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Rear struts by ericjon262
Started on: 01-01-2015 08:33 PM
Replies: 26 (944 views)
Last post by: Will on 01-12-2015 01:34 PM
ericjon262
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Report this Post01-01-2015 08:33 PM Click Here to See the Profile for ericjon262Send a Private Message to ericjon262Edit/Delete MessageReply w/QuoteDirect Link to This Post
ok, so there's been lots of discussion on struts both here, and on RFT, and I've never seen anyone try using a strut meant for another vehicle except in crazy custom applications. I'm no expert, but it seems to me like many struts could be adapted to the Fiero, the design isn't that crazy. why isn't this avenue more explored? the bolt pattern of the towers seem like a non-issue to me. it's just sheet metal, not hard to drill a new one, for a different hat. the spring perch isn't a big deal either, we cut those off to make coil overs. only thing I can see that would even be close to a big deal would be the lower mount to the knuckle.

am I crazy or missing something?
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Bloozberry
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Report this Post01-01-2015 08:56 PM Click Here to See the Profile for BloozberrySend a Private Message to BloozberryEdit/Delete MessageReply w/QuoteDirect Link to This Post
That depends... what feature are you looking for in an alternate strut that the current ones designed specifically for the Fiero don't have?
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ericjon262
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Report this Post01-01-2015 10:52 PM Click Here to See the Profile for ericjon262Send a Private Message to ericjon262Edit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Bloozberry:

That depends... what feature are you looking for in an alternate strut that the current ones designed specifically for the Fiero don't have?



there's nothing really specific at the moment, but we currently only have either stock replacement (KYB, monroe ect) or Koni, not really many options. I know KYB offers performance adjustable struts for many applications, but not the fiero, and they're significantly less expensive than Konis.
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Lou6t4gto
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Report this Post01-02-2015 05:41 PM Click Here to See the Profile for Lou6t4gtoClick Here to Email Lou6t4gtoSend a Private Message to Lou6t4gtoEdit/Delete MessageReply w/QuoteDirect Link to This Post
Wouldn't a Strut that is about 2" SHORTER than a stock Fiero strut be "better for lowering" ?? I'm in the process of assembling coil overs right now (12"/300 and 7" sleeves) and it seems to me,( maybe I'm wrong,) that as soon as you move the "Adj Color" down the sleeve to lower it, you are creating a space between the Car and the Top of the spring IF you lift the car so the STRUT is "FULLY Extended". (IF the car went a little "Airborn", wouldn't the spring move away from the upper seat ??
I'm sure a lot of people would like to know if that is true.
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qwikgta
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Report this Post01-02-2015 06:49 PM Click Here to See the Profile for qwikgtaClick Here to Email qwikgtaSend a Private Message to qwikgtaEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by ericjon262:

ok, so there's been lots of discussion on struts both here, and on RFT, and I've never seen anyone try using a strut meant for another vehicle except in crazy custom applications. I'm no expert, but it seems to me like many struts could be adapted to the Fiero, the design isn't that crazy. why isn't this avenue more explored? the bolt pattern of the towers seem like a non-issue to me. it's just sheet metal, not hard to drill a new one, for a different hat. the spring perch isn't a big deal either, we cut those off to make coil overs. only thing I can see that would even be close to a big deal would be the lower mount to the knuckle.

am I crazy or missing something?


I've asked myself this a thousand times. I always wanted to know if a set of "Air ride" struts made for the J-body would work on our cars. I can't believe that there is that much of a diff between GM struts for cars made about the same time as ours. Never had the $$$ to just toss around on this idea, so if anyone has any input, it would be great.

RJ
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hnthomps
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Report this Post01-02-2015 07:10 PM Click Here to See the Profile for hnthompsClick Here to Email hnthompsSend a Private Message to hnthompsEdit/Delete MessageReply w/QuoteDirect Link to This Post
I currently have auxiliary air adjustable shocks on the front of an 87 Mera (lowered vehicle) to get me over driveways, speed bumps, etc. without bottoming out. These are not primary shocks but serve to keep me from tearing out my exhaust and air deflectors. I had to search a bit for them but they are available with a bit of hunting and a custom mounting. Maybe a direct replacement could be found for the rears but I am currently using rear coil overs for adjustment in that area.

Nelson

[This message has been edited by hnthomps (edited 01-04-2015).]

