Spring Preload?

SKYHI · Postby **SKYHI** » Thu May 15, 2008 11:13 am

Hey guys,

I have my Tein Flex coilovers ready to go in the car and wondered how I determine the optimum spring preload on them?

Paul.

Juffa · Postby **Juffa** » Thu May 15, 2008 1:03 pm

Mine came with measurements for the distance between the upper mount and the lower spring perch. I think if you get on the Tein website you can download this as a PDF.

J

SKYHI · Postby **SKYHI** » Thu May 15, 2008 1:06 pm

After some more research I found out that the amount of preload really determines the amount of travel in the shock. Apparently it can be quite hard to find the sweet spot in the rear shocks as they are somewhat limited in the amount of travel they have before hitting the bumpstops. Emilio from 949 has suggested that I measure the droop between the ride height at rest and the same height when both front or rear wheels are unloaded. The droop should be approx 51mm front and 44mm in the rear.

There is also quite a bit of good info in this thread:

http://forum.miata.net/vb/showthread.ph ... =Tein+Flex

Paul.

Juffa · Postby **Juffa** » Thu May 15, 2008 1:10 pm

I was just going to point out that same thread

I must get around to trying some ideas from that thread.

J

SKYHI · Postby **SKYHI** » Thu May 15, 2008 1:11 pm

Juffa wrote:Mine came with measurements for the distance between the upper mount and the lower spring perch. I think if you get on the Tein website you can download this as a PDF.

J

Yeah I have this info in the paperwork that came with them but the actual amount of preload can vary depending on the car weight (mines stripped out) and the spring rates (I have 9kg fronts). It all seems to be a abit of trial and error depending on your preferences and what the intended use is, so I'll just play around a bit.

Paul.

CT · Postby CT » Thu May 15, 2008 3:15 pm

At full droop, make sure the spring is lightly trapped so it doesn't bounce around - that way you have maximum travel and don't get any extra bumps or noises from the suspension.

SKYHI · Postby **SKYHI** » Thu May 15, 2008 5:19 pm

CT wrote:At full droop, make sure the spring is lightly trapped so it doesn't bounce around - that way you have maximum travel and don't get any extra bumps or noises from the suspension.

Wouldn't that give you maximum rebound travel but vey little bump travel?

You'd be just about riding on the bumpstops?

Paul.

Mactype · Postby **Mactype** » Thu May 15, 2008 5:33 pm

Your working with the length of springs and shocks you have at hand.

Just set it up to give you the ride height your looking for. It all a compromise.

SKYHI · Postby **SKYHI** » Thu May 15, 2008 5:42 pm

Mactype wrote:Your working with the length of springs and shocks you have at hand.

Just set it up to give you the ride height your looking for. It all a compromise.

Preload and ride height can be adjusted by seperate adjustments. Adjusting the ride height will actually have no affect on the preload. Setting the preload is really about finding a balance between having enough bump and rebound travel. Not enough preload and you will not have enough bump travel therefore hitting the bumpstops, too much preload and you'll run out of rebound travel.

The rule of thumb seems to be set the preload to get the travel right and then adjust the ride height to suit.

Paul.

Red 2f MX5 · Postby **Red 2f MX5** » Wed Jun 04, 2008 9:34 am

I set my pre load exactly the way CT said. When the car is on a hoist or on stands have the spring so it is lightly trapped and doesn't move around.
Then adjust your ride height accordingly.
These are so easy to make ride height adjustments with.

Cheers
Brett

bruce · Postby **bruce** » Wed Jun 04, 2008 10:51 am

What a heap of work to get a good set up ! Sometimes you just wanna stay stock.

SKYHI · Postby **SKYHI** » Wed Jun 04, 2008 10:58 am

bruce wrote:What a heap of work to get a good set up ! Sometimes you just wanna stay stock.

Playing around with the car is actually what makes it interesting for a lot of people. There are only so many times a year you can actually get the car on the track, so you need something else to do in between. There is also no better way to learn about the cars than to be hands on with it .

Paul.

Red 2f MX5 · Postby **Red 2f MX5** » Wed Jun 04, 2008 11:34 am

Playing around with the car is half the fun. Making changes and seeing a difference on the track. They don't have to be expensive changes. Just little things like wheel alignment settings, shock settings. swaybars etc.
It helps people to understand the car they are driving and what it is capable of.
Most of the guys i know that own racecars love to play around with them. And sometimes the smallest of changes can make a huge difference. To me that is part of racing.

Cheers
Brett