autocrossing at redline

[travisb]

I have my first autocross in the BRZ this Sunday. I should go over the 1000 mile mark on Saturday.

I've autocrossed before in a 5-speed Miata and a 4-speed automatic Hyundai Accent before that.

I was always fine leaving those cars in 2nd gear without hitting the rev limit.

I'm wondering if I'll be hitting the limit in the BRZ. And if I do, is it ok to run it maxed out in 2nd for a few seconds or better to shift into 3rd? Will leaving it in 2nd cause any issues?

For reference, I found these numbers on another site for the twins.

At 7400 rpm the speeds in each gear are respectively:
1: 35 mph
2: 58 mph
3: 83 mph
4: 105
5: 127
6: 135

[codesplice]

I haven't found out from personal experience yet, but from reading around a bit it sounds like the rev limiter kicks like a mule and should probably be avoided if possible.



That said... I've browsed a lot of autox/track-related threads today and I can't remember or find where I saw that mentioned. (Trying to mentally prep for my first autox event in two weeks )

[juliog]

FYI, the stock ECU tune won't let you over-rev during acceleration and will cuts fuel/throttle after redline, you will experience loss of power for a couple seconds when that happens.

Keep in mind that you can still over rev —and potentially damage— the engine if you screw up a downshift, though.

[tahdizzle]

redline in 6th is not 135.

[dradernh]

Originally Posted by juliog

Keep in mind that you can still over rev —and potentially damage— the engine if you screw up a downshift, though.

No kidding - those money shifts can be brutal. On the wallet.

[travisb]

Originally Posted by tahdizzle

redline in 6th is not 135.

Correct. The site that made the reference, Car and Driver, said it was the top speed, drag limited.

[travisb]

So it looks like I'll have several things to worry about my first time out in this car:

1. potentially switching between 2nd and 3rd and back to 2nd quickly
2. traction control, I don't want to turn it completely off my first few times out
3. lack of traction on the stock tires

This should make it interesting.

[JB86'd]

I just did my first autocross with the stock tires recently, on a pretty big course at El Toro. I didn't find the revs a problem. Watching my gopro recordings I hit 57 for an instant, but again this was a large course. I ran once with VSC sport and then turned the TC off for the rest. The stock tires can definitely be "interesting" if you push them.

[cactus]

If it was a few weeks ago, I did the same event as @JB86'd and didn't hit the limiter. I have never hit the limiter at the events in Oakland, but the courses are kind of small.

Turn off traction control, that is the best way to learn how to control your car. I cant think of a better place to learn the limits of your car than a big, open parking lot. You wont learn where they are unless you get past them(slide, spin, plow like an Audi).

Stock tires dont have much grip, but they will get you to drive better then going out with super sticky tires your first time. They also squeal like pigs, so you know when you are over driving them.

[fstlane]

I've only shifted into 3rd a couple of times and it was on a large airstrip autox site. Generally you will loose more time by upshifting and downshifting rather then just riding the rev limiter in 2nd. I've ran up against the 7600rpm soft rev limiter on my OFT tune a few times and it was very subtle unlike the stock tune. If you're running the stock tune I would try setting your shift light to 7200rpm and lift a bit when it flashes so you can avoid the hard fuel cut.

[Thorpedo]

A few of us experience a very soft factory limiter for some reason... There seems to be a large variation that no one has figured out yet.

(I know it isn't actually though)

[Nm86]

Like mentioned above, you probably won't need to get out of second gear, I have only done so on one course, that being an airstrip. Also I tried the same course without shifting. On the limiter for a few seconds no big deal. I don't recommend you drive down the interstate hitting the limiter constantly but a few seconds won't hurt. Best advice stick it in 2nd and focus on driving.

[Vracer111]

Originally Posted by Nm86

Like mentioned above, you probably won't need to get out of second gear, I have only done so on one course, that being an airstrip. Also I tried the same course without shifting. On the limiter for a few seconds no big deal. I don't recommend you drive down the interstate hitting the limiter constantly but a few seconds won't hurt. Best advice stick it in 2nd and focus on driving.

When the limiter kicks in the engine rpms drop by 1000+ with power abruptly cut off for a little before coming back on gradually. Well that's what my car does, so I avoid hitting the limiter at all cost...because that's about 2 seconds of non nominal acceleration.

[SeanRTR]

Originally Posted by travisb

So it looks like I'll have several things to worry about my first time out in this car:

1. potentially switching between 2nd and 3rd and back to 2nd quickly
2. traction control, I don't want to turn it completely off my first few times out
3. lack of traction on the stock tires

This should make it interesting.

Turn of the traction control all the way for the love of god. You won't die, i promise.