1974 Challenger Restomod

[Dmod1974]

Figured I'd get an early start and burn some metal before I burn some food, so I wrapped up the front half of the exhaust system for my car.  3" mandrel bent stainless steel with X-pipe, Magnaflow mufflers, and dumps for the occasional track day.  I welded it up to hug the floor counters and keep it up as much as possible since my car is lowered. 

For those of you wondering why it isn't perfectly symmetric, it really can't be on these cars since the powertrain is offset to the passenger side so the pipes cannot fan out as much outboard.  They also don't start off in the same point since the engine banks are staggered, and naturally the header collectors are too.  It doesn't matter as long as it's close, and by the time they reach the mufflers they're back on track again.  You also need to make sure you don't run the pipe directly under where the seat studs will go....  I had to redo my RH piping because I wasn't paying attention.

I'm hoping to knock out the over the axle pipes this weekend, and I also have my seat frame narrowing done so I'll be sending the front and rear out to get recovered.

[Katfish]

Looks great, attention to detail is awesome!

[YellowThumper]

Looks great.
As the system always has a bit of back pressure, the balance is not that important. X takes care of that.
Nice job on tucking it up tight.

[dodj]

I have the same system, minus the dumps, but with an old school motor up front. I think you will be very happy with the tone. Sounds great with my 440.

[Dmod1974]

I have the same system, minus the dumps, but with an old school motor up front. I think you will be very happy with the tone. Sounds great with my 440.

Yeah, I had the same thing but with 2.5" exhaust on my old build and liked it. If it's too loud or drones I can always add some resonators behind the exhaust tips like the factory set up.

[Dmod1974]

I finished up one of the over the axle pipes - I think I'm starting to get the hang of this since I knocked it out in several hours instead of fumbling around for a day and a half like I did with the X-pipe when I started.

I have plenty of clearance between the axle and suspension, so when I blow up the 8 3/4" and move up to a Ford 9" I shouldn't have to rework the exhaust.  I might even be ok with the 3" inboard relocation too.  I welded in the boxes not knowing if/when I'd use them, and I was concerned that there would be no way to run a full exhaust with them, but I think I might be ok.  I'm assuming the coilover would basically stand "vertical" with that relo instead of angling outward, and I think I might still have adequate clearance between the pipe and spring if that's the case.

[moparmadman69]

Great job. You did a great job for not being an exhaust guy. When I did my Cummins exhaust I did it with pie cuts. I have 3" dies for my pipe bender but the radius is too big to get some of the compound bends that I needed to do in order to get dual exhaust to fit around my spare tire and then get it to come up higher to come out the middle of the bumper. I converted from single 4" out of the muffler to dual 3". I don't have a pic but I painted to tips red to match the plastics on my clevis pins. I couldn't swallow the cost to do it the way you did it. Mandrel bends are expensive. Even through my distributors they are expensive and we go through a TON of exhaust. Of course I probably had 18 hours into my tail pipes between fitting and TIG welding the 53 joints that I had LOL so I guess if I paid myself I never could've afforded it. Of course, being me I just wanted to do it different.

So if you ever need tighter radius or want to save money you could always go with the pie cut method. I use it every once in a while and it comes in handy. Next project will be a custom intake horn for my Cummins for better flow. Then maybe a custom cold air intake down to the turbo.

On a side note, I love when Chevy guys call to order an exhaust system from us and they are shocked that the exhaust isn't symmetrical. Then you inform them that nothing on a Mopar is symmetrical. It amazes me every time that they are this far into the car and are just now realizing that. 

Absolutely LOVE the build BTW!

Here are some pics of how I did mine a few months back.

[usraptor]

Nice job on the exhaust.     I admire people with welding and fabrication skills.   I took the easy way out and ordered a complete system from TTI.  However, I ordered the Dynomax  Super Turbo mufflers.  Afterwards, I also had electric cut outs/dumps installed after the X-pipe.  People love it at the car shows when I open them up.        Keep up the good work.   

[Dmod1974]

Thanks guys.  It was a PITA, but came out pretty nice, especially considering it was my first time building an exhaust.  The phone audio doesn't do it justice unfortunately, but it sounds great at idle, and unbelievable at WOT with the blower whine singing along with it too.

I built some wooden wheel cribs to get the car up high but still with its weight on the wheels so I can align it (it would have been great to have these when I built the exhaust.) 

It was going well until I got to the left side and couldn't get the caster/camber where I want them no matter what I did....  Then I realized one of the cam bolts was stripped and rotating without moving the eccentric washer on the outside of the shock tower.    I should have the replacement part on Sunday so I can dial it in and move on to setting toe.

I also managed to find a nice day before it started snowing this week to align the headlights and get the bezels on.  I painted the fender bolts, trunk hinge bolts, and strikers body color too since the body shop left them in black.  The zip lock bag over the bolt head trick worked perfectly in preventing chips and flaking during installation.

[dodj]

Very nice!

Should the area above the egg crate grille be blacked out? While you would almost never have that perspective, looking from that low into the grille, it kind of stands out to me in the picture.

[anlauto]

That's a pretty full engine bay...WOW 

[Dmod1974]

Very nice!

Should the area above the egg crate grille be blacked out? While you would almost never have that perspective, looking from that low into the grille, it kind of stands out to me in the picture.

I honestly don't know.  The repro grilles come unpainted, so I looked at a bunch of pics of them and some were and some weren't painted on that bar.  Obviously whatever pic I gave them to paint to match it wasn't.  You can't see it unless you're practically laying on the ground, so if I have to remove and repaint it I'm probably going to put it off for a while.  I want to make sure it's ready to drive come spring.

That's a pretty full engine bay...WOW 

Yeah, I know I've said it before but it is a TIGHT fit.  That engine swallows up the engine bay.

[jimynick]

Nice looking work and on a nice looking car. Funny lookin' grille for a '74 though. 

[YellowThumper]

Beautiful car.
Welded exhaust looks great.
Recently finished a first time exhaust on another project.
Fit, tack, remove, weld, replace, fit, tack, remove, repeat...
Not fun...

[Dmod1974]

Hopefully only another month or so before I can break this car in!  I painted the top part of my grille, installed the hood blackout, and installed my front and rear glass myself.  It was a pretty anxiety inducing process since you only have one shot before you have to cut the things back out, but it turned out pretty well.  I used 3/8" window butyl tape and a tube of CRL 7711 as CYA in a few spots to ensure a leak free install.  That stuff is extremely messy; I've never used another product so stringy and sticky.  Luckily, I taped/masked everything off and had some Rapid Tac adhesive remover on hand for cleanup.  I don't have any pics, but I also installed the trim and wiper arms.









I got my seats back from the upholsterer and installed too; I think they came out great.  I didn't want anything too flashy for this car.  Just black leather with orange accent stitching.










I bought a power steering analyzer to check the flow rate and relief pressure out of this Hellcat pump to make sure I don't have drivability or rack seal blowout issues once I start driving it.  I need to make sure both measurements are compatible with what the Hydroboost and late model Mustang rack require.