Pennock's Fiero Forum
  General Fiero Chat
  Best way to lower an '88 front end (Page 1)

Post New Topic  Post A Reply
Email This Page to Someone! | Printable Version

This topic is 2 pages long:  1   2 
Previous Page | Next Page
next newest topic | next oldest topic
Best way to lower an '88 front end by tshark
Started on: 06-01-2014 02:10 AM
Replies: 43 (1619 views)
Last post by: TXGOOD on 06-03-2014 02:48 PM
tshark
Member
Posts: 4374
From:
Registered: Feb 2014


Feedback score:    (6)
Leave feedback





Total ratings: 64
Rate this member

Report this Post06-01-2014 02:10 AM Click Here to See the Profile for tsharkSend a Private Message to tsharkEdit/Delete MessageReply w/QuoteDirect Link to This Post
...

[This message has been edited by tshark (edited 09-07-2018).]

IP: Logged
PFF
System Bot
Patrick
Member
Posts: 30937
From: Vancouver, British Columbia, Canada
Registered: Apr 99


Feedback score: (1)
Leave feedback





Total ratings: 445
Rate this member

Report this Post06-01-2014 02:39 AM Click Here to See the Profile for PatrickClick Here to Email PatrickSend a Private Message to PatrickEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by tshark:

...what is the best way?


Well, that might depend on your finances.

Just last week I installed a full set of lowering springs into my '88 Formula. I'm not 100% sure who makes them (as I got them through a friend of a friend), but I suspect they're from the The Fiero Store (as I don't know who else makes a full set for the '88). I'm actually surprised how low they've made the front of the Formula. With the rubber bump stops shaved 3/4", there's a one inch gap at the bump stops before bottoming out. With poly front swaybar bushings, Rodney's zero-lash end links, and KYB shocks (quite stiff) also mounted, I'm fortunately not finding the front suspension reaching the end of its travel on smooth roads (or at autocross).

If I hadn't of gotten these lowering springs, I would've cut and installed pre-'88 front springs.

[This message has been edited by Patrick (edited 06-01-2014).]

IP: Logged
tshark
Member
Posts: 4374
From:
Registered: Feb 2014


Feedback score:    (6)
Leave feedback





Total ratings: 64
Rate this member

Report this Post06-01-2014 02:42 AM Click Here to See the Profile for tsharkSend a Private Message to tsharkEdit/Delete MessageReply w/QuoteDirect Link to This Post
...

[This message has been edited by tshark (edited 09-07-2018).]

IP: Logged
Patrick
Member
Posts: 30937
From: Vancouver, British Columbia, Canada
Registered: Apr 99


Feedback score: (1)
Leave feedback





Total ratings: 445
Rate this member

Report this Post06-01-2014 03:10 AM Click Here to See the Profile for PatrickClick Here to Email PatrickSend a Private Message to PatrickEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by tshark:

So, you had to shave the bump stops?


Only if I wanted some suspension travel.
IP: Logged
jscott1
Member
Posts: 21674
From: Houston, TX , USA
Registered: Dec 2001


Feedback score:    (15)
Leave feedback





Total ratings: 415
Rate this member

Report this Post06-01-2014 03:12 AM Click Here to See the Profile for jscott1Send a Private Message to jscott1Edit/Delete MessageReply w/QuoteDirect Link to This Post
I've got Fiero store springs on the front of my 88 and I didn't shave anything. I like the stiffer ride a lot.
IP: Logged
California Kid
Member
Posts: 9538
From: Metro Detroit Area, Michigan
Registered: Jul 2001


Feedback score: N/A
Leave feedback





Total ratings: 275
Rate this member

Report this Post06-01-2014 04:23 AM Click Here to See the Profile for California KidSend a Private Message to California KidEdit/Delete MessageReply w/QuoteDirect Link to This Post
If you only want to drop front by 1 inch, it would seem to me that correctly cutting front factory springs, would be the best solution answer to your question. That way you know you've got a quality known spring, handling will improve, and front end will be a little firmer than stock.

Rodney's lowering ball joints while good, do not fit your criteria for going to larger brakes.

------------------

Car History: http://www.fiero.nl/forum/Forum1/HTML/025670.html

IP: Logged
Sourmug
Member
Posts: 4538
From: Calgary, Alberta, Canada
Registered: Sep 2002


Feedback score:    (29)
Leave feedback





Total ratings: 144
Rate this member

Report this Post06-01-2014 10:04 AM Click Here to See the Profile for SourmugSend a Private Message to SourmugEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by jscott1:

I've got Fiero store springs on the front of my 88 and I didn't shave anything. I like the stiffer ride a lot.


Same here.

[This message has been edited by Sourmug (edited 06-01-2014).]

IP: Logged
fieroguru
Member
Posts: 11356
From: Champaign, IL
Registered: Aug 2003


Feedback score:    (45)
Leave feedback





Total ratings: 255
Rate this member

Report this Post06-01-2014 10:36 AM Click Here to See the Profile for fieroguruSend a Private Message to fieroguruEdit/Delete MessageReply w/QuoteDirect Link to This Post
If you want to keep the stock wheels, lower the front, and have a chance at running the 12" C4 rotor upgrade, your only lowering options are to use cut springs or lowering springs.

