|
Leaf springs for a G-Machine application...
#36046
04/24/07 11:00 PM
04/24/07 11:00 PM
|
Joined: Sep 2003
Posts: 10,645
Houston, Tx
AlexP
OP
I Live Here
|
OP
I Live Here
Joined: Sep 2003
Posts: 10,645
Houston, Tx
|
The front suspension is falling into place on my car and I think it should perform well.
The suspension is looking to be set up like this so far..
-Energy Suspension polyurethane LCA, sway bar and strut rod bushings
-Moog LBJ's
-CAP Adjustable Tubular UCA's
-Moog 11/16" Tie rod ends
-Firm Feel Stage 3 box
-Moog Late B-pitman and idler arms
-1.22" Torsion bars
-Koni Adjustable shocks
-MP/Adcco 1.125" front sway bar
The torsion bars are a little bit bigger than I wanted, but the shocks should help alot in keeping them under control. I am a little excited to be a guinea pig for these bars, not alot of people have tried them. The alignment will be critical, I have still not yet figured that one out.
I can't decide what to do for the rear though.
I guess there are a few options, but all have their faults.
-MP XHD springs with a 7/8" rear sway bar.
My ride height remains the same, I can get a set for under $200 and they use my existing hangers. I don't know if the spring rate will be too tame in comparison to the front. This seems to make me the most comfortable.
-De-arched SS springs with the same sway bar.
E-berg used them on his Green Brick, and they worked very well. The MP chassis manual says that they can't be used for a turning application due to side loading, but the rebound of the spring (side to side motion) should be eliminated with the de-arch since it will be near flat like stock springs. Cost for the spring is the same and I have to get a set of different hangers. No biggie. I feel the spring rate on these will be fairly well matched to the front.
-Cal-tracs and the custom mono leaf springs
The most untested of the bunch. John Calvert thinks they would work well, and the springs would be custom matched to the car for the spring # and ride height. In his experience the bars them selves do about 75% of the work that the sway bar does. This is the most expensive option, but it is tailored to the car and offers a slight weight reduction.
I am trying to make the most of the cars handling abilities with the use of mostly stock components. IE; No tubular K-member with coilovers and no 4-link rear. Just over the counter stuff for the most part with some attention to detail. I think the biggest limiting factor in all of this will be the 15" wheel and tire combination, but I can live with that.
These are just my basic thought out ideas, please point out any faults or input any of your own ideas.
THANKS !
|
|
|
Re: Leaf springs for a G-Machine application...
[Re: AlexP]
#36047
04/24/07 11:41 PM
04/24/07 11:41 PM
|
Joined: Feb 2003
Posts: 4,204
Fort Worth, TX
Clair_Davis
master
|
master
Joined: Feb 2003
Posts: 4,204
Fort Worth, TX
|
On my Valiant(3600# with me, 3/4 tank of gas, spare & jack in the trunk, weight distribution is pretty good at 53/47 F/R), the 6-leaf HD reproduction springs I got from ESPO are great. The rate "eyeballs" at about 150#/in, roughly half the rate of my 1.14" t-bars. I think some of the SS springs are in this ballpark, some are lighter. I would try to get SOME info on the spring rate before you buy, but I wasn't so lucky. ESPO doesn't know the rates on their springs, but I took a chance anyway. I didn't want to rearch a set of springs after I got them, so I adjust ride height with an AREngineering front hanger. ESPO can build whatever spring you want, and can increase or decrease arch when they're built. Cost difference is minimal, like $40 or something.
Since not much of this is going where you wanted it to go, I'll say that without a rear sway bar, my car feels pretty dang neutral on "spirited" on/off ramps, and the turn-in is so good it actually surprises me. Too much time in a FWD farm implement, I guess. My advice would be to hold off on the rear bar until you've been in the seat for a while. That doesn't mean don't get it, if you're itchin' to spend money, just don't hook it up right off the bat.
In the end, I'd probably go with the MP XHD's, if they're a quality part. I've heard some negative experiences here on Moparts, so check that out first. The parts I got from ESPO have been great, and the price was good.
On the alignment, start out with 3+ degrees +caster, 0.5 to 0.75* -camber, and just a smidge of toe in, like 1/32" if the front end is fresh. More caster is better, but you can probably stop at 5 or so if you have the ability to get like 7. Not sure how much your UCA's will net you.
