Skip to main content
Topic: 2 1/2'' exhaust tubing over rear axle (Read 2327 times) previous topic - next topic

2 1/2'' exhaust tubing over rear axle

are you guys cutting your tail pipes before the axle and making the tubing height adjustable there?

i am finding it very difficult to use off the shelf 2 1/2 '' exhaust tubing a big challenge to make it over the rear axles without bumping into things.

i end up with almost a finger width of room in any direction.

2 1/2'' exhaust tubing over rear axle

Reply #1
Quote from: jcassity;466541
are you guys cutting your tail pipes before the axle and making the tubing height adjustable there?

i am finding it very difficult to use off the shelf 2 1/2 '' exhaust tubing a big challenge to make it over the rear axles without bumping into things.

i end up with almost a finger width of room in any direction.


You could cut and add where you need to, or take it to an exhaust shop and have them custom bend some for you.
Donnie
10 Second NA TBird
Fredericksburg Va

2 1/2'' exhaust tubing over rear axle

Reply #2
I used Dynomax 2.5" mandrel bent tail pipes for a 86-93 Mustang. They fit like a glove with room around everything. Are you bending/fabricating your own tail pipes?
88 Thunderbird LX: 306, Edelbrock Performer heads, Comp 266HR cam, Edelbrock Performer RPM intake, bunch of other stuff.

2 1/2'' exhaust tubing over rear axle

Reply #3
I have 3” mandrel bent pipes from MAC and all we had to do was lengthen the tail pipes 8” or so. Tight but they fit no issues.

83 351W TKO'd T-Bird on the bottle


93 331 Mustang Coupe - 368 rwhp

2 1/2'' exhaust tubing over rear axle

Reply #4
Quote from: thunderjet302;466569
I used Dynomax 2.5" mandrel bent tail pipes for a 86-93 Mustang. They fit like a glove with room around everything. Are you bending/fabricating your own tail pipes?

no,
i am installing already bent up tubing.
i was going to buy the JD Squared tubing bender to cover 3'' down to 2'' of dies but decided its cost prohibitive for the amount of use it would get.
Haystack made a good point about this tubing a while back,, why not use off the shelf stuff ,
my pipes fit but the total height of the arch that passes over the axle is what i consider "too tall".  i think what i am saying is that particular "radius bend is too long.
in reality everything fits Like a glove.

the top of the arch of my tail pipe section is so tall that i can get one finger between:
-the top frame / beam member
-the shock
-the axle stabilizer dog bone thing

you have a triangle of sorts of free area the tail pipe passes thru in square inches of space.
my tail pipe is at the peak of that triangle.

if the tail pipe arch were shorter by 1'' it would fit nice like a loose glove.... which is what i am after.

right now if i go with what i have, if chance loads down the trunk with weight or has rear seats filled with people, i am certain the rear of the car will drop down and put the peak of these tail pipe 'humps" directly on something metal up above.

2 1/2'' exhaust tubing over rear axle

Reply #5
the height is designated with the yellow lines.
the red line shows where i believe i should cut , expand and make a lap joint with my new pipe expansion tool.

this will lower the overall height of my arch.
[
we are going to sweep a 45deg tip about 12'' aft of the wheel well making it side exits.

thoughts?

2 1/2'' exhaust tubing over rear axle

Reply #6
I must buy the wrong shit too always seems like not enough room for my liking anyway. As you said, a finger or so. Never seems to have been an actual problem...but c'mon...too close for comfort.
1987 20th Anniversary Cougar, 302 "5.0" GT-40 heads (F3ZE '93 Cobra) and TMoss Ported H.O. intake, H.O. camshaft
2.5" Duals, no cats, Flowmaster 40s, Richmond 3.73s w/ Trac-Lok, maxed out Baumann shift kit, 3000 RPM Dirty Dog non-lock TC
Aside from the Mustang crinkle headers, still looks like it's only 150 HP...
1988 Black XR7 Trick Flow top end, Tremec 3550
1988 Black XR7 Procharger P600B intercooled, Edelbrock Performer non-RPM heads, GT40 intake AOD, 13 PSI @5000 RPM. 93 octane

2 1/2'' exhaust tubing over rear axle

Reply #7
When you connect the exhaust, you’re not connecting it to axle, you’re connecting (hanger brackets)it to the car. Whatever weight you put in the trunk shouldn’t have any effect on the arch hitting the body as the exhaust won’t move. If you shorten the arch, there’s a really good chance of the axle hitting the bottom of said arch, if you have weight in the trunk or not.


