Koni Yellows w/ Ground Control Coilovers..Tech by Ribs
09-04-2002, 10:04 PM
#1
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Koni Yellows w/ Ground Control Coilovers..Tech by Ribs
Im looking for the discussion Ribs posted on when he added the Front Ground Control Coilover kit that Paragon sells..I tried searching for it last night..I think Im an idiot because I sure couldnt find it...anyone have the link?
09-05-2002, 03:29 AM
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<a href="http://forums.rennlist.com/forums/ultimatebb.php?ubb=get_topic&f=15&t=004832" target="_blank">This might be it...</a>
Anywho, whadda ya wanna know? Here's mine:
And the online version of the included instructions: <a href="http://www.tech-session.com/Paragon/Tech/944_arhkit.htm" target="_blank">Click Here...</a>
Good Luck!
Anywho, whadda ya wanna know? Here's mine:
And the online version of the included instructions: <a href="http://www.tech-session.com/Paragon/Tech/944_arhkit.htm" target="_blank">Click Here...</a>
Good Luck!
09-05-2002, 02:08 PM
#3
Race Director
Thread Starter
Thanks skip..I was just looking to see if I could perform the koni hacksaw job and if my limited skills could pull off the ground control coilover setup while Im at it. I think I can..I think I can..
Also..is 30mm as big as you recommend going with the torsion bars utilizing the basic 951 suspension? (As I see talk of 32mm from time to time, but you only list upto 30mm)
And the 30mm torsion bars correlate with 350# springs up front correct?
TIA!
Also..is 30mm as big as you recommend going with the torsion bars utilizing the basic 951 suspension? (As I see talk of 32mm from time to time, but you only list upto 30mm)
And the 30mm torsion bars correlate with 350# springs up front correct?
TIA!
09-05-2002, 02:59 PM
#4
Race Director
Sam,
You can special order t-bars over 30mm from Paragon. They will cost about the same as the off the shelf hollow bars.
Couple of issues here.
First is how stiff do really want to go on the street? Too stiff and it will knock your teethout.
Second is the valveing for the Koni's they can only take 400-450lbs front string rates before they need to be custom valved. In order to keep a balanced car this also limits rear rates.
Skip is the really guru on this.
As for front to rear spring rate balance my calcuations are as follows
(Front is spring rate.Rear is effective wheel rate
-----------------F-----R----F/R Ratio
Stock/Stock --- 140 -- 126 -- 1.11
250/Stock ----- 250 -- 126 -- 1.98
250/28mm ----- 250 -- 254 -- 0.98
300/29mm ----- 300 -- 294 -- 1.03
350/30mm ----- 350 -- 335 -- 1.04
400/31mm ----- 400 -- 382 -- 1.05
450/32mm ----- 450 -- 434 -- 1.04
400/30mm ----- 400 -- 335 -- 1.19
From this you can roughly estimate f/r handling balance. Compared to stock you can see how just 250lbs springs would cause understeer.
Right now i am running 350/28mm bars (Ratio of 1.38) in my 2450lb track car. The balance is good, but I achieve that with adjustable sway bars. My rear sway bar is full stiff and I am running alot of neg camber up front (4 deg or so). I have 30 mm bars coming to help. This with 30's I can achieve the nice balance I had with the 250/28 setup, just touch more oversteer than stock. This will allow me to take out some rear sway bar and this will hopefully help me on corner exit traction. With no LSD suspesion settings are very important to prevent the inside wheel from spinning.
Any way my guess is the 250/28 or 300/29 is probably the most you want to use on the street even with a full interior. Unless you don't mind a very stiff ride
You can go 50lbs higher in front(F/R Balance) if you want more understeer. This is not really bad on a street car.
You can special order t-bars over 30mm from Paragon. They will cost about the same as the off the shelf hollow bars.
Couple of issues here.
First is how stiff do really want to go on the street? Too stiff and it will knock your teethout.
Second is the valveing for the Koni's they can only take 400-450lbs front string rates before they need to be custom valved. In order to keep a balanced car this also limits rear rates.
Skip is the really guru on this.
As for front to rear spring rate balance my calcuations are as follows
(Front is spring rate.Rear is effective wheel rate
-----------------F-----R----F/R Ratio
Stock/Stock --- 140 -- 126 -- 1.11
250/Stock ----- 250 -- 126 -- 1.98
250/28mm ----- 250 -- 254 -- 0.98
300/29mm ----- 300 -- 294 -- 1.03
350/30mm ----- 350 -- 335 -- 1.04
400/31mm ----- 400 -- 382 -- 1.05
450/32mm ----- 450 -- 434 -- 1.04
400/30mm ----- 400 -- 335 -- 1.19
From this you can roughly estimate f/r handling balance. Compared to stock you can see how just 250lbs springs would cause understeer.