Clair
|
|
|
Re: Leaf springs for a G-Machine application...
[Re: AlexP]
#36048
04/24/07 11:51 PM
04/24/07 11:51 PM
|
Joined: Jan 2003
Posts: 10,522
Freeport IL USA
poorboy
I Live Here
|
I Live Here
Joined: Jan 2003
Posts: 10,522
Freeport IL USA
|
From your discription of the front suspension, it sounds like you plan on turning some corners pretty hard. With that in mind, personally, the caltracks would be out. I think the way they are set up would put some real binds on the mono leaf under hard cornering, enough to scare me.
Along the same lines, I would think that by de-arching the SS springs, you are going to loose any advantage they may have over the stock HD springs, esspecially once you throw a rear sway bar into the mix. The shorter SS springs aren't going to help much in the cornering either.
I'd do the HD springs, sway bar, and some good rear shocks. Might consider adding an extra leaf to the spring packs and also adding spring clamps on each leaf end on both of the front segments. Be carefull about flattening out the rear leaf springs too much, if one drops past center and the other doesn't, it can shift the rear axle. Gene
|
|
|
Re: Leaf springs for a G-Machine application...
[Re: AlexP]
#36051
04/25/07 08:08 AM
04/25/07 08:08 AM
|
Joined: Feb 2003
Posts: 4,204
Fort Worth, TX
Clair_Davis
master
|
master
Joined: Feb 2003
Posts: 4,204
Fort Worth, TX
|
Quote:
Espo is questionable in my eyes. I sent them an email last week and they gave me the worst response that I have ever gotten from a vendor. I don't know how well they truly "know" their product.
...
I think the front end set up may eliminate most of the factory induced under steer. If I can get controllable power over steer, I could feel pretty content without a rear bar.
...
On a side note, what would be the consequence of getting two of the same sided leaf springs ? What motion does the extra leaf on one side control ? This was an early morning thought from a few weeks ago that has been nagging me. What if I got two of the 'extra leaf' springs and used those ?
Not knowing what ESPO said, it's hard for me to imagine them screwing up what they do with springs. I think they have some pretty standard shop drawings, and then add/subtract/arch to the customer's request. Very little detailed info comes from them (which is too bad).
The front setup you're going for will INCREASE understeer, all else being equal. That's why you need to get a feel for what the rear end will do with the new springs. I found the unknown-quantity higher-rate rear springs to be a good match for the front bars on my Valiant, but only by accident. The rate is much lower than some successful autoXers I know, so I was a little worried at first. I have an ADDCO rear bar - in the rafters of the garage. Once I determine that I need it, I'll put it on, but I don't have the need now.
The extra leaf controls axle wrap on the one side of the car. Two extras makes a balanced pair, side to side, that's all. Power oversteer is controlled by your right foot, not the sway bar. Adding right foot to a tail-happy car could get un-fun pretty quickly.
Clair
|
|
|
Re: Leaf springs for a G-Machine application...
[Re: AlexP]
#36052
04/25/07 09:48 AM
04/25/07 09:48 AM
|
Joined: Sep 2003
Posts: 1,688
Marlboro, NY, USA
Rick_Ehrenberg
top fuel
|
top fuel
Joined: Sep 2003
Posts: 1,688
Marlboro, NY, USA
|
Biggest problem I see here is a F/R roll rate unbalance. Unless you go with 12-leaf truck rear springs (kidding), the car sure sounds like it will understeer. I'm not sure what exactly you'll be using the car for...I'm an old fart and I guess I don't quite understand the term "G Machine". If the car will be used on short tracks, especially, you'd want the car pretty loose. Mild looseness is also fun on a canyon carver. But as speeds increase - like Silver State - your setup gets closer and closer to spot-on! All these cars (classic Mopars) have less and less understeer as speeds increase.
On the rear leafs: I've played with some of the Espo and Eaton springs, all seem quite good. The Eatons, in fact, were like factory XHDs: plastic interliners at the tips of each leaf, PLUS zinc interleafs! But getting the right rate and arch can be a daunting task.
