TTO: a force to be reckoned with.

[CobraDan]

http://www.drivingfast.net/car-control/oversteer.htm

[twobjshelbys]

Originally Posted by CobraDan

http://www.drivingfast.net/car-control/oversteer.htm

Very interesting!

Drifting is just controlled oversteer. I guess I always knew that but the pictures there demonstrate it well.

[tin-man]

I'm certainly gettinga lot of help and knowledge from the members and I thank all of you most humbly. Please keep these coming and I am thankful the driver in the vid lived to talk about it. Seeing that vid makes me fully apprecaite the power that is latent within the Cobra and the absolute destructive force that can be experienced if not driven correctly and not set up to optomize any racing or track events.

With respect, guys, John, AKA, tin-man

[dallas_]

You probably won't find any of those books in the last bookstore you were in though.

[tin-man]

Originally Posted by dallas_

You probably won't find any of those books in the last bookstore you were in though.

I went in the "Wong Fook Hing Book Store" here in Zhuhai and asked for a Cobra book, they gave me a book about snakes and smiled most politely, go figure.

John, AKA, tin-man Zhuhai, P.R.C.

[Silverback51]

Originally Posted by tin-man

I went in the "Wong Fook Hing Book Store" here in Zhuhai and asked for a Cobra book, they gave me a book about snakes and smiled most politely, go figure.

John, AKA, tin-man Zhuhai, P.R.C.

Was it a cook book?

[RallySnake]

Tin-Man,

You got some good advice here, but not the BEST advice. Taking your new Cobra to a track day is a bad idea. Going to a driving school is good, but not the best first step. I have been driving my Arntz Cobra 25 years now and have had many "near death" experiences. My Guardian Angel is pretty beat up! I will explain how to stay alive.

The first step is to take your Cobra to an SCCA Solo2 event. If there's any question about which class to enter, just ask for B Street Prepared. These events are set up on large parking lots and the course is lined with rubber cones. You drive around the course as fast as you can and the electronic timing gives you a very accurate result. The important thing is, that you do this at low speeds. You may hit 50 or 60 on the longest straight. At these speed, you can make massive mistakes and lose nothing but a little rubber off your tires and a ding in your ego when the workers laugh at you. It is tremendous fun! You will find out how badly your car handles and what is going to happen at the limits of traction without endangering fellow motorist. The people at Southern California events are very friendly and can give you tips on tire pressures and suspension setups.

On my first event, I swung around a left hand curve and my rear end suddenly snapped to the right at about 45 mph and the side of my helmet was pelted with bits of gravel and rubber. That's when I learned how important a front roll bar is. On another event, I couldn't get the front wheels to grip and slid them through the turns. That's how I learned that I needed a rear rollbar. As I progressed, I kept improving my car and my driving.

Early on, you learn to get your braking done before you turn the wheel, then, use power to accelerate through the turn. Later, you learn that if you leave the braking until the last possible moment and stab the brake pedal hard just before you turn in, the brakes will help you rotate the car. If you get it just right, the car will slide and you will countersteer, apply throttle and catch it and come out of the turn with the rear tires smoking and feeling like a hero. If you are a very slight bit too late on the brakes, the car will continue all the way around and rubber cone will fly in all directions amd you will encounter more laughter. When you have reached this level and are very confident knowing exactly when the tires will let go and how to handle the situation, you are ready to proceed to run your car at higher speed at a track day.

RS

[WardL]

Great advice and it sounds like a LOT of FUN too! On the class, I thought it was BS, when is it BSP? Opps, forget it, I'll get written up for stealing a thread.

[tin-man]

Originally Posted by RallySnake

Tin-Man,

You got some good advice here, but not the BEST advice. Taking your new Cobra to a track day is a bad idea. Going to a driving school is good, but not the best first step. I have been driving my Arntz Cobra 25 years now and have had many "near death" experiences. My Guardian Angel is pretty beat up! I will explain how to stay alive.

RS

Whenever anyone recounts a many near death experience I pay attention and am borderline anal retentive. Jeeez, if this car can make a turn at a lowly speed of 45mph and still spin out, how can anyone ever attempt a high speed turn without losing their cool??