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fieroguru
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Report this Post01-02-2015 07:27 PM Click Here to See the Profile for fieroguruSend a Private Message to fieroguruEdit/Delete MessageReply w/QuoteDirect Link to This Post
Fiero struts (12.1" collapsed, 17.7" extended):


The big thing to notice is the bottom oval bolt hole for the camber adjustment. The top mounting point for the Fiero is fixed, so the camber is adjusted between the strut and the upright via this slotted hole. Most other struts (besides the sister cars - pontiac 6000, dust buster minivans, etc) adjust camber at the top of the strut tower, so the bottom hole isn't slotted (even if it is, then bolt spacing between the two bolts comes into play). Then you get into shank length at the top of the strut, strut protrusion down into the area where the CV's are. etc...

1991 Pontiac Transport (10.4" collapsed, 17.0" extended) - this one will likely work if you just want a shorter strut, but its body diameter is 35mm vs. 2" or about 51mm.


88 Cavalier (11.3" collapsed, 17.6" extended) - also has a built in steering arm:


98 Cavalier (13.1" collapsed, 19.9" extended):


98 Chevy Venture Front (10.7" collapsed, 16.5" extended):


88 Camaro (10.6" collapsed, 17.2" extended):


88 Mustang (14.5" collapsed, 24.1" extended):


98 Mustang (14.4" collapsed, 20.7" extended):


You can spend countless hours just picking applications on Autozone's website and pulling up pictures of the parts for comparison.
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Lou6t4gto
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Report this Post01-03-2015 12:37 AM Click Here to See the Profile for Lou6t4gtoClick Here to Email Lou6t4gtoSend a Private Message to Lou6t4gtoEdit/Delete MessageReply w/QuoteDirect Link to This Post
so the Chevy Venture looks to be about the closest and a little over an Inch :Shorter" fully extended.. With Lower hole "Oval ed" ? Wonder how far apart the holes are ? And how stiff are they compared to a Stock fiero ?
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fieroguru
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Report this Post01-03-2015 07:51 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 Lou6t4gto:

so the Chevy Venture looks to be about the closest and a little over an Inch :Shorter" fully extended.. With Lower hole "Oval ed" ? Wonder how far apart the holes are ? And how stiff are they compared to a Stock fiero ?


The Pontiac Transport struts are the closest. The Chevy Venture does not have the bottom hole slotted. The next step is to go to a parts store with an old fiero strut, pull out one of the Transport ones and start measuring the critical dimensions. Not hard, just takes time, and you have to be motivated to find a solution.

This isn't an area I have any personal interests in pursuing further, so someone else will have to take it from here.
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Bloozberry
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Report this Post01-03-2015 08:54 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 Lou6t4gto:
Wouldn't a Strut that is about 2" SHORTER than a stock Fiero strut be "better for lowering" ?


The FIero's total strut travel is 17.7" - 12.1" = 5.6" so using a 2" shorter strut would reduce that to 3. 6". When setting up a suspension, the rule of thumb is to allow approximately 60% of the strut's total travel for the upward movement when the car is at ride height. That would mean you would have about 2.1" of upward travel (jounce) and 1.5" of downward travel (rebound). Compare that to a stock Fiero with 3.4" of jounce and 2.2" of rebound and you'll see that a 2" shorter strut will compromise handling since it will limit the suspension's ability to follow the road. Bear in mind that total travel will be even shorter since you need to leave about a 1/4" buffer zone to avoid bottoming out the strut and ruining it. They aren't made to act as travel limiters.

But lowering the car with stock length struts is also a problem. Lowering the rear by 2" limits your upward stock travel to about 1.4" (which I can assure you, will result in bottoming out the strut in normal driving). One way to gain some more travel is to flip the top bushing which results in about an inch more travel giving you close to 2.4" of jounce. But then you have to bear in mind that the bottom of the cradle in a stock car sits only 6" above the ground, so lowering the car 2" and flipping the top bushing will put the bottom of your cradle (and oil pan) only 1.6" above the asphalt when the suspension is fully compressed.

These are only the mechanical problems with lowering 2". It doesn't even begin to address the performance issues. The best compromise is to limit the amount you lower the car to 1" or so. If you still don't like the big fender gap, then buy larger diameter wheels to give the appearance of having been lowered.

 
quote
Originally posted by Lou6t4gto:
I'm in the process of assembling coil overs right now (12"/300 and 7" sleeves) and it seems to me,( maybe I'm wrong,) that as soon as you move the "Adj Color" down the sleeve to lower it, you are creating a space between the Car and the Top of the spring IF you lift the car so the STRUT is "FULLY Extended".


