to have 2 3" inlet/dual 2.5" outlet Flowmasters. I have room in my design to get the pipes around the whole 4-link/rear-end assembly, but I don't have room between that and the headers. Can I route my exhaust through the framerails to save space and clean up the overall appearance? I'm planning on using 3x3x1/4" box for the frame, so it wouldn't heat up nearly as fast as exhaust tubing bacause of the thickness. Please give me your thoughts on this and any constructive criticism that will help me out. Thanks.

 

[LaidHombre]

Here's my dilemma: I'm designing a body-dropless chassis (SFBD), and I'm really hurting for room for my exhaust. I want to run it all the way to the back of the truck, but I don't have much room under the cab area. I have to have room under there for the trans, driveshaft, possibly part of a fuel cell, and body mounts, etc. I don't want to have to cut the cab for anything other than the trans tunnel. I'm planning on running a smallblock v8 with 3" outlet headers. I want to run dual 3" pipes all the way to the back behind the axle where I want to have 2 3" inlet/dual 2.5" outlet Flowmasters. I have room in my design to get the pipes around the whole 4-link/rear-end assembly, but I don't have room between that and the headers. Can I route my exhaust through the framerails to save space and clean up the overall appearance? I'm planning on using 3x3x1/4" box for the frame, so it wouldn't heat up nearly as fast as exhaust tubing bacause of the thickness. Please give me your thoughts on this and any constructive criticism that will help me out. Thanks.

Well I haven't given it much thought but a couple quick problems I see are that the cab mount bushing will get hot from the cab mounts on the frame carrying heat. Also any brake of fuel lines could not be screwed with clamps to the rails for heat problems etc etc. Also wiring running front to back(tail lights/fuel pump, etc) will have to be routed away from the frame-lots of small problems created. I have similar problems to overcome with my frame once i get to that stage too, so i know what you mean

 

[alcoholic]

i thought of this as well and came up with the same thoughts as laidhombre, you could use that exhaust wrap but that excelerates rust and is ugly, why not get rectangular tubing that is the same hight as the frame or smaller and use that (16 gauge) as the exhuast with hangers and all? thats what i was thinking of doing, are you using 3X3 fore the frame? use 2X3 16 gauge on its side for the exhaust

 

[alcoholic]

or you could use oval tubing http://www.spintechmufflers.com/spintech/spintechindex.asp

 

[layinbody31]

i thought of this as well and came up with the same thoughts as laidhombre, you could use that exhaust wrap but that excelerates rust and is ugly, why not get rectangular tubing that is the same hight as the frame or smaller and use that (16 gauge) as the exhuast with hangers and all? thats what i was thinking of doing, are you using 3X3 fore the frame? use 2X3 16 gauge on its side for the exhaust

well I thought of that too, but then it would be the same problem as using regular exhaust tubing, except that the box tubing would be thicker than exhaust tubing. Either way, if I use tubing for the exhaust running under the body, it would either have to be wrapped with heat tape, or there would have to be heat tape on the bottom of the cab to prevent lots of heat transfer into the cab.

 

[83blazerlaynframe]

glad someone else started this thread i was about to ask that same question.... thats a good idea about the 2x3 box tubing for the exhaust.... u have alot of dynamat on my floor and im gettin brand new carpeting with the heat stuff attatched to it so i dont think that would be a problem.. any other ideas?? i have a 350 in my blaze with 700r4 tranny im gona b doin a stock floor bodydrop to the rockers, shavin the pinch off... so im kinda pushin it on the free space issue.... would a box tubing give the exhaust a different tone???

 

[83blazerlaynframe]

anyone???

 

[SlimJimmy]

Why not make the frame from square tubing wide enough to run some exhaust pipe through the middle of it..that way heat wont be in direct contact with the frame rails and they would be thick enough that it shouldnt be a problem.

 

[Dragginbody]

what do you guys think about this idea?

 

[layinbody31]

what do you guys think about this idea?

ummm...it was mine?

 

[alcoholic]

lol

 

[alcoholic]

Why not make the frame from square tubing wide enough to run some exhaust pipe through the middle of it..that way heat wont be in direct contact with the frame rails and they would be thick enough that it shouldnt be a problem.

sounds cool but itls probly rattle and drive you bonkers, also if he is using 3x3 1/4 wall that means its 2.5x2.5 inside...

 

[Driving4Life]

The frame being used for exhaust obviously can speed up rust. So the 2x3 square tubing idea isn't bad. There are companies that make insulation material for the floors of cars mainly for the trans hump but it is thin enough to run all over the floor and then cover it with carpet. That would eliminate you heat problem in the cab.

BTW, Any pics of the work up? I was thinking about doing this myself. Also what are you using to weld up the frame because I was under the impression that MIG welding wasn't really for structural support. More just sheetmetal.

 

[Lowdad]

what about running the exhaust outside the frame in the cab area??

 

[Driving4Life]

body mounts... and frame holes.

 

[Wicked Mayhem]

what about when the engine torques arund etc.. will that be fine being tied into the chassis?

 

[jjrambo]

anything to do with running the pipe throught the frame no good. on any kind of drive longer than 30 mintues there goes heat so bad that anything touching that frame will melt.

best idea to do is the oval tubing with heat tape on the under side fo the cab and a heat sheild around the top half of the pipe. use some wire bands to hold it on with some simple fins to keep it off of the pipe some and you should be fine. other wise there will be to much heat on the bottom of the cab.

might melt that dynomat as well if you heat up the cab.

 

[dragginbalz]

. Also what are you using to weld up the frame because I was under the impression that MIG welding wasn't really for structural support. More just sheetmetal.

Where do people come up with this stuff??

Don't believe the hype

t

 

[iLLblazer]

I was under the impression that MIG welding wasn't really for structural support. More just sheetmetal.

why? crank up the heat and go to town. 90% of the trucks u see with frame builds are migged.

 

[Dragginbody]

ummm...it was mine?

well obviously since you started the thread.

i actually didnt see this thread before.


my idea is not to run exhaust tubing thru the frame, but rather use the 3x3 as the exhaust.

i may do it, i may not. i just wanna get my blazer drivable. lol