Right now i am running 350/28mm bars (Ratio of 1.38) in my 2450lb track car. The balance is good, but I achieve that with adjustable sway bars. My rear sway bar is full stiff and I am running alot of neg camber up front (4 deg or so). I have 30 mm bars coming to help. This with 30's I can achieve the nice balance I had with the 250/28 setup, just touch more oversteer than stock. This will allow me to take out some rear sway bar and this will hopefully help me on corner exit traction. With no LSD suspesion settings are very important to prevent the inside wheel from spinning.
Any way my guess is the 250/28 or 300/29 is probably the most you want to use on the street even with a full interior. Unless you don't mind a very stiff ride
You can go 50lbs higher in front(F/R Balance) if you want more understeer. This is not really bad on a street car.
09-05-2002, 03:02 PM
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Hi Sam,
My $0.02 on the coil-over kit:
It's very streetable, in that it doesn't clunk, squeak, squeal or make any other objectionable noises when you go over bumps.
Installation's a snap, and once it's in place, there is no need for a spring compressor to change coils. On my car, with the suspension at full droop on jackstands, the top of the coil just drops out of the top perch, but it's self-aligning when you put the weight back on the wheels.
Last, the "hacksaw" inserts end up having a much more professional appearance than the name implies--struts come with a nice rubber cap that fits over the cut end of the strut tube.
Good luck!!
My $0.02 on the coil-over kit:
It's very streetable, in that it doesn't clunk, squeak, squeal or make any other objectionable noises when you go over bumps.
Installation's a snap, and once it's in place, there is no need for a spring compressor to change coils. On my car, with the suspension at full droop on jackstands, the top of the coil just drops out of the top perch, but it's self-aligning when you put the weight back on the wheels.
Last, the "hacksaw" inserts end up having a much more professional appearance than the name implies--struts come with a nice rubber cap that fits over the cut end of the strut tube.
Good luck!!
09-05-2002, 03:44 PM
#6
Race Director
Thread Starter
Thanks for the help guys..exactly what I was looking for.
Im after a really stiff street car. I only put about 5,000 miles a year on it (if that), with auto-x when poss. and some track days in the near future, I think Ill be very happy with it. Stock is just way to soft for me.
Im after a really stiff street car. I only put about 5,000 miles a year on it (if that), with auto-x when poss. and some track days in the near future, I think Ill be very happy with it. Stock is just way to soft for me.
09-05-2002, 04:50 PM
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Sam,
Yeah, the thing that skip linked to was my write up of the procedure. A few things...you can saw more off the top of the strut housing and it will still work, but less will not because the new strut insert will not seat properly...I think 56mm from the top of the strut body was where I made the final proper cut. If you plan on painting your housings, a better spraypaint than the ace-hardware-store-brand-crap that I used...fast drying is a must (my strut housings are still not dry) and quality is always good (krylon?)...any school bus yellow will be a near perfect match. 400# in the front is not too stiff at all...none of my passengers have ever compained about the stiffness of the car, and it actually absorbs potholes and railroad tracks much better than it did with the worn stock suspension (it feels like it tracks faster so there is less of a thud, but the whole car tosses a bit...a trade off I guess). I still have to do the rear torsion bars...maybe this fall sometime.
Yeah, the thing that skip linked to was my write up of the procedure. A few things...you can saw more off the top of the strut housing and it will still work, but less will not because the new strut insert will not seat properly...I think 56mm from the top of the strut body was where I made the final proper cut. If you plan on painting your housings, a better spraypaint than the ace-hardware-store-brand-crap that I used...fast drying is a must (my strut housings are still not dry) and quality is always good (krylon?)...any school bus yellow will be a near perfect match. 400# in the front is not too stiff at all...none of my passengers have ever compained about the stiffness of the car, and it actually absorbs potholes and railroad tracks much better than it did with the worn stock suspension (it feels like it tracks faster so there is less of a thud, but the whole car tosses a bit...a trade off I guess). I still have to do the rear torsion bars...maybe this fall sometime.
