What have we gotten ourselves into? Added a rear spoiler to the Austin Healey Sprite for GP SCCA Autocrossing.

As noted from the last event, we have introduced a lot of understeer into Don’s ’66 Austin Healey Sprite.

To counter this, and to help keep the inside rear tire from spinning all the time, we decided to add a rear spoiler w/in the limits of G Prepared (GP) class for the next event. Don did a spectacular job mocking up & installing the spoiler. I helped a little by drilling the first few holes, hee hee.

Anyway, a few “interesting” things happened:

- We oversteered early mid-corner & even worse after mid-corner w/ any kind of throttle input over 5-10%. This was not an issue in the other 2 events earlier this year.
– this was totally unexpected, but keep reading.
- The inside tire still spins @ lower speed exits

So, after a lot of discussion between the two of us & w/ other colleagues, it seems we did increase the downforce by quite a bit. However, because of this, the quaife differential is now able to put more power to the outside rear wheel, which explains a lot of the of drifting action going on.

Regardless, we both felt this makes the car too difficult to drive. We had to change our driving lines to keep the car from getting upset, but those were defnitely not the fast lines… :(

We tried several band-aid solutions, such as adjust the rear height & playing w/ the shock settings, etc. We can probably also change the angle of the spoiler, but the spoiler is in fact doing exactly what it is suppose to do. If anything, we want a little more downforce at lower speeds!

We finally decided it was time to give the welded differential a try again. We’ll see how that goes next event!

In the mean time, here’s what the sexy little red sprite, I’m naming her “Austin” unofficially since I don’t think she has a name yet, looks like now:

Don's Austin Healey Sprite GP with spoiler

And here is a video of me trying to take the fast line (more vids on the youtube page):

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