Ideal Ride Height and Adjusting Koni Coil Overs

[Mike289]

I'm an FFR owner again. My first post here, I picked up an MK4 last month. I've noticed the front end of the car sits higher than the rear as far as the fender to tire gap goes and one front corner of the car is about an inch higher than the other side measuring from the ground to the top of the fender lip.

I'm curious what ride height is ideal and if minor adjustments will require a front end alignment. At the very least I'd like to make the front even on both sides. Also, is there a special tool or spanner wrench required to adjust the coil overs and if so where can I buy one?

[Scott Zackowski]

Some variation allotted but most go with 4 inch Front and 4 1/4-4 1/2 inch Rear.

If suspension is not broken in yet, it will settle over time, so may want to start with 4 1/2 Front & 5 Rear.

Measured from lowest part of the frame to ground, which is usually the large frame tubes running down each side of the car.

Ride height adjustments will affect your front end caster and camber, and if a solid rear axle, it will affect the pinion angle.

I am not sure how much of a small change in ride height you can get away with before it significantly affects the the front alignment and pinion angle. But I am fairly certain it is not much, probably less than 1/2 inch.

[Mike289]

Thanks. I'll check from the frame to the ground as you suggested rather than the fender lip to ground since I'm betting the body is not perfectly symmetrical. It is a solid axle rear and it has about 4500 miles on it now so things should be pretty settled.

[edwardb]

Ride height has nothing to do with the body. It's completely how the frame sits in relation to the ground. But be careful how you set ride height. When doing it manually (e.g. without the benefit of corner scales) it needs to be done a certain way and very systematically. Since you don't know how the car was set up, I'd recommend starting from scratch. (1) Jack the car up enough that the suspension is hanging. Ideally all four corners, but you could do front and back separately. (2) With the suspension hanging, loosen the collars on the coilovers to where the coils are loose. Then tighten the collar until the collar is just touching the spring and barely holding the spring from moving. Do the same for all four. This is your baseline adjustment. (3) Lower the car to the ground put all the weight on the suspension. Good idea to bounce each corner up and down a bit to make sure it's settled. (4) Now measure front and rear ride height. You will probably be well above the suggested 4-inch front and 4-1/4 to 4-1/2 inch rear. Measure on both sides. (5) Raise the car back up and adjust the collars exactly the same on the front pair and the rear pair as needed for the desired ride height. Front and rear doesn't have to be the same number of turns (e.g. turn front 2 and rear 3 turns) but side-to-side front and rear need to be exactly the same every time you adjust them. (6) Lower the car back on the suspension, bounce, and measure again. Repeat as needed until the desired ride height is achieved front and back, again only adjusting the front and rear pairs exactly the same amount every time. Some have tried to draw a correlation between the number of turns and the amount the suspension moves. You may get a feel for this as you're doing it, but I've never tried to exactly figure it out. Just adjust until it's right.

When done, it's possible you may find it's slightly different from side-to-side, e.g. front RH is 4-inches, front LH is 4-1/8 inches. That's OK and don't try to adjust this out by turning only one side. The only time it's OK to turn only one coilover is if you have corner scales and can see the exact effect and keep everything in the proper balance. If it's way off from side to side (unlikely) then something else is wrong, e.g. coil spring lengths. Also, if the body is now way off, e.g. gaps at the wheel wells aren't reasonably even, then again something is wrong with the body mounting.

With the ride height set, now you can do the front end alignment. The ride height won't be affected. Also, as you can see from these suggested instructions, a tool isn't necessary for the coilovers. If you adjust them without weight on them, you should be able to adjust by hand.

Hope this helps and good luck.

[Mike289]

Thanks that's good to know! I do not have scales so I'll follow your process. I'll check the frame in relation to the ground first if that all looks even it it could be the way the body was mounted. The car drives perfect and the alignment is great otherwise. The difference in wheel gaps is not noticeable unless I take a tape measure from side to side.

[CraigS]

I agree w/ EdwardB's procedure but will add one point. Just as a double check, when you adjust the collars to barely touch the springs, count how many threads are exposed beyond the collar. That number should be the same left and right but not front to rear.

[GoDadGo]

I agree w/ EdwardB's procedure but will add one point. Just as a double check, when you adjust the collars to barely touch the springs, count how many threads are exposed beyond the collar. That number should be the same left and right but not front to rear.

I used this method (Counting Threads For Each Koni) and my preliminary ride height ended up at 4.5" front and rear.
When we scaled the chassis, when the sucker was running last summer, the corner weights were darn near perfect.
Getting the car to level out was a 1/4 turn of the collar on one front and 1/2 turn on the rear on the right side.
Just understand that I've got the 3-Link rear so it is easier to adjust than the IRS set up.

