Also, a note about front coil overs. You can do it, but there's a problem. On the front, the spring is contained by the A-Arms. With a coil-over setup, the spring is contained by the shock/spring setup. That means the shock absorber mount now has all of the stress of both the shock AND the spring - with all the weight of the car being suppoted on the shock mount.
The Fiero control arms were designed for the loads to be distributed this way. According to Held Motorsports, the front control arms are too weak to be used with coil-overs, and I tend to agree. If you want to do front coil-overs, you need to use tubular control arms designed for coil-overs.
[This message has been edited by Formula88 (edited 10-06-2005).]
What is the difference if one has a 7-8" spring on the perch or a 12" without the perch if the spring rate is the same?
I can see that maybe the longer one allows the rear of the car to lift more on a bump, but it will compress down to the same amount, correct?
I have 7" 300# Eibachs on mine, and I am going to sell them. A little hard with my huge rear sway bar. I am looking at a 225#, and may cut the perch and go with longer replacements.
How low does the 12" allow? I might need to go to a 10" since my car is pretty low:
Does the longer spring compress less with the same weight, since the weight is divided among more coils? The distance between coils is the same with long and short springs, correct?
Either way, I am selling my 300# Eibachs. Too stiff with the rest of my suspension mods. They only have about 200 miles on them.
Does the longer spring compress less with the same weight, since the weight is divided among more coils? The distance between coils is the same with long and short springs, correct?
Either way, I am selling my 300# Eibachs. Too stiff with the rest of my suspension mods. They only have about 200 miles on them.
Shows how they look before installation. I fabricated a boot also, to keep the struts clean.
spring rate is measured by the weight it takes to compress a specified distance - with two coils of the same spring rate but different length - one can take more compression before coil bind than the other, its a problem people were running into withthe really short springs and why they upgraded to 10 or 12 " coils... with the same spring rate the ride height is determined by the position of the spring perch
I am going to have to measure when I get home, to see if I need a 10 or 12". My car is very low, and I do not know if the 12's will allow this ride height.
with the 12"s and the right length threaded sleeve - the sleeve sits all the way down by the knuckle - the stock spring perch has to be completely removed.
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01:25 PM
Dec 6th, 2005
fierohoho Member
Posts: 3494 From: Corner of No and Where Registered: Apr 2001
Originally posted by northeastfiero: Do you think a 400lb spring would be too stiff for a car with a 3800sc and a 4t65hd in it
I think "too stiff" is one of those "butt of the beholder" things. I have 400lb's in the back of mine. It's decidedly firm. Too stiff? Well... sometimes I think so... sometimes it's nice.
I'm thinking of going to something softer though.
Oh - V6, turbo, 5spd. So not so heavy. Yet a bit more than stock.
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07:48 PM
Jan 17th, 2006
GSXRBOBBY Member
Posts: 3122 From: Southern Indiana USA Registered: Aug 2003
Most guys are using 300lbs. springs and a few are using 350lbs. its all in how you want the car to feel, a "solid sports car feel" go with 350 or a smooth ride go with 300lbs.
I think "too stiff" is one of those "butt of the beholder" things. I have 400lb's in the back of mine. It's decidedly firm. Too stiff? Well... sometimes I think so... sometimes it's nice.
I'm thinking of going to something softer though.
Oh - V6, turbo, 5spd. So not so heavy. Yet a bit more than stock.
Too stiff can also be determined by the dampening characteristics of your struts.
------------------ My Web page | The Turbo Super Duty Build. You know that little voice that says it can't be done? I duct-taped mine's mouth shut and pushed it down a flight of stairs.
I dont know much about this stuff but im interested in doing this. I have a 87 gt auto that i would also like to get the rear bumpsteer correction kit from held motorsports. Would these two mods be compatable which each other?
