spring rates question

[Jack93prj]

Hey guys so I am planning on racing autocross and I am playing with my spring rates. I already have the kit that Ground control sends you (350f/300R) with Koni yellows and progress rear sway bar combined with Megan racing camber and toe arms...so I have the supporting mods, well mostly.

I am planning on buying 400 ft/lbs for the front, and putting the rear on the 350 ft/lb springs that are now in the front. I believe that it will track about the same with a hint of over steer and very little under steer. I am just trying to limit my roll with the slightly upgraded Spring rates. What do you guys think?

I am 99.9% sure that the koni's can handle the rates and won't have an issue with underdamping the springs but won't know unless I do it or another member on here has run similar suspension.

[Jack93prj]

Also has anyone seen extended lower ball joints(roll center adjusters) for cb7s?

[i-07]

they dont make adjustable lower ball joints just uppers.

i have fnf type ones 663 front 336 rear and i loved it when i did autocross

[wildBill83]

I don't think your front springs will swap to the rear, the koni cups are different diameter and so are the strut hats, not to mention the length of the springs are WAY different from front to rear.

[Jack93prj]

Well with the ground control coil-over they can swap around its just a 2.5in by 6in spring with different spring rates and because I matched my koni's with ground control I don't use the cup that comes with the konis for lowering springs.

I called Ground control and they straightened things out quite a bit.

I was also wasn't talking about adjustable ball joints but extended lower ball joints...They makes them for my civic and S2000 and a large number of other cars, but I was just wondering if anyone had see them for the cb7.

[i-07]

Well with the ground control coil-over they can swap around its just a 2.5in by 6in spring with different spring rates and because I matched my koni's with ground control I don't use the cup that comes with the konis for lowering springs.

I called Ground control and they straightened things out quite a bit.

I was also wasn't talking about adjustable ball joints but extended lower ball joints...They makes them for my civic and S2000 and a large number of other cars, but I was just wondering if anyone had see them for the cb7.

nope and are you thinking of the arms?

[Granite CB7]

I've seen what you're talking about, for the CB/CD chassis, take a look:
http://www.hardrace.com/products.asp...5&strClass3=61

[Jack93prj]

I've seen what you're talking about, for the CB/CD chassis, take a look:
http://www.hardrace.com/products.asp...5&strClass3=61

Oh thank goodness these roll center adjuster (extended ball joints) will help so much once I get this thing on the track again. Thanks man

These are going on my ej8
http://www.inlinefour.com/buclp1raexba.html

[mndude07]

Someone just math model the cb7 suspension...otherwise you are making random assumptions about how the suspensions behaves. Until then, nothing anyone says or thinks, even me, is valid.

We don't know what that spring rate swap will do to your car without more data.

Do you have a data logger on the car? Can you take suspension position and velocity data?

You could easily be increasing the rear ride frequency too much and making the car tail happy. This tail happiness would be easily perceived as a good thing compared to the large amount of understeer the car has in stock form, however, if it is too high, the rear end could be unstable and while it will "feel" more responsive, it might actually be making the car slower.

From experience, I can tell you that 485F/300R with a progress rear sway had a very good feel, but it can't be quantified at this time, so right now the correct answer is "it depends"....on quite a few variables

[Jack93prj]

You sir are totally right... I just haven't had the time to pull stuff off my accord to find the un-sprung weight and everything I need to do to find the Motion ratios, and the ride frequency

That was the point of the post, because I was busy with school I was just wondering if any had gone in depth on the subject.

Right now it depends on the slope of the corner but it can get to sliding for sure.... How does 485 ft/lbs feel on the front? I understand a bit of roll is nesscary to keep traction but with on 350ft/lb its just to soft and I compress my suspension WAY to much mid corner.

[mndude07]

You sir are totally right... I just haven't had the time to pull stuff off my accord to find the un-sprung weight and everything I need to do to find the Motion ratios, and the ride frequency

That was the point of the post, because I was busy with school I was just wondering if any had gone in depth on the subject.

Right now it depends on the slope of the corner but it can get to sliding for sure.... How does 485 ft/lbs feel on the front? I understand a bit of roll is nesscary to keep traction but with on 350ft/lb its just to soft and I compress my suspension WAY to much mid corner.

I intend to do a large modeling project after the new year. 485/300 springs with a large rear sway bar made the car feel quite neutral. I had crappy tires on though, which gave out way before the suspension was really getting worked.

[Jack93prj]

I guess I am going to have to take a weekend and figure this all out do a good right up or something