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Jul 14, 2011 18:04:51 GMT
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The Audi 80's drag coefficient is 0.30, it was actually etched on the rear quarter windows of some models. Theoretically speaking, a cars weight shouldn't be too much of an issue when on the move. Maintaining a constant speed the cars only fighting drag, not trying to accelerate a mass, so besides a slight increase in rolling resistance, a heavier car isn't actually going to make much difference on long cruises. Obviously around town it will make a big difference though. It's also worth thinking about the cars frontal area, it's all well and good saying it's got a low coefficient of drag, but if it's got a big frontal area it's still going to have a high overall drag. true, although from the acres of literature i've read, and without being at all an expert (my expertise is in wildfire!) it appears that the way air exits a car, is more important than how it hits the car to begin with. this as a very general rule is why wagons are less economical than sedans, because they have a flat squared off back.
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Jul 14, 2011 18:08:39 GMT
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awesome article, thanks! I was already planning a full undertray on whatever I get. the hybridz.org site has alot of info on vortex generators and such, as well as general 'smoothing' of cars. what I find so baffling, is while newer cars have eliminated drip rails and gone for a smooth 'look' for alot of them, the aero of the car is actually awful.
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RobinJI
Posted a lot
"Driven by the irony that only being shackled to the road could ever I be free"
Posts: 2,995
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Jul 14, 2011 22:36:47 GMT
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The Audi 80's drag coefficient is 0.30, it was actually etched on the rear quarter windows of some models. Theoretically speaking, a cars weight shouldn't be too much of an issue when on the move. Maintaining a constant speed the cars only fighting drag, not trying to accelerate a mass, so besides a slight increase in rolling resistance, a heavier car isn't actually going to make much difference on long cruises. Obviously around town it will make a big difference though. It's also worth thinking about the cars frontal area, it's all well and good saying it's got a low coefficient of drag, but if it's got a big frontal area it's still going to have a high overall drag. true, although from the acres of literature i've read, and without being at all an expert (my expertise is in wildfire!) it appears that the way air exits a car, is more important than how it hits the car to begin with. this as a very general rule is why wagons are less economical than sedans, because they have a flat squared off back. Yep, you are indeed correct. However when I said frontal area I was referring to the area the vehicle displaces when viewed from the front. In other words the area of its frontal silhouette. A drag coefficient is a measurement of drag created in relation to both its speed and area. Without taking into account the area it's a completely meaningless number. In order to directly compare vehicles drag you really need to know their CdA (Drag Coefficient x Frontal Area).
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stevek
Yorkshire and The Humber
Posts: 728
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Jul 14, 2011 22:39:13 GMT
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The Vauxhall Carlton (0.28) and the Calibre (0.26 for the basic 8V) have quite impressive drag figures. Interesting subject
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Jul 14, 2011 23:05:18 GMT
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It's also worth thinking about the cars frontal area, it's all well and good saying it's got a low coefficient of drag, but if it's got a big frontal area it's still going to have a high overall drag. What he said. The other thing to consider is that drag coefficient can't be measured directly; drag force is measured experimentally then CdA calculated from this, and divided by frontal area to give Cd. There is no one way of measuring frontal area of a car, it depends on what you define as the front and what approximations you make when measuring. So yeah, don't treat it as gospel. EDIT: Yeah, again, what he said. Damn my slow posting... ;D
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Last Edit: Jul 14, 2011 23:08:44 GMT by Rich606
1989 Peugeot 205. You know, the one that was parked in a ditch on the campsite at RRG'17... the glass is always full. but the ratio of air to water may vary.
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speedy88
Club Retro Rides Member
"Nice Cortina mate"
Posts: 2,296
Club RR Member Number: 118
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Jul 14, 2011 23:55:33 GMT
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240 estate + D5. something I've always wanted to do. Epic MPGs and epic everything else.
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is it a plug and play swap (almost) speedy?
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speedy88
Club Retro Rides Member
"Nice Cortina mate"
Posts: 2,296
Club RR Member Number: 118
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hahaha I really don't think so. It would be dreamy if it was though Sooo many issues I can already think of off the top of my head. Parts clearing other parts/it fitting in the bay at all. Doesn't stop me wanting to make the best all-rounder retro in the world
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Last Edit: Jul 15, 2011 0:11:45 GMT by speedy88
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Jul 22, 2011 19:28:57 GMT
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Just to let you know, using some serious Google fu (I'm taking 4 days of solid searching/forum reading of dead end threads) that I have gotten somewhere with the concept of a 'plug and play transplant' TDi engine in an RWD 240z What we did know...
The 'ACME Adapters' etc. route are all reliant on either a Suzuki Samurai or a Toyota W57/58/59 truck transmission - often wrongly reported as a Supra gearbox, when people say that they actually mean the bellhousing from the rarer than unicorn truck transmission - the hardest to find one...which they would then bolt on to a Supra box. The Samurai gearbox is weak but works fine in a toy 4x4 because it's never travelling fast, at speed though, expect an exploded gearbox, it could work in a car as the gearbox is divorced from the transfer box (I think I got that right). The Toyota box is geared fine for a truck, but not for a sports car, the gearing is just too short, and is inevitably impossible to find with a serious premium on it if you can find one. What Google fu has taught me...