The cheap way to get a higher spring rate is to get some 84-87 GT front springs and cut 1 3/4 to 2 1/2 coils from them (depending on how low you want it). This will raise the stock rate about 30% and firm up the ride, but not be as firm as most lowering springs.

Just as an FYI for those who didn't take the time to see where the 88 front bump stops hit... this is with the front spring and shock removed with 205/50/16 tires (about 24" in diameter) and the wheel raised with a jack so the bump stop is making contact with the crossmember. This extra gap is additional travel that can be used to help avoid bottoming out on the bump stops - less harsh of a ride (even if you like firm springs).



The bump stops come out with a 13mm socket (single nut holding them in place) and are easy to cut down:
Stock with the cut line:


Cut:


New wheel/fender gap when sitting on the bump stops:


If you run KYB front shocks, they are longer than stock and can bottom out internally when the bump stops are cut, so you should add a couple of spacers between the shock and the lower a-arm (some 1/2" nuts work well). Here just the KYB shock is installed and the bump stop removed and I had a very similar wheel gap, so it adding the spacers allows the bump stop to compress w/o bottoming out the shock.



With the shock spacers installed:


------------------
Website: fieroguruperformance.com
Products: 88 13" Brake Kit, 88 12" Brake Kit, 88 Lateral Link Relocation, 84-87 Machined Front Hubs, Custom Machining
Engine Swaps:
LS4/F40, HSR/SBC/F23, Pro-Flo/383/Getrag, 4.3CPI/4T60, Ramjet SBC/Getrag, 4.9/Isuzu, Carb SBC/Isuzu, 4.5/Isuzu

IP: Logged
Bloozberry
Member
Posts: 7760
From:
Registered: Jan 2009


Feedback score: N/A
Leave feedback





Total ratings: 308
Rate this member

Report this Post06-01-2014 12:21 PM Click Here to See the Profile for BloozberrySend a Private Message to BloozberryEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by California Kid:

If you only want to drop front by 1 inch, it would seem to me that correctly cutting front factory springs, would be the best solution answer to your question. That way you know you've got a quality known spring, handling will improve...


That's a common misconception that handling will improve by cutting the springs on an otherwise stock front end. It reduces anti-dive geometry, increases roll moment, increases roll center lateral movement, increases rate of toe change, and decreases rate of camber change all for the worse. Some of these parameters are only changed marginally, but nevertheless they do not represent a positive change. By shortening their springs, what most people experience and wrongfully equate to better handling is simply a stiffer suspension.

 
quote
Originally posted by Fieroguru:
If you want to keep the stock wheels, lower the front, and have a chance at running the 12" C4 rotor upgrade, your only lowering options are to use cut springs or lowering springs.


This is correct however if you decide to use larger diameter wheels, then another option opens up for you that solves all of the problems mentioned above: drop spindles. They are available from several sources including Arraut Motorsports and I believe West Coast Fieros too, though they are the most expensive option.
IP: Logged
California Kid
Member
Posts: 9538
From: Metro Detroit Area, Michigan
Registered: Jul 2001


Feedback score: N/A
Leave feedback





Total ratings: 275
Rate this member

Report this Post06-01-2014 01:24 PM Click Here to See the Profile for California KidSend a Private Message to California KidEdit/Delete MessageReply w/QuoteDirect Link to This Post
Bloozberry, I think your splitting hairs on the whole issue. Theory is one thing, actual results are another. I'm attaching Herb Adams recommendations for the OP, so he can review, and make up his own mind.

Herb Adams:

The following article is an excerpt from a 1991 Kit Car magazine article from Herb Adams VSE. I have only included the suspension information. Herb Adams was a GM engineer who went on to produce some of the best handling "massaged" Pontiacs of the 1970s to 1990s.

FROM THE GROUND UP

Making a standard production car handle well on the racetrack often requires a variety of modifications. Each change is aimed at correcting one or more problem areas. You should start from the ground up by selecting the right tire sizes.

The basic handling problems any rear- or mid-engine car is that the center of gravity is behind the traction center of the tires. Rear-engine race cars compensate for this by using larger tires on the back and smaller tires on the front. This moves the traction center to the rear so it is on, or behind, the center of gravity. You can use larger rear tires on your Fiero for the same benefit. The stock rear fenders have room for Goodyear ZRS 255/50x16 tires on 16x9 wheels, although 225/50x16 tires on 16x8 wheels will also provide improvement.

The basic stability of your mid-engine Fiero can also be improved by moving the center of gravity forward. The easiest way to do this is to move the battery from the rear to the forward luggage compartment, or fit it ahead of the right front wheel well. The latter location requires more work, but it does preserve some of the limited storage space.


BEEF UP YOUR BUSHINGS

The rear control arms on a stock Fiero are mounted the the frame with rubber bushings. They allow the rear arms to move forward under power and rearward under braking, and the effect on handling is a change in steering direction whenever the throttle or the brakes are applied. The other problem with the earlier Fiero rear control arm bushings is that they deflect inward during cornering, which changes the rear wheel camber angle. Both of these handling problems can be corrected by replacing the stock rubber control arm bushings with steel bushings.