On one car I built recently - one that was intended as more of a cruiser, an early B-body - I used A-body MP XHD repro leafs; I was worried that the car was gonna sit TOO low and be too soft. WRONG. In fact, overall, I'd have to say that I'm impressed with them - it was the first pair of 'em that I've used in about 10 years. But I think that the probably aren't stiff enough to counterbalance your killer front end.
Monoleafs without some add-on control arm are useless. And I don't know enough about Cal-Tracs to comment on using them in a handling application...basically, I defer to those who have hands-on (tires-on/) experience.
Which brings us to MP S/S springs: First, if I were to duplicate my Valiant today, I'd absolutely use another pair of dearched S/S's. But this time I'd use 2 right side springs. And I'd surely stay with quadrashocks for axle windup control.
The nice thing about the S/S springs is that they are made in four spring rates. Good, because unless you're the kind of guy who goes to Vegas, wins $10K on the first try and walks, you might well need a couple of attempts to get it right.
Which brings me to the bottom line: It's really tough to do this kind of engineering / planning on paper. Even the most sophisticated engineering firms (British Midlands) and automakers use computer programs to get in the ballpark, but then go to a heavily instrumented 4-post hydraulic table - and the street and track - to get it really dialed in.
Rick
|
|
|
Re: Leaf springs for a G-Machine application...
[Re: Clair_Davis]
#36053
04/25/07 10:46 AM
04/25/07 10:46 AM
|
Joined: Sep 2003
Posts: 10,645
Houston, Tx
AlexP
OP
I Live Here
|
OP
I Live Here
Joined: Sep 2003
Posts: 10,645
Houston, Tx
|
Quote:
Quote:
Espo is questionable in my eyes. I sent them an email last week and they gave me the worst response that I have ever gotten from a vendor. I don't know how well they truly "know" their product.
...
I think the front end set up may eliminate most of the factory induced under steer. If I can get controllable power over steer, I could feel pretty content without a rear bar.
...
On a side note, what would be the consequence of getting two of the same sided leaf springs ? What motion does the extra leaf on one side control ? This was an early morning thought from a few weeks ago that has been nagging me. What if I got two of the 'extra leaf' springs and used those ?
Not knowing what ESPO said, it's hard for me to imagine them screwing up what they do with springs. I think they have some pretty standard shop drawings, and then add/subtract/arch to the customer's request. Very little detailed info comes from them (which is too bad).
The front setup you're going for will INCREASE understeer, all else being equal. That's why you need to get a feel for what the rear end will do with the new springs. I found the unknown-quantity higher-rate rear springs to be a good match for the front bars on my Valiant, but only by accident. The rate is much lower than some successful autoXers I know, so I was a little worried at first. I have an ADDCO rear bar - in the rafters of the garage. Once I determine that I need it, I'll put it on, but I don't have the need now.
The extra leaf controls axle wrap on the one side of the car. Two extras makes a balanced pair, side to side, that's all. Power oversteer is controlled by your right foot, not the sway bar. Adding right foot to a tail-happy car could get un-fun pretty quickly.
Clair
I am getting that the distinct feeling that using the 1.22" bars is going to make matching of components near impossible without trial and error.
Clair, thanks for righting my comments. I need as much help thinking this through as possible. 
Rick, Ideally I would like to be able to run the short track stuff like the tracks available in this area. Events such as the Silverstate are not the type of action I am after, my car would fall apart if I kept it above 100 for a few miles.
All in all, I am looking to have a few steps up in terms of a controllable mopar. If I could get 1" bars, I think the match of XHD springs would be almost perfect in terms of balance for the car.
|
|
|
Re: Leaf springs for a G-Machine application...
[Re: AlexP]
#36054
04/25/07 02:27 PM
04/25/07 02:27 PM
|
Joined: Jan 2003
Posts: 5,386
Pikes Peak Country
TC@HP2
master
|
master
Joined: Jan 2003
Posts: 5,386
Pikes Peak Country
|
Roll couple is the term that is used to describe the amount of load each end of the car is going to need to handle. Since there is more weight on the front, you want more roll couple % on the front to control it. This is why you would go with higher wheel rates up front. Wheel rates are measured directly at the tire contact patch on the ground and are a combination of the torsion bar and sway bar up front and the leaf spring and sway bar out back.
