When flipping the strut plate, the bottom surface of the bump stop moves up as well.
Does this create the potential for the tire to hit/rub the plastic wheel well liner, or perhaps other issues? 84-87 toe-link hitting the frame rail? My Fiero is covered in snow; can't look now.
Tire rubbing is largely dependent diameter and width of tire and offset of wheel. If the wheel/tire combo is close to stock, tires should not nub. Wider/taller tires likely will. This is less of an issue with the 88's as the 88 knuckle is taller (from wheel center), so you reach the end of strut travel with the wheel further from the underside
Tie tie rod link will likely interfere with the frame rail. On page 18 of Will's thread he cycles his 84-87 suspension to full compression w/o any springs or bump stops and the strut hat in stock orientation, the tire rod is about 1/8 from the frame. The flange and rail could be trimmed slightly for additional clearance.
Originally posted by fieroguru: Tie tie rod link will likely interfere with the frame rail. On page 18 of Will's thread he cycles his 84-87 suspension to full compression w/o any springs or bump stops and the strut hat in stock orientation, the tire rod is about 1/8 from the frame. The flange and rail could be trimmed slightly for additional clearance.
That's good info, thanks for finding it.
Flipping a KYB strut plate will move the strut rod up by ~1.050".
Probably with the right bumpstop the toe link can be kept far enough away from the frame rail notch.
I suppose that without a spring, if the rear of the car is jacked up via the knuckle (the entire rear end weight squishing one bumpstop) that would represent a worst-case bumpstop squish.
[This message has been edited by pmbrunelle (edited 01-29-2022).]
With the sway bar disconnected (if you have one) and no spring, it is quite easy to cycle to the suspension to full compression. While it is there, you might as well put the trans in neutral and spin the wheels by hand to check for Tripot binding. As you maximize the limits of suspension travel, tripot clearance becomes more important to check. Especially if you like to lower the drivetrain as low as possible in the chassis.
I did a complete new suspension on my 85 GT, rebodied as a 308. Bushings, rear struts, shocks and Eibach springs. I flipped the strut towers before installing new springs and it lowered my rear suspension about .5" I do have more travel as well, no bottoming out. The springs are what lowered it the most. I also installed 2" wheel spacers in front and 2 3/8" wheel spacers in the rear to give it the proper stance. I wasn't thinking about handling when I did the wheel spacers but...WOW. Unbelievable handling, like a rally car, Very tight and responsive.
I flipped the strut towers before installing new springs and it lowered my rear suspension about .5"... The springs are what lowered it the most.
For clarification... it was just the new springs that lowered your suspension. Flipping over the top mounting plates played no part in lowering the suspension.
quote
Originally posted by wilberto:
I also installed 2" wheel spacers in front and 2 3/8" wheel spacers in the rear to give it the proper stance.
It's possible that using spacers of that thickness contributes to lowering the car as well, as the wheels being pushed out by that distance changes suspension geometry, leverage on the springs etc. Maybe fieroguru could comment on this.
[This message has been edited by Patrick (edited 01-30-2022).]
Tire rubbing is largely dependent diameter and width of tire and offset of wheel. If the wheel/tire combo is close to stock, tires should not nub. Wider/taller tires likely will. This is less of an issue with the 88's as the 88 knuckle is taller (from wheel center), so you reach the end of strut travel with the wheel further from the underside
Tie tie rod link will likely interfere with the frame rail. On page 18 of Will's thread he cycles his 84-87 suspension to full compression w/o any springs or bump stops and the strut hat in stock orientation, the tire rod is about 1/8 from the frame. The flange and rail could be trimmed slightly for additional clearance.
Bump stop removed; measurements taken at metal-to-metal contact between the gland nut of the Koni strut and the dished washer underneath the strut top mount. Tire pictured is 285/30-18 on a C5 Corvette 18x9.5 Conestoga (61mm offset) with a 1" spacer/adapter.
Flipping the top mount and installing a bump stop would result in a bit more wheel travel possible, but the tire would definitely rub the fender on large excursions.
Not sure if this was previously mentioned, but why not just install the tie rod end to the bottom of the knuckle rather than on the top to compensate for the additional height as a result of the kyb strut plate being upside-down?
