What is the gap between the top of tire to wheel well after lowering your car?

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What is the gap between the top of tire to wheel well after lowering your car?

November 13, 2016, 05:52:16 AM

I see from my searches that when forum members have lowered their car with different springs that nearly everyone describes the result in Inches Dropped. I don't know what the starting height of my 87 T-Bird was because the springs have broken on my car. Those of you that have lowered your car can you tell me what is the measurement result you got from the top of the tire to the fender wheel well lip along with the springs you used? FYI, the door sticker on my car says it weighs 2284 LB GAWR Front and 2292 LB GAWR Rear. Thanks.

What is the gap between the top of tire to wheel well after lowering your car?

Reply #1 – November 14, 2016, 04:42:46 AM

I don't have a bird, so I can't help you with the measurement.

What I can do is let you know that the Grand Vehicle Weight Rating (GVWR) on the door is the maximum vehicle weight rating. So basically, it's the maximum weight of the vehicle, with the maximum amount of passengers of an average weight, full fluids, and a full trunk. The curb weight, which usually isn't specified by a lot of manufacturers is what the vehicle weighs empty.

Update

Reply #2 – February 02, 2017, 06:55:28 AM

I've done a lot of measuring and raising of my 87 T-Bird Sport and I figure that with stock springs the fender wheel well lip to top of tire gap is roughly 3" on all four corners and 27.00" up from the ground. Due to both my cars original front springs breaking I had to square them up at a length of 14.25". This dropped the front end 1.50". The bad part of this is both front wheels now have about -5 degree ( tilted in at top ) camber and the front air dam is now 5.125" off the ground compared to stock height of 7.68". This will most definitely not clear any parking lot curb tire stops.

What is the gap between the top of tire to wheel well after lowering your car?

Reply #3 – February 02, 2017, 09:11:38 AM

Caster Camber plates specifically for our cars...

http://www.maximummotorsports.com/Thunderbird-Caster-Camber-Plates-1983-1988-P258.aspx

What is the gap between the top of tire to wheel well after lowering your car?

Reply #4 – February 03, 2017, 07:05:19 AM

5 degrees negative camber is unlikely. I dropped 2.5 inches on sn-95 GT springs and ended with 2.7 degrees negative camber, which I was only able to correct to 2.25 degrees negative without CC plates. I know this because I have an alignment rack at work. WITH CC plates, as linked above, I was able to dial in factory camber at -0.75 and improve my return to center by increasing caster to +4.5. With my drop, I did NOT create a bump-steer problem. Using an extended balljoint, such as you would during some SN-95 steering knuckle swaps, can give you bump steer, so watch out for that. Also, with my drop I tended to rub the inner fenders when cornering (and not that hard). I fixed it with a pair of ST suspensions sway bars (36mm and 24mm).

What is the gap between the top of tire to wheel well after lowering your car?

Reply #5 – February 03, 2017, 08:32:36 AM

Mine was terrible after I dropped it but prior to dropping it I had to slot the struts to get the right camber. These cars were not built to very good tolerances which has been documented with the gangster lean some of the Mustangs had. Regardless of all that the CC plates will most likely fix his issue.

What is the gap between the top of tire to wheel well after lowering your car?

Reply #6 – February 06, 2017, 10:32:22 PM

Quote from: Aerocoupe;459083

Mine was terrible after I dropped it but prior to dropping it I had to slot the struts to get the right camber. These cars were not built to very good tolerances which has been documented with the gangster lean some of the Mustangs had. Regardless of all that the CC plates will most likely fix his issue.

Quote

Posted by: TheFoeYouKnow, "5 degrees negative camber is unlikely."

How I made my measurement was to place a straight edge on the wheel rim lip and used an angle gauge. This is similar to those magnetic angle gauges you'd have to attach to the brake rotor spindle nut. So when I jacked the front end up to get a 3" tire/fender gap ( which I think is the stock gap ) and the lower control arms were level with the ground. The gauge measurement read roughly 0 degrees.

If the measurement is correct I don't know how caster/camber plates would be able to correct -5 degrees when the top of the strut bushing is currently resting on the outer edge of the fender strut opening mounting hole. Would likely have to elongate the fender opening.

I too was thinking about elongating the upper hole of the two strut/spindle mounting holes. Then inserting a piece of metal to take up the slack. Something like the adjustable camber bolts. Once that bolt is tighten it will secure the metal piece. Just need to get the right width of metal to get the proper camber setting.

What is the gap between the top of tire to wheel well after lowering your car?

Reply #7 – February 06, 2017, 11:17:58 PM

So let's get some terminology going here. The area under the hood that the top of the strut comes through is called the strut tower. The next thing would be to take a picture of the stock upper strut mount from the front of the car that also shows the entire top of the strut tower. With that I can just about tell you if the CC plates will help. My money is on them doing the trick.

What is the gap between the top of tire to wheel well after lowering your car?

Reply #8 – February 08, 2017, 02:56:59 AM

Quote from: Aerocoupe;459159

So let's get some terminology going here. The area under the hood that the top of the strut comes through is called the strut tower. The next thing would be to take a picture of the stock upper strut mount from the front of the car that also shows the entire top of the strut tower. With that I can just about tell you if the CC plates will help. My money is on them doing the trick.

Here's what the strut towers look like.
Right

Left

What is the gap between the top of tire to wheel well after lowering your car?

Reply #9 – February 08, 2017, 04:36:30 AM

Yup. maxed out to positive. Caster/camber plates are your only hope, and then get to a professional with a good alignment rack. Tell him you want -0.75 to -1.25 Camber and +4.0 to +4.5 Caster, since caster influences Toe, he'll have to correct that also. If you're on stock spindles and balljoints you shouldn't have to worry about bump-steer.

What is the gap between the top of tire to wheel well after lowering your car?

Reply #10 – February 08, 2017, 08:53:14 AM

The Maximum Motorsports CC plates will fix your issues. You have a lot of room left for adjustment with their units as they are much smaller at the point which the strut attaches which allows you to move the strut rod closer to the outside of the car. Here is a picture of them on my '83:

You can see that there is plenty of adjustment on these units (pardon the dust as this is when I was rebuilding the car for the third time) as my car is in the weeds. I have the main plates in the negative orientation as I need more adjustment to get the camber back to not eating the tires. You can go here and read up on the installation of these and how to set them up properly:

http://www.maximummotorsports.com/content/install/pdf/front_susp/MMCC8388r4.pdf

They also give recommended alignment specs on the bottom right of page three, this is where just yanking the strut rod back and dialing in some camber can get you into trouble as going past a point will possibly induce bump steer.