Rear spring rate on 2000 Insight?

commuter · 08-20-2005, 12:17 AM

I already posted this in the general discussion forum, but I need to find out the rear spring rate on the 2000 Insight. I'm having custom struts and shocks made and the manufacture would like to know so that they can figure that into the new shock equation.

Insightful Trekker · 08-20-2005, 08:05 AM

Hi Mike,

Sorry as you probably already know that bit of technical information is not in the Service manual. Unless another member has done something similar to what your trying and calculated the rate I don't know where else you can find it except to do the measurement yourself.

HTH!

commuter · 08-21-2005, 11:29 AM

Thanks for the input. I figured that is what would have to happen.

Dougie · 08-21-2005, 11:09 PM

There's a formula, you know. All you need to do is lie down and take a couple of measurements...

commuter · 08-21-2005, 11:16 PM

Quote:

Originally Posted by Dougie

There's a formula, you know. All you need to do is lie down and take a couple of measurements...

I'm listening. How is it done.

Dougie · 08-22-2005, 09:24 AM

Well, here's the formula. However, if you're paying somebody to make new springs then you're going to have to take the old ones off, so it would be much better to measure them. Your spring guy can do that if you hand him the spring. They're not hard to take out.

The dangerous thing about the formula is that very slight errors in measurement can make a big difference in the result. Note especially that the wire diameter is raised to the fourth power...

http://faq.f650.com/FAQs/SpringRateFAQ.html

commuter · 08-22-2005, 12:20 PM

I'm not planning on replacing the springs as the class I run in for AutoX says that the car needs to stay at stock height. The rear springs are a little light and soft, but I'm hoping we can make the shocks compensate for that. Thanks again for the formula.

commuter · 08-22-2005, 12:23 PM

Quote:

Originally Posted by Dougie

Well, here's the formula.

Are the figures that are now in the formula, at the link, the specifications of the Insight rear spring, or just random figures?

kapps · 08-22-2005, 12:46 PM

They have to be random. There's no way the Insight has 1000+ lb. in. springs. I bet they're somewhere in the 120-150 range.

Dougie · 08-23-2005, 12:11 AM

Those numbers are not for the Insight. I would use the formula for curiosity only.

If you're spending money for springs, especially if you want to change the rate and keep the same ride height, you're going to need to take the car to the spring guy so he can measure the current height, then take out the spring and measure the rate, and then fabricate a new spring that has your desired rate and an appropriate length.

If you go through this, let us know!