Steel bushings are required for this application because of extreme loads resulting from driving and cornering forces. I have found that the only bushings that hold up are aircraft-quality hardened steel on hardened steel mono-balls. Steel sleeves must be welded to the control arms to secure the mono-balls in place. This operation requires that the rear arms be removed from the car. The installation takes time and money, but is well worth the results. Changing the rear control arm bushings is the most significant change that can be made to improve your Fiero's handling. *

When the rubber is removed from the rear control arm bushings, there is potential for more ride harshness and road noise. This is usually not a problem because the rear sub-frame is still mounted to the body with rubber mounts.

If you want ultimate handling on the racetrack and you're not concerned about noise, you can replace the rubber sub-frame mounts with steel or aluminum to keep the sub-frame from moving in relation to the body. The handling improvements gained by this modification are less than when the control arm rubber is removed, but it does provide some advantage on the racetrack.

The front control arm bushings are also mounted in rubber so they deflect when cornering loads are applied. If these bushings are replaced with steel and nylon bushings, there is a noticeable improvement in front-end cornering power. Since the weak link in the Fiero handling is not the front suspension, and because there is less weight on the front end, changing the front control arm bushings is not recommended unless race ready handling is desired. The arm must be removed from the car to replace the bushings.


NEUTRALIZING UNDERSTEER

Besides the rear control arm bushings, adding and/or changing the stabilizer bars are the most significant handling improvements you can make on your Fiero. Due to the Fiero's inherent tendency to spin-out at the limits of its cornering power, Pontiac engineers tuned the cars handling characteristics to provide an excessive amount of understeer. This trait ensures safe handling for the majority of drivers, but does not permit fast cornering. The stock Fiero uses a front stabilizer bar and no rear stabilizer bar to create the desired understeer. If your Fiero has steel rear control arm bushings, its rear suspension is capable of absorbing more cornering force, so some amount of rear stabilizer can be used. I have found that by increasing the effectiveness of the front stabilizer bar, we can use a large rear stabilizer bar. By matching the size of the front and rear bars, it is possible to make a Fiero handle with neutral steer instead of excessive understeer. Neutral steer provides the maximum cornering speed because all the tires work at the same level. Large front and rear stabilizer bars limit the body roll angle and positive camber, which keeps the tires from losing cornering power

The use of large front and rear stabilizer bars doesn't have any significant effect on ride quality or road noise. The addition of the front and rear bars will also make a significant improvement in steering response and precision. The 1.25 inch diameter rear bar recommended by my company, (Herb Adams VSE, Dept. KC,23865 Fairfield Place, Carmel, CA 93923 408/649-8423) is tuned to be used in conjunction with a one inch front stabilizer bar. Do not use a rear bar without the front; doing so will result in oversteer, which can be dangerous.

Using a larger front bar improves the steering precision, allowing removal of the stock steering dampener. The Fiero dampener reduces steering wheel kickback and vibration, but with a more effective front stabilizer bar, these problems are minimized so it is no longer needed. Removing the steering dampener also allows the steering wheel to turn faster for improved handling and overall control.


SPRINGS, SHOCKS AND OTHER STUFF

Spring rates on stock Fieros are correct for most purposes, but the problem is that most of these cars are too high off the ground. The best way to lower either the front or the rear is to cut the existing springs. By cutting half a coil off a spring and reforming the ends, you can lower your Fiero about one inch. Lowering the car reduces the available ride travel, but for most driving conditions, there is no loss of ride quality. With Koni adjustable shocks and struts, you can tune the ride quality in relation to to improved handling.

The brakes on an '88 Fiero are extremely good even on the racetrack. Unfortunately, it's not an easy conversion to mount the '88 brakes onto an '84-'87 Fiero. This means you will have to suffer with the barely effective brakes now on your car. I have tried many things to improve the stock brakes, but there doesn't seem to be an easy solution. Semi-metallic pads offer some advantage for a limited fix. **

As for chassis reinforcements, the basic Fiero structure is heavy and pretty stiff. I didn't notice any structural improvement after installing a rollcage for racing purposes, so I don't recommend this modification for street use.


GETTING A LINE ON ALIGNMENT

The camber adjustment on the front of a Fiero is accomplished by rotating the upper ball joints from front to the back. The ball joint is offset between the mounting bolts so you have your choice of two positions. For the best handling, you want the position that gives the most negative camber. Usually this isn't much, so you'll need to move the holes to get more. I don't recommend more then one degree of negative camber for street use.

For more caster, move the spacers between the upper control arm and the frame bracket, positioning the upper arm as far back in the car as possible. You only need one degree of positive caster to have good handling and you can usually obtain this by moving the spacers on the Fiero.

As for toe-in, it should be 1/16-inch at the front to provide good control and stability under braking. Rear toe-in is set by turning the rear tie rods. It's important to have between 1/16-inch and 1/8-inch toe-in at each rear wheel. Measure each rear wheel in relation to the rocker panels when determining rear toe-in. If you measure one wheel versus the other, you can end up with the proper toe-in, but the car will probably dog-track.