..some more Google fu has tracked down a company in the Netherlands - not far from where a good dutch friend of mine lives that actually rapid prototyped a *proper* bellhousing, cast and machined it, sell it with a hydraulic ford mondeo clutch and a custom made flywheel as a whole 'kit' which will work with a standard VW starter motor and a Ford 5-speed T9 gearbox, although it'd also fit a fancy *read expensive* Quaiffe and another box made by an English company. I've sent them an email, asking the total range of VAG engines this will fit, for 500 odd quid, I'll bite, being that I'd like my Z to last for atleast another 40 years even if I'm the one growing OSR crop to process into biodiesel Will let you know what they say Some photos of what they've made.. Personally...I'd much rather my Z does 600-800 miles to a tank...than the 186 miles it does on its guzzling L28 and also...DOUBLE THE TORQUES...
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Jul 22, 2011 19:47:20 GMT
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Personally...I'd much rather my Z does 600-800 miles to a tank...than the 186 miles it does on its guzzling L28 and also...DOUBLE THE TORQUES... Domo, camerashy-san I hawe been watching Wangan Midnight this week, and I hassa say L28 3.1 Twin-oh Turb-oh issa bess foh TORQUES!
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speedy88
Club Retro Rides Member
"Nice Cortina mate"
Posts: 2,296
Club RR Member Number: 118
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Jul 22, 2011 20:09:23 GMT
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hahaha I really don't think so. It would be dreamy if it was though Sooo many issues I can already think of off the top of my head. Parts clearing other parts/it fitting in the bay at all. Doesn't stop me wanting to make the best all-rounder retro in the world If anybody was interested in this, it appears that you can use the M90 gearbox to make this work. The main problem would be engine management but it can be done. With patience.
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Jul 23, 2011 17:34:10 GMT
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Okay...
Had a very prompt reply from 'Henry' there is no problem with a TDi, the only one being is that the bellhousing requires the engine to be dead upright, rather than at a slight slant. Time to track down some TDi dimensions then...
...in better news...chap has accepted my offer on the 280z I was looking at...just waiting on the broker to get back to me with insurance quotes (insurance quotes here the UK look cheap!)
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Jul 23, 2011 17:39:38 GMT
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Personally...I'd much rather my Z does 600-800 miles to a tank...than the 186 miles it does on its guzzling L28 and also...DOUBLE THE TORQUES... Domo, camerashy-san I hawe been watching Wangan Midnight this week, and I hassa say L28 3.1 Twin-oh Turb-oh issa bess foh TORQUES! Domo arigato *said swishing long white beard* but wrong you are Ronin...race prepped JohnC race car make...275 ftlbs torques... ...VW TDi make....planet moving torques....
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Jul 23, 2011 17:41:58 GMT
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plus if I remember from watching Wangan...doesn't the car end up destroyed...?
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Jul 23, 2011 17:45:45 GMT
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Many, many times, but it keeps getting rebuilt. At the moment where I am in the series (again...) it's running 600bhp on a carburettor turbo.
In the "live action" film, the crashes are amusing. There's lots of smoke, and noise, and then the car looks to have crashed into a tarpaulin that covers all of the damaged parts, rather conveniently. LOL.
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Jul 23, 2011 17:47:38 GMT
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Pretty sure they refer to the crashed car once...and it pans to a shot of a crushed S130 (280zx)...not a S30 (240z) very amusing the 'live action' one.
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Jul 23, 2011 18:54:13 GMT
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could I toss a BMW M51 into the mix? My old E34 has one and its chipped to 180bhp & 275 torques and it pulls 1600kg of German pig iron very well, I return 35mpg (42 on a run), I'm sure it'd do sooo much better in a lightened Z.
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Nissan Laurel SOLD BMW E34 Diesel SOLD Toyota Soarer 4.0 V8 SOLD Audi A4 1995 TDI SOLD Peugeot 205 1.9 TD SOLD Lexus IS300 SC
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Jul 23, 2011 19:20:20 GMT
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Why don't you scrap a Dodge/GMC/Ford pickup with a v8 diesel?
Serious poke and cheaper than shipping a cast bellhousing from the Netherlands.
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Click picture for more
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Jul 23, 2011 19:43:21 GMT
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BMW diesels aren't as easily available here, they're almost all petrol models, that and the spares are astronomic here - theres several cheap porsche 914's here that I've looked at, test drove two, but the availability and cost of spares is big $$. Tdi Jettas are ten a dozen though.
As for the big V8/V10 diesels, you have to be kidding, the Cummins units they use here are close to 700lbs with gearbox and ancillaries...that's doubling the engine/trans weight, not to mention upsetting an almost perfect 50/50 front/rear weight distribution. There is no diff that will fit that can take the torque of those things, AND...the gearbox would stretch probably all the way to the back of the front seats.... and believe me, they are NOT cheap! Putting 700lbs of engine in a car that weights 2000lbs stripped out with the stock engine seems madness to me.
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RobinJI
Posted a lot
"Driven by the irony that only being shackled to the road could ever I be free"
Posts: 2,995
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Jul 27, 2011 12:05:57 GMT
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I spotted this while looking through Performance VW at work the other day, these guys do a bell housing and mounts kit to fit a 1.9tdi VW lump into a Jeep. I don't know if there's a rear drive equivalent of the Jeeps box, but it's another option at least. www.hpamotorsport.com/tdiconversions.htm
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