Diffuser Design help - Andylaurence

Please discuss here all your remarks and pose your questions about all racing series, except Formula One. Both technical and other questions about GP2, Touring cars, IRL, LMS, ...
garygph
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Joined: 13 Oct 2008, 14:25

Re: Diffuser Design help - Andylaurence

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That's one area of improvement for my driving. The car turns in nicely on the brakes as can be seen at Crystal Palace. The reason I sometimes hit the throttle on the way in is I've slowed down too much and I instinctively jump n the throttle. It's completely wrong, but it's something I'm aware of and working towards resolving. I don't get much seat time, so learning the tracks is often tricky. I did 62 minutes in total behind the wheel this year on 4 different circuits, so finding the right braking point is tricky. The nature of sprinting is that you're against the clock on your third lap. Two timed practice runs (usually 1 lap, sometimes 1.75 laps) in the morning are usually followed by two timed (again, usualy a lap) runs that count for the result in the afternoon. I'm inexperienced with both the car and the circuits as it was my first time at most of the tracks this year and I only competed in this car in one event prior to 2011. I hope to improve dramatically in 2012...
WOW! :shock: that is very little time to learn so much that you need. Maybe forget spending time and money altering the car and use the budget just to get to track days to practise practise practise!! :lol:

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andylaurence
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Re: Diffuser Design help - Andylaurence

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Yes, airflow in the cockpit is probably an issue. I have nothing to support either way. In my category, Sports Libre, there is a minimum cockpit opening. Admittedly, I think it's smaller than the opening I have, but I like the option of taking a passenger if I wish at track days. I'm strapped into a foam seat with a 6 point harness, so I'm well located laterally, despite what it looks like!

I have a budget to do test days and to alter the car, so I don't really need to compromise too much. Unfortunately, it's not possible to do track days at all of the circuits so learning them is proving hard. Anglesey and Castle Combe are the only ones I did this year that I can do test days at. Crystal Palace is used just two days a year and Silverstone Stowe circuit doesn't run test days. I have no plans to revisit Anglesey this year and there's only a few unsilenced test days a year at Castle Combe and they're all mid-week, which clashes with work. I will be doing testing to get more general seat time, but it won't help with learning the circuits. It's the same for everyone though.

Smokes
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Joined: 30 Mar 2010, 17:47

Re: Diffuser Design help - Andylaurence

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have you tried getting seat time in r factor?

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andylaurence
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Re: Diffuser Design help - Andylaurence

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rFactor isn't quite the same. I usually watch videos on YouTube to get an idea of the circuit. You certainly can't rely on rFactor for braking points and turn-in. Check out this video of Crystal Palace in rFactor and compare it to this onboard video from my car in May. You couldn't learn the real place from the rFactor circuit. I watched a few onboard videos in the week leading up to the event and walked the course on the Saturday to spot important areas. I was within a second of FTD on the Monday, so I think that was good enough. I would recommend walking any course before you drive it - there are things you'll spot when walking that you'll miss when driving, but you'll see the symptoms and wonder why you're off the pace...

garygph
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Joined: 13 Oct 2008, 14:25

Re: Diffuser Design help - Andylaurence

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Your lap time sounds very competitive, well done. this type of racing sounds like you have to be a type of Sebastien Loeb!! Very challenging.

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andylaurence
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I was third overall, but my car was one of the fastest there as most of the cars were road-based and/or classic cars. I was short on power, overweight and had worse aero than the winner, but that aside, I just wasn't fast enough on the day. Next time...

wesley123
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Joined: 23 Feb 2008, 17:55

Re: Diffuser Design help - Andylaurence

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By the way, you got any sponsors? SPonsorship money can definately be for good use with what you plan to do
"Bite my shiny metal ass" - Bender


Smokes
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Joined: 30 Mar 2010, 17:47

Re: Diffuser Design help - Andylaurence

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what type of pad are you running is the braking consistant each lap or does it take a lap or two for them to get to the right temp. Tarox do a massive range or compounds.

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andylaurence
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Re: Diffuser Design help - Andylaurence

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I run the softest pads I can. In the classes where cars are based on production cars, people run standard road pads. The most times I've ever hit the brakes is 10 times in one run, most events are less than half a dozen. We don't have to worry about the second lap so much as a sprinter never completes the second lap - 1.75 laps is as long as any sprint course gets. To give you an idea, the entry form normally states how many corners there are. I don't mean how many corners the circuit has, but how many corners you do between the green light and the chequered flag. As such, there's no such thing as consistency. At the first corner, the brakes and tyres are completely cold. At the chequered flag, the tyres and brakes can usually be touched with a bare hand! Getting tempereature into the tyres and brakes needs to be done as quickly as possible to make the most of them.

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tomislavp4
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Joined: 16 Jun 2006, 17:07
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Re: Diffuser Design help - Andylaurence

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Nice thread guys. andylaurence, have you closed the cooling ducts for the brakes? You can win some time by doing it because it reduces drag. You probably know this allready but just in case you missed it.

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andylaurence
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There are no cooling ducts for the brakes, but I have not sealed off the intakes above the splitter. They're big holes and no doubt contribute to front end lift and drag. It's another small thing on the list of tasks to complete before next season. Given the lack of brake cooling needed, I have considered covers on the wheels to make them flat like this:

Image

Of course, I need to weigh up (pun intended, no matter how poor) the increase in rotational inertia and unsprung mass versus the benefit of reduced drag.

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tomislavp4
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Joined: 16 Jun 2006, 17:07
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Re: Diffuser Design help - Andylaurence

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Such measures not only reduce drag but also help you get the brakes up to working temperature faster, make sure you take that in consideration ;)

Smokes
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Joined: 30 Mar 2010, 17:47

Re: Diffuser Design help - Andylaurence

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racecar engineering did an article on the benefit of wheel covers using cardboard and VW single seater.

with regard to brake temp have you done any hill climbs such as harewood? You might get more understaing about spritn lapping from that.

garygph
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Joined: 13 Oct 2008, 14:25

Re: Diffuser Design help - Andylaurence

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seeing that getting temp into the tyres is a big problem and slicks needing to be way hotter than your hand can handle to be near or on optimum, have you considered high performance road car tyres? I feel that a really good one has more grip than a cold slick anyday and you can attack the corners earlier in the lap as well. It is just that the high grip a slick gives you is in a narrow temperature band as far as I know. Anyone agree?