For setting rear camber, move the shock strut slotted hole where it connects to the rear upright. For street driving, you want at least one degree of negative camber; for racing, you need about two degrees.

NOTE: Many of the recommendations given above can be applied to any street driven Fiero, they are, however, somewhat severe for daily driving. Polyurethane instead of steel bushings would be more streetable although poly bushings can cause binding and lots of squeaks and groans from the suspension, and the 84-87 brakes can be converted to vented GA type parts. (This article did date from 1991) Remember, Herb Adams is a master of chassis engineering and following his lead will produce a far better handling Fiero, but possibly one which is less forgiving. You decide how far you want to go.
IP: Logged
jscott1
Member
Posts: 21674
From: Houston, TX , USA
Registered: Dec 2001


Feedback score:    (15)
Leave feedback





Total ratings: 415
Rate this member

Report this Post06-01-2014 01:26 PM Click Here to See the Profile for jscott1Send a Private Message to jscott1Edit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by fieroguru:

...

Just as an FYI for those who didn't take the time to see where the 88 front bump stops hit... this is with the front spring and shock removed with 205/50/16 tires (about 24" in diameter) and the wheel raised with a jack so the bump stop is making contact with the crossmember. This extra gap is additional travel that can be used to help avoid bottoming out on the bump stops - less harsh of a ride (even if you like firm springs).



You are the guru and understand this far better than me, but it would seem to me that cutting the bump stops comes with some significant level of risk, especially if you are running larger than stock wheels. My 17 inch wheels with Fiero store lowering springs have clearance issues already and my 19 inch wheels, well, they barely fit now with stock suspension. So I would say that for those of us that don't know what we are doing, leaving the bump stops alone is probably the better choice.

[This message has been edited by jscott1 (edited 06-01-2014).]

IP: Logged
PFF
System Bot
Bloozberry
Member
Posts: 7760
From:
Registered: Jan 2009


Feedback score: N/A
Leave feedback





Total ratings: 308
Rate this member

Report this Post06-01-2014 01:58 PM Click Here to See the Profile for BloozberrySend a Private Message to BloozberryEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by California Kid:
Bloozberry, I think your splitting hairs on the whole issue. Theory is one thing, actual results are another.


Herb Adams studied the handling for '84-'87 cars. He posts no "actual results" nor recommendations regarding what should or shouldn't be done to an '88 to make it handle better. To expect that the two entirely different suspension systems would improve equally by doing the same things is comparing apples to oranges. Herb Adams achieved a better handling car by making a whole series of changes including dropping the suspension, increasing roll bar stiffness, changing bushings to aluminum, adding larger wheels, changing the alignment specs, etc etc. Simply cutting a coil from the front of a different car doesn't mean that it too will handle better... in fact I'm pretty sure I've proven otherwise in my build thread. But to each his own.
IP: Logged
California Kid
Member
Posts: 9538
From: Metro Detroit Area, Michigan
Registered: Jul 2001


Feedback score: N/A
Leave feedback





Total ratings: 275
Rate this member

Report this Post06-01-2014 03:27 PM Click Here to See the Profile for California KidSend a Private Message to California KidEdit/Delete MessageReply w/QuoteDirect Link to This Post
The OP stated that he wanted to "maintain handling", not improve it. A 1 inch drop (cutting springs) with correct alignment settings is not going to detrimental to what he's trying to achieve.
IP: Logged
jscott1
Member
Posts: 21674
From: Houston, TX , USA
Registered: Dec 2001


Feedback score:    (15)
Leave feedback





Total ratings: 415
Rate this member

Report this Post06-01-2014 03:51 PM Click Here to See the Profile for jscott1Send a Private Message to jscott1Edit/Delete MessageReply w/QuoteDirect Link to This Post
I might want to add that stock 88 springs are getting to be quite rare. I would rather see him not cut stock 88 springs. When I bought my Fiero store 88 front springs I had several offers to buy my stock 88 and sold them easily. That was 10 years ago. I imagine stock 88 fronts are even harder to find now.
IP: Logged
Bloozberry
Member
Posts: 7760
From:
Registered: Jan 2009


Feedback score: N/A
Leave feedback





Total ratings: 308
Rate this member

Report this Post06-01-2014 04:47 PM Click Here to See the Profile for BloozberrySend a Private Message to BloozberryEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by California Kid:
The OP stated that he wanted to "maintain handling", not improve it. A 1 inch drop (cutting springs) with correct alignment settings is not going to detrimental to what he's trying to achieve.


I'm not arguing what the OP wanted, I'm countering your statement that cutting the front springs will improve handling. It will not, no matter what alignment settings he uses.

(Edit for spelling.)

[This message has been edited by Bloozberry (edited 06-01-2014).]

IP: Logged
Patrick
Member
Posts: 30937
From: Vancouver, British Columbia, Canada
Registered: Apr 99


Feedback score: (1)
Leave feedback





Total ratings: 445
Rate this member

Report this Post06-01-2014 05:05 PM Click Here to See the Profile for PatrickClick Here to Email PatrickSend a Private Message to PatrickEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by jscott1:

...it would seem to me that cutting the bump stops comes with some significant level of risk... So I would say that for those of us that don't know what we are doing, leaving the bump stops alone is probably the better choice.