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09-05-2002, 05:46 PM
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We also have the procedure online at tech-seeion for the cut-n-drill strut modification:
<a href="http://www.tech-session.com/Paragon/Tech/944_koni_1414S.htm" target="_blank">Koni 8641-1414S Installation</a>
Seems you've got the info requested about rates. My generic statement is that the fronts and rears shold be near equal, with any extra headed to the front. The front spring is ~90% effective, so you have to remember that when comparing. The <a href="http://www.tech-session.com/Paragon/Info/944_tbar_rate_comparison.htm" target="_blank">Spring Rate vs. Wheel Rate Table</a> on the tech-session site explains how to get wheel rates for torsion bars, coil-overs, and combinations.
For the street/autocross setup, I would go with something a bit less than 400# in the front - maybe 300 front, 28mm rear. The 400/30 setup is a bit harsh for street use, though not unbearable IMHO.
FWIW, the relationship of wheel rate differential is not linear - as front spring rates start to exceed 400#, the rear does not need to maintain the 90-100% rule - it drops to as low as 70-75% at spring rates of 600-700#. This has been discussed before here, and should still be in the archives, but has primarily to do with weight balance and loading (you can't accelerate as fast as you can brake). Also, tire selection is key to this balance - the lower aspect ratio is usually in the rear, making it a stiffer spring (be aware of sidewall construction - Hoosier, etc)
Good Luck!
<a href="http://www.tech-session.com/Paragon/Tech/944_koni_1414S.htm" target="_blank">Koni 8641-1414S Installation</a>
Seems you've got the info requested about rates. My generic statement is that the fronts and rears shold be near equal, with any extra headed to the front. The front spring is ~90% effective, so you have to remember that when comparing. The <a href="http://www.tech-session.com/Paragon/Info/944_tbar_rate_comparison.htm" target="_blank">Spring Rate vs. Wheel Rate Table</a> on the tech-session site explains how to get wheel rates for torsion bars, coil-overs, and combinations.
For the street/autocross setup, I would go with something a bit less than 400# in the front - maybe 300 front, 28mm rear. The 400/30 setup is a bit harsh for street use, though not unbearable IMHO.
FWIW, the relationship of wheel rate differential is not linear - as front spring rates start to exceed 400#, the rear does not need to maintain the 90-100% rule - it drops to as low as 70-75% at spring rates of 600-700#. This has been discussed before here, and should still be in the archives, but has primarily to do with weight balance and loading (you can't accelerate as fast as you can brake). Also, tire selection is key to this balance - the lower aspect ratio is usually in the rear, making it a stiffer spring (be aware of sidewall construction - Hoosier, etc)
Good Luck!
09-05-2002, 07:10 PM
#9
Race Director
Thread Starter
id like to keep it as neutral as possible.
so 350#/30mm for street? also adding 968 mo30s if not at the same time, soon after...
thanks all!!
so 350#/30mm for street? also adding 968 mo30s if not at the same time, soon after...
thanks all!!
09-05-2002, 07:13 PM
#10
Burning Brakes
Skip/Ribs/Anyone out there...
How high a rate can you go on the front springs before you begin to have issues with the ball joints on the 85.5 and later cars?
I've heard discussion that for DE/track use, one shouldn't really run more than 250 lbs or so without upgrading to Charlie or Fabcar arms.
Any opinions or experience with failures, etc?
Currently I'm running a new set of OEM aluminum arms on my 87 "S"and am looking to upgrade springs/bars in the near future.
The car is used for about 90% for track use with the current stock setup, so I am not concerned with ride quality other than to get it to the track.
How high can I go with the OEM arms?
Now, if I just hadn't suffered the dreaded tensioner failure and cracked the head...
Matt
How high a rate can you go on the front springs before you begin to have issues with the ball joints on the 85.5 and later cars?
I've heard discussion that for DE/track use, one shouldn't really run more than 250 lbs or so without upgrading to Charlie or Fabcar arms.
Any opinions or experience with failures, etc?
Currently I'm running a new set of OEM aluminum arms on my 87 "S"and am looking to upgrade springs/bars in the near future.
The car is used for about 90% for track use with the current stock setup, so I am not concerned with ride quality other than to get it to the track.
How high can I go with the OEM arms?
Now, if I just hadn't suffered the dreaded tensioner failure and cracked the head...
Matt
09-06-2002, 08:42 AM
#11
I have Koni yellows with Ground control coil-overs in the front and i love it. I believe I am using 275# springs.......
When getting my components I made a decision to keep this as an aggressive street car. I think if I had tried to make it a combo race/street I would have compromised both and never been quite happy.
I love the suspension setup though...
t.
When getting my components I made a decision to keep this as an aggressive street car. I think if I had tried to make it a combo race/street I would have compromised both and never been quite happy.
I love the suspension setup though...
t.