You are going with the highest over the counter wheel rates possible on the nose of your car. You will need a corresponding increase in the rear to match it. As such, you could go with the stock XHD springs at approx 140# spring rate, (actually less than that at the wheel once motion ratios are applied) they are quite a bit under the 300# wheel rate the t-bars produce (not including the sway bar mulitplication), so you may need a 3/4 to 1 inch rear sway bar to match things up, depending on your personal preference for under/oversteer.
Another option to consider is going to an oval track supplier such as Speedway Motors and buying leafs designed for turning corners. You can buy specific spring rates from 80 to 200 pounds in monoleaf steel, monoleaf fiberglass, or multileaf steel configurations. When buying these types of springs you will need to specify the free arch you want. 4" should be about right as once they are installed and loaded, they will lie flat.
Again, consideration of using a rear sway bar will factor into deciding the springs to get. In general I'd say go softer then add sway bar sizing to dial things in or you could go heavier and not use a bar at all. For a ball park guess, I'd say 160# if using a bar, or 200# with no bar.
For a point of comparison, Mopar's oval track leaf springs are 120# and are completely flat when installed. These are recommended for use with torsion bars up to 1.16 with a 1" sway bar and no rear sway bar. The XHD springs are in the 140# range, SS springs are typically 160#. However, the SS springs also have a fair amount of arch to them which is great for the starting line leverage required for drag racing, but not great for round the corner handling.
Personally, I don't think a 1.22 is that radical for a performance handling application. By comparison, the 300# wheel rate these produce would be along the lines of a 600# coil spring in a GM. There are a lot of Camaros out there running 600# springs in the G-machine genre. When I was running oval track, we routinly used 800 and 1000 pound springs up front with 160 to 200 pounders out back. I also liked the car plenty loose and this got it there.
|
|
|
Re: Monoleaf springs for a G-Machine application...
[Re: TC@HP2]
#36055
04/25/07 04:10 PM
04/25/07 04:10 PM
|
Joined: Sep 2003
Posts: 1,688
Marlboro, NY, USA
Rick_Ehrenberg
top fuel
|
top fuel
Joined: Sep 2003
Posts: 1,688
Marlboro, NY, USA
|
Quote:
<snip>....going to an oval track supplier such as Speedway Motors and buying leafs designed for turning corners. You can buy specific spring rates from 80 to 200 pounds in monoleaf steel, monoleaf fiberglass....<snip>
Ah, yes, who wouldn't love the reduced mass? But monoleafs are terrible at windup control (launches, or heavy braking forces), and Chrysler Engineering has tested nearly every composite / fiberglass leaf out there - they desperately wanted to use them on minivans, where the rear axle is just along for the ride. But every one failed durability testing (at the "ends", not surprisingly) so they seem to be good only for single-purpose race cars, not street cruisers that actually might hit a pothole.
Rick
|
|
|
Re: Spring/Wheel rate
[Re: TC@HP2]
#36056
04/25/07 04:23 PM
04/25/07 04:23 PM
|
Joined: Sep 2003
Posts: 1,688
Marlboro, NY, USA
Rick_Ehrenberg
top fuel
|
top fuel
Joined: Sep 2003
Posts: 1,688
Marlboro, NY, USA
|
Quote:
...Personally, I don't think a 1.22 is that radical for a performance handling application. By comparison, the 300# wheel rate these produce would be along the lines of a 600# coil spring in a GM. There are a lot of Camaros out there running 600# springs in the G-machine genre. When I was running oval track, we routinly used 800 and 1000 pound springs up front with 160 to 200 pounders out back. I also liked the car plenty loose and this got it there...
This may well be true. But on a stock Camaro with a bolt-on subframe, there's typically such a lack of torsional rigidity in the platform that, once a certain point (in spring rate) is reached, it really doesn't matter how stiff you make the springs! That, in my experience, is not true for full-unibody Mopars.
Of course, as you mentioned, weight distribution / bias is a key factor in setting this up. I've always tried to keep the weight as close to 50/50 as possible, which, of course, is a common goal.