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01:35 PM
Mar 9th, 2006
fierohoho Member
Posts: 3494 From: Corner of No and Where Registered: Apr 2001
I dont know much about this stuff but im interested in doing this. I have a 87 gt auto that i would also like to get the rear bumpsteer correction kit from held motorsports. Would these two mods be compatable which each other?
Can you post a link to the Bumpsteer kit so I could look at it to see if it's compatable?
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06:26 AM
Mar 25th, 2006
Matts85GT Member
Posts: 69 From: Gardners, PA USA Registered: Mar 2006
I have koni struts that came on the car. I ground away the spring perch and installed HELD coilover treaded collor and strut relocation addapter. The addapter is necesarry because I have an 88 cradle on my 86. My Springs are 12 inch 2.5 ID GroundControl Eibach 325 Lbs. The Coilovers is adjusted to a slightly lowered height from stock. I want to lower it further but I already have ran out of travel as it is . Driving overv a medium sized bump the top of the strutbody smacks into the spring retainer ring that is wended to the botom of the strut relocation addapters from Held Motorsport. The impact is jarring to say the least.
I wonder whether buying a new set of Koni Special (red) struts will solve the problem. Perhaps my perticular Konis are different (longer strut body) as they are older and not extrernaly adjustable as the new omes (8741-1063)
Is there anybody who has Konis that would be willing to measure the length of their Koni strut body? Maybe one of us is in the process of rebuilding has their struts off the car will take a tape measure to it hopefull . Please also mention if they can be adjusted while on the car and how old they are. Thanks in advance!
Also is anybody with konis struts and held addapters finding that the koni strut body is wider at the top causing it to not fit inside the upper spring perch of the held adapters. How is your ride?
Last but not least, I was looking at the koni .pdf files you can download from their site and noticed they offer a "Cut Your strut" cartrages they offer. You are supposed to hacksaw your old strut body to the desired length and drill a hole in the bottom of the strut. Then you incert the Koni cartrage and secure with a ring and nut at the bottom of your old strut. You can buy the cartages with the stroke and damping range you specify. You can even have bump adjustment aswel as the more standard rebound adjustment. Has anybody done this or heard of anybody that has?
Thanks Iwan
edited to add: that I posted this message as a new topic after I typed here, hopefully it will be noticed easier than when part of this 6 pager
[This message has been edited by fiero-iwan (edited 04-30-2006).]
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06:37 PM
PFF
System Bot
May 23rd, 2006
slade1274 Member
Posts: 339 From: Monroe, GA, USA Registered: Mar 2006
So, What are you guys using to ballance out the ride height in the front? I assume most of you will lower the rears a bit with the coil overs, but all the searching I did found only full sets of four lowering springs.... can you just by the fronts anywhere?
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04:12 PM
May 24th, 2006
fierohoho Member
Posts: 3494 From: Corner of No and Where Registered: Apr 2001
Now I've seen everything from 175 to 400 lb/in springs for the rear. Let me post this as a question. I drive my 88 GT alot around town, and on short trips up to 2 hours on the highway because like all of us, I love driving my fun little car. I do not race or take it to the drag strip, although I'd like to take it on a course some day. It has the stock 2.8 V6. What spring rate do yall suggest for coilover springs put over KYB struts?
As a second question, what spring rate would I want if I swapped the engine with the 3800 SC all else remaining equal?
Thanks in advance for the input, and +'s for good advice.
I'm considering this for my 88GT. Can someone please recommend a suggested spring rate for the 88GT rear?
Thanks.
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03:08 PM
fiero-iwan Member
Posts: 352 From: Eindhoven,Netherlands,Europe Registered: Mar 2003
I have 325Lbs 12inch springs from groundcontrol. I chose these a little stiff for my upcomming L67 Swap. Stiff ride with the 2.8 but not too stiff in my oppinion. That is untill my shocks bottom out, Jarring to say the least, but that is due to having the wrong shocks for the car. Al the springperch cutting for nothing,
oh well.... Anybody out there who has new Koni struts for their car willing to measure the strutbody length for me? The strutbody I have now is 35cm long which leaves about 1 inch of travel before bottoming , on my lowered fiero. I really need to make sure new koni's are short enough! Asking info on the koni's via a koni dealer but the communication is SLOOOOW...