[Mike289]

Well I went ahead and measured distances from each 4 inch round tube to the ground. Both fronts are at 4 inches, rears are at 5. The rear does not seem to sit up too high, wheel gaps in the rear are close to the same as up front 2 1/2 to 3 fingers for me. So I won't mess with the ride height for now. The differences side to side could be the way the body was mounted or the mold itself. I can live with it as is. Thank you all for the help!

[Mark Reynolds]

Additional Step: after letting the car back down, before bouncing, you need to roll the car back and forth a few feet to allow the front suspension (and rear if it is IRS) to roll into it's settled and relaxed position.

[toadster]

any guidelines to the initial Koni DA setting? from pics it seems 4-5 threads up from bottom? for the front shocks...

126554

[edwardb]

any guidelines to the initial Koni DA setting? from pics it seems 4-5 threads up from bottom? for the front shocks...

126554

It's pretty academic at this point. Run the adjusters to where they're just holding the spring tight and start there. That will likely put your ride height on the high side. Adjust from there once the build is complete and it's on the ground. Get them close when you're ready for alignment.

[toadster]

It's pretty academic at this point. Run the adjusters to where they're just holding the spring tight and start there. That will likely put your ride height on the high side. Adjust from there once the build is complete and it's on the ground. Get them close when you're ready for alignment.

front settings according to the manual are 15.5" center to center - looks way too high IMHO but may need to adjust the collar down from the overall height...

126560 126561

[edwardb]

front settings according to the manual are 15.5" center to center - looks way too high IMHO but may need to adjust the collar down from the overall height...


Same answer. You can't tell anything at this point. Can only suggest again to set them both with the springs barely captured and move on.

Question: Looking at your picture, the top shock mount bolt isn't through the nut. There should be at least several threads showing. Is it tight? If it is, you need a longer bolt there.

[65 Cobra Dude]

One minor point that needs mentioning - make sure your tire pressures are set before doing all this. Most people set them to ~ 1 lb per 100 lb’s of weight. I set mine at 24 lbs.

Henry

[rich grsc]

Are the new Koni's supposed to be body down?

[Jeff Kleiner]

Are the new Koni's supposed to be body down?

Yes, the double tube ones like these must be body down. The single tube 30 Series---the red ones---can be installed either way.

Jeff

[rich grsc]

Good to know. :cool: I run the the old ones body up.

[GTBradley]

Good write-up, Paul, thanks. I’m wondering, if I were to buy one scale capable of 700 lbs max could I do my corner weights with that? I know I would need to put all four wheels on platforms the same thickness as the scale and there would be a lot of moving it back and fourth, but is there any reason this wouldn’t be inaccurate? (Assuming of course that the scale is accurate).

[edwardb]

Good write-up, Paul, thanks. I’m wondering, if I were to buy one scale capable of 700 lbs max could I do my corner weights with that? I know I would need to put all four wheels on platforms the same thickness as the scale and there would be a lot of moving it back and fourth, but is there any reason this wouldn’t be inaccurate? (Assuming of course that the scale is accurate).

I'm far from an expert on the subject. Borrowed a corner weight setup and used it on my 20th Anniversary Roadster. That's it. My inclination is that probably wouldn't be very useful. The system I used (Intercomp Racing Model SW500) measured each wheel individually and total, plus left pair, right pair, rear pair, and cross weights. I think it would be difficult, or at least impractical, to duplicate reliably one wheel at a time. As it turns out, using the method I described above, it was so close there wasn't any reason to change anything so I didn't. It was nice to have confirmation that I had a decent setup. But for a street driven car I think most agree not mandatory to corner weight if you're careful when adjusting.

[toadster]

Same answer. You can't tell anything at this point. Can only suggest again to set them both with the springs barely captured and move on.

Question: Looking at your picture, the top shock mount bolt isn't through the nut. There should be at least several threads showing. Is it tight? If it is, you need a longer bolt there.

yes, you have good eyes :)
they aren't torqued down in the pic

[CraigS]

GT, in theory I think a single scale could work but the amount of work involved would be horrendous. You would need to build platforms that are the same thickness as the scale I'd say within a tolerance of 1/16 inch max. Then you need more platforms to put behind those so you can roll the car off the 3 platforms + scale, so you can swap the scale to under another tire. And your garage floor would probably need to be shimmed so you have 4 spots that are all the same height. I don't think it is worth the effort especially after reading EdwardB's success w/ his car and technique.

