New "milder" Setup

[Loren]

As some of you may know, I've been running a K-Sport coilover kit pretty much since I bought the car in April of 2008. I never used the soft rear springs (2.2k) that came with the kit, I started out with 4kg/mm rear springs (the fronts are 4k) and upped them to 7k a while back. I also have a 23mm rear bar (thanks, Garm!) and a fairly aggressive alignment. The car has handled VERY well with this setup, but the ride quality on the street and the clunkiness of the rear spring setup (I kludged on some Tein springs that I had laying in the garage, they didn't fit quite right) was really starting to get on my nerves.

So... I decided to move myself back to the local autocross club's version of "stock class". It's a pretty liberal class, really. A lot of stuff is allowed, but a few key things aren't. The biggest thing is springs. I have to run stock springs at stock ride height.

Last weekend, I pulled most of the K-Sport kit, went back to completely stock in the front and stock springs w/ K-Sport shocks in the rear. The ride was surprisingly HORRIBLE! I didn't have time to mess with the shocks last weekend, and thought I had them extended near their max, and they were clearly at the end of their travel with the car at rest. The shocks behave oddly at full extension, not wanting to compress, even set at full soft... and with no room to extend... it was almost like having a solid steel bar for a shock! The rear suspension was totally locked tight at the stock ride height. I thought I might need to get another set of rear shocks (or fit the stockers back on there for a while).

Today, I pulled the rear tires to look at the rear shocks. I was half right. I was pretty sure I'd set the height within about an inch of its limit, and I did. But, it was 1" from their shortest length, not their longest. I had over 6" of shock length to play with! So, I used probably 5" of that and set the shock length so that the rear suspension can go full-droop without interference from the shocks.

Happily, now with the rear shocks set at full soft, the ride is delightfully smooth. (but still nicely balanced due to the big rear swaybar) And cranking the rear stiffness up a few turns shifts the weight transfer more to the front to plant the front in aggressive driving. I'll be testing it tomorrow at an autocross.

Also have a new set of Dunlop Star Specs (195/55-15) in the garage ready to go on next week.

The key thing I learned this week is that just like not having enough suspension travel due to lowering the car too much, if you don't have enough EXTENSION travel on your shocks, the ride can be just as bad, if not worse. An interesting situation that I'd never found myself in before.

[The Spectacle]

Interesting.

[Loren]

Autox test passed with flying colors. Even with my crappy worn out Toyo T1-R tires, it was very nice. Can't wait to get the Star Specs mounted and kick some ass at the next autox in a couple weeks!

[justjesus]

Interesting read. Thanks for that info.
keep us posted on the autoX as well!

[Shinmei2006]

Hey Loren,

Fellow TR member here (seen your spitfire at Jeff's shop a while back too).

How'd the AutoX go with the semi-stock setup?

Also, heard great things about the Star Specs.

[Bluevitz-rs]

I did the same thing this winter on my echo. But only because my koni's were rusting beyond belief. I have a TRD rear bar added to stock built-in bar, plus a 25mm front bar. I have the complete stock front spring strut combo, and stock spring with TRD shocks rear setup. I was amazed how well it handles. The car is still very flat through corners and is very neutral. But I do notice the stock front struts wallow a bit if pushed hard through corners with any bumps or dips.

So I think if I was to Solo, it would be an awesome setup with the Konis and stock springs.

Do you have to run stock struts up front, or was it the only thing you had to mount the spring to?

[Loren]

Hey, gang. Yeah, I'm running stock front struts because I couldn't fit the stock springs to the K-Sport struts without fabbing up some kind of a spring perch. The stock struts are new (5k miles), so they should be okay for a while.

Mounted the new Star Specs a couple days ago. Man, they feel good! Autocrossing this Sunday, but I'm scheduled to drive someone else's car. Might take a couple runs in the Yaris just for fun, though.

[Loren]

Finally got some runs on an autox course with some times today.

April 24 Autox Results
If you scroll down to the "Mod Street Tire DSP/FSP" section, you'll find me. It's a little misleading, however, as I mostly co-drove another car today. The first TWO runs are my Yaris. The rest were in the #580 car.

Here are the best times from the above results sorted by time:
Results by Time

FYI, in its current state, my Yaris would actually run in our slowest class, the "Prod street tire GS/HS" class. (listed as Class J on the results by Time sheet) I'd have won that class with my 52.1 in the Yaris today if I wasn't competing in the E3 class.

This is on the stock suspension with K-Sport rear shocks (from the coilover kit) and the 23mm rear bar on 195/55-15 Star Specs.

With the rear shocks set at about 3/4, I'm very pleased with how the car handles. I found the Subaru that I drove today would understeer A LOT more at a much lower speed... and he's on the same tires. Very pleased am I.

(Mods, I just realized that I originally posted this in the "Performance" category, should probably be filed under "Suspension". If anyone cares.)

Might have some video later. I know someone shot some. The car doesn't 3-wheel dramatically, as it did with the full coilover kit, but I hear it looked pretty good out there!

[Loren]

Not the best video (my videographer must have lost me because I was going so fast ) , but it's always fun to see a Yaris on an autocross course.

http://www.youtube.com/watch?v=Cwy79bdIWso

[Bluevitz-rs]

For stock springs it sure corners fairly flat. :)

[Loren]

Originally Posted by Bluevitz-rs

For stock springs it sure corners fairly flat. :)

That's the result of the 23mm rear bar and the rear shocks set at about 3/4 stiff. It felt really good. I had no complaints.

I'll try going full stiff on the rear shocks and see how I like that. Once I have the rear shocks dialed in (the only adjustment I have on the suspension now besides alignment), then I'll start playing with tire pressures. I'm sure it will be a little bit better with everything tweaked just right.