Thanks Iwan
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03:22 PM
Jun 29th, 2006
fiero_silva Member
Posts: 1493 From: Winnipeg, Manitoba, Canada Registered: Jun 2003
OK, so nobody was able to tel me the length of the koni strut body. Not even my dealer who supplies konis was able to get me a measurement. I finally bit the bullit and ordered a new set of koni red struts. They measured 33,5 cm in length. 1,5cm shorter than my old konis. Hopefully this wil be enough extra travel. Pitty though the konis do not come supplied with bump rubbers.....
Maybe this will be of some use to somebody else wondering about the same thing...
Iwan
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10:15 AM
SLOWnSTEADY Member
Posts: 1706 From: Hiawatha, IA Registered: Jul 2005
Would installing aftermarket springs in the front work for evening the height compared to the back, or could you install coilovers in the front without having to buy tubular control arms?
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02:42 AM
PFF
System Bot
fiero_silva Member
Posts: 1493 From: Winnipeg, Manitoba, Canada Registered: Jun 2003
Would installing aftermarket springs in the front work for evening the height compared to the back, or could you install coilovers in the front without having to buy tubular control arms?
You can't do coil overs in the front without tubular control arms or some serious modifications. All the front requires to lower it though is shorter springs, and/or drop spindles.
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10:12 AM
RCR Member
Posts: 4410 From: Shelby Twp Mi Registered: Sep 2002
SLOWnSTEADY: How did these work out for you? I had emailed the guy several times, but I didn't like the answers I was getting back so I stayed away from them.
Bob
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12:38 PM
Custom84cp Member
Posts: 295 From: Dallas, TX, USA Registered: May 2000
SLOWnSTEADY: How did these work out for you? I had emailed the guy several times, but I didn't like the answers I was getting back so I stayed away from them.
Bob
Same here, I did not like there answers either, I asked for pic's to get a better idea of what they had and got no reply. i'll spend my $ somewhere else. Thanks.. Steve
from what i gathered reading over this thread twice is that the best set-up seems to be 2.04 diameter 7 inch sleeves with a 2 5/8 diameter 12 inch spring. Is this correct? After reviewing some websites for parts i cant seem to find one that sells just the sleeves and the part the spring actually sits on, they all seem to have the full kit with the hat and everything for $50+.
------------------ Fiero- mild 2.9 160hp Caprice- wild 383 500hp --Adam-- ASE Certified Technician IM AOL: FieroGT5speed
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10:01 PM
TG oreiF 8891 Member
Posts: 776 From: Cleveland, Ohio; USA Registered: Aug 2004
from what i gathered reading over this thread twice is that the best set-up seems to be 2.04 diameter 7 inch sleeves with a 2 5/8 diameter 12 inch spring. Is this correct? After reviewing some websites for parts i cant seem to find one that sells just the sleeves and the part the spring actually sits on, they all seem to have the full kit with the hat and everything for $50+.
A1 Racing (www.a1racing.com) will sell you several different diameters and lengths of sleeves. All but the perches marked for corvettes come with plastic tipped set screws to keep the perches in place (don't ask how I know ) and the guy on the phone was very helpful. I got the 2.08 inch diameter sleeves hoping that it would be easier to get over Koni's if / when I buy them some day - but I really don't think it will. For now, they slipped right over my KYB struts and I used some rubber orings to take up the slack - we'll see how it works.
) and the guy on the phone was very helpful. I got the 2.08 inch diameter sleeves hoping that it would be easier to get over Koni's if / when I buy them some day - but I really don't think it will. For now, they slipped right over my KYB struts and I used some rubber orings to take up the slack - we'll see how it works. 