Now I am begining to realize maybe this car is more than I ever bargained for given the power and torque I have and there is no doubt in my mind I will become a permanent fixture at Bondurant Driving School until I have the confidence to take it out for a real spin.

That said, I need some advice from anyone who has an automatic tranny and are willing to share their driving experiences particularly when slowing down going into a curve.

Guys, please forgive my naivette here, I'm still waiting for my car and am doing what I consider is my due diligence in endevoring to determibne what I will experience real time when I drive, thus all my questions. I fully realize taking the beast out for its first dance will see how much I have assimilated from all your experiences and advice.

I am humbled by all your collective experiences and am thankfull for the opportunity of being a member of a club populated by such Cobra enthusiasts.

Keep the advice coming and thanks.

Cheers, John, AKA, tin-man

[Tommy]

Originally Posted by tin-man

I need some advice from anyone who has an automatic tranny and are willing to share their driving experiences particularly when slowing down going into a curve.

I had the good fortune to spend a day at the GM test track near Mesa, Arizona some years ago. I spent more than an hour that day flogging a 1989 Corvette auto around an oversized autocross track they had set up. I'd make one pass through the three minute size course then hit the long straight for a minute to cool the brakes and do it again. I used up a set of tires during that hour. The Corvette had an automatic transmission and antilock brakes. The GM driver who showed me how to drive the car said the key to quick times was to trust the antilock feature and brake late and hard. The automatic transmission seemed to always be in the gear I wanted when I wanted it. I don't recall it ever adversely affecting my entry into a turn. I left thinking that an auto transmission car would likely be quicker around that course than a manual, especially if I were the one driving it.

One other comment - You're wise to have great respect for the potential to lose control of a Cobra. But don't go overboard. If you plan to drive the car hard, or you doubt your ability to resist the urge to open it up from time to time, then your caution is warranted. But if you take it easy while you're getting accustomed to it, and you save your spirited driving for autocross events and the track, you should be fine. Even on the track, there's nothing that says you have to enter every corner at 100% of your car's capability. If you enter a corner using 75% of the car's grip and mishandle the power or brakes a little, you've got a pad that can allow you to learn from your mistakes without going off the track.

[WardL]

Something else to consider. I have Michelin tires and they have a reputation for being a little unpredictable. Maybe they hold the road well, but then unexpectedly they brake loose when you don't expect it. What about the operating temperature of the tires? Seems like even in autocross you start off with cold tires and with such a short track with no warm-up lap, you will always be on cold tires! I think it is another variable, if you start hot rodding around when your engine get's warmed up that's ok for the engine, but who remembers to warm up their tires?

[patrickt]

John, what is the status of your car? Last I remember there was a problem with the trans spacer and starter motor, but that seems like ages ago. Is delivery scheduled?

[tin-man]

Originally Posted by patrickt

John, what is the status of your car? Last I remember there was a problem with the trans spacer and starter motor, but that seems like ages ago. Is delivery scheduled?

Eventually got the parts for the tranny, but the power steering motor had a fitment issue with the side of the body and the body had to be modified[cut]to allow the motor to fit. Then there was an issue with the steering mechnism that needed some part of the frame modified, [cut]. While I have been worried about the body and frame modifications I have been assured there is no affect on the structural integrity of the body or frame.

Unfortunately, there is now some issue with the tranny linkage that needs sorting out but other than that is should be ready I am guessing some time in June. I have asked for a list of what else has to be done and that is forthcoming. Not sure if this is beacuse I am in China, but it sure is taking a long time.

Cheers, John, AKA, tin-man

[xb-60]

Originally Posted by tin-man

Guys, please forgive my naivette here, I'm still waiting for my car and am doing what I consider is my due diligence in endevoring to determibne what I will experience real time when I drive, thus all my questions. I fully realize taking the beast out for its first dance will see how much I have assimilated from all your experiences and advice.

I am humbled by all your collective experiences and am thankfull for the opportunity of being a member of a club populated by such Cobra enthusiasts.

Keep the advice coming and thanks.

