[sqidd]

I searched all over the place but can not find what the stock spring rates are for the 07-09 GT500’s. Anyone by ay chance have this data? Know where to get it?

I’m trying to put a chart together of what GT500 OEM parts will work well with GT lowering springs. The GT500 shocks/struts have more damping to cope with the GT500 spring rates and I’m betting that some of the less aggressive lowering springs would work great with GT500 shocks/struts. I’ll be measuring some GT500 swaybars Monday and comparing them to the FRPP swaybars and the Eibach ones also to see where they sit. I’m thinking/hoping you could get a great street setup with GT lowering springs, GT500 shocks/struts, GT500 swaybars, GT500 LCA’s and GT500 strut mounts. I also know where there are piles of unused GT500 suspension parts for a song.

So who knows what those GT500 spring rates are?

 

[Guest]

How frickin ironic dude. I joined a american shelby forum as "ameriCAN" and started a thread titled 2007 oem spring rates. I also called griggs racing and maximum motorsports. Nobody knows anything. I actually called shelby of america but got the answering service. Believe man, I am trying too. That was today.

 

[jonballi]

No...but I have thought the same thing for my GT.

Subscribing

I searched all over the place but can not find what the stock spring rates are for the 07-09 GT500’s. Anyone by ay chance have this data? Know where to get it?

I’m trying to put a chart together of what GT500 OEM parts will work well with GT lowering springs. The GT500 shocks/struts have more damping to cope with the GT500 spring rates and I’m betting that some of the less aggressive lowering springs would work great with GT500 shocks/struts. I’ll be measuring some GT500 swaybars Monday and comparing them to the FRPP swaybars and the Eibach ones also to see where they sit. I’m thinking/hoping you could get a great street setup with GT lowering springs, GT500 shocks/struts, GT500 swaybars, GT500 LCA’s and GT500 strut mounts. I also know where there are piles of unused GT500 suspension parts for a song.

So who knows what those GT500 spring rates are?

 

[duckbubbles]

I don't know what the rates are, but I put a set of GT500 new take-off springs on the rear of my otherwise stock suspension '08GT and they raised the rear 1/2 inch. They were the same overall length as the stockers. I put the stockers back on, but left the (GT500) rear shocks and sway bars on. That stuff is an improvement over the stock GT stuff. The ride on the rear is actually less choppy that the GT shocks. I haven't put the front struts on, yet, but I will keep the stock springs.

When compressing the GT and GT500 shocks (off the car) the stock (GT) shocks had a lot more rebound damping. Compression felt pretty equal. This may be that the GT500 shocks have a higher nitrogen charge, but I don't know that for sure. I'll put the front struts on pretty soon.

Frank

 

[sqidd]

How frickin ironic dude. I joined a american shelby forum as "ameriCAN" and started a thread titled 2007 oem spring rates. I also called griggs racing and maximum motorsports. Nobody knows anything. I actually called shelby of america but got the answering service. Believe man, I am trying too. That was today.

It's amazing that spring rates ARE the suspension and you can't get good data at all.

In the motorcycle performance suspension world spring rate is everything. Its all you hear about all day long. Most riders have multiple springs with them at all times.

I'm also looking for the 2010 GT and GT Vert spring rates also. I have been on Google forever and couldn't find $h!t. What a PITA. Here is a list of what I have so far:

Type is either Progressive (P) or Linear (L)

Rates are in in/lb (inch per pound)

Spring.......... ....F Type........ F Rate .......R Type ..........R Rate

OEM GT ................L ...............136............L....................142
05-09

OEM GT ................? ...............?................?......................?
2010


OEM GT500 ...........? ...............?................?...................166
07-09

OEM GT500 ...........? ...............?................?.....................?
2010

H&R Supersport.......P. ............?-275 ...........P ................?-245

Steeda Ultralights ...L ...............195 ............L ...................175

Steeda Sport .........L ...............200 .............L ...................175

Steeda Comp .........L ...............225 .............L ...................185

FFRP K Springs* ......P ............173-239 .........P ..............195-236

Ebach Pro* ............P ............173-239 .........P ..............195-236

Ebach Sportline .......L .........Way Too Stiff, FOR RACE USE ONLY!!

BMR (pn SP009) .......P ..........160……............ L ..................140


*Yes, the Ford K springs and the Ebach Pros are the same springs

 

[duckbubbles]

My GT500 rear springs are tagged SLR P/N 7R3V-5560-LA.
The fronts are tagged SJF P/N 7R3V-5310-JB.
I hope this helps.