I've read Fieroguru's posts on this subject previously, and they've been a great help in dealing with the suspension on my '88. It stands to reason that if shorter springs are used to lower a car, then the factory bump stops may need to be modified in order to maintain sufficient suspension travel.

Prior to installing my lowering springs last week, I removed the factory springs in the front, and then reassembled the front end with NO springs (or shocks) so I could see exactly how much clearance at full compression my 225/50/16 tires on 16x7 38mm offset wheels had with the rest of the car. It also allowed me to measure how far the shocks would need to be compressed.

I could probably get away with taking a little bit more than 3/4" off the rubber bump stops (and it's so easy to do with the '88 setup), but I left it at that as I didn't want to create possible issues with the KYB shocks being compressed to the end of their travel. (Yes, I've added the half inch spacers at the bottom as recommended by Fieroguru.)

The test was to see if I could feel the front end bottoming out any at autocross yesterday. I'm pleased to say... no bottoming out, and no tire clearance issues. The car handled great.

[This message has been edited by Patrick (edited 06-01-2014).]

IP: Logged
jscott1
Member
Posts: 21674
From: Houston, TX , USA
Registered: Dec 2001


Feedback score:    (15)
Leave feedback





Total ratings: 415
Rate this member

Report this Post06-01-2014 05:38 PM Click Here to See the Profile for jscott1Send a Private Message to jscott1Edit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Patrick:

I've read Fieroguru's posts on this subject previously, and they've been a great help in dealing with the suspension on my '88. It stands to reason that if shorter springs are used to lower a car, then the factory bump stops may need to be modified in order to maintain sufficient suspension travel.

Prior to installing my lowering springs last week, I removed the factory springs in the front, and then reassembled the front end with NO springs (or shocks) so I could see exactly how much clearance at full compression my 225/50/16 tires on 16x7 38mm offset wheels had with the rest of the car. It also allowed me to measure how far the shocks would need to be compressed.

I could probably get away with taking a little bit more than 3/4" off the rubber bump stops (and it's so easy to do with the '88 setup), but I left it at that as I didn't want to create possible issues with the KYB shocks being compressed to the end of their travel. (Yes, I've added the half inch spacers at the bottom as recommended by Fieroguru.)

The test was to see if I could feel the front end bottoming out any at autocross yesterday. I'm pleased to say... no bottoming out, and no tire clearance issues. The car handled great.



I couldn't make heads or tails of the photo showing the half inch spacers at the bottom of the shocks. Is there a photo taken further away so I can get my bearings of what I'm looking at? Like I said I don't know a fraction as much about suspension so I need a little guidance.... nevermind I just figured it out. If I ever get my 17" wheels fixed I will do the bump stop mod... (maybe) depending on clearance issues with my wheels. Something under there is already shaving my tires as it is.

[This message has been edited by jscott1 (edited 06-01-2014).]

IP: Logged
fieroguru
Member
Posts: 11356
From: Champaign, IL
Registered: Aug 2003


Feedback score:    (45)
Leave feedback





Total ratings: 255
Rate this member

Report this Post06-01-2014 05:38 PM Click Here to See the Profile for fieroguruSend a Private Message to fieroguruEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by jscott1:

but it would seem to me that cutting the bump stops comes with some significant level of risk, especially if you are running larger than stock wheels.



Your concern isn't really isolated to trimming bump stops, but anytime you run larger diameter tires, you should check tire to fender clearance under full compression.

Lowering ball joints and dropped spindles also allow the wheel/tire to go closer to the fender than stock, just like trimming the stock bump stops...

While the pictures show my fingers between the wheel and fender, I didn't specifically mention that is my recommended clearance in this thread. So as you trim the bump stops, trim them to leave a finger width between the two. If you cut too much, just put a washer under the bump stop to raise it back up.
IP: Logged
jscott1
Member
Posts: 21674
From: Houston, TX , USA
Registered: Dec 2001


Feedback score:    (15)
Leave feedback





Total ratings: 415
Rate this member

Report this Post06-01-2014 05:43 PM Click Here to See the Profile for jscott1Send a Private Message to jscott1Edit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by fieroguru:


Your concern isn't really isolated to trimming bump stops, but anytime you run larger diameter tires, you should check tire to fender clearance under full compression...


Good point, I didn't do this, I should. Got away with it for 10 years, but when I took my wheels off I was shocked to see something was shaving my tires. Could have been catastrophic if I didn't catch it in time.
IP: Logged
tshark
Member
Posts: 4374
From:
Registered: Feb 2014


Feedback score:    (6)
Leave feedback





Total ratings: 64
Rate this member

Report this Post06-01-2014 06:44 PM Click Here to See the Profile for tsharkSend a Private Message to tsharkEdit/Delete MessageReply w/QuoteDirect Link to This Post
....

[This message has been edited by tshark (edited 09-07-2018).]

