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I assume there's a reason for it...but I can't think of one.
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Jun 25, 2013 18:29
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Godholio posted:I assume there's a reason for it...but I can't think of one. If your engine is tuned such that there's a significant probability of it grenading during its useful life (such as during a 24 hour endurance race), you'll need to swap it out to continue competing. If you drive an alternator through a mechanical coupling (such as pulley wheels and a drive belt) to the engine, you have to decouple it before you can swap out the engine and re-couple it when you install the replacement. If you slap it on the transmission you're mechanically coupled to a far less dodgy system. Of course, then you need to make swapping the alternator attached to the transmission pretty easy.
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Jun 25, 2013 18:59
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Could always just make it easy to pull the entire engine/accessories assembly as a single unit rather than swapping accessories, then you just keep a preassembled powerplant as a spare and dump it in when it's needed. Hell, I've driven the truck to Pennsylvania on a weekend trip (500 miles each way) with an engine hoist, full drivetrain, and full set of tools in the bed because I wasn't sure if it would make it and didn't have time to drop the new engine/trans in before leaving. Had all the accessories bolted on already, etc.
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Jun 25, 2013 19:04
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Dwight Eisenhower posted:If your engine is tuned such that there's a significant probability of it grenading during its useful life (such as during a 24 hour endurance race), you'll need to swap it out to continue competing. If you drive an alternator through a mechanical coupling (such as pulley wheels and a drive belt) to the engine, you have to decouple it before you can swap out the engine and re-couple it when you install the replacement. If you slap it on the transmission you're mechanically coupled to a far less dodgy system. The reason the announcer on the broadcast gave was parasitic drag. With the alternator running off the accessory belt, it would soak several HP from the engine. Seeing as alternators are pretty robust and not generally prone to failing, they make it shaft driven and away from any potential horsepower loss. I don't know if it's right, but it made sense at 2a.m. when I heard it.
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Jun 25, 2013 19:43
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Good example of the poo poo that goes on at pikes peak. See this thing: After crashing last year, he built this "NSX" tube frame car from scratch with a twin turbo LSX, and brought it to pikes peak without doing any testing. Control arm broke on the second corner during the first practice run:  Driver OK, sounds like most of the damage is just to the very expensive body work.
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Jun 25, 2013 19:45
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jamal posted:Good example of the poo poo that goes on at pikes peak. See this thing: Is that Cody's car? He seems to have some pretty bad luck this last couple of years, with two crashes in a row and a score of very unsatisfied customers, I think this crash might be his end. Ouch, just saw this on Jalopnik and NSXPrime. GTi_guy fucked around with this message at 19:56 on Jun 25, 2013 |
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Jun 25, 2013 19:53
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D C posted:It makes more sense in a bike, the exhaust would come out right below the seat, right infront of the back tire, wouldnt want the extra heat hanging out around there, and then theres room from the front for a longer, tuned exhaust, around the bottom of the bike (which also keeps CG lower). I think it's less exhaust concerns and more intake. You need somewhere to put the airbox and injectors / carbs, with a reasonably short and straight shot from the fuel tank and into the head. If you just tilt the engine the other way you get packaging issues with the transmission and rear suspension. Plus the exhaust pipe tends to be more tolerant than titchy intake components of rocks and stuff thrown up by the front wheel. A lot of exhausts end up wrapping back around under the seat, in front and above the rear tire anyway.
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Jun 25, 2013 19:56
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jamal posted:
HRE should use this as an ad for their wheels.
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Jun 25, 2013 20:01
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GTi_guy posted:The reason the announcer on the broadcast gave was parasitic drag. With the alternator running off the accessory belt, it would soak several HP from the engine. Seeing as alternators are pretty robust and not generally prone to failing, they make it shaft driven and away from any potential horsepower loss. You might lose a horsepower or two driving an alternator via a belt versus a shaft, but the laws of thermodynamics are unavoidable...you are still going to need engine power to drive an alternator regardless of where it's driven from. I was under the impression that in the case of the front-engined GT cars that the alternator is put in the rear for weight distribution and to keep the engine packaging more compact (to help with aero). As for the Audis, the only reason I can see that they put their alternator in the stupidest place in history is because it might be related to the hybrid system.
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Jun 25, 2013 20:20
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kastein posted:Hell, I've driven the truck to Pennsylvania on a weekend trip (500 miles each way) with an engine hoist, full drivetrain, and full set of tools in the bed because I wasn't sure if it would make it and didn't have time to drop the new engine/trans in before leaving. Had all the accessories bolted on already, etc. Well, this is probably the most AI thing I'm going to hear all summer. GTi_guy posted:The reason the announcer on the broadcast gave was parasitic drag. With the alternator running off the accessory belt, it would soak several HP from the engine. Well, yes, but surely the alternator will add drag to the engine regardless of where it is in the power train (within reason).
