How do I figure out what I have?

[Jamiez]

So my car has been up on jack stands for a few weeks as I've been going over the brakes.  Crawling under there I've been face to face with the rather rusty Monroe Max Air Hi-Performance shocks that one of the previous owners mounted under there.  I know air shocks weren't stock but a lot of people ran them back in the day to adjust the stance.  I also no the preferred method for doing that is actually to mount different leaf springs back there.

Since I'm not driving the car anyhow, now might be the time to take a look at cleaning the whole thing up.  I like the stance the car has, but I have no idea if it has a stock leaf set or perhaps someone already mounted a 1" back there.  How can I tell?  I hear ESPO (sp?) is a good choice for replacement leaf springs?

And if I drop the air shocks, I'll need replacement regular shocks back there.  Who makes decent shocks?

I don't race, autocross, or anything like that, I do very little street/highway driving so I am not worried about needing to hook up off the line.  However the car does have larger than stock tires (P295/50R15 105S M+S BF Goodrich TAs)  so I worry about buying the wrong stuff and having to worry about wheel rub

[ChallengerHK]

Can't answer all of that, but here's what I can answer.

Springs - I have ESPO. Price was right, and you can order them in whatever rise over "stock" you want. I put stock in quotes because someone here (I think it's HP2) has made a good case for the idea that, from the factory, most of our cars actually sat low in the back. HP2 also makes the point that ESPO spring rates are an unknown, but if you're not worried about knifing around corners you probably won't notice the difference in tuning. Also, a lot of folks here have said that their MP springs settled after a very short time (weeks or a few months), although others claim that theirs have been fine.

Shocks - I avoid air shocks after a friend's son had a blowout on a corner and ended up in rehab for a year. Just my opinion; other people love them. I use Edelbrock IAS Performer, which do the job nicely and cheaply. If you're more interested in performance, a lot of folks here go for Bilstein, and I may as well at a later date.

[MEK-Dangerfield]

It's tough to answer this one since your car has air shocks,  so you really don't know if stock height springs will work for you.

You got some real meat back there, so I would think the ESPO springs, with at least 1" over stock height would work for you. As far as shocks go, those Bilstein's are the shocks most prefer, but they are pricey. I went with KYB's, but like you...I'm not out running Grand Prix type of races. I saw a major improvement in handling.  Really, anything is better than the old Monroe and Gabriel shocks. 

[brads70]

I went with the ESPO plus 1+ 1/2 over stock. All springs will settle in the first few weeks. My wheel opening at the center of the wheel to ground is 26 3/4 rear,  front is 24 3/4 mind you I don't know if the different years of cars affects those measurement? Might give you something to compare to? Are your rear shackles stock? Like not long ones from back in the day?

[Jamiez]

Shackle looks stock, it only has one position (not one of those with multiple holes) the whole thing fits neatly in the valance with the bumper guard in place, I'm guessing it's stock but I suppose I could measure it.

On the passenger spring I've found this label:


Unfortunately there's not much of it left...maybe someone recognizes it? It looks like it reads 5 something 5?

[brads70]

Shackle looks stock, it only has one position (not one of those with multiple holes) the whole thing fits neatly in the valance with the bumper guard in place, I'm guessing it's stock but I suppose I could measure it.

Thats good then , ya I had air shocks in my first Challenger back in the 80's , not good when one blew out. Looked like it had hydraulics!  My current Challenger had them when I first got it. That was one of the first things I changed. New springs and rear end and shocks.

[HP2]

What is the leaf count on both sides? That will tell me more than stickers. Include half leafs, if any.

Do your 295s sit inside the wheel opening or do they stick out? With air shocks, I assume they stick out. With a 1" spring relocation and maybe a change in rim backspacing, you can get this much tire in the wheel well without needing more arch in the springs nor air shocks to get lift and clearance.

So the stanc eyou like, is that with or without air in the shocks?

[Jamiez]

Not sure what exactly qualifies as fitting in or sticking out when it comes to wheel openings.  Here is how they sit:



I'll take a leaf count when I am out in the garage again.  I'm assuming there is air in the shocks, but to be honest I've never checked.  I've only just now gotten around to looking at the rear end.