IP: Logged
Patrick
Member
Posts: 30937
From: Vancouver, British Columbia, Canada
Registered: Apr 99


Feedback score: (1)
Leave feedback





Total ratings: 445
Rate this member

Report this Post06-01-2014 07:47 PM Click Here to See the Profile for PatrickClick Here to Email PatrickSend a Private Message to PatrickEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by tshark:

Sounds as if the lowering springs aren't that great, either.


Not sure why you're drawing that conclusion, but unless you race your Fiero for a living and you need the best with no regards to the cost, lowering springs are just fine if you wish to drop the car a bit.
IP: Logged
PFF
System Bot
Bloozberry
Member
Posts: 7760
From:
Registered: Jan 2009


Feedback score: N/A
Leave feedback





Total ratings: 308
Rate this member

Report this Post06-01-2014 10:14 PM Click Here to See the Profile for BloozberrySend a Private Message to BloozberryEdit/Delete MessageReply w/QuoteDirect Link to This Post
As I alluded to earlier, the effect of using 1" drop springs on handling isn't going to be significant unless you're competitive.

Nevertheless, if you want to use drop spindles they are a simple bolt on part. You have to pop the upper and lower ball joints, as well as the tie rod end from the stock knuckle, then reverse the procedure to install the new drop spindle. If you buy the Arraut Motorsports drop spindle, it comes with a new bearing assembly that is similar to the bearings in the rear of the car except that both halves have been bolted together. This is handy because you get away from '88 front bearings which are nearly extinct and very pricey. Once the new knuckle is installed, slip on your new C4 rotor, Fiero caliper, and bolt on the wheel. That's it except for an alignment, of course. No need to modify the bump stops since they are exactly the same distance away from the frame as stock.

As Fieroguru mentioned earlier though, there is a limit to how low you can go even with drop spindles. Here is a drawing of the stock '88 front end for reference:



Everything is to scale except the inner profile of the wheel since I didn't have a stock wheel to measure. The effect of a drop spindle is that everything including the control arms stay exactly where they are except that the wheel bearing, rotor, and wheel are moved higher up on the knuckle. The higher up these components are raised though, the closer the lower control arm gets to the rim (red arrow), so there is a static limit to how much of a drop you can have using stock wheels. There's also a dynamic limit as well. With too large a drop on the spindles (or too much cut off springs) the underside of the upper frame rail can become a concern because the tire can rub against it when your suspension is fully compressed (green arrow). This usually isn't a problem unless running larger diameter tires in combination with drop spindles (or springs).

All this to say that if you buy drop spindles and intend to use the C4 rotors and stay with 15" wheels, I believe you will be OK with a 1" drop. If you go to a 2" drop spindle, you'll probably end up with your lower control arms interfering with the rim.

[This message has been edited by Bloozberry (edited 06-01-2014).]

IP: Logged
tshark
Member
Posts: 4374
From:
Registered: Feb 2014


Feedback score:    (6)
Leave feedback





Total ratings: 64
Rate this member

Report this Post06-01-2014 10:29 PM Click Here to See the Profile for tsharkSend a Private Message to tsharkEdit/Delete MessageReply w/QuoteDirect Link to This Post
..

[This message has been edited by tshark (edited 09-07-2018).]

IP: Logged
jscott1
Member
Posts: 21674
From: Houston, TX , USA
Registered: Dec 2001


Feedback score:    (15)
Leave feedback





Total ratings: 415
Rate this member

Report this Post06-01-2014 10:35 PM Click Here to See the Profile for jscott1Send a Private Message to jscott1Edit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Bloozberry:

Here is a drawing of the stock '88 front end for reference:



Everything is to scale except the inner profile of the wheel since I didn't have a stock wheel to measure.




Sweet looking model.. I love it. Do you have one with full compression? I'm curious to figure out what's shaving my tire, the LCA is the prime suspect.
IP: Logged
Bloozberry
Member
Posts: 7760
From:
Registered: Jan 2009


Feedback score: N/A
Leave feedback





Total ratings: 308
Rate this member

Report this Post06-02-2014 06:53 AM Click Here to See the Profile for BloozberrySend a Private Message to BloozberryEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by tshark:
So, if I stick with the ball joints, I need the longer end links, and to trim my bump stops. And an alignment. If I go with the lowering springs, I just replace the springs with cut springs? Oh, and the alignment and bump stops.
Did I miss anything?


That's it.

 
quote
Originally posted by jscott1:
Do you have one with full compression? I'm curious to figure out what's shaving my tire, the LCA is the prime suspect.


I haven't drawn one for the stock suspension and in all honesty it would take you a lot less time to remove a wheel and do a close inspection. Where is the tire being affected? If it's the sidewall, how far between the bead and the tread? If it's the tread, how far is it from the centerline of the tire? What width tires, rims and what offset are you using?