[This message has been edited by jjd2296 (edited 02-02-2022).]
Originally posted by Will: Flipping the top mount and installing a bump stop would result in a bit more wheel travel possible, but the tire would definitely rub the fender on large excursions.
Assuming I install the spring with the same preload (1/4") in both cases (standard/flipped), the coilover assembly will provide exactly the same compression/droop travel relative to the resting position.
So the main difference between standard/flipped would be a ~1" difference in ride height.
Standard: Car CG a bit higher, less risk of rubbing things
Flipped: Car CG a bit lower, more risk of rubbing things
Next spring/summer I will check which alternative I prefer by cycling the suspension with my tire of choice.
My main focus is to make my Fiero easy to drive / predictable, while not having the highest limits. If I lose a bit of grip because its CG is higher, I won't cry over that.
Not sure if this was previously mentioned, but why not just install the tie rod end to the bottom of the knuckle rather than on the top to compensate for the additional height as a result of the kyb strut plate being upside-down?
That would require using a tapered reamer to cut the correct taper into the knuckle and would create large amounts of bump steer.
Assuming I install the spring with the same preload (1/4") in both cases (standard/flipped), the coilover assembly will provide exactly the same compression/droop travel relative to the resting position.
So the main difference between standard/flipped would be a ~1" difference in ride height.
Standard: Car CG a bit higher, less risk of rubbing things
Flipped: Car CG a bit lower, more risk of rubbing things
Next spring/summer I will check which alternative I prefer by cycling the suspension with my tire of choice.
My main focus is to make my Fiero easy to drive / predictable, while not having the highest limits. If I lose a bit of grip because its CG is higher, I won't cry over that.
If you moved the lower perch to maintain pre-load, then yes, that would change ride height.
Without moving the lower perch, there's no change in ride height.
At the higher ride height, the Fiero suspension has a higher roll center. '88's actually like this. Lowering the car lowers the roll center more than the car is lowered, so even though the CG is lower, the roll moment ends up HIGHER due to longer lever arm from CG to roll center.
[This message has been edited by Will (edited 02-03-2022).]
I just flipped the hats. I've read numerous articles on this subject...some people say it lowers the vehicle, some say it doesn't. I've got it where I want it so that's fine with me. We may be using different terminology for the same part, that can vary from manual to manual.
I just flipped the hats. I've read numerous articles on this subject...some people say it lowers the vehicle, some say it doesn't.
It doesn't.
quote
Originally posted by wilberto:
I've got it where I want it so that's fine with me.
I'm glad you got it where you want it, but it wasn't from flipping the hats.
Wilberto, the whole reason why I started this thread nine years ago was because of all the erroneous information that was floating around online about this simple mod. I felt there needed to be a thread at PFF where this was set straight once and for all. I have to admit I'm rather surprised that after all that's been posted in this thread, that there still appears to be some confusion. Several contributors to this thread, some much more knowledgeable than myself, have all agreed and stated quite clearly that flipping over the hats does not affect ride height at all. It is what it is.
I haven't visited the forum since sometime before this discussion began in 2013. It is nice to return and see that these kind of discussions are still going on.
My Fiero has been lowered three times in the past 26 years of ownership. The last time, it received 2" drop spindles in the front, 4 OMG firm springs and adjustable coil overs in the rear.
The final adjustment, after ride height was determined, was to reverse the top hat in the rear for the purpose of slightly increasing rear suspension travel. That change required the previously mentioned, small modification in the vents that is hardly noticeable. When the ride is similar to a shifter cart, you appreciate an additional .5" in suspension travel.
I can also verify that occasionally, an unexpected dip in the road will cause tires to contact the fender well liners. Those rub marks help identify where the liners need to be modified.
I haven't visited the forum since sometime before this discussion began in 2013. It is nice to return and see that these kind of discussions are still going on.
Welcome back... but aw man, another thread with missing images. I'll have to see if I can locate my missing images to re-post.
On a stock height Fiero, I would say no unless you are jumping the car. Now, on a lowered car hitting the inner liner is always an issue depending on the ride height.
With my 87 lowered with coil overs in the back I never had an issues with toe or hitting liner. The front is another issue as there isn't as much tuck room.
I'll have to see if I can locate my missing images to re-post.
