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 Post subject: Really, how fast?
PostPosted: June 22, 2012, 12:40 pm 
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Joined: February 12, 2008, 2:08 am
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Location: Olympia WA
I have my car on the track now and I am having a blast (mostly autocross). Last week I took it to a high performance driving experience. Since it was the first event of the year they put a chicane 2/3 way down the straight away. My car was pulling hard at 7,000 rpm in 4th (107 mph). I am still grinning. My car red lines at 9,000 rpm and in 5th that would be about 140 mph. Maybe I am a chicken, yet this is pretty darn fast and I already feel awfully exposed.

How fast do you really go in your car?

At what speed do you start thinking about your welding skill?

What is your experience at speed?

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● I have a dream: My car has a new type of engine: a half-turbine half-reciprocated engine. I invented it! ~ Dr. Felix Wankel
● It has occurred to me, amateurs built the ark and professionals built the titanic.


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 Post subject: Re: Really, how fast?
PostPosted: June 22, 2012, 12:49 pm 
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My Locost will be redline-limited to 100 mph, and you're right, that's plenty fast in a Locost. At that speed I think I'd worry less about welds breaking and more about body panels flying off.


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 Post subject: Re: Really, how fast?
PostPosted: June 22, 2012, 12:54 pm 
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I dont' race, but IIRC those who do speak of hitting an aerodynamic wall around 110-120 inherent to our sevens.


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 Post subject: Re: Really, how fast?
PostPosted: June 22, 2012, 1:32 pm 
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With just a little more practice 100 will not feel so fast. It is in fact plenty fast if something goes wrong or you lose control of the car. It can travel a considerable distance sideways or backwards etc.

At some point north of 100, you really just don't have the time to worry about things like welds or cracks or loose bolts. These thoughts and worries need to be transferred to other down time during the day and season and year when you spend time looking at your car. Try to actually "see it" instead of just routinely looking at it. Find different things to look at and inspect them and think about the story they might be trying to tell you.

Over 100 you need to be with the car full time. Develop an attention "budget". A small part of this budget needs to be devoted to monitoring the driver for signs of stress, do not forget this. Other parts devoted to the car's feel, the line you should be on, upcoming brake zones, traffic in front and behind, things to do better next lap. You can keep reevaluating how to spend this budget ( must be part of the budget ), but if you spend it all on one thing you are on borrowed time.

Sounds like your car has received shake down or qualifying time at autocross events and this first track excursion. Keep going over it and it should serve you well for as much as this motor is going to give you.

I really enjoy road racing. It gives you enough time to keep working at getting better, instead of just 60 second runs.

More things to consider, maybe for next year if you keep up the road racing... Do you use arm restraints? Can you get spare rims and put on slicks ( big safety item - you slow down way faster when traveling sideways or backwards )? Lower the car or the CG?

Your car will out corner and out brake other street cars even at 130. It will take a little practice though. Do learn to get good with your brakes. My Formula Ford will do 130 or so and I brake so late that sometimes when I pull up next to a Corvette or Mustang etc. I actually upshift when they get on the brakes. Mostly I do that to demoralize them :twisted:

Have fun, keep us posted and get us some video!

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 Post subject: Re: Really, how fast?
PostPosted: June 22, 2012, 2:25 pm 
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horizenjob wrote:
My Formula Ford will do 130 or so and I brake so late that sometimes when I pull up next to a Corvette or Mustang etc. I actually upshift when they get on the brakes. Mostly I do that to demoralize them :twisted:


Sometimes racing is more fun than at other times.

Tom

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 Post subject: Re: Really, how fast?
PostPosted: June 22, 2012, 9:15 pm 
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Location: Olympia WA
Budgeting my concentration, I like that. I do take my suspension apart during the winter and inspect it, I think I am seeing it… I am glad I did not powder coat everything, so I can see if there are cracks.

I do like the days on the big track, because I can think about things. In autocross there is just trying to catch up to the car!
Arm restraints, I have not looked at those before, and I can see their value now. I am running the car on 20” Hoosiers (R25), and it has stick than I know what do to with. I find myself thinking I am at the edge and then turn in a bit more and they keep sticking. The car is 3” off the ground with the 20” tires, so the CG is pretty low.

I have heard about the aerodynamics of the cars really getting in the way of much more speed. I have a 3” windshield which cuts down a bit of the resistance, and it was pulling.

I am getting a much better idea of fast, and fast 3” off the ground with no sheet metal around you is REALLY FAST!

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● Aerodynamics are for people who can't build engines. ~ Enzo Ferrari
● I have a dream: My car has a new type of engine: a half-turbine half-reciprocated engine. I invented it! ~ Dr. Felix Wankel
● It has occurred to me, amateurs built the ark and professionals built the titanic.


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 Post subject: Re: Really, how fast?
PostPosted: June 25, 2012, 3:23 pm 
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kill no cone wrote:
I am getting a much better idea of fast, and fast 3” off the ground with no sheet metal around you is REALLY FAST!
They call that the "Pucker Factor"!

:mrgreen: Really jealous of the fun your having :mrgreen: Really Jealous!!

