I am looking at some coilovers for my 1991 Civic and the choices are making my head spin.

I daily drive my car, but am also building it for weekend drag. I have a boosted D16 in it and am trying to slaughter my 60 ft times. They suck. I am going to be pushing 300hp/250tq soon and need something that will hook with slicks.

I'm trying to find a springrate that won't be crazy and make me hate my car, but I don't want to squat the *** when taking off and the occasional spirited drive.

Is there some sort of calculator that I can put in my vehicle weight/travel/etc to help me decide.

 

There are calculators out there that can give you a ballpark figure for spring rates but you'll need to plug in more than just vehicle weight (not sure what you mean by "travel"), and you're target isn't going to be anything like a 60' time. Simply put, what you're looking for does not exist.

But something tells me that there should be some more intangibles factored into your decision, seeing as to how the car is a daily driver and you don't really know what you want. All cars will squat during a launch, and terms like "crazy" and "hate my car" and "spirited drive" can mean lots of different things to different people.

Very basically though, some of the easiest ways to reduce squat are to increase rear spring rate, raise the rear ride height relative to the front, increase front rebound damping and increase rear compression damping. Depending on how involved you get with your suspension (changing just springs, getting adjustable height coilovers, getting adjustable height and single adjustable coilovers, getting double/triple/quadruple adjustable coilovers), you can do some or all of these things. For a daily driver, I don't see why you'd get anything more than a quality set of adjustable height coilovers.

 

I plan on getting one, but am torn as to the spring rate to get.

My car is pretty damn light and I don't want it getting squirrely on the road. But again, I don't want it to be so soft I can't cut a good 60 ft.

 

You're not going to "slaughter" your times with spring rates.

The stiffer you go in spring rate the more quicky you'll transfer weight from the front wheels to the back wheels (but at X acceleration the amount of weight that ultimately transfers will not change, this is only affected by CG height and wheelbase length), so with stiffer springs (especially rear springs), on launch you might lose traction sooner rather than later.

Note that rear 'squat' it'sn't a cause of rearward weight transfer but is a product of it. If rear squat is substantial then you may even get an advantageous dynamic lowering of the CG (lower CG will result in less weight transfer either longitudinally or laterally), but in this respect you want to avoid front lift. So, theoretically you might want softer rear springs and bump setting on the rear dampers (to encourage rear squat), and a stiff front damper rebound setting (to slow the rate of front rise). Keep in mind though, that stiffer front damper rebound rate (or stiffer rear damper bump rate) will speed up the rate at which any weight transfer occurs.