The mid turn boost

[Bogie]

Here is an observation I've made that may come in handy for new SKY owners, especially those intent on turning off Stability Control.

This is particularly acute when at a stoplight making a left hand turn on a multi lane highway across multiple lanes, but can also rear its head when turning right as well. The key characteristic is a longer sustained turn than normal.

Although we have a small turbo with minimal lag, we still have lag. I've discovered that when accelerating to turn left after stopping at a red light, the turbo tends to kick in midway through the turn, resulting in a boost of acceleration at the apex of the turn. If you are not accustomed to this boost, it can be of sufficient magnitude to break loose the rear wheels (which are already busy providing both acceleration for the turn as well as lateral grip). If you have decide to turn Stability Control Off, it can wipe you out.

Just something to think about. Be cognizant of it. Especially with Stability Control Off.

[TulsaSky]

Sounds like you did a donut in the middle of the intersection?
You did write it was an observation not just a theory, so are we or just maybe embarrassed?
Dang it were is the video camera when you need it
Did that once in our Corvette pulling out of my work parking lot and all the constraints were on fish tailed right, left and then got it back in my lane, thank goodness no one was is the other lane


TulsaSky

[Darkwing]

This was one of the first things I tried when I got mine (in an empty parking lot) just to see where the threshold was. Bogie's right the car will spin.

[puggsleyssky]

Always a treat to read anything Bogie has to say!!!!!

[nomead]

There are already some videos on youtube for this.

What I have noticed is how easy it is to cherp the tires anytime, but especially in a turn directly out of a stop.

I believe that the turn makes it happen more frequently because of the LSD.
One of the tires breaks free because the LSD is trying to keep the wheels going more-or-less the same speed through the turn. This tiny tire rotation, in turn, contributes to breaking loose when boost kicks in.
Sound about right?

[MidniteBlues]

In fact there is a video that was posted on this phenom that really happened on a real day down here in Florida last year. Couldn't find the name of the run, but the guy was making a left turn spun out, lost control, crossed over the lane backwards, right in front of a pickup truck.. I'll keep looking for it.. It was a central Florida run/group... Thankfully nobody got hurt or any damage to anybody.. (except the drivers pride)..

Here it is found it...
Whoops - Do NOT try this - EVER!

[RedHeaded RedLine]

Originally Posted by Bogie

Just something to think about. Be cognizant of it. Especially with Stability Control Off.

Cognizant of it, I am counting on it! -J

[lorennerol]

Originally Posted by RedHeaded RedLine

Cognizant of it, I am counting on it! -J

Yep- if you know and count on it, you have fun. If you don't know about it you get embarrassed.

[mos119]

thanx bogie...keep em comin

[Bogie]

Originally Posted by TulsaSky

Sounds like you did a donut in the middle of the intersection? :

Nope. I keep ESC on all the time. I do remember several months back getting an ESC active event when doing this. And I initiated ESC the other day, but it was somewhat intentional.

The true beauty of ESC is it gives you the freedom to push the envelope without reaping the consequences of pushing too far. I do things in this car I would never do in a car without ESC. But I keep in mind all the time that ESC will not save me if I jump too far ahead of Newton. So it's always entered by slowly creeping up to the limit...a bit more....a bit more.... a bit more...listen to what the tires are telling me....feeling the steering.....all senses in tune for the cues that the vehicle is ready to break loose.

It also lets me know the vehicle has designed understeer (I've heard one of the kappa engineers say this too), but it doesn't take much throttle to change the equation.

I also know that if you break loose in a stable turn, the ESC provides a very smooth response.

[Antonio]

heh heh. overpowering mid turn = WHEEEEEEEEEEEE Scare your significant other, impress the neighbors!

[TulsaSky]

You need to take you Sky to a road track like Hallet in Oklahoma. I was not sure but Harry behind me in his Porsche said Yep I was sliding around the turns, felt like it but when the tires a squalling like wild pigs and your griping the steering wheel at 10 and 2 you feel something letting go just not sure what But in the Sky it slides then somehow catches seems the Corvette not even on a track just kept sliding for a longer time.
Funny how in the Sky I feel in control but more then once our Corvette seemed to get away from me, fish tail when I was not expecting it, maybe I was learning in the Corvette since I drove it first before I got Skybaby.
I had to miss the Jaguar Slalom this year, this is very similar to the SCCA Autocross I would suggest everyone that owns a Redline try and attend one of these events to "TEST" your ability and your cars limits.

TulsaSky

[mikecronis]

Traded-in my 2006 Elise for the 2008 Sky. I noticed EXACTLY the same thing, that during a decent left-hander, while engaging throttle that boost'll kick in and your nice, linear powerslide will result in a vicious ass-spin from hell!

