car: 92 si
suspension mods : gsr front and rear sways
purpose of car: 99% DD, a liitle drag and would like to try autox

I have decided to get GC's and koni's , but I am not sure which rates to get.

the roads where I live are pretty decent, I would like to lower the car somewhere around 1.5-1.75, not looking to slam. the reason I chose this set up is so I can get a stiffer spring without being super low, also if I get into autox I could get stiffer springs later. I also don't want to change the balance of the car too much, this already seems a bit more tail happy then my coupe . IDK what rates to go with I was thinking something like 380f/300-320r.

also if anyone has expierence with sellers, selling this combo on this forum who did you get it from and how was your expierence, would recommend them?

I don't plan on getting tophats since I'm not going that low

TIA

 

up

 

TTT

 

What exactly is the question?

 

just any input on which rates to go with, i want something a little stiffer than the OTS rates, I am not sure if the rates I have listed will get me what I want

 

up

 

A competitive autoX set will be tail happy on the street. You have to pick the venue you will drive most of the time. Then try to build in some adjustability by selecting components that you can adjust for each venue. Spring rates (and ride height), unfortunately, are fundamental to handling. Most of the other components are used to fine tune.

Beyond 325/350 for the front begins the transition into the stiff zone ( 2-2.5Hz)...the back can be a little lighter or heavier depending on how much rotation you want. What other modifications have you made? Swaybar?

Koni single adjusable dampers are basically at their max when mated to a 400# spring FYI. So stay under that rate if you want these to last.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by egsleepercivic &raquo;</TD></TR><TR><TD CLASS="quote">just any input on which rates to go with, i want something a little stiffer than the OTS rates, I am not sure if the rates I have listed will get me what I want </TD></TR></TABLE>

My DC2 is a bit heavier than your car, but I daily on 400/400 rates, stock front bar, Comptech 24mm rear. The front is a little soft (I bottom occasionally), and the rear is a bit stiff (gf says she needs a sports bra to ride shotgun), but it has a reasonable amount of rotation for auto-x and HPDE use.

Since you have such a wimpy rear bar, and have intentions of both drag and auto-x, you'll want a stiffer rear. It helps with both rotation during auto-x, and preventing squat on launch. However, the stiffer the rear, the worse the ride quality, and the harder it is to keep the tail behind you in panic maneuvers.

380/320 would be a reasonable starting point if you don;t intend to lower it too much. If you want to use a front camber kit or lower the car more than 1", I'd look into upping the rates a bit. You need to increase front rate with a camber kit, because of how much travel they remove from the front suspension.

 

I guess I just need to know what the OTS rates are then maybe just increase those a little.

As far as autox or drag I not really looking for a set up tailored to either of these, I am mainly looking for a street set up that would be suitalble for a sprited drive in the mountains. the only time I drag my car is when I make change to the engine or get some other mod. As far as autox Its something I would like to do for fun and if I really got into and wanted to be more competitive this set up would allow me to add heavier springs later down the road if needed.

So I guess I am just looking for a starting point. right now I am thinking something like 350f 300r.

thanks for your opinions any more would be appreciated

thanks again

 

Why will a camber kit decrease suspension travel? Aside from the mis-matched K-Mac units out there, the length of the ball joint stud should be the same as the stock ball joint...unless there is something special about a camber kit in particular, ride height determines travel, yes?

And like the above, I'm not picking on anyone, just clarifying...why would a swaybar prevent squat? Assuming a car accelerates on even ground, a swaybar is simply along for the ride. We're discussing drag racing here...accelerating out of a corner is different.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by meb58 &raquo;</TD></TR><TR><TD CLASS="quote">Why will a camber kit decrease suspension travel? Aside from the mis-matched K-Mac units out there, the length of the ball joint stud should be the same as the stock ball joint...unless there is something special about a camber kit in particular, ride height determines travel, yes?

And like the above, I'm not picking on anyone, just clarifying...why would a swaybar prevent squat? Assuming a car accelerates on even ground, a swaybar is simply along for the ride. We're discussing drag racing here...accelerating out of a corner is different.</TD></TR></TABLE>

The balljoint on an adjustable UCA is much taller than stock. Probably because of the mounting for it on the sliding plate. Thats where you lose available suspension travel.

Before I added a front camber kit, I rolled tucking tire and only bottomed out the shocks once in a blue moon (GC extended upper mounts help there). Once I added the camber adjusting UCA, I raised the car up to a 2 finger gap, bottom out regularly, and have dents from UCA contact with the shock tower. Definitely not worth it for a street car, but I wanted more camber than lowering provided for auto-x use.

I said that since he has a wimpy bar, that stiffer rear spring rates would be beneficial for both auto-x rotation, and preventing squat on drag launches. A swaybar doesn't do anything in pitch, only roll (in theory).

 

See, that's exactly why I mentioned the K-Mac kit. I don't know if that is the kit you are using, but it is not a proper kit for many of the US cars. I've used two different adjustable kits - Skunkworks and Omni and both have the same balljoint dimensions as the stock arms. The other unbfortunate side affect using the K-Mac or any kit like it is that setting your ride height based upon that poor ball joint design throws camber compensation curves off - changes roll centers and instant centers which affect the swing arm - camber curve. Seriously, throw those away.

As long as the left and right side of the front and rear suspension/wheels move in sinc, there is no twist in a sway bar. Agreed. Squat and dive for example. Pitch, roll, yaw or any combination cause the bar to twist...or hit a one wheel bump.

Just to be clear, I ordered the K-Mac kit many years ago...2000? and sent it back right away. I purchased the kit from Truechoice...still waiting for my refund of $500.00...


Modified by meb58 at 10:41 AM 2/7/2008