[Railroad]

I zip tied my springs to the top spring stop. Also, if you have slack in the springs when you unload the suspension, be sure the spring does not catch on the shoulder of the adjuster nuts. This only happens if the spring has space on the bottom to the nut. After everything settles, the adjusters will be against the springs for the proper height, on my car.

[GTBradley]

GT, in theory I think a single scale could work but the amount of work involved would be horrendous. You would need to build platforms that are the same thickness as the scale I'd say within a tolerance of 1/16 inch max. Then you need more platforms to put behind those so you can roll the car off the 3 platforms + scale, so you can swap the scale to under another tire. And your garage floor would probably need to be shimmed so you have 4 spots that are all the same height. I don't think it is worth the effort especially after reading EdwardB's success w/ his car and technique.

I think you’re probably correct, but it would be nice to know the actual weights and at 70 bucks this 700 pound scale looks pretty good. I don’t think using it this way really would be that much extra effort, though. Sure you have to build platforms that are long enough to roll back and forth on, but any time you change the collar position the car needs to be bounced and rolled back and forth anyway. The only extra step here would be moving the scale left and right when you do. And floor is going to have its issues whether using a four wheel scale or one. I assume that all garage floors that are otherwise in good condition slope to to the outside somewhat.

[steno]

Ride height has nothing to do with the body. It's completely how the frame sits in relation to the ground. But be careful how you set ride height. When doing it manually (e.g. without the benefit of corner scales) it needs to be done a certain way and very systematically. Since you don't know how the car was set up, I'd recommend starting from scratch. (1) Jack the car up enough that the suspension is hanging. Ideally all four corners, but you could do front and back separately. (2) With the suspension hanging, loosen the collars on the coilovers to where the coils are loose. Then tighten the collar until the collar is just touching the spring and barely holding the spring from moving. Do the same for all four. This is your baseline adjustment. (3) Lower the car to the ground put all the weight on the suspension. Good idea to bounce each corner up and down a bit to make sure it's settled. (4) Now measure front and rear ride height. You will probably be well above the suggested 4-inch front and 4-1/4 to 4-1/2 inch rear. Measure on both sides. (5) Raise the car back up and adjust the collars exactly the same on the front pair and the rear pair as needed for the desired ride height. Front and rear doesn't have to be the same number of turns (e.g. turn front 2 and rear 3 turns) but side-to-side front and rear need to be exactly the same every time you adjust them. (6) Lower the car back on the suspension, bounce, and measure again. Repeat as needed until the desired ride height is achieved front and back, again only adjusting the front and rear pairs exactly the same amount every time. Some have tried to draw a correlation between the number of turns and the amount the suspension moves. You may get a feel for this as you're doing it, but I've never tried to exactly figure it out. Just adjust until it's right.

When done, it's possible you may find it's slightly different from side-to-side, e.g. front RH is 4-inches, front LH is 4-1/8 inches. That's OK and don't try to adjust this out by turning only one side. The only time it's OK to turn only one coilover is if you have corner scales and can see the exact effect and keep everything in the proper balance. If it's way off from side to side (unlikely) then something else is wrong, e.g. coil spring lengths. Also, if the body is now way off, e.g. gaps at the wheel wells aren't reasonably even, then again something is wrong with the body mounting.

With the ride height set, now you can do the front end alignment. The ride height won't be affected. Also, as you can see from these suggested instructions, a tool isn't necessary for the coilovers. If you adjust them without weight on them, you should be able to adjust by hand.

Hope this helps and good luck.
I agree completely... put your front tires on a couple of folded trash bags. The front end will settle easier that way .

[CraigS]

GT can you post a link to that $70 700# scale please. Compared to real race scales at about $1000, I'd buy 4 of them for $280 and be way ahead.

[GTBradley]

GT can you post a link to that $70 700# scale please. Compared to real race scales at about $1000, I'd buy 4 of them for $280 and be way ahead.
I had been looking at heavy weight scales for a while before finding one on Amazon that the reviews seem to like. Most are 600 lbs to 660, but the added capacity of 700 lbs max was nice. It doesn’t have a separate display, but it does speak the weight. The display I thought was recessed, but after closer inspection I see it actually protrudes. This could be dealt with by cutting a plywood shim. BTW, the price went up overnight.

700 (https://www.amazon.com/dp/B00MQ8A5UY/ref=cm_sw_r_cp_tai_xaiNEb3PTB9CF)

There’s also a 660 lbs scale with separate display and memory. At 660 it would handle up to a 2640 lb car, probably enough. I don’t know what the accuracy is, but I might try this one and if it is inaccurate I’ll send it back.

660 (https://www.amazon.com/dp/B01BURKQNW/ref=cm_sw_r_cp_tai_w8hNEbT23GXPA)