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Jun 25, 2013 20:28
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Dwight Eisenhower posted:If your engine is tuned such that there's a significant probability of it grenading during its useful life (such as during a 24 hour endurance race), you'll need to swap it out to continue competing. If you drive an alternator through a mechanical coupling (such as pulley wheels and a drive belt) to the engine, you have to decouple it before you can swap out the engine and re-couple it when you install the replacement. If you put it on the engine and are expecting to need to change engines, you could work around this by just having the spare engine already fitted with its own alternator / other accessories, and using quick connect / disconnects on as many fittings as possible.
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Jun 25, 2013 20:32
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The simplest explanation I can come up with is weight distribution. That's what, 20, 25 pounds you can relocate? Also cuts down on wiring if you have rear battery, so that's another pound of copper out of the way.
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Jun 25, 2013 20:38
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Looks like the RS200 just crashed as well. http://jalopnik.com/pat-doran-father-of-liam-doran-went-off-at-pikes-peak-575232114
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Jun 25, 2013 20:40
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There might also have been a heat/packaging issue. THe engine bay is absolutely crammed with parts and also gets incredibly hot. I know for a fact F1 alternators get absolutely abused and I imagine the bellhousing offers a much more hospitable environment than being packed around radiators, water and oil scavenge pumps.
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Jun 25, 2013 20:48
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jamal posted:Good example of the poo poo that goes on at pikes peak. See this thing: Saw this being built over Facebook. That "before" picture was literally the day before Down. To. The. Wire. Testing is important. Adiabatic fucked around with this message at 21:12 on Jun 25, 2013 |
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Jun 25, 2013 21:08
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Not that large containerships always have transmissions, but it is common on ships to drive a shaft generator off the propeller shaft. At sea this powers the ships electrical needs, while a generator does the same job when the main plant is offline. I was on one ship where the generator could backfeed the shaft generator and turn it into a motor and very slowly turn the propeller shaft in an emergency.
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Jun 25, 2013 21:32
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Adiabatic posted:Saw this being built over Facebook. That "before" picture was literally the day before If I had a dollar for every time I see someone bring out a race car untested to a (timed) track day. I'd have my own untested race car.
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Jun 25, 2013 21:34
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G-Mach posted:If I had a dollar for every time I see someone bring out a race car untested to a (timed) track day.
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Jun 25, 2013 21:59
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Adiabatic posted:Saw this being built over Facebook. That "before" picture was literally the day before I don't know much about race cars, but I know enough about composites to ask why that 'expensive bodywork' looks like utter poo poo. Well, why does it? That might be a failure in it's own right. I get that it's a homebuilt carbon fiber body, but that work is a bit....lacking. What gives?
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Jun 25, 2013 23:19
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Almost looks like the fiber mats were stretched over a wireframe as opposed to being laid in a mold, might have something to do with it. Those front fenders look wrinkly as gently caress.
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Jun 25, 2013 23:27
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TotalLossBrain posted:I don't know much about race cars, but I know enough about composites to ask why that 'expensive bodywork' looks like utter poo poo. Well, why does it? His Facebook page mentioned on June 12 that he had essentially 3 days to build a body for that beast. I Guess the bright side is now he has 364 to remake the body.
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Jun 26, 2013 00:32
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Fucknag posted:Almost looks like the fiber mats were stretched over a wireframe as opposed to being laid in a mold, might have something to do with it. Those front fenders look wrinkly as gently caress.  It does look really bad.
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Jun 26, 2013 00:42
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Fucknag posted:Almost looks like the fiber mats were stretched over a wireframe as opposed to being laid in a mold, might have something to do with it. Those front fenders look wrinkly as gently caress. I don't think I've ever seen homemade carbon fiber look "good", really. I've seen some very functional poo poo, but never anything that is highly symmetric.
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Jun 26, 2013 01:00
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CF is really loving hard to do.
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Jun 26, 2013 01:04
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To do CF (and fiberglass, for that matter) properly, you need to use a vacuum press. His stuff looks pretty good for hand-laid, there are few air bubbles and most of the important surfaces are wrinkle free. A really good CF job would have you apply the CF with the resin, press it in a vacuum, then clear/hot coat it afterwards to bring out that distinctive mat look. The worst part of this car is the overlap at the seams. Don't know about anyone else, but that gap between the front wing thing and the body is kind of worrying. Fiberglass would have probably been better for this car, it's a little more forgiving.
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Jun 26, 2013 01:49
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Our trailer lost a wheel today...  ...and of course we had no spare.  Had to ratchet strap the axle up, move 1 of the 3 pallets of sod we were carrying to the bed of the pickup, and let the air out of the truck's suspension to bring the rear up enough to limp it along.