IP: Logged
Fiero Vampire
Member
Posts: 366
From: Phoenix, AZ, USA
Registered: Nov 2013


Feedback score: (2)
Leave feedback

Rate this member

Report this Post06-02-2014 07:03 AM Click Here to See the Profile for Fiero VampireSend a Private Message to Fiero VampireEdit/Delete MessageReply w/QuoteDirect Link to This Post
Not to argue about which method is better it’s always a personal choice, but I personally went with drop spindles from AMS, I just recently purchased a set and would highly recommend them for multiple reasons, 1.) You get to retain the stock geometry of the 88 suspension. 2.) Improved wheel bearing instead of the weaker stock 88 bearing. 3.) You can have the spindles setup for the C12 Brake rotors for no additional charge. 4.) No need to modify your bump stops. 5.) No need to cut springs or buy lowering springs. 6.) No need to buy lowering ball joints. 7.) Every article I've ever read has pretty much stated that the best way to lower a vehicle is with drop spindles although costly, to be honest when you add up the things you don’t have to buy and future cost savings of using the 84-87 wheel bearings I really don’t think they’re really all that expensive, just my opinion anyways. I guess you can always sale your unused wheel bearings and old spindles to help offset the cost.
IP: Logged
LZeitgeist
Member
Posts: 5662
From: Raleigh, NC, U.S.A.
Registered: Dec 2000


Feedback score:    (8)
Leave feedback





Total ratings: 126
Rate this member

Report this Post06-02-2014 10:01 AM Click Here to See the Profile for LZeitgeistClick Here to Email LZeitgeistSend a Private Message to LZeitgeistEdit/Delete MessageReply w/QuoteDirect Link to This Post
wrong thread

[This message has been edited by LZeitgeist (edited 06-02-2014).]

IP: Logged
Steven Snyder
Member
Posts: 3313
From: Los Angeles, CA
Registered: Mar 2004


Feedback score: (2)
Leave feedback





Total ratings: 106
Rate this member

Report this Post06-02-2014 02:47 PM Click Here to See the Profile for Steven SnyderClick Here to visit Steven Snyder's HomePageClick Here to Email Steven SnyderSend a Private Message to Steven SnyderEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by jscott1:

I might want to add that stock 88 springs are getting to be quite rare. I would rather see him not cut stock 88 springs. When I bought my Fiero store 88 front springs I had several offers to buy my stock 88 and sold them easily. That was 10 years ago. I imagine stock 88 fronts are even harder to find now.


Considering how cheap custom springs are these days (something like $100 a pair or less from Blue Coil if I remember correctly), I don't think this is a big deal. If the world runs out of the supply of stock height 88 springs just order some custom ones with the same specs as stock.
IP: Logged
carbon
Member
Posts: 4767
From: Eagan, MN
Registered: Apr 2004


Feedback score: (2)
Leave feedback





Total ratings: 133
Rate this member

Report this Post06-02-2014 04:11 PM Click Here to See the Profile for carbonSend a Private Message to carbonEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by tshark:

I have a brand new set of '88 front wheel bearings. Don't want to waste them. Hmmm. Don't want to damage my stock springs, either. The front just doesn't look right.

So, if I stick with the ball joints, I need the longer end links, and to trim my bump stops. And an alignment. If I go with the lowering springs, I just replace the springs with cut springs? Oh, and the alignment and bump stops.

Did I miss anything?


Longer end links? Yes. However, you don't need to mess with the bump stops for lowering ball joints... The bump stops only come into play if you change the range of motion of the lower control arm, ball joints do not do this.
IP: Logged
tshark
Member
Posts: 4374
From:
Registered: Feb 2014


Feedback score:    (6)
Leave feedback





Total ratings: 64
Rate this member

Report this Post06-02-2014 04:42 PM Click Here to See the Profile for tsharkSend a Private Message to tsharkEdit/Delete MessageReply w/QuoteDirect Link to This Post
...

[This message has been edited by tshark (edited 09-07-2018).]

IP: Logged
Fiero Vampire
Member
Posts: 366
From: Phoenix, AZ, USA
Registered: Nov 2013


Feedback score: (2)
Leave feedback

Rate this member

Report this Post06-02-2014 07:36 PM Click Here to See the Profile for Fiero VampireSend a Private Message to Fiero VampireEdit/Delete MessageReply w/QuoteDirect Link to This Post
You wouldn't have to remove the wheel bearings they are inside the spindles and the drop spindles already have them installed.
IP: Logged
PFF
System Bot
tshark
Member
Posts: 4374
From:
Registered: Feb 2014


Feedback score:    (6)
Leave feedback





Total ratings: 64
Rate this member

Report this Post06-02-2014 07:43 PM Click Here to See the Profile for tsharkSend a Private Message to tsharkEdit/Delete MessageReply w/QuoteDirect Link to This Post
...

[This message has been edited by tshark (edited 09-07-2018).]