This is definitely a problem. The way to cure it is to weld a tube inside the top of the strut tower to guide and capture the top of the spring if it leaves the upper seat. The alternative is to limit the rebound travel of the suspension mechanically with stoppers so that it can't extend beyond the point where the spring is unseated.
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fieroguru
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Report this Post01-03-2015 10:27 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 Bloozberry:


This is definitely a problem. The way to cure it is to weld a tube inside the top of the strut tower to guide and capture the top of the spring if it leaves the upper seat.


Here is a picture!
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Lou6t4gto
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Report this Post01-03-2015 06:59 PM Click Here to See the Profile for Lou6t4gtoClick Here to Email Lou6t4gtoSend a Private Message to Lou6t4gtoEdit/Delete MessageReply w/QuoteDirect Link to This Post
funny that you post that now. I just finished making something like that about 1/2 hr ago. It's actually 2 1/2" exhaust pipe welded to the lower large washer that slips onto the top of the strut. the 2 1/2 inch pipe slips tightly inside if the spring and keeps it in place even if the spring tries to slip down a couple of inches when fully extended. the bump stop is Inside the 2 1/2 inch tube. I won't receive my 7" "Sleeves" until Tuesday, so final assembly has to wait. I'm only lowering the car an inch and will use 18" wheels rear and 17s front . (but that has to wait for "Funds" !
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Report this Post01-03-2015 07:14 PM Click Here to See the Profile for Lou6t4gtoClick Here to Email Lou6t4gtoSend a Private Message to Lou6t4gtoEdit/Delete MessageReply w/QuoteDirect Link to This Post
Is What you have pictured, the outer shell of a Bushing ??
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fieroguru
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Report this Post01-04-2015 07:05 AM Click Here to See the Profile for fieroguruSend a Private Message to fieroguruEdit/Delete MessageReply w/QuoteDirect Link to This Post
Its is a piece of exhaust tubing. It needs to be thin walled (16-18ga) as this tube needs to allow the strut body (and potentially the coil over sleeve) to go inside it, while the spring can go outside of it. If it isn't thin enough or properly positioned, the strut will hit this inner sleeve and limit suspension movement while making the ride very harsh.

You can also run the sleeve on the outside of the spring. Then you don't have to worry about interference with the strut body.

[This message has been edited by fieroguru (edited 01-04-2015).]

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wftb
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Report this Post01-04-2015 10:37 AM Click Here to See the Profile for wftbClick Here to Email wftbSend a Private Message to wftbEdit/Delete MessageReply w/QuoteDirect Link to This Post
Finding a good adjustable strut for the back of the fiero would be awesome , but really time consuming .My dream strut would have separate jounce and rebound adjustments and have a threaded bottom mount for height adjustment without messing up the travel .I have a similar setup at all 4 corners of a 91 civic wagon , and you can get them for just about any newer Honda made .If you could cut the mount off an old strut and figure out a way to mount a front civic strut in to it , you would have a nice setup . I gave up on the idea , and now I am making upper control arms so I can use brand new QA1 coilovers in the back .
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Report this Post01-04-2015 10:58 AM Click Here to See the Profile for wftbClick Here to Email wftbSend a Private Message to wftbEdit/Delete MessageReply w/QuoteDirect Link to This Post
Not a good pic but if you look at the bottom of this strut you can see how it is just designed to fit in to a socket The bottom stub has about 2" of useful height adjustment .Right now in the pic , it is threaded all the way in to the shock body .Fine tuning ride height is done with the spring collars . I am sure the bottom of a fiero strut could be cut off and the stub could be securely mounted somehow in to the resulting socket .Then you could use a camber adjusting plate to make a mount at the top .You can get all kinds of different spring rates and this shock has a knob that goes in the top with 36 damping settings . D2 brand showing .
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Will
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Report this Post01-04-2015 11:18 AM Click Here to See the Profile for WillClick Here to Email WillSend a Private Message to WillEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Lou6t4gto:
that as soon as you move the "Adj Color" down the sleeve to lower it, you are creating a space between the Car and the Top of the spring IF you lift the car so the STRUT is "FULLY Extended". (IF the car went a little "Airborn", wouldn't the spring move away from the upper seat ??