Cheers, John, AKA, tin-man

Well said, tin-man! I, like you, don't have a Cobra replica in my garage yet, and also like you, I am on an 'intelligence gathering mission' in preparation for that great day.
Almost all forum members are extremely forthcoming and generous with advice and good natured humour, but just occasionally, when giving my opinion, I have been criticized because I am a 'wannabe'.
I unreservedly appreciate the opportunity of being a member of this great community of enthusiasts. The collective experience and knowledge, mixed with light-hearted banter is much appreciated.

Cheers!
Glen

[xb-60]

Originally Posted by tin-man

Eventually got the parts for the tranny, but the power steering motor had a fitment issue with the side of the body and the body had to be modified[cut]to allow the motor to fit. Then there was an issue with the steering mechnism that needed some part of the frame modified, [cut]. While I have been worried about the body and frame modifications I have been assured there is no affect on the structural integrity of the body or frame.

Unfortunately, there is now some issue with the tranny linkage that needs sorting out but other than that is should be ready I am guessing some time in June. I have asked for a list of what else has to be done and that is forthcoming. Not sure if this is beacuse I am in China, but it sure is taking a long time.

Cheers, John, AKA, tin-man

Hi John. A couple of questions or comments....
1. Looking at your engine description - Roush 511IR with 572HP - I suspect you may be able to comment significantly on my 'How much power is enough' question when yours is on the road....
2. Is your auto to be setup conventionally with throttle actuated kickdown? Even with quite low powered cars, a mid corner change down that might not have been fully expected can easily unsettle the rear end (of the car). And then you're at high speed in reverse. Or getting giddy.
3. Are you really in China?

Cheers,
Glen

[Barnsnake]

Tin-Man,
Your desires to understand the dynamics of these vehicles are well founded, but I think you may be stressing a bit too much over this issue.
Here's the bottom line:
If you charge into a corner faster than the vehicle is capable of taking the corner (let's call that 105%), you're going off. This applies to a mini-van, a Prius, a Peterbilt, or a Cobra. Some may go off forwards with understeer, some sideways in a drift, and some backwards with oversteer.
Now let's say you went into the corner at 98% (which you should never even approach outside of a racetrack), you can theoretically make the corner. The key is to give the vehicle what it needs to maximize its cornering ability. With the mini-van or the Prius, which inherently understeer, if you lift off the throttle it will improve the vehicle's front wheels ability to turn and you'll likely make it. With the Cobra, apply enough power to maintain your speed and steer. Exactly how much power YOUR car will want applied can only be known through practice in a controlled environment.

The bottom line:
A properly set up Cobra replica will have much higher cornering limits than most anything else you'll drive. You are unlikely to enter a corner at anything approaching 90% unless you are racing or just being stupid. Public roads might have water, oil, or gravel at a blind apex, so driving at 90% is foolhardy.
It's my guess that you are about 500 times more likely to scare yourself with an ill-timed application of the throttle pedal than with an occurerence of lift-throttle oversteer. It's just good to be aware of the dynamics when a layer of dirt in a blind apex turns 70% into 90%.
"Slow in, fast out" unless you're Bob Bondurant (and he had plenty of practice).

[mdross1]

Growing up on dirt roads in the country and loving to drive fast had to learn how to power steer in order to stay on the road.After building my big block Cobra had to learn where the breaking point was on asphalt.When conditions are right it is a blast,the smell of burning rubber is addicting.No doubt things can get out of hand in a hurry,just have to be prepared and drive through it.In todays world you really need to be on a track or even a parking lot way after hours.Remember the law will never understand if you get caught.

[tin-man]

Originally Posted by Barnsnake

Tin-Man,
Your desires to understand the dynamics of these vehicles are well founded, but I think you may be stressing a bit too much over this issue.
Here's the bottom line:
If you charge into a corner faster than the vehicle is capable of taking the corner (let's call that 105%), you're going off. This applies to a mini-van, a Prius, a Peterbilt, or a Cobra. Some may go off forwards with understeer, some sideways in a drift, and some backwards with oversteer.
Now let's say you went into the corner at 98% (which you should never even approach outside of a racetrack), you can theoretically make the corner. The key is to give the vehicle what it needs to maximize its cornering ability. With the mini-van or the Prius, which inherently understeer, if you lift off the throttle it will improve the vehicle's front wheels ability to turn and you'll likely make it. With the Cobra, apply enough power to maintain your speed and steer. Exactly how much power YOUR car will want applied can only be known through practice in a controlled environment.