I've never been a fan of large rear swaybars (mind you, I'm not talking race car, I'm talking canyon carver / street driver). Unless extreme care is taken to reduce or eliminate their progressiveness (solid frame mounts, ball joint or heim joint "ends"), the car may transition from understeer to oversteer at the most inopportune moment. While you'd think that multi-leaf rear springs would also be quite progressive, in reality it doesn't seem to be so. Probably this because, unlike truck leafs, all leafs are already in contact with each other at normal ride height.
I think we all agree, however, that this is still a black trial-and-error art!
Rick
|
|
|
Re: Spring/Wheel rate
[Re: plymouthfan]
#36059
04/25/07 10:28 PM
04/25/07 10:28 PM
|
Joined: Jan 2003
Posts: 4,395
The Pale Blue Dot
Skeptic
master
|
master
Joined: Jan 2003
Posts: 4,395
The Pale Blue Dot
|
Quote:
I am trying to make the most of the cars handling abilities with the use of mostly stock components. IE; No tubular K-member with coilovers and no 4-link rear. Just over the counter stuff for the most part with some attention to detail. I think the biggest limiting factor in all of this will be the 15" wheel and tire combination, but I can live with that.
Quote:
Have you considered something like this Street Lynx system A Body Joe just installed?
 
|
|
|
Re: Leaf springs for a G-Machine application...
[Re: AlexP]
#36060
04/26/07 07:28 AM
04/26/07 07:28 AM
|
Joined: Jan 2003
Posts: 2,836
Detroit boy in Saugerties, NY
BrianShaughnessy
master
|
master
Joined: Jan 2003
Posts: 2,836
Detroit boy in Saugerties, NY
|
Quote:
-Cal-tracs and the custom mono leaf springs
The most untested of the bunch. John Calvert thinks they would work well, and the springs would be custom matched to the car for the spring # and ride height. In his experience the bars them selves do about 75% of the work that the sway bar does. This is the most expensive option, but it is tailored to the car and offers a slight weight reduction.
I'd agree with Johns assessment of the caltracs. I like my caltracs. I just run the stock R/T springs but I really haven't seen a need for me to run a rear bar yet.
I upgraded to a FFI 1.125 front bar. Haven't had a chance to really road test it yet.
I'm not trying to run autocross or anything... I just live in a area north of Rick where straight roads just don't exist.
The caltracs were necessary due to the truck dana 60 without pinion snubber provisions.
Black Betty: '69 Charger RT: 440 6 pack, TKO600 5 speed, 3.73 Dana.
Sinnamon: '69 Charger RT: 440, 727, 4.30 8.75. High School Sweetheart.
El Grande: '98 Grand Cherokee 5.9 Limited.
|
|
|
Re: Spring/Wheel rate
[Re: plymouthfan]
#36063
04/26/07 09:56 AM
04/26/07 09:56 AM
|
Joined: Jan 2003
Posts: 9,336
central New Jersey
dbdartman
master
|
master
Joined: Jan 2003
Posts: 9,336
central New Jersey
|
I'm loving this thread & soaking it up like a sponge! Like Clair, I built my suspension using intuition & "best guess" technology. Again, like Clair my Dart seems incredibly well balanced in 270° 20-25MPH on/off ramps (both front & rear seem to lose lateral traction at the same time around 55-60MPH). I guess we both got real lucky...  I should be able to give some comment on the mono-leaf/cal-track combo this time next year as we're installing this in my bro's 69 B-body wagon (already has 1.16" 1/2-mile banked track T-bars, 1.125" front sway bar & Koni shocks, limiting factor is still the 255/60/15's). Alex, if you PM me your phone #, I'll be happy to talk about what I know & have done (wont' cost me, have unlimited L/D at any time) at your convenience. 
|
|
|
Re: Spring/Wheel rate
[Re: AlexP]
#36064
04/26/07 07:44 PM
04/26/07 07:44 PM
|
Joined: Jan 2003
Posts: 5,386
Pikes Peak Country
TC@HP2
master
|
master
Joined: Jan 2003
Posts: 5,386
Pikes Peak Country
|
Quote:
More and more I see Camaro guys using stock 5 leaf springs, Koni's and Cal-tracs with no rear bars.