Alternative way to address the spring length issue: tender spring (not my car):



Also: "collar"
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GODFATHER
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Report this Post01-05-2015 03:35 PM Click Here to See the Profile for GODFATHERClick Here to Email GODFATHERSend a Private Message to GODFATHEREdit/Delete MessageReply w/QuoteDirect Link to This Post
I'm pretty sure the fiero strut is the shortest lenght one out there. I even went as far as calling monroe's tech line because the lenghts they listed and the measurement I was getting where not the same and the tech told me the measuements that where listed on line and catalog are not the right ones. I hope someone else has better luck.
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Report this Post01-07-2015 02:55 PM Click Here to See the Profile for Lou6t4gtoClick Here to Email Lou6t4gtoSend a Private Message to Lou6t4gtoEdit/Delete MessageReply w/QuoteDirect Link to This Post
Got the "Sleeves" yesterday (7") supposed to be for 2" struts. Had to hone about .050" out of them, (Mic'ed bothe struts and sleeves) before they would slip on even tight ! WHY can't anyone sell something that "Actually FITS" right out of the box ?! I got the Sleeves from Summit (took UPS 8 Days to get them from Indiana to Fla), some service! (summit shipped them immediately, UPS is terrible) struts are KYB. They are "ON" now, just have to adjust them.
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Will
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Report this Post01-07-2015 08:32 PM Click Here to See the Profile for WillClick Here to Email WillSend a Private Message to WillEdit/Delete MessageReply w/QuoteDirect Link to This Post
The tops of the Konis are swaged out a bit to allow the use of the gland nut which makes the struts rebuildable.

There are 2.17 ID sleeves on the market...
http://www.a1racing.com/cok12452-h.aspx
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MiloFiero
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Report this Post01-09-2015 02:48 PM Click Here to See the Profile for MiloFieroClick Here to Email MiloFieroSend a Private Message to MiloFieroEdit/Delete MessageReply w/QuoteDirect Link to This Post
Accidentally started a post quite similar to this one. Im really wanting to bag my car. and to save money, it would be nice to find a strut that is similar to the Fiero so when i go to buy bags i can save a couple pennies. I read some where that the mk1 Jetta was quite similar but the top hat was different. Im not too sure and really dont have the ability to measure. would love to see if that was true. VW air ride set-ups are a bit cheaper!
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Report this Post01-10-2015 12:48 PM Click Here to See the Profile for Lou6t4gtoClick Here to Email Lou6t4gtoSend a Private Message to Lou6t4gtoEdit/Delete MessageReply w/QuoteDirect Link to This Post
all installed and adjusted to height. when Jacked, up with wheels off the ground, the" spring to upper perch gap" is about 1 1/2" ! (it's got the 2 1/2" pipe holding the top centered), so it comes back down correctly, so I GUESS it should be OK. Is that "Normal" for the coil overs ?
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Report this Post01-10-2015 01:52 PM Click Here to See the Profile for wftbClick Here to Email wftbSend a Private Message to wftbEdit/Delete MessageReply w/QuoteDirect Link to This Post
That is what mine always did when jacked up .The alternative would be to use a 14" spring with a lighter rate and add a sway bar , but I always just let the car down slow and made sure they slid to place .
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Report this Post01-10-2015 04:35 PM Click Here to See the Profile for Lou6t4gtoClick Here to Email Lou6t4gtoSend a Private Message to Lou6t4gtoEdit/Delete MessageReply w/QuoteDirect Link to This Post
Already got the rear sway bar. I think you're right, I was thinking before you posted, really the only way to fill the gap is shorter Struts or longer Springs with a lot less Lb Rating (mine are 300, might have been better with 225/250) so the weight of the car will bring it down more, then the sway bar should keep thing in order.
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Will
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Report this Post01-11-2015 11:42 AM Click Here to See the Profile for WillClick Here to Email WillSend a Private Message to WillEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Lou6t4gto:

all installed and adjusted to height. when Jacked, up with wheels off the ground, the" spring to upper perch gap" is about 1 1/2" ! (it's got the 2 1/2" pipe holding the top centered), so it comes back down correctly, so I GUESS it should be OK. Is that "Normal" for the coil overs ?


Look at the photo I posted above. Note the small retention spring at the base of the main spring... Once you get the right length of spring for your jounce travel, such that the suspension hits the bump stop before the spring goes into coil bind, then deal with the spring being shorter than rebound travel via the extra retention spring that keeps the main spring engaged, but itself coil binds under the weight of the car.
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Report this Post01-12-2015 01:26 PM Click Here to See the Profile for Lou6t4gtoClick Here to Email Lou6t4gtoSend a Private Message to Lou6t4gtoEdit/Delete MessageReply w/QuoteDirect Link to This Post
thought of that, but wouldn't that compressed spring "sandwiched" under the coil just be a major source of a squeak ? maybe I'm just "Overthinking this"
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Will
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Report this Post01-12-2015 01:34 PM Click Here to See the Profile for WillClick Here to Email WillSend a Private Message to WillEdit/Delete MessageReply w/QuoteDirect Link to This Post
Never heard of that happening.

It's completely coil bound... squashed flat. The main spring doesn't squeak on the adjustable perch, does it?
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