Remember... in cars like this it's not how fast it goes... it's how fast it gets there!! If you need proof... 911 beats it in the straight every time, but look at how far it pulls ahead in the twisty bits??

[youtube]http://youtu.be/sxwRgSZiKTk[/youtube]

Cheers and Enjoy!

KS

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 Post subject: Re: Really, how fast?
PostPosted: June 25, 2012, 4:54 pm 
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On a big track, aero is a really big problem with Locost-shaped and open-tube cars. A guy did a back-to-back comparo with an A.t.o.m and a BMW M5. Performance-to-weight heavily favored the A.t.o.m and yet it lost due to its horrible drag at speed. The Locost is similiar, a real giant killer on a twisty course, but get it out on a track where average speed is high and it won't be able keep up.

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 Post subject: Re: Really, how fast?
PostPosted: June 25, 2012, 6:18 pm 
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Quote:
Budgeting my concentration, I like that.


There's a good book by Keith Code called "A Twist of the Wrist" where he talks about this. It's a motorcycle road racing book but this part was excellent advice. I learned this the hard way. I don't remember all he said about this but think it makes sense to budget some attention to being aware of what's going on in general. That's especially hard to do when first starting to drive a car this quick, but that's when it's most important.

Quote:
I think I am seeing it…


Here I mostly mean race days and during the season. It's easy to just look at the car and see familiar things. And on the day of an event your tired and excited and distracted by so many things, but some day you may just notice the smallest of things - and it could be a big deal. One thing I did was to try to look at some part of the car in more detail and pick different things to do that with during the day or different events etc. I found a couple of pretty good issues that way.

Quote:
20” Hoosiers (R25), and it has stick than I know what do to with. I find myself thinking I am at the edge and then turn in a bit more and they keep sticking.


I always got the feeling that the faster I went, the faster I could go. It's like the car responds to being used hard. It's probably getting heat in the tires and also improving yourself. I remember I didn't really figure out waht the car could till one day I went way to deep into my braking zone by mistake. I remember thinking OMG and really clamping on the brakes and I just about stopped the car before the corner. After that was when things started to get really interesting. It's genuinely hard to drive up to a turn as deep as you can before braking with a light car on hot slicks.

So far as I can tell when you road race, you never stop feeling that you can get batter. You can only get so much better in a given day, but you will always want to keep coming back for more.
:cheers:

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SketchUp collection for LocostUSA: "Dream it, Build it, Drive it!"
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 Post subject: Re: Really, how fast?
PostPosted: August 16, 2012, 10:32 pm 
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horizenjob wrote:
There's a good book by Keith Code called "A Twist of the Wrist" where he talks about this. It's a motorcycle road racing book but this part was excellent advice.


GREAT book suggestion, thank you. Changes the way a person thinks when in the car.
JEB

horizenjob wrote:
Quote:
Budgeting my concentration, I like that.


There's a good book by Keith Code called "A Twist of the Wrist" where he talks about this. It's a motorcycle road racing book but this part was excellent advice. I learned this the hard way. I don't remember all he said about this but think it makes sense to budget some attention to being aware of what's going on in general. That's especially hard to do when first starting to drive a car this quick, but that's when it's most important.

Quote:
I think I am seeing it…


Here I mostly mean race days and during the season. It's easy to just look at the car and see familiar things. And on the day of an event your tired and excited and distracted by so many things, but some day you may just notice the smallest of things - and it could be a big deal. One thing I did was to try to look at some part of the car in more detail and pick different things to do that with during the day or different events etc. I found a couple of pretty good issues that way.

Quote:
20” Hoosiers (R25), and it has stick than I know what do to with. I find myself thinking I am at the edge and then turn in a bit more and they keep sticking.


I always got the feeling that the faster I went, the faster I could go. It's like the car responds to being used hard. It's probably getting heat in the tires and also improving yourself. I remember I didn't really figure out waht the car could till one day I went way to deep into my braking zone by mistake. I remember thinking OMG and really clamping on the brakes and I just about stopped the car before the corner. After that was when things started to get really interesting. It's genuinely hard to drive up to a turn as deep as you can before braking with a light car on hot slicks.

So far as I can tell when you road race, you never stop feeling that you can get batter. You can only get so much better in a given day, but you will always want to keep coming back for more.
:cheers:

_________________
● Aerodynamics are for people who can't build engines. ~ Enzo Ferrari
● I have a dream: My car has a new type of engine: a half-turbine half-reciprocated engine. I invented it! ~ Dr. Felix Wankel
● It has occurred to me, amateurs built the ark and professionals built the titanic.


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 Post subject: Re: Really, how fast?
PostPosted: August 16, 2012, 10:59 pm 
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One of the many things I do before a race is clean the car by hand with a rag. Every piece. Lift the car up on jack stands and slide along underneath and clean it. This is how you see little things before they turn into big things. I have found a bolt or two started coming lose and a cracked header and all kinds of stuff. I learned this from when I used to road race bikes. It is a great way to look at the car. I see some dirty cars and think to myself, when the hell did you look at that area last. Have a look at an Indy car or some high end racing before a race, the cars look brand new. It has helped me a lot and it also keeps the car reliable. Besides that, the car looks good too. Just my two cents worth.
:cheers:

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 Post subject: Re: Really, how fast?
PostPosted: August 17, 2012, 1:46 pm 
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Graham, that's a great idea. Thanks for the tip and feel free to add others.