I've considered it and debated it for several days. I think the key is to modulate the throttle to less-than-halfway while still accelerating briskly. By doing this, the boost never goes above 4 or 5 PSI and the acceleration will remain linear instead of exponential and uncontrollable.

It's actually quite a delight to have to relearn hard turns with this vehicle as that turbo is incredibly naughty.

There are a few other possibilities I thought of:

Firstly, the car desperately needs a stiffer suspension. It's so... mushy! Perhaps an under-car thicker bar might help? I don't see any during a search on this forum. I'm checking with SaturnMotorSports.

Secondly, the car desperately needs a thicker rear tire. I believe a 275/40-18 will be the same tire height to the 2 thousandths of an inch and will fit in the rear well.

Thirdly, stiffer Eibach springs are in order I think, perhaps a lowering of 1/4".

Anyone try these things yet?

[Elff]

I'm curious, why did you go from an Elise to a Sky?
I love the elise.

I decided to put this to the test to see just how bad this can be {and after watching the You Tube of the person spinning out from a dead stop}

Sooo, in an empty parking lot, I put the sky into competition mode, cranked the wheel left and stomped it.
Basically the car switched ends and barely even moved forward.

I was expecting one hell of a donut, I just wasnt expecting the something that crazy.

Needless to say, and to quote/paraphrase the driver on a really fun TV show
"My smile was so wide, it ate my ears"

Unless I am on a racetrack, or an empty parking lot, this puppy is being driven with both traction and stability control ON!!!!

[Bogie]

Originally Posted by mikecronis

Firstly, the car desperately needs a stiffer suspension.

Look into the Z0K suspension package for the Solstice. Don't remember if it's good to go on the SKY or not, but it's what they run on the SCCA Solstices. I hear it's very good on the track.

[|V3nom|]

Originally Posted by Bogie

Here is an observation I've made that may come in handy for new SKY owners, especially those intent on turning off Stability Control.

This is particularly acute when at a stoplight making a left hand turn on a multi lane highway across multiple lanes, but can also rear its head when turning right as well. The key characteristic is a longer sustained turn than normal.

Although we have a small turbo with minimal lag, we still have lag. I've discovered that when accelerating to turn left after stopping at a red light, the turbo tends to kick in midway through the turn, resulting in a boost of acceleration at the apex of the turn. If you are not accustomed to this boost, it can be of sufficient magnitude to break loose the rear wheels (which are already busy providing both acceleration for the turn as well as lateral grip). If you have decide to turn Stability Control Off, it can wipe you out.

Just something to think about. Be cognizant of it. Especially with Stability Control Off.

im not trying to be rude or anything, just straight up, but if you have ANY common sense you should know that accelerating in a turn will cause the tires to break loose. im not talking a little bump on the accelerator, i mean flooring it. you have to be a complete id10t to not know, this being with the esc off of course. ive never done this but i dont need to to figure it out. SHOULD be common sense but there are those people...

[Elff]

Wjat Bogie is saying is that on a turbo, and our Turbo in particular, it's more abrupt than a natually aspirated or supercharged car.

[Bogie]

Originally Posted by |V3nom|

accelerating in a turn will cause the tires to break loose.

Not true. Acceleration reduces your lateral grip, it does not eliminate it altogether. The more applied to acceleration, the less you have for lateral. The more you use for lateral, the less you have for acceleration. As long as the COMBINED lateral and acceleration grip is less than the grip of the tire, the tires will not break loose.

The point here is a normally aspirated engine has a linear acceleration curve, which allows a driver's linear throttle input to be map to a linear acceleration profile on the turn. A turbocharged car does not have a linear mapping once the turbo spools and kicks in. Hence, a linear throttle input can reap a non linear acceleration response. If a driver is not cognizant of the non-linear boost that can occur at the curve apex, and accelerates as if driving a normally aspirated vehicle, they run the risk of breaking loose where they would not otherwise do so with a non turbo vehicle.

[|V3nom|]

moral of the story: dont accelerate through a turn if you havent driven your car more than once .

[RedHeaded RedLine]

Originally Posted by mikecronis

Firstly, the car desperately needs a stiffer suspension. It's so... mushy! Perhaps an under-car thicker bar might help? I don't see any during a search on this forum. Secondly, the car desperately needs a thicker rear tire. I believe a 275/40-18 will be the same tire height to the 2 thousandths of an inch and will fit in the rear well.
Thirdly, stiffer Eibach springs are in order I think, perhaps a lowering of 1/4".
Anyone try these things yet?

Yeah! Could you just see a chick, 5th grade teacher crawling under the car and helping installing an Eibach swaybar... -J