The bottom line:
A properly set up Cobra replica will have much higher cornering limits than most anything else you'll drive. You are unlikely to enter a corner at anything approaching 90% unless you are racing or just being stupid. Public roads might have water, oil, or gravel at a blind apex, so driving at 90% is foolhardy.
It's my guess that you are about 500 times more likely to scare yourself with an ill-timed application of the throttle pedal than with an occurerence of lift-throttle oversteer. It's just good to be aware of the dynamics when a layer of dirt in a blind apex turns 70% into 90%.
"Slow in, fast out" unless you're Bob Bondurant (and he had plenty of practice).

Yep, I may be over reacting, but I would rather do that than get creamed because I did not ask the right questions.

Remember guys, I have no teachers but those who are on this site. Bondurant's downstream aways, so in the meantime, you are all I got.

Cheers, John, AKA, tin-man

[tin-man]

Originally Posted by xb-60

Hi John. A couple of questions or comments....
1. Looking at your engine description - Roush 511IR with 572HP - I suspect you may be able to comment significantly on my 'How much power is enough' question when yours is on the road....
2. Is your auto to be setup conventionally with throttle actuated kickdown? Even with quite low powered cars, a mid corner change down that might not have been fully expected can easily unsettle the rear end (of the car). And then you're at high speed in reverse. Or getting giddy.
3. Are you really in China?

Cheers,
Glen

Glen, been here for over twenty years building and ramping up factories for whoever wants to have a footprint here.

I will certainly comment on the power factor when I finally get my car and will find out if the auto transmission does or does not do an autodownshift.

Cheers, John, AKA, tin-man

[Tom Wells]

Auto trans on the track?

Been doing it for nine years, everywhere from Roebling Road to Sebring and many others.

First, please take note that my TTO crash in 2003 was certainly not due to a downshift by adding more power LOL

Second, the reason I do it is I'm too linear for shifting and heel and toe clutch management.

I can remember left foot is STOP and right foot is GO. Add shifting, throttle blipping and clutch actuation and I'd never learn to go around the track at all!

There were a few gotchas.

There needs to be a big enough trans cooler.

The torque converter needs to have a low enough stall speed and permit enough oil circulation to avoid heat excess heat generation.

The trans needs to be modified to produce crisp shifting to minimize heat generation and also to make sure there's enough oil flow to take advantage of the cooler.

After getting that right, the car can be run as hard as possible for thirty minute sessions at Sebring without any overheating problems with the trans.

The absence of shifting has a huge advantage for me: I can concentrate on the correct racing line, where to brake and accelerate and yes(!) even passing.

It was a long learning curve with the hardware because I could not find precedent and had to work out each item myself. It took four transmissions, three torque converters and a lot of hard nosed negotiation with vendors before it came together.

There is very little experience available in road racing as most cars have engines that may be a bit small for the job. There is some added hp loss compared with a stick shift; the big block doesn't seem to mind.

The most similar usage I've found is -GASP- mud trucks! They have large engines and often get used for a full tank of gas playing on the back 40 between trips to the race track. Anyone who builds a converter for mud trucks can probably build a successful version for road racing.

The biggest problem to date has been separating experience from opinion.

(note to self: this separation can be problematic for all kinds of other car-related technical questions and even non-car related questions)

Most folks who have never done this have opinions that are incorrect. Even pros.

Case in point: I went to a recognized torque converter maker and asked for a very low stall speed converter, say about 1600 rpm lockup. The maker then proceeded to talk me out of it by opining (note: opinion, not experience, at the name brand professional level, sigh) that he could make a looser, low heat converter for me. It didn't work. Boiling trans fluid after ten minutes is a no-fun experience...

The mud truck guy nailed it on the first try.

In all, I find the auto trans car much easier and more pleasant to drive both at the track and on the street. Finally. Just put it in Drive and go do stuff! YMMV

Tom