Frank

 

[hubkap]

Rears are linear at 166 lb/in (through 09) but can't find info on the fronts...sorry.

 

[Itchy]

I don't know how reliable these number are but there is some information on springs and roll-bar rates here


Also, somewhere I found that the 07-09 GT500 has 190 lb/in / 162 lb/in (F/R) springs. I can't find my source for that but the numbers made it into my Ride Ration spreadsheet.

 

[bcb00gt]

I had these numbers for the GT and GT500 from someone at Steeda that had posted them somewhere else.

Stock GT - Front: 134lb, Rear: 120lb
GT500 - Front: 190lb, Rear: 162lb

 

[sqidd]

I had these numbers for the GT and GT500 from someone at Steeda that had posted them somewhere else.

Stock GT - Front: 134lb, Rear: 120lb
GT500 - Front: 190lb, Rear: 162lb

I thik I read those same numbers for the GT but it was a vert. I'm ot 100% sure though (seems bckward to me)

I don't know how reliable these number are but there is some information on springs and roll-bar rates here


Also, somewhere I found that the 07-09 GT500 has 190 lb/in / 162 lb/in (F/R) springs. I can't find my source for that but the numbers made it into my Ride Ration spreadsheet.

Here is a list of what I have so far:

Type is either Progressive (P) or Linear (L)

Rates are in in/lb (inch per pound)

Spring.......... ....F Type........ F Rate .......R Type ..........R Rate

OEM GT ................L ...............136............L....................142
05-09

OEM GT Vert...........? ...............134................?...............120
05-09

OEM GT ................? ...............?................?......................?
2010


OEM GT500 ...........? ...............190.............?...................166
07-09

OEM GT500 ...........? ...............?................?.....................?
2010

H&R Supersport.......P. ............?-275 ...........P ................?-245

Steeda Ultralights ...L ...............195 ............L ...................175

Steeda Sport .........L ...............200 .............L ...................175

Steeda Comp .........L ...............225 .............L ...................185

FFRP K Springs* ......P ............173-239 .........P ..............195-236

Ebach Pro* ............P ............173-239 .........P ..............195-236

Ebach Sportline .......L .........Way Too Stiff, FOR RACE USE ONLY!!

BMR (pn SP009) .......P ..........160……............ L ..................140


*Yes, the Ford K springs and the Ebach Pros are the same springs

I'm goig to see if the junk yard will let me take some springs to test sometime this week.:bigthumbsup

It looks like some OEM GT500 shocks/struts would be a good match for the Steeda Ultralights

 

[sqidd]

I don't know how reliable these number are but there is some information on springs and roll-bar rates here

Good link:bigthumbsup

 

[hubkap]

I thik I read those same numbers for the GT but it was a vert. I'm ot 100% sure though (seems bckward to me)

I'm goig to see if the junk yard will let me take some springs to test sometime this week.:bigthumbsup

It looks like some OEM GT500 shocks/struts would be a good match for the Steeda Ultralights

Let me know if you wind up with leftover GT500 shocks / struts...I know you're just looking for springs but....if you think they'd be a good match for my Ultralites, well....that's good enough for me :bigthumbsup

I pay well :smilie

 

[sqidd]

Let me know if you wind up with leftover GT500 shocks / struts...I know you're just looking for springs but....if you think they'd be a good match for my Ultralites, well....that's good enough for me :bigthumbsup

I pay well :smilie

I'll post with what I come up with. I'm doing the wifes new car. I'm going to throw some light-ish lowering springs at it ad I am hoping the GT500 struts/shocks, swaybars and upper strut mounts are a good combination. I'm going to go to the yard, collect some springs, measure the swaybars and see what i come up with. I'm looking for lowered but not harsh without breaking the bank.

I don't know how reliable these number are but there is some information on springs and roll-bar rates here

Any idea what the second roll bar designation is for? For example a 34x5.1 I am guessing is a 34mm diameter bar. The second number eludes me though.

The only thing I can think is it may designate where the mounting hole is located which would determine it's leverage. The adjustable aftermarket bars have multiple mounting holes.

If the 5.1 designates the mounting hole location where is it measured at/from/etc?

I dunno

 

[Itchy]

Any idea what the second roll bar designation is for? For example a 34x5.1 I am guessing is a 34mm diameter bar. The second number eludes me though.

The only thing I can think is it may designate where the mounting hole is located which would determine it's leverage. The adjustable aftermarket bars have multiple mounting holes.