86' T/C 4.6L DOHC
16' Chebby Cruze 1.4L Turbo
17’ Peterbilt 389 600hp 1850ftlb Trq 18spd

[SIGPIC][/SIGPIC]

“Heavy Metal Mistress”
[/COLOR][/SIZE]

2 1/2'' exhaust tubing over rear axle

Reply #8
You want enough of a space under the tube for the axle to move up and down, hence why the tubing is close to the frame and what not. It's bigger in diameter than the stock stuff. I've been running unmodified Dynomax tailpipes on mine for 11 years with no issues. It's close but it'll be fine. Once attached the exhaust isn't really moving around anyway.
88 Thunderbird LX: 306, Edelbrock Performer heads, Comp 266HR cam, Edelbrock Performer RPM intake, bunch of other stuff.

2 1/2'' exhaust tubing over rear axle

Reply #9
Quote from: 1BadBird;466582
When you connect the exhaust, you’re not connecting it to axle, you’re connecting (hanger brackets)it to the car. Whatever weight you put in the trunk shouldn’t have any effect on the arch hitting the body as the exhaust won’t move. If you shorten the arch, there’s a really good chance of the axle hitting the bottom of said arch, if you have weight in the trunk or not.

well,, that sure did straighten me out,, not sure what i was thinking. 
i think its one of those common sense things i never had to think about

thanks!!!!!!!!!!!!!

the pipe follows the body so up high is ok.

2 1/2'' exhaust tubing over rear axle

Reply #10
Lol it’s called a brainfart. I have them waaaay to much lately :hick:


86' T/C 4.6L DOHC
16' Chebby Cruze 1.4L Turbo
17’ Peterbilt 389 600hp 1850ftlb Trq 18spd

[SIGPIC][/SIGPIC]

“Heavy Metal Mistress”
[/COLOR][/SIZE]

2 1/2'' exhaust tubing over rear axle

Reply #11
so after you specifically told me what you said,, i went out and did this after toiling with "how to" get a decent support on the tubing yet not have the cats bumping the floor. 

i went out there thinking,, yeah, yeah,, ok,, the pipes follow the body,, got it....................

u bolt the pipes to the tunnel metal bar.............. yup good to go.................. NOT!!!!!!!!!

when the engine torques i suspect this principle will slowly yank all my band clamps loose.

so..
i will revise.

man why do i get all caught up in stupid stuff that ends up taking me days to make me happy ............??

its alright though,, i think i can cut that bracket into two pieces and make them just long enough to reach over each individual pipe.
secure the metal bracket(s) to thier original mounts on the floor pan but have a rubber gasket between.

keep the uBolt system and all should be well.  this will separate the torque on each pipe run and allow the pipes to twerk and tweek and move as they need.

the downside is i have to chop out that date code thats on the top of this metal bracket.

there is a net gain though because it allows more room to drop the drive shaft down when needed.

2 1/2'' exhaust tubing over rear axle

Reply #12
You think you over complicate stuff, you need to look up project binky on YouTube
Quote from: jcassity
I honestly dont think you could exceed the cost of a new car buy installing new *stock* parts everywhere in your coug our tbird. Its just plain impossible. You could revamp the entire drivetrain/engine/suspenstion and still come out ahead.
Hooligans! 
1988 Crown Vic wagon. 120K California car. Wifes grocery getter. (junked)
1987 Ford Thunderbird LX. 5.0. s.o., sn-95 t-5 and an f-150 clutch. Driven daily and going strong.
1986 cougar.
lilsammywasapunkrocker@yahoo.com