Handeling Thread

[yellowss7]

Since it is our own run group, I'm sure we can get some agreement to take a lap or 3 at a moderate pace to show the new guys the line. As you correctly assumed, you definitely want the car settled before mashing the go pedal or you will go around, as the backend is last to settle as you go over the hill.

I find that the key is aiming for the curbing on the right with the car following the angle of the curbing, remember that the track is curving to the right, so if you take a line that aims for the middle of the track, you will go straight off. That's where people get into trouble as they try to steer while the car is light and nothing good can happen then.

 

Turn one is similar in that it is also blind and although not off camber, you can get light on it as well and again, if you put two wheels off, trying to come back on will most likely result in meeting the tire wall on the right. There are some YouTube videos, that prove that, like this one.

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[xcarguy]

Turn one is similar in that it is also blind and although not off camber, you can get light on it as well and again, if you put two wheels off, trying to come back on will most likely result in meeting the tire wall on the right. There are some YouTube videos, that prove that, like this one.

 

That's food for thought! :ack:

[HOTTTCAR]

Lost a friend that way at Heartland before they got the tires placed in front of the wall .....new Porsche ...front fuel cell.

Gale

[AndyB]

Not sure this is the correct place to bring this up but it definitely effects handling so wheel/tire size?

Although my white spoked Revolutions look great my very inexperienced butt tells me their 195.50.15 size might be too much tire for the car.

Can my old (1976) Caterham/twin cam combo which only churns out 140 hp at the best of times and weighs in at 1165lbs plant sufficient weight to give optimum grip? I am running Dunlop Direzza Z1 Star Spec for mainly road use and a little autocross.

[Kitcat]

Best tire? Derserves its own thread:). It's like asking what the best oil is.

 

But...,I ran 205x50x 15' Toyo RA1'a on my X-flow wh/weighed a bit less and made less power and the tires were perfect on and off the track. They weighed a ton, BTW.

 

You dont want super grip unless you have a dry sump/Accusump set up as the grip advantage is soon offset by oil starvatin and a dead engine(:.

[Nick OTeen]

At long last, a Handeling thread.

 

Hallelujah.

[JBH]

After watching that video of a crash on Lightning, I am going to start a driving thread that emphases proper line and smoothness.

 

With respect to handling, that BMW was downright evil.

 

Kitcat - I run Hoosiers and never see oil starvation. I'm not sure you need an Accusump (though I wish I had a dry sump), but maybe I am not driving fast enough.

Edited February 10, 2014 by JBH
I changed from "should start a thread" to starting one

[BruceBe]

...Kitcat - I run Hoosiers and never see oil starvation. I'm not sure you need an Accusump (though I wish I had a dry sump), but maybe I am not driving fast enough.

 

Often, you do not "see" oil starvation, especially if you're relying on a gauge, and waiting until you have a moment to look.

 

The tendency toward oil starvation is exaggerated by track configuration. Long, sweeping, high-grip and high G-loaded turns are the worst. Turn 2 at Thunderhill is a benchmark turn for oil control.

 

Kitcat - I wouldn't recommend pulling the Accusump.

 

Cheers,

-Bruce

[xcarguy]

Often, you do not "see" oil starvation, especially if you're relying on a gauge, and waiting until you have a moment to look.

 

The tendency toward oil starvation is exaggerated by track configuration. Long, sweeping, high-grip and high G-loaded turns are the worst.

 

Cheers,

-Bruce

 

At the risk of hijacking (but, hopefully not) this great handling thread, I wanted to chime in add a bit of substantiation (at least, from my perspective and experience) to BruceBe's excellent comments. Last year, I did three HPDE’s at MSR Cresson and ran the 1.7 course each time. The first HPDE, I ran the track CW; the last two were run CCW. While my input here refers to my own experience with my LS6 in lieu of my Duratec, Zetec, etc.-powered brethren, the idea is still the same.

 

It’s no secret in the LS circles that most makes of LS engines have oil starvation issues (for lack of a better term) in hi G-load turns to the left; right-handers, not so much an issue. Below, I’ve posted a video from each of those HPDE’s. Installed on my car, in addition to the oil pressure gauge, is a 20psi low oil pressure switch which activates a red light (mounted about mid-dash) anytime the switch senses a drop in oil pressure below 20psi.

 

The first video (CW run) reveals no low oil pressure light illumination at any time during the session.

 

The second video is of the second HPDE (CCW). All throughout the session (starting around 3:41 in the video), the low oil pressure light illuminated momentarily during turns, coming out of turns, combinations of both. So, to substantiate BruceBe’s point, I NEVER saw the light while on track because of WHERE and WHEN the light was illuminating. I was too busy setting up for the turns, looking for the apex and track out. I’m checking my gauges only after well established on the straights, not while in turns or coming out of turns. It wasn’t until I reviewed the video that I saw just how much the light was illuminating in running the course CCW vs running it CW. Luckily, there was no engine damage. In all fairness, the oil pressure could have been dropping each time to just below 20psi, but I’ll never know for sure because the oil pressure gauge is hidden behind the steering wheel in the videos.

 

The third video (third HPDE: CCW) is after I installed an aftermarket oil pan baffle and a new windage tray which, for my engine, made all the difference. During the last session of that particular day, I let Lance Adams (friend and instructor) drive my car. I sat shotgun and observed things in ways I simply couldn’t when driving. One of those was the oil pressure gauge; nowhere on track did it ever drop below 50psi. And the 20psi light never illuminated.

 

 

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But back to the points BruceBe made; I never ‘saw’ the oil starvation issue in the second video while on-track, and track configuration definitely played a huge part in ‘exaggerating’ the oil starvation situation.

 

Having said all of this, simply hunting and pecking through the videos will substantiate the points BruceBe made; sorry for Creed and bad audio. And don’t rake me over the coals for hunting lines, apexing too early. etc. . . . . I’m working on it. :jester: And yes, I should probably move the low oil pressure light to a better location.

 

Okay, back to HANDLING!!!!!

Edited February 14, 2014 by xcarguy

[JohnK]

Comments on the fabrication.

. . .

At this point (late January 2014)I'm hopefully not too many months away from being able clean, prime and paint all the bits and install them. I have in progress a support I'm fabricating for the differential. And I'm desperately searching for a differential I can buy that has an LSD and 4.111 ratio - which the car really deserves. And, of course, am looking fwd to installing and testing out my little project.

 

Should I make the headlines due to me and my car's new suspension's involvement in a spectacular crash sometime this coming summer, I hope you're listening to the news so you can say, “Hey, I knew that guy!”

 

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Just a heads up here that I have completed this little project and

---Over a thousand miles on the road, It hasn't flung me into the weeds by handling badly and none of my fabrications have broken.

---It does work as intended, and it does what I intended it to do even better than I'd hoped considering so much of the work depended on seat-of-the-pants decision making.

 

Apologies for taking so long to get back to the topic but I wound up having to do other fixes along with the rear suspension and there were some other things that kept me away from the project. As I fiddle with the details I'll put together a wrap-up to tie the last bits together.

 

Net: the car now shows just a bit of understeer and tossing the car into a corner the rear end is PLANTED just as solidly as the front. It worked.