Marcus, thanks for this extremely interesting idea. How did you begin practicing it? Did you cycle through a memorized list or use certain parts of the track to remind you of certain things or what? Could you say how often you cycle through the list, if it is a list? Has doing this become somewhat unconscious?


Pete


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 Post subject: Re: Really, how fast?
PostPosted: August 17, 2012, 2:04 pm 
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So has anyone found ways to help downforce on the car to reach the 150mph mark? Me personally 130 in my 240 is plenty. I'm sure with a car like the locost my pucker factor would be alot lower at first.

I just don't see putting a spoiler on one of these. Maybe a rear diffuser and some front canards and a wind splitter. Being that the whole bottom of the car is flat that can hurt and help. Any unwanted wind under the car can cause lift and we deff don't want any of that.

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 Post subject: Re: Really, how fast?
PostPosted: August 17, 2012, 10:24 pm 
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Those of us putting on a Lola-ish body won't have the advantage of an aero wall to keep us under 120. This sounds like a fun thing, but we ARE talking about a 50 year old rookie driver in a car built by a 50 year old rookie welder.

Which of course means that I'm likely to pull off those panels a bit more often and check for cracks.

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 Post subject: Re: Really, how fast?
PostPosted: August 18, 2012, 3:57 am 
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The voice of reason
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kill no cone wrote:
horizenjob wrote:
There's a good book by Keith Code called "A Twist of the Wrist" where he talks about this. It's a motorcycle road racing book but this part was excellent advice.


GREAT book suggestion, thank you. Changes the way a person thinks when in the car.
JEB


I'm glad you liked it. It's been a long, long time since I read it. I remembered thinking it was well written, by a person that teaches real racing professionally - not a journalist etc.

So perhaps you can provide some details. I remember he talks about an "attention budget" and that has always stuck with me. I don't remember the amounts to spend on things. What I took from it was to be self aware and leave enough mental capacity to be able to have some larger picture of what's gong on. A little bit for checking gauges and along with that paying attention to the feel and the sound of the car so you also know to check the gauges. Noticing a tiny shiny spot on my car's half shafts one day during lunch and remembering on the hardest slowest most banked turn a slight surge and thumpy feeling. That was the rubber doughnuts failing, the halfshaft yokes were banging the yokes on the transaxle. So the car went on the trailer...

A little bit for traffic and lap planning. Especially when I'm new at a place or for me, I don't get tot he track very often right now - I try to pick one corner at a time to focus the bulk of my efforts. Not every corner, because that's just to much to retain. So I push hardest one place at a time. Trying to start with the corner that has the longest straight after it or some measure of importance. It doesn't mean I slouch around the rest of the track, it's just the real effort goes into one place. That let's you build a little courage and plan and visualize what your going to do next lap at that same place, instead of flushing your mind with general panic as you flounder thru 3 other corners at your absolute limit. So no slouching, but take your risks one place a time.

On the straights I make sure to keep attention on the driving by really putting the car where I want it. I try to follow a line all the way down the straight.

OK, so you guys can laugh at me but I'll ell you how I learned this the hard way. I drove a couple of events in a Crossle 16F, a really pretty and tiny FF that looked like a 1965 F1 car. Over that winter I had a good mechanic go over it. He was laughing when I went in a few weeks later. It had been really messed up, so much bump steer it just made the dial gauge spin in circles. Then he dynoed the motor and found the previous owner had put the jets back in the wrong holes.

I went back to the track and picked up 3 seconds. I already knew the track well from a street car, so I was really flying. I was in way over my head but not really picking up on it. I noticed I kept having to put my tongue back in my mouth. It was just hanging out and flopping around. I was doing this probably 10 times a lap. Then I noticed I could actually feel my cheeks sliding across my face in the corners.

I'd been following a real SCCA veteran and he took a really unusual line thru turn one. I thought I'd try it too. It was probably my second session. At some point at the exit of the turn, me thinking things were fine, I noticed the car was pointed down the straight but it was just not hooked up at all. I was in some marbles and off the line and it just wasn't going to stick. There was a corner station and a gully / stream to the right. I let the car come around and got on the brakes and clutch. I was going about 110. and went down that short straight and hit the wall in the next corner going backwards after a couple of rotations. I can still see the smoke rising off the pavement, in 1981.

So, when your tongue hangs out, go into the pits. That was happening because my concentration had become so complete and fixated that my mind had let my face muscles go completely slack. What ever brain cells would put an expression on your face had been drafted. I was way over committed. Take a break. You will only get so much better in one day. At a new track I pick up 2-3 seconds after sleeping over night, and I do that with less effort and mental strain.

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SketchUp collection for LocostUSA: "Dream it, Build it, Drive it!"
Car9 Roadster information - models, drawings, resources etc.


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