Don't get too wrapped up in the 5 leaf vs 6 leaf vs 7 leaf. The leaf count is only part of the equation and it is entirely possible ot have a 5 leaf pack that is equal in rate to a 7 leaf pack. Thickness of the leaves, end design, interliners, steel alloy as well as leaf count can all be factors in the overall rating
|
|
|
Re: Spring/Wheel rate
[Re: plymouthfan]
#36065
04/27/07 10:50 AM
04/27/07 10:50 AM
|
Joined: Jan 2003
Posts: 5,386
Pikes Peak Country
TC@HP2
master
|
master
Joined: Jan 2003
Posts: 5,386
Pikes Peak Country
|
Quote:
Have you considered something like this Street Lynx system A Body Joe just installed?
https://board.moparts.org/ubbthreads/show...part=1&vc=1
This is a very nice set up. while the coil over change allows a greater range of spring rates and the link arrangment is somewhat lighter than leaf springs, it doesn't have any adjustment in it for roll center alterations. Not that this is a big deal for most guys as once it is set, they learn to live with it and they never run it in varying track conditions that require tunability. However, with a few simpler mods than this system requires, leaf springs can be set up to have changeable roll centers which can then be used to alter the amount of rear bite you need in your set up.
|
|
|
Re: Spring/Wheel rate
[Re: TC@HP2]
#36066
04/27/07 11:48 AM
04/27/07 11:48 AM
|
Joined: Jan 2003
Posts: 1,692
Seattle WA
RichV
top fuel
|
top fuel
Joined: Jan 2003
Posts: 1,692
Seattle WA
|
Quote:
Quote:
Have you considered something like this Street Lynx system A Body Joe just installed?
https://board.moparts.org/ubbthreads/show...part=1&vc=1
This is a very nice set up. while the coil over change allows a greater range of spring rates and the link arrangment is somewhat lighter than leaf springs, it doesn't have any adjustment in it for roll center alterations. Not that this is a big deal for most guys as once it is set, they learn to live with it and they never run it in varying track conditions that require tunability. However, with a few simpler mods than this system requires, leaf springs can be set up to have changeable roll centers which can then be used to alter the amount of rear bite you need in your set up.
A big advantage to coil springs over leaf springs is that your roll rate is 30 to 50% lower with coil springs than leaf springs for the same wheel rate. The result of the higher roll rate is that you have to optimize your leaf spring rate for roll rather than for ride. You can increase your rear roll rate from the 30%, but you can not decrease it to a coil spring level with conventional bushings. Stiffer spring bushings such as poly or nylon will increase the roll stiffness of leaf springs as will angling the rear springs. I wish the Street Lynx kit were a five link rather than a four. Even the GM suspension designers, who used four links for many years now admit they are flawed.
|
|
|
Re: Spring/Wheel rate
[Re: RichV]
#36067
04/27/07 07:09 PM
04/27/07 07:09 PM
|
Joined: Sep 2003
Posts: 10,645
Houston, Tx
AlexP
OP
I Live Here
|
OP
I Live Here
Joined: Sep 2003
Posts: 10,645
Houston, Tx
|
Here is another option that I have found for getting the proper rate leaf springs... Alltime racing leafs These guys look like they know a thing or two about going around corners in a classic mopar.
|
|
|
Re: Leaf springs for a G-Machine application...
[Re: AlexP]
#36069
04/27/07 11:33 PM
04/27/07 11:33 PM
|
Joined: Jun 2006
Posts: 254
Vista, CA
71Chip
enthusiast
|
enthusiast
Joined: Jun 2006
Posts: 254
Vista, CA
|
What made you decide to go with those huge torsion bars with 15" wheels?
Seems like the car won't be good at anything. Terrible ride, understeer, no weight transfer at the strip.
I have some tires in my backyard right now I am saving. They are 235/60 BFG Comp T/As that are unique side-to-side and were custom shaved by a road racing outfit. A lot of classic road race porsches run 15 inch wheels and huge spring rates with great success but I really think you need a expensive, well set up tire to pull it off.
71 Challenger
|
|
|
Re: Leaf springs for a G-Machine application...
[Re: 71Chip]
#36070
04/27/07 11:38 PM
04/27/07 11:38 PM
|
Joined: Sep 2003
Posts: 10,645
Houston, Tx
AlexP
OP
I Live Here
|
OP
I Live Here
Joined: Sep 2003
Posts: 10,645
Houston, Tx
|
Quote:
What made you decide to go with those huge torsion bars with 15" wheels?