If the 5.1 designates the mounting hole location where is it measured at/from/etc?

I dunno

I think it is the wall thicness of the tube

 

[Muckerpuck]

American muscle's springs section has spring rates for all the springs they sell, they had a couple that arnt on your list. It might be worth comparing and syncing.

 

[duckbubbles]

I think it is the wall thicness of the tube

That is what I think, too. While I had both front sway bars off, GT and GT500, the 500 bar was noticeably heavier, but had the same external dimensions.

Frank

 

[sqidd]

I think it is the wall thicness of the tube

That is what I think, too. While I had both front sway bars off, GT and GT500, the 500 bar was noticeably heavier, but had the same external dimensions.

Frank

Hmmmmmm, makes sense, good thinking.:smartass: I am going to measure an assortment of bars over the next few days and some of them are on cars. I hope there are marks of somekind that I can find. If they were all off the cars I could weigh them but I am going to be stuck with just diameters on some of them.

I don't kow how much wall thickness changes net rate either. I can't imagine it effects it nearly as much as the diameter but I may be way off in left field also. I have a friend who used to fabricate/build/maintain Can Am cars back in the day. I'll ask him, he knows all that stuff.

I would like to be able to put a "Bar Chart" together also. I know I would like to play with different bars to get my car balanced better. Between having the blower hanging over the front, UCA with no resistace to twist (effectively reducing roll rate) and huge rubber on the rear my FRPP swaybars are a bit outside of what they were set up for.

Now all I need is a list, pile of bars a parking lot and some cones.:gringreen

American muscle's springs section has spring rates for all the springs they sell, they had a couple that arnt on your list. It might be worth comparing and syncing.

I noticed that yesterday. I'll do it in the middle of the night sometime. The downside is that I am not excited about more aftermarket rates, I want a list of all the stock rates so I know what to expect from their matching shock/strut packages. I'm guessing with the right data a lot of people could set up some killer street setups without spending much money at all. I kow where there are crates of brand new OEM GT and GT500 springs, shocks, struts and swaybars that can be had for a song.:bigthumbsup

I just put together a swaybar chart with the data I have here:
http://www.allfordmustangs.com/foru...005-2010-mustang-gt-tech/232313-swaybar-size-chart-please-help.html#post2033948

Check it out and if you have some of the bars that have no data (in RED) can you measure them and post them up so the chart can be completed?

Thanks!:bigthumbsup

 

[Itchy]

I don't kow how much wall thickness changes net rate either. I can't imagine it effects it nearly as much as the diameter but I may be way off in left field also. I have a friend who used to fabricate/build/maintain Can Am cars back in the day. I'll ask him, he knows all that stuff.

ok I'll preface this by saying I'm on the way back from a wedding and had too much to drink.

I don't know the equation for sway bar rate off the top of my head but the torsional stiffness of a bar is GJ/L. J for a round bar is pi*d^4/32 (I think) it's pi*(d_o^4-d_i^4)/32 ... Same concept applies for a swaybar with angled ends.

I'll try to write this out in a more clear format tomorrow when I'm on an actual computer, and have had some water.

 

[sqidd]

ok I'll preface this by saying I'm on the way back from a wedding and had too much to drink.

I don't know the equation for sway bar rate off the top of my head but the torsional stiffness of a bar is GJ/L. J for a round bar is pi*d^4/32 (I think) it's pi*(d_o^4-d_i^4)/32 ... Same concept applies for a swaybar with angled ends.

I'll try to write this out in a more clear format tomorrow when I'm on an actual computer, and have had some water.

My head just exploded!:grinroll:

 

[Itchy]

My head just exploded!:grinroll:

The short answer is that my previous posts are correct and all things being equal (the only change is diameter, wall thickness, or both) the stiffness of one bar to another can be compared based on the 4th power of the diameter i.e. D^4

for tubular sway bars the ratio of Bar1(Do^4-Di^4) vs Bar2(Do^4-Di^4) can be used.

If you have "How to Make your Car Handle" by Fred Puhn you've probably seen:

K (lbs/in) =

500,000 D^4
------------------------------------
(0.4244 x A^2 x B) + (0.2264 x C^3
​

A - Length of end perpendicular to B (torque arm - inches)
B - Length of center section (inches)
C - Length of end (inches)
D - Diameter bar (inches)

I'm in the process writing up an explanation of where that equation came from for anybody who cares. For those of you who don't care, just blindly use the equation above.