Ridetech 4-link rear end clearance

[Wall]

I am working on my ridetech 4-link install and have the rear end positioned at my intended ride height. The lower links are mounted in the 2nd position on the rear end brackets and are parallel to the ground but it looks like there's not much clearance between the rear end and floor in a few areas.

I took a few photos to show the areas of concern. Is my ride height too low or is this normal? Just seems like there's not enough room right now.

[Josh@Ridetech]

What is the measurement from center to center on your shock mounts (at ride height)?

[Wall]

I will check when I get home today.

[Wall]

What is the measurement from center to center on your shock mounts (at ride height)?

Measurement was 13 7/8 from eye to eye so it is a little low. Don't I need to shoot for 14.5 to 15in?

[Josh@Ridetech]

You're a little under what we typically run. Crank the shocks up to 14.5" and then check your clearance again. If you can, take some more pictures at that height as well.

[Wall]

Josh, I messed with it a few minutes tonight but didn't have time to verify all my measurements, right now it looks like 2 1/8 between the tunnel and DS flange and 2 1/2 between the diff and trunk floor.

I won't call those final measurements yet since I only had a few minutes to mess with it.

BTW do you know what the motion ratio is for this setup?

[Josh@Ridetech]

Josh, I messed with it a few minutes tonight but didn't have time to verify all my measurements, right now it looks like 2 1/8 between the tunnel and DS flange and 2 1/2 between the diff and trunk floor.

I won't call those final measurements yet since I only had a few minutes to mess with it.

BTW do you know what the motion ratio is for this setup?

No worries! Just let me know when you get them.

On this setup, your almost at a 1:1 ratio with the straight axle.

[Wall]

Josh I finally got a chance to look at the car again and take a few pics but first I have to verify my pinion angle and tack weld the brackets on the rear end.

I jacked up the rear to check for clearance and the first point of contact was between the front 4-link cross-member and the diff housing. I'm running a narrowed 8.8 rear out of a 02 GT. I lowered the rear down to where there was about 1/2"-5/8" of clearance between the diff and cross-member and measured the shock eye to shock eye mounts which was 12.5".

I took a few pics of the car at 12.5" and 14.5" shock measurements. I also took a pic of the area where the diff and cross-member would hit. With the shocks at 14.5" the ride height is a little higher than I wanted but I can live with it, I just don't want to go any higher.

[dhutton]

Looks like that interference will be affected by the pinion angle. Have you set it and what is it?

Edit, deleted. I was out in the weeds here... ��

Don

[Wall]

Looks like that interference will be affected by the pinion angle. Have you set it and what is it? It looks like it is pointing up in the pic. Should it be pointing down?

Don

Don, the pinion angle is 3.2 deg at ride height and it is pointing up. I went by the ridetech 4-link instructions and measured the angle on the engine harmonic balancer and set the rear end to that. The engine actually measured 3.3 deg and I was trying to match that but ended up with 3.2 on the rear.

[dhutton]

I will defer to ridetech but which lower coilover mount holes are you using? There is a least two options if I remember right.

Don

[Wall]

I will defer to ridetech but which lower coilover mount holes are you using? There is a least two options if I remember right.

Don

I'm using the lowest coil-over mount. Only thing that my be different with my car is I'm using the weld on lower control arm brackets since I'm running a 8.8 rear. Would you have set the pinion angle different?

[dhutton]

I'm using the lowest coil-over mount. Only thing that my be different with my car is I'm using the weld on lower control arm brackets since I'm running a 8.8 rear. Would you have set the pinion angle different?

No I'm just thinking you should be using the coilover mount that positions the coilover mount highest if that makes sense.

Don

[marolf101x]

Coil over mount location only adjusts ride height. For that low stance it'll be at the bottom of the bracket.

Here's the skinny. . .you are using a rear end we've never fit in a 1st gen. Not saying we cannot make it fit, but that's the major issue.
The shock is the compression limiter when using a coil over, so the rear end should move and clear everything until the shock fully compresses and bottoms out on the bumpstop on the shaft.

As stated by Josh we recommend roughly 14.25"-14.5" shock eye-to-eye measurement at ride height. Why do we suggest a ride height of 14.25"? In any suspension system you want 5" of overall travel for good ride quality. We prefer to use 60% of that travel for compression (bump), and 40% for droop (rebound), as you hit more bumps than you jump the car. That means you need 3" compression travel.
Our 5.2" stroke shock we use in the rear has a fully compressed height of 11.25". Add to that 3" for compression travel, and you get 14.25".

Bottom line, you need to create clearance when the shock mounts are 11.25" apart (or the shock is fully compressed, if you put it in for mockup, which you should! Make sure you have clearance at full compression, and if one side is fully compressed and one side is fully extended).
Whatever it takes to create that clearance is what will be required. If you cut the tubes of the 4-link cross member, just be sure to brace them or whatever is required to make them strong again.

Pinion angle could help that situation by rotating the front of the axle down a bit. 3.2 degrees up is not terrible, we typically like to be under 3 degrees if we can.
See if you can raise the rear of the trans slightly to put the tail shaft at less than 3 degrees down.

[Wall]

Thanks for your reply Britt. I thought I might have to do some modifications since I'm using a different rear but just wanted to make sure I wasn't missing anything before I start.

I will try adjusting the pinion angle and see how much that helps. I may have to modify the cross-member and possibly the trunk floor above the center section to get the clearance needed for a 5.2" shock.