Seems like the car won't be good at anything. Terrible ride, understeer, no weight transfer at the strip.
I have some tires in my backyard right now I am saving. They are 235/60 BFG Comp T/As that are unique side-to-side and were custom shaved by a road racing outfit. A lot of classic road race porsches run 15 inch wheels and huge spring rates with great success but I really think you need a expensive, well set up tire to pull it off.
I respect your opinion, but I don't totally agree to any of the above.
|
|
|
Re: Leaf springs for a G-Machine application...
[Re: AlexP]
#36071
04/28/07 02:00 AM
04/28/07 02:00 AM
|
Joined: Jan 2007
Posts: 2,431
SK,Canada
gregsrt
top fuel
|
top fuel
Joined: Jan 2007
Posts: 2,431
SK,Canada
|
Thanks for the link to All Time Racing. They look like they've got some cool products for my Challenger. Why does everyone think the SS springs have so much arch? I ran a set of 3600lb auto trans ones in my 69 Bee with them mounted on the upper most hole on the front hanger and my car sat low. I don't have any pics though as I sold it 5 years ago. 
Last edited by gregsrt; 04/28/07 02:12 AM.
An association of men who will not quarrel with one another is a thing which has never yet existed, from the greatest confederacy of nations down to a town meeting or a vestry.
Thomas Jefferson
|
|
|
Re: Leaf springs for a G-Machine application...
[Re: TC@HP2]
#36072
04/28/07 07:47 AM
04/28/07 07:47 AM
|
Joined: Jan 2003
Posts: 5,386
Pikes Peak Country
TC@HP2
master
|
master
Joined: Jan 2003
Posts: 5,386
Pikes Peak Country
|
Quote:
Again, consideration of using a rear sway bar will factor into deciding the springs to get. In general I'd say go softer then add sway bar sizing to dial things in or you could go heavier and not use a bar at all. For a ball park guess, I'd say 160# if using a rear sway bar, or 200# with no bar.
Sorry. I guess I buried this in the middle of too long a response earlier.
The Alltime guys definetly know their stuff, but they do tend to be pricey.
The SS springs may not have "a lot" of arch but the point is for a handling application, the spring should be flat. Even the old DC and MP manuals say flat is mandatory for maximum cornering effort. While you can use hangers and shackles to get a SS spring to a decent ride height, it still has some arch to it which can create a lever arm against the mounting points. A flat spring reduces this leverage. Think of it this way, breaker bars are longer than ratchets to give you more leverage for breaking loose those stubborns bolts. Side loading a leaf spring with arch would work the same way.
Speaking of which, adjustable front hangers are a great way to get two inch drop from a mounting point. Another is to replace shackles with sliders. A slider is a u shapped frame with horizontal slots running down the sides. A bearing runs in two track the length of the slots on each side. The rear of the leaf spring is bolted in between these two bearings. Instead of pivoting like a shackle, the leaf slides back and forth on the bearings. This is a 2" drop in mounting point over a shackle. I've only ever used these in copetitin, so I can't say how they would work in a street application.
Another advantage to solid or bushing mounted leaf spring is the width of the spring resists twisting as well which helps increase roll resistence compared to a coil spring.
However, as mentioned in an earlier post, if you simply want to use a leaf spring as a spring and not the whole suspension locating system, you can swap out the front bushing for a spring eye pivot. This allows the spring to twist and roll with the car and not resist twisting. Once it has this freedom of movement, sway bars and panhard bar/watts link become a requirement to locate the suspension and provide roll resistence. The advantage of doing this in a track application is that the rear roll center location can be easily changed with just minor adjustments. This can have a tremendous impact on how a car will hook up exiting a corner. It also allows you to run a lower spring rate since the leaf now acts exclusively as a spring and not a roll resistor. FYI, this is how the trans am cars of 1970 were set up and they continue to use this set up in vintage racing to this day.