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Jun 26, 2013 02:02
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drat, that outer bearing is well beyond hosed. Looks like you need new bearings, seals, a hub, and a wheel/tire. You're lucky the spindle nut had a cotter pin in it and stayed in place, if that had come off the threads would probably be trashed too, then you'd need a spindle or even a whole axle depending on if the spindles are replaceable. They appear to be, if I had to guess that's one of those older Ford compact car wheel bearing assemblies that trailer makers love to use on their stuff, but I'm not entirely sure.
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Jun 26, 2013 02:07
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Devyl posted:Ya know, it's pictures like these that make me wonder. The person who did that was competent enough to understand compressing the spring, but not the fact that Autozone rents out spring compressors. I mean, seriously. The rear springs on the US first-gen Focus require some ingenuity to install. A local tech says there's a weird compressor that they have to use on them due to the location.
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Jun 26, 2013 02:16
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General_Failure posted:Post pictures that give mechanics nightmares. No one. We were swapping out the mill from a '70 to a '68 & while we had it out we went through it & whilst replacing all the worn-out bits I taught my son how to adjust valve clearances. He was 15 there.  It is a damned sight easier, though, to install a new exhaust manifold/muffler unit with it out on a table. (edit) arg, imgur is calling everything I upload a security error. poo poo. (edit2) imgur no like Adblock. September 2000:  April 2001: 
PainterofCrap fucked around with this message at 04:17 on Jun 26, 2013 |
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Jun 26, 2013 03:17
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hit F5 and then log back in when it tells you your images aren't publically available. imgur has a bad case of cookie amnesia and forgets I'm logged in at least 4-5 times a week.
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Jun 26, 2013 03:27
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What utter poo poo. It doesn't look anything like the carbon fibre of a Veyron Grand Sport Vitesse. They should be ashamed, trying to race where they obviously don't belong. Why did they even show up? What were the organizers thinking?
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Jun 26, 2013 03:36
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I know appearance and functionality are often not hand-in-hand, but it really looks made of silver-spraybombed cardboard.
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Jun 26, 2013 03:46
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joat mon posted:
Well, it did break and then crash in literally the second corner. They should make everyone without professional motorsports or extensive hillclimb experience start out in a spec miata or something. It's a miracle no one died last year (A friend of mine was only inches from getting hit when dallenbach's mechanical failure caused him to go off the road at 120), and the passenger in the evo at the top got super lucky. It's only a matter of time before something seriously bad happens with the way things have been going, especially now that everyone with a half-assed time attack car wants to do it.
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Jun 26, 2013 03:51
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jamal posted:Well, it did break and then crash in literally the second corner. It's amazing how many people seem to not get the whole "you gently caress up, you die here, this is not a racetrack" mantra.
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Jun 26, 2013 04:17
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Splizwarf posted:I know appearance and functionality are often not hand-in-hand, but it really looks made of silver-spraybombed cardboard. Yeah, but does it have functionality at all? There's a space frame underneath it that actually does all the structural poo poo. CF is only really useful in monocoque structures, isn't it? Other than the spoiler and splitter (which don't look that bad), that's all "cosmetic", in that GF makes an aerodynamic fairing just as well for a lot less time, cost and effort. Or he could rip all the other poo poo off and drive it like an Ariel Atom.
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Jun 26, 2013 06:25
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Das Volk posted:It's amazing how many people seem to not get the whole "you gently caress up, you die here, this is not a racetrack" mantra. "It'll never happen to me"
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Jun 26, 2013 06:55
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BlackMK4 posted:"It'll never happen to me" "I'm going to bring a untested race car that I just finished a day before I have to go to loving Pikes Peak. What could possibly go wrong?" You would think after last year people would think twice about this stuff. G-Mach fucked around with this message at 07:04 on Jun 26, 2013 |
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Jun 26, 2013 07:01
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You're implying that that type of person thinks the first time.
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Jun 26, 2013 07:04
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Captain Postal posted:Yeah, but does it have functionality at all? There's a space frame underneath it that actually does all the structural poo poo. CF is only really useful in monocoque structures, isn't it? Other than the spoiler and splitter (which don't look that bad), that's all "cosmetic", in that GF makes an aerodynamic fairing just as well for a lot less time, cost and effort. Or he could rip all the other poo poo off and drive it like an Ariel Atom. It's a good way to make light and stiff surfaces that see high aerodynamic loads. He would definitely be better off driving it with less giant wings on the car though. Generally you want to get the drivetrain and chassis/suspension dialed in before throwing huge aero loads into the mix. From a basics standpoint, it has a big splitter and big wing and such so there will be a reasonable amount of downforce. But there is no way of knowing how that downforce will be applied and what will happen at speed. If I had to guess, very pitch sensitive and unpredictable.
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Jun 26, 2013 07:29
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I don't pretend to be an expert in building a race car, but I think the old adage in aviation "if it looks right, it'll fly right" has an application here. In this case, it becomes "if it looks half-assed and sloppy, it'll drive half-assed and sloppy".
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Jun 26, 2013 07:36
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