[ragtopdodge]

Put on some regular Monroe gas shocks back there (do not get KYB gas-a-justs; too stiff) and you'll be fine.  If you want to spend some serious coin, some Konis or Bilsteins are the way to go.

Then, see where your car sits.  If it's too low, then get your springs re-arched.  Should be places local to you that can get that done.  No shipping costs req'd then.

[Jamiez]

I prefer options that do not involve talking to people.  I'd much rather pay shipping.

Anyhow here are photos of the springs on the car.

Passenger side (4 I think):


Driver's side (again 4 I think):

[ChallengerHK]

I prefer options that do not involve talking to people. 

I thought I was misanthropic 

[Road_Runner]

I used to run air shocks on the Roadrunner and eventually switched to trackpak springs negating the need for anything other than longer standard shocks.  As mentioned earlier, find the air inlet and let all the air out, have someone large bounce the back of the car up & down & see how close the rear tires get to the fender. There will also be some slight side-to-side movement when the cars on the road so take that into account too.  (be sure you have some way to refill the shocks when you do this because it could be undriveable) From the look of your tires, I'm guessing its at least going to be very close without the air shocks or stouter springs.  I can tell you from experience, the wheel well lip does a number on the sides of your tires real quick when you have a problem.  If I were you and wanting to run that big a tire on back I would seriously look into the Dr Diff 1" spring location kits.  I'm betting you're going to need it if you lose the air shocks.  Good luck.

Later, Jim

[HP2]

Looks like you have the stock lo-po spring pack that was standard on all /6 and 318 cars. As such, I'd venture a guess to say they do not have anything more than the factory arch that with 30 years of service on it. If you look at them installed with all the weight on the ground, I'd bet they look nearly flat. Odds are they have maybe an inch of arch in this position. When new, they ranged between 1-2" of installed arch. If you are putting only enough air in the shocks to lift it up an inch, this is porbably not enough pressure to make a big difference in the pounding the shock mounts take. If you're pump 120 psi into the shocks and lifting things of 3-4 or more inches, then your going to be beating things up.

It also appears your 295s are on an 8" width wheel, with I'd guess it to have 4.5" of backspace. This is good in your situation because it 1) pulls the tire in towards the spring and away from the fender lip and 2) the 8" width pulls in the width of the tire a slight amount which will help eliminate interference. Looking at it, you may be in a position where the tire just clears the fender lip when the suspension compresses. To check, you can have a friend bounce the rear while you watch suspension travel and fender lip/tire position. You could also drive it at an angle up a driveway so you compress one side of the suspension while the other stretches. This will also give you an idea of how much lateral displacement occurs. If everything clears okay, you good. I'd try this with both the desired amount of air in the shocks and with no air in the shocks to view the difference.

I also noticed a sway bar in your picture. This will help limit lateral deflection of the rear during cornering. It also would complicate a swap to a 1" inboard spring relocation by potentially requiring a sway bar swap.You could try to trim a 1/4" off the wheel opening lip than try to swap out the rear and that is only if there is contact between this lip and the tire. If I was in in your position with your car, I'd be more apt to try rolling just a small section of the upper portion of the opening up a slight amount so you don't have a razors edge next to the tire. If you keep this roll to just a 1/4" you don't alter the look at all and you can retain the wheel opening moldings, but you do eliminate the sharp edge that can shred a tire.

Cool paint job, BTW. 

[Jamiez]

Thanks for the advice HP2, as soon as I get done messing with the brakes I'll get if off the jack stands and see how it sits. I'll slap a air pressure gauge on the shocks and see what they are currently set at. I'll check the fender lip as well.  I seem to remember there was decent clearance when I checked.

It came from the factory as a 360 Rallye car, so it should have had the "better" stock suspension, including the sway bars. I know the car was "restored/upgraded" in 1979 when it picked up the custom paint job and a few other items.  Unfortunately that's old enough that it's hard to tell original suspension parts from replacement ones. The air shocks for example have enough age to them that you could mistake them for stock (if air shocks were an option).

Just for future reference how does one measure wheel width and backspace? Is it just as simple as sticking a tape measure on it or is it more complicated?

[Jamiez]

Does the car have to be on the ground to get a pressure reading from the shocks?  I quickly checked it while jacked up and they read pretty low...between 15 and 20 PSI