As an aside to drag racing with a handling set up; yes, you reduce the effeciency of weight transfer and suspension movement, and consequently, will increase you e.t. over a similarly powered car built exclusively for straight line performance. However, a handling set up will be less sensitive to track, tire, and atmospheric changes and will be deadly consistent in later rounds where cooling things down in an effort to maintain consistency becomes a factor. Not to mention that turn on the return road is a lot less scary. 
|
|
|
Re: Spring/Wheel rate
[Re: Moparmatty]
#36073
04/28/07 08:21 AM
04/28/07 08:21 AM
|
Joined: Nov 2005
Posts: 15,118
85086
moparpollack
Lil Herman
|
Lil Herman
Joined: Nov 2005
Posts: 15,118
85086
|
Nope  that's $920 a pair 
56 Plaza 63 D100 step side 67 Coronet, 68 Roadrunner, 69 Super Bees, 69 Coronet 500 convertible, 70 Roadrunner Post, 79 D150 360, and a severe case of Mopar a,d,d
|
|
|
Re: Spring/Wheel rate
[Re: moparpollack]
#36074
05/01/07 10:30 AM
05/01/07 10:30 AM
|
Joined: Jan 2003
Posts: 5,386
Pikes Peak Country
TC@HP2
master
|
master
Joined: Jan 2003
Posts: 5,386
Pikes Peak Country
|
Since a lot of members here use Summit, here is info straight from their latest catalog.
Afco oval track springs, mono leafs, $55 ea, 5" arch. Available in 34, 47, and 64 spring rates
Multi-leaf Chrysler style spring packs $130 ea
5" arch available in 142, 152, 166, 194 # ratings.
Another vendor worth checking out is Landrum. They also specialize in leaf springs.
So it isn't that tough to get specialized spring rates at a reasonable cost from a vendor who knows what they are selling you.
|
|
|
Re: Spring/Wheel rate
[Re: TC@HP2]
#36075
06/12/07 05:16 AM
06/12/07 05:16 AM
|
Joined: Jan 2003
Posts: 2,273
Bern, Switzerland
6o4o
top fuel
|
top fuel
Joined: Jan 2003
Posts: 2,273
Bern, Switzerland
|
I also got a 1.22 Tbar on the front and will reinforce my 72 Satellite BIG time in the next few months (subframe connectors, all XV motorsports reinforcement available, 10point rollbar, torque boxes etc.)
I got red konis front & rear, 83/4 3.55 SG rearend.
I got reillymotorsports tubular UCA, 11.75" spindles with alu MC manual (probably going to change to Viper brakes from Andy later this year), reinforced LCA, FF stage 2 PS box, reinforced k-member, biggest FF swaybar on front and endlinks.
On the rear I removed my stock swaybar and I bought the flex-a-form fiberglass leafsprings. So far I didn't test all of this, I just calculated for a long time and asked people. There are some good books out there that will help you get into ballpark. But I also would guess, that you need to get around 200lbs/inch on the rear with those tbars, ALTHOUGH rather having understeer than oversteer! A rear swaybar will get you more to the oversteer side.
I heard of a guy here that got problems with his flex-a-form (delaminating) but here are 3 guys in Germany that got some g-machine Mopars with those fiberglass springs (since years) and no problems so far...
To be honest, I also don't trust them yet, but I will try them and see. Corvettes did use them for many many years with success and I won't be driving over pot holes with my car. But a check from time to time is surely not a bad idea.
I got by the way 200lbs/inch at 4". Should be flat when the car sits on it. You can tell him the spring rate and arch. I wouldn't go lower with the spring rate on fiberglass, I heard they start to oscillate at high speed because they got less damping than a steel spring. The german guy here even got 250lbs/inch. The weight reduction is also massive!
They did cost 400$/pair.
|
|
|
Re: Spring/Wheel rate
[Re: 6o4o]
#36078
06/14/07 12:03 AM
06/14/07 12:03 AM
|
Joined: Sep 2003
Posts: 10,645
Houston, Tx
AlexP
OP
I Live Here
|
OP
I Live Here
Joined: Sep 2003
Posts: 10,645
Houston, Tx
|
Quote:
I will have to learn to trust them! 
I trust SS springs and I won't have to tread lightly with them, other people have shown that they can work for what I need.
You convinced me that the shocks I need are the Konis. My car will be mostly street so I don't think I could ever utilize what QA1's can offer me.
|
|
|
|
|
I got sucked in reading all the suggestions and forgot the basic idea of the thread 
