Front spring comparison

Topic: Front spring comparison (Read 5615 times) previous topic - next topic

Front spring comparison

Reply #15 – December 27, 2014, 10:06:19 PM

I've got the later model springs on mine, the fronts were new from Moog, but the rears were salvaged. I like my stance, but with aluminum heads, you'd be at that .75 drop you're looking for, maybe just a bit more. With iron heads, I've dropped almost 2, maybe 1 7/8

http://www.foxtbirdcougarforums.com/showthread.php?37723-lowering-springs&p=436498#post436498

Front spring comparison

Reply #16 – December 27, 2014, 10:53:56 PM

Quote from: TheFoeYouKnow;442038

I've got the later model springs on mine, the fronts were new from Moog, but the rears were salvaged. I like my stance, but with aluminum heads, you'd be at that .75 drop you're looking for, maybe just a bit more. With iron heads, I've dropped almost 2, maybe 1 7/8

http://www.foxtbirdcougarforums.com/showthread.php?37723-lowering-springs&p=436498#post436498

Hopefully the 8598 springs drop the nose down 1-1.5 inches or so. It went up about 1 inch with the aluminum heads. I'll find out in the spring when I swap the stock front springs out.

Front spring comparison

Reply #17 – April 10, 2015, 09:27:13 PM

I put the MOOG 8598 springs in today. They dropped the nose down about an inch. Previously there was about 3.5" between the top of the tire and the fender lip in the front of the car. The 8598 springs dropped the nose down so there is 2.5" between the top of the tire and the fender. That matches the rear which has 2.5" of space between the top of the tire and quarter panel lip. The stock LX V8 springs were approximately 1 inch taller than the 8598 springs. The 8598 springs are the same height as Turbo Coupe springs. So apparently Turbo Coupe springs "should" work in the front of an aluminum headed 5.0 car.

Before:

After:

Before:

After:

The Thunderbird now is the same height as my wife's 2012 Mustang. Which is good.

Front spring comparison

Reply #18 – April 11, 2015, 11:25:37 AM

For comparison purposes stock Turbo Coupe (with automatic) front spring on the left and stock LX V8 front spring on the right. The Turbo Coupe front spring is the same height as the MOOG 8598 spring I used.

One could probably get away with cutting one coil off the stock V8 LX front spring when swapping to aluminum heads. My car probably has close to 100lbs less weight over the nose since it no longer has iron heads, cast iron exhaust manifolds, or the Thermactor system. The car still weighs 3560 with no driver. It probably was close to 3660 stock with no driver, hence the taller spring.

The ride of the car with the MOOG 8598 springs hasn't changed and in fact feels better than with the stock front springs.

Front spring comparison

Reply #19 – April 11, 2015, 11:34:56 AM

But you have to take into consideration spring rates. They may end up the same height but there could be differences in performance. If the springs rates are the same or very close and the type of spring is the same (variable vs linear) then the comparison makes sense.

Darren

Front spring comparison

Reply #20 – April 11, 2015, 11:48:51 AM

Quote from: Aerocoupe;446991

But you have to take into consideration spring rates. They may end up the same height but there could be differences in performance. If the springs rates are the same or very close and the type of spring is the same (variable vs linear) then the comparison makes sense.

Darren

True. I went with the MOOG 8598 spring as several people have used it with success so it was a know quantity.

Front spring comparison

Reply #21 – April 11, 2015, 11:52:48 AM

Rates are almost identical FWIW. 415-425 lbs/in.

I'm surprised you aren't lower. You running stock Arms? What size tire?

Front spring comparison

Reply #22 – April 11, 2015, 12:11:49 PM

Quote from: V8Demon;446997

Rates are almost identical FWIW. 415-425 lbs/in.

I'm surprised you aren't lower. You running stock Arms? What size tire?

03 Cobra Front arms, Prothane spring isolators, 225/55/16 tires. Maybe it will settle over time.

Front spring comparison

Reply #23 – April 12, 2015, 09:34:36 AM

I think that some of you guys are confusing spring rates and loaded ride height rating here, which are two different things. You can certainly have two or more different springs with the same rate but different ride height. When Ford specs out the springs for a certain model of car, there can be 5+ different springs as mentioned, all with the same spring rate. However, the weight needed to compress it to the ride height spec is different ... that's what they use to tune the height when there is added weight from extra options, etc.

Up until the 1970s, on the Ford parts microfiche catalogue cards, the various part numbers of springs would be listed in charts showing the spring rate, and the weight spec to compress the spring to ride height. Even through the 80s, the info would be published sometimes, but I haven't seen anything like that from Ford for many years, unless it's in a technical service bulletin for ride heights on a truck.

Here's an example ... the 87-93 Fox 5.0L Mustangs all had the same spring rate (except the 93 Cobra), but there were about 7 different OEM front springs, and 5 or 6 for the rear. This was to make up for the range of weight variations from a stripper no A/C 5-speed coupe, to a hatchback, to a GT hatchback with a bit more weight, all the way to a loaded up AOD ragtop car with A/C. This is typically done by adding a bit more free height to the springs. The old Ford Motorsport M-5300-C spring kit for the Mustangs were just LX coupe base rear springs, and 5.0L Fox LTD police package no A/C springs. I remember looking at the tag IDs on them in the late 80s when I had my 87 LX hatch and was starting with the mods on it.

So the long and short of it, comparing spring rates between various springs isn't going to give you a direct indication of how the ride height will come out.

cheers
Ed

Front spring comparison

Reply #24 – April 12, 2015, 03:46:20 PM

No, but the charts I posted links to earlier up will.....