IP: Logged
Bloozberry
Member
Posts: 7760
From:
Registered: Jan 2009


Feedback score: N/A
Leave feedback





Total ratings: 308
Rate this member

Report this Post06-02-2014 09:41 PM Click Here to See the Profile for BloozberrySend a Private Message to BloozberryEdit/Delete MessageReply w/QuoteDirect Link to This Post
All you would need is just the spindles:



And a set of rear wheel bearing assemblies that have been modified with a large bolt through them (modified on the left, stock on the right):



When assembled, they look like this:



So as mentioned before, you'll have to remove the stock rotors and calipers, pop the two ball joints and the steering tie rod off of the stock knuckle, then reassemble in reverse order with the new knuckle. That's it.
IP: Logged
jscott1
Member
Posts: 21674
From: Houston, TX , USA
Registered: Dec 2001


Feedback score:    (15)
Leave feedback





Total ratings: 415
Rate this member

Report this Post06-02-2014 10:51 PM Click Here to See the Profile for jscott1Send a Private Message to jscott1Edit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Bloozberry:


I haven't drawn one for the stock suspension and in all honesty it would take you a lot less time to remove a wheel and do a close inspection. Where is the tire being affected? If it's the sidewall, how far between the bead and the tread? If it's the tread, how far is it from the centerline of the tire? What width tires, rims and what offset are you using?


PM sent.
IP: Logged
Fiero Vampire
Member
Posts: 366
From: Phoenix, AZ, USA
Registered: Nov 2013


Feedback score: (2)
Leave feedback

Rate this member

Report this Post06-02-2014 11:20 PM Click Here to See the Profile for Fiero VampireSend a Private Message to Fiero VampireEdit/Delete MessageReply w/QuoteDirect Link to This Post
The Drop Spindles I purchased from AMS are a complete assembled unit with the spindle & rear wheel bearing assembly complete.
IP: Logged
Patrick
Member
Posts: 30937
From: Vancouver, British Columbia, Canada
Registered: Apr 99


Feedback score: (1)
Leave feedback





Total ratings: 445
Rate this member

Report this Post06-03-2014 12:46 AM Click Here to See the Profile for PatrickClick Here to Email PatrickSend a Private Message to PatrickEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Fiero Vampire:

The Drop Spindles I purchased from AMS are a complete assembled unit with the spindle & rear wheel bearing assembly complete.


So... I'm curious now. What would a pair of those set you back?
IP: Logged
fieroguru
Member
Posts: 11356
From: Champaign, IL
Registered: Aug 2003


Feedback score:    (45)
Leave feedback





Total ratings: 255
Rate this member

Report this Post06-03-2014 06:22 AM Click Here to See the Profile for fieroguruSend a Private Message to fieroguruEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Patrick:

So... I'm curious now. What would a pair of those set you back?


http://www.arrautmotorsports.com/parts/suspensions

$550 + shipping.
IP: Logged
Patrick
Member
Posts: 30937
From: Vancouver, British Columbia, Canada
Registered: Apr 99


Feedback score: (1)
Leave feedback





Total ratings: 445
Rate this member

Report this Post06-03-2014 11:26 AM Click Here to See the Profile for PatrickClick Here to Email PatrickSend a Private Message to PatrickEdit/Delete MessageReply w/QuoteDirect Link to This Post

Thanks for the link. Lots of goodies there to dream about using someday.
IP: Logged
Rickady88GT
Member
Posts: 9615
From: Central CA
Registered: Dec 2002


Feedback score: N/A
Leave feedback





Total ratings: 196
Rate this member

Report this Post06-03-2014 12:48 PM Click Here to See the Profile for Rickady88GTClick Here to Email Rickady88GTSend a Private Message to Rickady88GTEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by jscott1:


You are the guru and understand this far better than me, but it would seem to me that cutting the bump stops comes with some significant level of risk, especially if you are running larger than stock wheels. My 17 inch wheels with Fiero store lowering springs have clearance issues already and my 19 inch wheels, well, they barely fit now with stock suspension. So I would say that for those of us that don't know what we are doing, leaving the bump stops alone is probably the better choice.



I am not trying to take up issue with either of you, so I will just say that each car may have a different set of "mods" or parts to work with. So each may very and a one size fits all is hard to do. I have the pre-88 GT cut springs in my 88, and have cut the bump stops. BUT I cut mine differently than has been pictured. Mine do not have a "flat spot" or such a blunt top as shown. I cut the bump stops so they still have a "point" on them. The shape of the bump stop "pointed top" is to help absorb the impact better than a blunt top. I am no saying this is the only way to do it, but cutting the bump stops with a more "stock' shape and not such a flat top may help reduce the harshness of a unforgiving bump stops?
Also seems like the lower ball joints would be some what over stressed if it is constantly hitting the uncut bump stops?

[This message has been edited by Rickady88GT (edited 06-03-2014).]

IP: Logged
Fierofreak00
Member
Posts: 4218
From: Martville, NY USA
Registered: Jun 2001


Feedback score:    (20)
Leave feedback





Total ratings: 170
Rate this member

Report this Post06-03-2014 01:17 PM Click Here to See the Profile for Fierofreak00Click Here to Email Fierofreak00Send a Private Message to Fierofreak00Edit/Delete MessageReply w/QuoteDirect Link to This Post
]
IP: Logged
Previous Page | Next Page

This topic is 2 pages long:  1   2 
next newest topic | next oldest topic

All times are ET (US)

Post New Topic  Post A Reply
Hop to:

Contact Us | Back To Main Page

Advertizing on PFF | Fiero Parts Vendors
PFF Merchandise | Fiero Gallery | Ogre's Cave
Real-Time Chat | Fiero Related Auctions on eBay



Copyright (c) 1999, C. Pennock